INVESTIGATOR: Hay, G. M.; Baham, A.; Jenny, B. F.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

DAIRY CATTLE IMPROVEMENT THROUGH DHI

OBJECTIVES: To provide support for a DHI program that will provide Louisiana producers with data for improving efficiency of operations and provide data for use in research and educational programs.

APPROACH: The DHI program in Louisiana is run as a cooperative effort between the Department of Dairy Science, Dairy Extension, and the Louisiana DHIA. The state program is part of a national program involving the National DHIA and the USDA. A certified DHIA supervisor obtains individual cow milk samples and appropriate management data monthly from participating herds. Results from milk analysis are compiled with farm data through a centralized computer system. A complete set of records is returned to the producer for use in decision making. Records are also made available to the Department of Dairy Science, Dairy Extension and the USDA for use in research and educational programs.

PROGRESS: 1993/01 TO 1997/12
Over the past five years the number of herds participating in the DHI program have declined from 264 in 1992 to 167 in 1997. During this same time period the total number of herds in Louisiana declined from 704 to 557 herds. Economic conditions over the past two years and changes in testing rules by National DHI have had a negative impact on number of herds participating in the program. Herds participating in DHI currently represent about 30% of the total herds and 34% of the dairy cows in Louisiana. DHI herds produce about 40% of the total milk produced in the state. Herds participating in the DHI program average 3577 pounds more milk per cow per year than non DHI herds. At a milk price of $14.50 per cwt, this represents an increase of over $500 per cow per year for herds participating in the DHI program. Cost of the program is approximately $18 per cow per year. All information from cows in the Louisiana DHI program is being electronically transmitted to the Dairy Records Management System in Raleigh, North Carolina.

INVESTIGATOR: Baham, A.; Chandler, J. E.; Jenny, B. F.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

A FULL SERVICE A.I. PROGRAM FOR IMPROVING GENETIC SUPERIORITY IN DAIRY AND BEEF LIVESTOCK

OBJECTIVES: To provide scientific and operational support for a full A.I. program in dairy and beef cattle in Louisiana.

APPROACH: The Dairy Improvement Center provides facilities and some scientific support for the A.I. program operated by Louisiana Animal Breeders Cooperative (LABC). Through the program and in conjunction with LABC, a farmer-owned cooperative, and Federated Genetics, a federation of cooperatives, a wide selection of superior sires are available to breeders in Louisiana. The program also provides a range of services to the cattle breeders in the state. Approximately 10 bulls are sampled annually in an effort to identify superior bulls for the program.

PROGRESS: 1993/01 TO 1997/12
The Dairy Livestock Development Program has completed five years of successful service to the Louisiana dairy and beef industry. During this period, AI program benefits were coordinated with activities of the Louisiana Animal Breeders Cooperative and its successor organization, Genex Cooperative, Inc. The merger to form Genex in 1996 provided economic benefits and stability as well as enhanced genetics for members and customers. A Cooperative Agreement was completed in 1996 between Genex and the LSU Agricultural Center to provide an operational basis for AI activities carried out by the LSU Dairy Improvement Center. Research and educational activities are coordinated with activities of the Department of Dairy Science, Cooperative Extension Service and other related departments.  Some annual accomplishments during this period include: 1)an average of 8,135 units of semen were custom collected from privately owned bulls with the majority from Louisiana beef bulls; 2)an average of 117,467 units of NAAB-CSS approved semen were processed on the AI stud dairy and beef bulls; 3)an average of 70,000 units of retail semen sales; 4)an average of 5 Holstein and 2 Jersey sires were progeny sampled; 5) AI service, herd analysis and consultation were provided to over 800 cattlemen each year; and 6)an average of 35 tours of the facilities were carried out for farmers, university students and foreign visitors. In addition to continued participation in educational activities promoting AI, the program continues to serve and support facilities and animals for research and teaching.

INVESTIGATOR: Baham, A.; Chandler, J. E.; Jenny, B. F.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

A FULL SERVICE A.I. PROGRAM FOR IMPROVING GENETIC SUPERIORITY IN DAIRY AND BEEF LIVESTOCK

OBJECTIVES: To provide scientific and operational support for a full A.I. program in dairy and beef cattle in Louisiana.

APPROACH: The Dairy Improvement Center provides facilities and some scientific support for the A.I. program operated by Genex. Through the program in conjunction with Genex, a farmer-owned cooperative, and Cooperative Resources International, a wide selection of superior sires are available to breeders in Louisiana. The program also provides a range of services to the cattle breeders in the state. Dairy bulls are sampled annually in an effort to identify superior bulls for the program and increased emphasis is being placed on the custom collection programs for beef bulls.

PROGRESS: 1998/01 TO 1998/12
The Dairy Livestock Development Program completed a successful service year to the Louisiana dairy and beef industry. During this time period, AI program service and benefits were coordinated with activities of Genex Cooperative, Inc. The formation of Genex in 1996 provided economic benefits and stability as well as enhanced genetics for AI members and customers in Louisiana. The continuation of the 1996 Cooperative Agreement between Genex and the LSU Agricultural Center provides an operational basis for coordinating the AI activities carried out at the LSU Dairy Improvement Center. Educational and research activities are coordinated with activities of the Departments of Dairy Science and Animal Science, Cooperative Extension Service and other related departments. Some of the accomplishments in 1998 include: (1) over 71,000 units of semen were collected from customer-owned bulls with the majority of this business in beef bulls; (2) the custom collection activity involved 16 breeds of beef and dairy and also involved 76 bulls; (3) AI service to some 750 cattlemen in Louisiana; (4) continued sampling program for progeny testing of dairy bulls; (5) herd analysis and mating programs for some 60 dairy herds and 7,500 cows; (6) facility tours were carried out for some 40 groups and participants varied from international visitors to local livestock owners.  In addition to continued promotion and participation in educational activities promoting AI, the AI program also coordinates and supports facilities and animals for research and teaching.

INVESTIGATOR: McGregor, J. U.; Boeneke, C. A.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

FLUID DAIRY PRODUCTS AS INGREDIENTS IN RETAIL COFFEE HOUSE BEVERAGES

OBJECTIVES: 1. Evaluate current milk preparation and handling practices in retail coffee houses; 2. Measure the effect of processing procedures, composition, and shelf-life on performance characteristics of milk used in freshly prepared coffee house beverages; 3. Measure the performance characteristics of commercially available fluid dairy products at the retail level;
4. Create a dairy ingredient application guide for the use of fluid milk products in retail coffee house outlets.

APPROACH: Current practices will be evaluated by conducting focus group sessions with store personnel and through observation. The following measurements will be made: frothing times, number of steam cycles during frothing, storage temperature, time from frothing to final use of milk, age of milk used, milk temperature, humidity, etc. In-store performance and standardized laboratory experiments will be carried out to determine the effect of heat (HTST, ESL, UHT), homogenization (low, normal, high), milk solids-not-fat fortification (0, 1, 2%), fat content (0, 1, 3.25%) and milk age (0, 7, 14d) on coffee beverage performance. Analysis will include: composition (fat, protein, carbohydrate, minerals), foaming/frothing rates and retention at various temperatures, pH, viscosity, color, protein denaturation, free fatty acids, flavor. Of particular interest will be the performance of extended shelf-life products. Lack of adequate refrigerated storage space is a major problem for coffee shop retailers. The focus of the application guide will be on helping retailers create and develop new products. The continued growth of coffee houses will depend on their ability to meet customer demands for exciting innovative new products.  Local and regional fluid milk processors will be able to use the application guide to help retailers expand their product lines and therefore increase milk utilization.

PROGRESS: 1998/01 TO 1998/12
Coffeehouses are the fastest growing type of food/drink outlet in the U.S. The two most popular drinks served in coffeehouses are cappuccino and café latte. Fluid milk is a major ingredient in both of these beverage products. Personnel working in coffee shops sometimes complain about poor or inconsistent frothing and froth retention in milk. We have completed a study to determine the effect of fat content and whey protein fortification on milk frothing properties. Skim (.39%), lowfat (1.69%), and whole (3.20%) milk with and without added WPC (1% fortification) were tested for frothing properties. For each sample, 200 grams of milk were frothed with a Faema Expresso machine (model c85/1) using a 7.5-cm diameter cylinder for 25 seconds. Froth characteristics were observed and initial height of froth, height of froth after 4 minutes of dissipation froth stability, and air cell size were recorded. Skim milk had a mean froth height of 3.23 cm. Skim milk with 1% WPC had a mean forth height of 3.15 cm. Lowfat milk had a mean froth height of 2.40 cm. Lowfat milk with 1% WPC had a mean froth height of 3.27 cm. Whole milk had a mean froth height of 2.72 cm. Whole milk with 1% WPC had a mean froth height of 3.20 cm. The froth of milk fortified with 1% WPC remained more stable over time, and gave a "creamier/heavier" froth at all fat levels.

INVESTIGATOR: Baham, A.; Chandler, J. E.; Jenny, B. F.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

A FULL SERVICE A.I. PROGRAM FOR IMPROVING GENETIC SUPERIORITY IN DAIRY AND BEEF LIVESTOCK

OBJECTIVES: To provide scientific and operational support for a full A.I. program in dairy and beef cattle in Louisiana.

APPROACH: The Dairy Improvement Center provides facilities and some scientific support forthe A.I. program operated by Louisiana Animal Breeders Cooperative (LABC). Through the program and in conjunction with LABC, a farmer-owned cooperative, and Federated Genetics, a federation of cooperatives, a wide selection of superior sires are available to breeders in Louisiana. The program also provides a range of services to the cattle breeders in the state. Approximately 10 bulls are sampled annually in an effort to identify superior bulls for the program.

PROGRESS: 1993/01 TO 1997/12
The Dairy Livetock Development Program has completed five years of successful service to the Louisiana dairy and beef industry. During this period, AI program benefits were coordinated with activities of the Louisiana Animal Breeders Cooperative and its successor organization, Genex Cooperative, Inc. The merger to form Genex in 1996 provided economic benefits and stability as well as enhanced genetics for members and customers. A Cooperative Agreement was completed in 1996 between Genex and the LSU Agricultural Center to provide an operational basis for AI activities carried out by the LSU Dairy Improvement Center. Research and educational activities are coordinated with activities of the Department of Dairy Science, Cooperative Extension Service and other related departments. Some annual accomplishments during this period include: 1)an average of 8,135 units of semen were custom collected from privately owned bulls with the majority from Louisiana beef bulls; 2)an average of 117,467 units of NAAB-CSS approved semen were processed on the AI stud dairy and beef bulls; 3)an average of 70,000 units of retail semen sales; 4)an average of 5 Holstein and 2 Jersey sires were progeny sampled; 5) AI service, herd analysis and consultation were provided to over 800 cattlemen each year; and 6)an average of 35 tours of the facilities were carried out for farmers, university students and foreign visitors. In addition to continued participation in educational activities promoting AI, the program continues to serve and support facilities and animals for research and teaching.

INVESTIGATOR: Bateman, H. G.; Williams, C. C.; Fernandez, J. M.

PERFORMING INSTITUTION:DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

USING AMINO ACIDS TO IMPROVE RUMINAL FERMENTATION AND MILK PRODUCTION BY LACTATING DAIRY COWS

OBJECTIVES: 1. To determine if providing amino acids to the ruminal environment will stimulate ruminal fermentation in vitro. 2. To determine the effects of feeding amino acids to lactating dairy cows on ruminal fermentation and duodenal flow of dry matter, organic matter, N, fiber, and fatty acids. 3. To determine the effects of feeding amino acids to dairy cows on milk production, milk composition, and production of milk components.

APPROACH: A three phase approach will be used. In phase 1, ruminal fermentation in continuous culture will be used to investigate the effects of methionine and lysine on ruminal fermentation. Phase 1 will also be used to determine levels of methionine and lysine that are expected to result in changes in ruminal fermentation when fed to lactating dairy cows. Phase 2 will determine the effects of feeding methionine and lysine on duodenal flow of nutrients. In this phase, lactating dairy cows will be surgically modified and fitted with cannula's in the rumen and duodenum. These cows will be fed diets that contain differing levels of free methionine and lysine (levels determined from phase 1) and characteristics of ruminal fermentation and duodenal flow of nutrients measured. In phase 3, 40 lactating dairy cows will be fed diets differing in levels of free methionine and lysine to measure the effects of these amino acids on milk production and milk component production.

NON-TECHNICAL SUMMARY: Feed costs account for approximately 40 percent of the total cost of milk production by a dairy farm. Feeding free amino acids may improve fermentation in the rumen and allow for more accurate feeding of dairy cows. This trial is designed to gather data that will allow a dairy producer to determine if feeding free methionine and lysine will improve ruminal fermentaion and increase milk production or decrease their feed cost.

PROGRESS: 2000/07 TO 2000/12
Continuous culture fermentors have been purchased and initial set up completed. Additionally, cows have been fitted with ruminal cannulas to provide the ruminal fluid needed to innoculate the fermentors. A series of trials are planned that will investigate the impact of free methionine hydroxy analogue and lysine on ruminal fermentation in the fermentors. These trials should begin in the first quarter of 2001.

IMPACT: 2000/07 TO 2000/12
This project will allow protein recommendations for feeding dairy cows to be refined and more closely match the cows requirements for the amino acids methionine and lysine. By more closely matching the protein recommendations to the requirements of the cow, producers can better fine tune the rations offered and may lower their feeding cost or increase production or both.

INVESTIGATOR: Chandler, J. E.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

RELATIONSHIPS OF BULL SPERM CHROMOSOME CONTENT AND CONFIGURATION WITH SEMEN QUALITY & FERTILITY

OBJECTIVES: To use genetic engineering techniques (PCR and FISH) to validate methods for separating bovine spermatozoa according to desired sex chromosome. To maintain seminal quality and fertility during the separation process. To determine from spermatozoal mitochondrial DNA (mtDNA), the proportions of embryonic mtDNA which is transmitted from the spermatozoa and how this may be affected by the use of sexed semen. To evaluate Dairy Herd Improvement Association records as a source of data for use in estimating bull fertility and how fertility may be influenced by the use of sexed semen.

APPROACH: Sex separated sperm will be evaluated by PCR and FISH. Sperm DNA will be purified with enzyme digestion. PCR will be used to amplify sperm DNA by Taq polymerase. Amplified DNA will be electrophoresed on agarose gel stained with ethidium bromide. Gels will be photographed under UV light and analyzed for fluorescent intensity by image analysis. Sex separated sperm will be evaluated for viability and mitochondrial function using staining and videomicroscopy techniques. For quality compromised samples, motility will be stimulated with colostral whey, blood serum, and caffeine. Sire-daughter and daughter-dam mtDNA comparisons will be made to determine the extent of mtDNA inheritance from each parent using PCR techniques. Purebred and reciprocal crossbred progeny will be tested to quantify percentage of paternal mtDNA as affected by using sexed semen. Non-return data will be obtained from technician breeding receipts on cows that have records in the DHI database. Proportions of successful services from the DHI database will analyzed by weighted least squares methods. The weight used will be the number services per subclass. Means from the analysis will be used as estimates of bull fertility. Since DHIA data include birthday of calf and heifer calf identification for current lactation, LSNRATE will be used to monitor fertility of bulls whose semen has been sexed to ascertain how the separation process affects fertility.

PROGRESS: 1998/01 TO 1998/12
The collection frequency effect on variation in percent Y-chromosome bearing spermatozoa (%Y) from ejaculates within individual males was examined. Secondly, a spectroscopic measure of methylene blue reduction for estimating mitochondrial function and its correlation with motility was evaluated. Five sexual rested bulls were collected 6X/week. On each of the 3 days, 2 ejaculates were collected by artificial vagina 20 minutes apart. Ejaculates were processed separately, packaged in .5 ml straws, frozen and stored in liquid nitrogen. DNA from individual ejaculates was extracted and quantified at 260 nm. A Y-chromosome specific segment of DNA was amplified by polymerase chain reaction and the product separated by gel electrophoresis. Ethidium bromide stained bands were detected by image analysis. Ejaculates were evaluated 4 times. A second experiment used 4 sexual rested bulls collected 1X/day. Two bulls were collected 1X/week and two bulls collected every 21 days. Results were expressed as %Y per ejaculate on a within gel basis. Differences between first collection ejaculates were significant, ranging from 17 to 71%Y. The differences remained large (range 4 to 64%Y) for the second ejaculates. The differences lessened for the third(28 to 46%Y)and fourth collection(22 to 41%). Mean differences were least for the last two collections(49 to 55% and 42 to 55%). Small collection intervals reduced the ejaculate within bull variation in %Y. In Experiment 2, %Y was cyclic with a period of 30 days for bulls collected weekly. As in Experiment 1, %Y had a negative quadratic response with a nadir at 40 days for bulls collected on a 21-day interval. Spectroscopically evaluated methylene blue reduction rate could be used to relate spermatozoal mitochondrial function to motility. Methylene blue reduction under acidic conditions with Zinc powder was evaluated to set starting amounts, reaction time and rates. Absorbance(609 nm) was collected every 15 seconds for 10 minutes. A standard curve was constructed to calculate the methylene blue molar extinction coefficient. The rate of reduction by sperm was compared to the previously mentioned chemical reaction. Fresh ejaculates were assessed for concentration by spectrophotometer and motility was evaluated with phase microscopy on a heated stage. Semen was diluted using a 2.9% sodium citrate in 0.1M glucose solution to 100,000,000 cells/ml. Using a simple kinetics program, absorbance was recorded every fifteen seconds for 10 min in a heated water-jacketed cell. Absorbance and motility of a 3-ml sample were measured every half hour for 2.5 hours. These procedures were replicated three times. It was found that 234 microM of methylene blue was reduced in 10 minutes. The methylene blue molar extinction coefficient was 22.016 liters/moles. Methylene blue reduction rates were correlated to sperm motility (r=0.42,Ho:rho=0(P<0.08)). Optimizing the %Y variation and PCR identification would allow ejaculate selection for artificial insemination to alter the sex ratio of individual calf crops. Mitochondrial function was related to sperm motility. This could be used to quantitate sperm function for use in bull selection schemes.

INVESTIGATOR: Baham, A.;  Chandler, J. E.; Jenny, B. F.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

A FULL SERVICE A.I. PROGRAM FOR IMPROVING GENETIC SUPERIORITY IN DAIRY AND BEEF LIVESTOCK

OBJECTIVES: To provide scientific and operational support for a full A.I. program in dairy and beef cattle in Louisiana.

APPROACH: The Dairy Improvement Center provides facilities and some scientific support for the A.I. program operated by Genex. Through the program in conjunction with Genex, a farmer-owned cooperative, and Cooperative Resources International, a wide selection of superior sires are available to breeders in Louisiana. The program also provides a range of services to the cattle breeders in the state. Dairy bulls are sampled annually in an effort to identify superior bulls for the program and increased emphasis is being placed on the custom collection programs for beef bulls.

PROGRESS: 1998/01 TO 1998/12
The Dairy Livestock Development Program completed a successful service year to the Louisiana dairy and beef industry. During this time period, AI program service and benefits were coordinated with activities of Genex Cooperative, Inc. The formation of Genex in 1996 provided economic benefits and stability as well as enhanced genetics for AI members and customers in Louisiana. The continuation of the 1996 Cooperative Agreement between Genex and the LSU Agricultural Center provides an operational basis for coordinating the AI activities carried out at the LSU Dairy Improvement Center. Educational and research activities are coordinated with activities of the Departments of Dairy Science and Animal Science, Cooperative Extension Service and other related departments. Some of the accomplishments in 1998 include: (1) over 71,000 units of semen were collected from customer-owned bulls with the majority of this business in beef bulls; (2) the custom collection activity involved 16 breeds of beef and dairy and also involved 76 bulls; (3) AI service to some 750 cattlemen in Louisiana; (4) continued sampling program for progeny testing of dairy bulls; (5) herd analysis and mating programs for some 60 dairy herds and 7,500 cows; (6) facility tours were carried out for some 40 groups and participants varied from international visitors to local livestock owners. In addition to continued promotion and participation in educational activities promoting AI, the AI program also coordinates and supports facilities and animals for research and teaching.

PROGRESS: 2000/01 TO 2000/12
The Dairy Livestock Development Program completed a successful service year to the Louisiana dairy and beef industries. During this time period, AI program service and benefits were coordinated with activities with Genex/CRI Cooperative, Inc. The continuation of the 1996 Cooperative Agreement between Genex and the LSU Agriculture Center provides an operational bases for coordinating the AI activities carried out at the LSU Dairy Improvement Center as well as enhancing genetics for members and AI customers in Louisiana. Educational and research activities are coordinated with the Department of Dairy Science, the Louisiana Cooperative Extension Service, and other departments. Some of the accomplishments of 2000 include: 1)approximately 103,100 units of semen were collected from Genex and customer-owned bulls with the majority of the business in beef bulls; 2)the custom collection activity involved 17 breeds of beef and 116 bulls; 3)AI service to some 685 cattlemen in Louisiana; 4)continued sampling program for progeny testing of dairy bulls; 5)herd analysis and mating programs for some 60 dairy herds and 8500 cows; 6)facility tours were carried out for 29 groups with participation varying from local livestock owners to international visitors; 7)one proven Holstein bull is being routinely collected for semen distribution as a result of our progeny testing program. In addition to continued promotion and participation in educational activities promoting AI, the AI program also coordinates and supports facilities and animals for research and teaching.

IMPACT: 2000/01 TO 2000/12
Artifical insemination is an important tool that provides livestock owners access to bulls proven to be of the highest genetic superiority. The program provides breeders in Louisiana with a wide selection of superior sires along with a full service, custom collection program.
 

INVESTIGATOR:  Chandler, J. E.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

SEX CHROMOSOME VARIATION AS RELATED TO QUALITY, FREEZABILITY, FERTILITY AND SEX RATIO IN FARM SPECIES SPERMATOZOA

OBJECTIVES: 1. To use techniques such as image analysis or polymerase chain reaction (PCR) to select ejaculates of variable primary sex ratio both within and among sires to be used in the manipulation of sex rations in producers' calf and farrowing crops. 2. To improve the efficacy of a patented semen separation appratus both as to sperm number yield and sperm quality. 3. To determine how spermatozoal separation technologies affect semen quality, particularly spermatozoal mitochondrial function, i.e, motility. 4. To determine relationship between sperm mitochondrial function, as measured by methylene blue reduction, mitochondrial DNA fingerprint, parental energy use and parental mitochondria DNA fingerprint.

APPROACH: OBJECTIVE 1: Boar ejaculates will be collected from boars, extended and an aliquot will be taken while the remainder of each ejaculate will be used for AI. Breeding and farrowing records will be compiled for statistical analysis. Sperm DNA will be extracted and amplified in a duplex PCR with unique sequences from the X and Y crhomosomes. Digital images of agarose gels with ethidium bromide stained PCR products will be obtained for image analyses. The intensity density of each band will be corrected with an internal standard and then be compared to an external standard. White blood cells (WBC) DNA obtained from boars and sows will be used as the external standard. The WBCs from each sex will be pooled for an X: Y chromosome gradient. The WBC-DNA will be extracted, amplified, and electrophoresed alongside the samples. The WBC PCR product band will be compared with individual samples on a within gel basis. Primary sex ratio data from PCR analysis will be compared with secondary sex ratio data obtained from farrowing records. Experiment 2: Semen will be collected from boars and individual ejaculates screened using the procedure described in Experiment 1. Semen will be extended and frozen, pending PCR screening results, used for AI. Ejaculates that differ from a 1:1 sex ratio will be used in AI. Resulting piglet gender data will be compiled and compared with PCR data to determine the predictability of the screening process for secondary sex ratios. The PCR screening protocol will be adapted to bovine semen.  OBJECTIVE 2. To improve the separation efficiency, experiments will be conducted with the SEPDEVICE using bull semen with known %Y-chromosome bearing spermatozoa. Ejaculates that contain a high percentage of large, or  Y-chromosome bearing, sperm will be manimpulated to attempt to decrease the incidence of clogging. The dimensions of the SEPDEVICE will be changed to accommodate a larger volume of semen while maintaining the original design principles. Semen handling methods will be adopted to sustain the quality of the spermatozoa as they are being processed through the SEPDEVICE. Acrosomal integrity and motility of the spermatozoa will be monitored to evaluate the impact of the modification of the design or application of the SEPDEVICE on seminal quality. Specific PCR with image analysis will be used to evaluate separation effectiveness. OBJECTIVE 3: Fresh bovine ejaculates will be used for the methylene blue testing and motility. Blood samples will be drawn from the dams of these bulls. White blood cells will be harvested and cultured to increase cell numbers. Cell viability will be evaluated by trypan blue. Methylene blue in a glucose containing buffer will be added to the culture tubes. Methylene blue reduction rates will be calculated similar to that reported for spermatozoa.
OBJECTIVE 4: Spermatozoal mitochondrial DNA fingerprints will be used to relate mitochondrial fingerprints from the bull and dams. Spermatozoa will be decapitated and the head and tails will be separated with Percoll. The mtDNA will then be extracted and random PCR primers will be used to produce profiles comparison between related individuals.

NON-TECHNICAL SUMMARY: Offspring gender selection in farm animals will enable meat and milk producers to increase production efficiencies by reducing the number of the less or non-productive sex. The relationship between mitochondrial function and sperm motility is needed to better evaluate bull fertility. This project evaluates a technique for picking ejaculates that are skewed from the 50:50 X to Y chromosome bearing sperm. Understanding the sperm motility can be used in evaluating bull fertility. The project will cover the futher development of a patented device to augment the naturally occurring skew.

PROGRESS: 2000/01 TO 2000/12
Objectives:1)To evaluate the percent Y-chromosome DNA bearing sperm (%YCDBS)in bovine ejaculates by duplex gel and real time polymerase chain reaction(PCR). 2)To evaluate the use of cochettes (a flat plastic bag)as semen freezing containers. Experiment 1: Ejaculates were processed separately, packaged in .5 ml straws, frozen and stored in liquid nitrogen(LN). Individual ejaculate DNA was extracted and quantified by spectroscopy. For the duplex gel technology(DG-PCR), primers were designed for single copy genes specific to the X-(factor IX, F9)and Y-(SRYB)chromosomes. Amplified X and Y products were separated by gel electrophoresis, extracted and quantified at 260 nm. PCR product was electrophoresed on agarose gels containing ethidium bromide. Gels were imaged on a UV transilluminator with a SIT camera. Image analysis software was used to determine the integrated density of the bands. Standards were made to contain the following ratio of X to Y product (0:100, 20:80, 40:60, 60:40, 80:20, and 100:0). Unknowns were analyzed with the same primers and the images were quantified by comparison to the standard curve. Real time PCR(RT-PCR) was done on the same DNA, using primers for the same gene as duplex gel technology. The reporter flouroprobes were FAM for F9 and VIC for SRYB. Correlation analysis was done on DG-PCR and RT-PCR ejaculate means. The mean RT-PCR was 53.51% YCDBS with 0.45 standard error, ranging from 44.46 to 60.83% YCDBS across ejaculates. The mean DG-PCR was 55.00% YCDBS with 0.69 standard error, ranging from 42.55 to 73.51% YCDBS across ejaculates. The correlation between %YCDBS per ejaculate as determined by DG-PCR and RT-PCR was 0.15 (P>|r|=28, H0:Rho=0). Experiment 2. A rack for suspending cochettes about two inches above the LN level was constructed to accommodate twelve cochettes in two rows of six. Bovine semen collected by artificial vagina was evaluated for concentration and percent progressive motility (PPM). Semen was extended to 15 million motile cells/straw in a classical two part, egg yolk-sodium citrate-glycerol extender containing antibiotics. The second extender part was added to cooled semen by drip method. The semen was packaged into .5 ml French straws or cochettes (5 ml each). Air was removed from the cochettes and they were heat-sealed. The cochettes and straws were frozen via a standard straw protocol. Freezing was achieved by reducing the temperature from 5C to -135C in 8 minutes. Both straws and cochettes were then plunged into LN. Straws were thawed in a 37C water bath for 20 seconds. Semen was incubated in a 37C water bath. Cochettes were thawed in a circulating 37C water bath for 20 seconds. They remained in the water bath for 1 more minute before opening. Samples were evaluated on a warm coverslipped slide for PPM with phase microscopy. An aliquot was fixed with 0.2% gluteraldehyde for acrosomal integrity (PIA)evaluation. Samples were incubated for 3 hours and re-evaluated for PPM and PIA. PIA was determined by apical ridge presence using DIC microscopy. The quality of the semen frozen in straws was no different from that in cochettes(P>0.05).

IMPACT: 2000/01 TO 2000/12
Significance:Both DG-PCR and RT-PCR techniques showed variation in the %YCDBS from ejaculate to ejaculate. This variation and PCR identification could allow producers to select ejaculates for artificial insemination that would alter the sex ratio of the calf crop. Cochettes could be used as a semen freezing container for species (fish, swine and equine) that require large inseminate volumes.

PUBLICATIONS: 2000/01 TO 2000/12
Paul, J.B., Canal, A.M. and Chandler, J.E. 2000. X and Y chromosome specific duplex PCR standardized to quantify sex ratio variation in bulls and boars. J. Dairy Sc. 83, Suppl 1:198.

INVESTIGATOR: Williams, J.; Eilts, B.;  Chandler, J. E.

PERFORMING INSTITUTION: VETERINARY CLINICAL SCIENCES
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

QUANTITATIVE ASSESSMENT OF B-MODE TESTICULAR ULTRASOUND IMAGES USING IMAGE ANALYSIS IN MALE GOATS

OBJECTIVES: To establish and document the use of image analysis of B-mode ultrasound images (B-Mode) of testicular parenchymal morphology as a method of identifying testicular degeneration that is otherwise imperceptible on visual evaluation of B-mode images. To correlate the image analysis of B-mode images with histomorphometric analysis of testicular degeneration. Overall goal of project is to develop a technique to aid in the selection of bulls with maximum fertility and to identify bulls with testicular degeneration of subnormal fertility. Intact male goats will serve as the model for bulls.

APPROACH: Sixteen intact male goats will be utilized in this project. Each goat will be electroejaculated for evaluation of the semen. Sonographic evaluation of testicular parenchyma will be performed using a linear array 5 MHZ transducer placed on the scrotal surface. Images will be captured on videotape for image analysis. Regions of interest within the image designated for image analysis will be within the focal zone of the transducer (1x9 cm). Testicular degeneration will be induced by partial ligation of one testicular artery per goat to 25% of baseline blood flow. Goats will be sonographically examined and castrated for histomorphometric analysis on predetermined post-operative days. Image analysis of testicular degeneration will be correlated to histomorphometric analysis of testicular degeneration.

PROGRESS: 1998/01 TO 1998/12
There has been essentially no change in the status of the experimental data since the last report. Equipment difficulties still prevent image analysis of the remaining 25% of the testicular images. Hopefully, this problem will be overcome this year and the final image analysis obtained. Statistical analysis of image data is expected to follow uneventfully.

INVESTIGATOR: Gough, R. H.; McGregor, J. U.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

QUALITY OF RAW AND PASTEURIZED MILK BASED ON ADENOSINE TRIPHOSPHATE CONTENT AND BACTERIAL NUMBERS

OBJECTIVES: To compare use of adenosine triphosphate content and standard bacterial enumeration for ascertaining the bacteriological quality of raw and pasteurized milk; to determine the effect of using gram positive bacterial inhibitors and various preliminary incubation temperatures on the bacteriological profiles in raw and pasteurized milk.

APPROACH: A method for measuring ATP in raw and pasteurized milk will be developed and an application developed for making quality checks at the receiving station and processing plant. Various gram positive bacterial inhibitors will be tested in order to select one that will give accurate results when pasteurized milk is being evaluated. Modified aerobic bacterial
enumeration procedures will be evaluated to determine if they could be easily utilized in a quality assurance program in a dairy plant.

PROGRESS: 1989/01 TO 1995/10
An assessment of milk quality was studied using a combination of preliminary incubation, filtration, aerobic plate count and adenosine triphosphate content, as measured by Relative Light Units (RLU). In raw milk samples a correlation of 0.87 was found between aerobic plate count and Relative Light Units at an aerobic count level of 100,000 CFU/ml. When the raw milks were preliminary incubated (PI) before analysis for aerobic plate count and RLUs at 12.8 and 15.6 C for 18 hours the correlations for both were 0.97. These results could be used as a tool in microbial screening of raw milk. In preliminary studies a filtration unit was used to concentrate bacteria in raw milk samples in lieu of preliminary incubation. A correlation of aerobic plate count to RLU was 0.67. Pasteurized low-fat milk samples were analyzed for coliform count (CC), standard plate count (SPC) and a psychrotrophic bacteria count (PBC). The average of the results were 13,000 CFU/ml for SPC, less than 1 CFU/ml for CC and 900 CFU/ml for PBC. The samples were then stored at 7 C to determine shelf life (1,000,000 CFU/ml) using SPC criteria. The average shelf-life for the low-fat milk was 8.2 days. By the use of PI bacteria counts the average shelf-life should have been 6-10 days. Using similar criteria pasteurized milks were also analyzed and shelf life was determined to be 14 days at 7 C. By using a combination of PI and SPC a shelf-life prediction can be determined which could effectively be used to track product quality.

PROJ NO: LAB03173 AGENCY: CSRS LA.B
PROJ TYPE: HATCH PROJ. STATUS: NEW
START: 13 DEC 1995 TERM: 30 NOV 2000 FY: 1999

INVESTIGATOR: Gough, R. H.; McGregor, J. U.; Drapcho, C.

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

TREATMENT OF DAIRY PROCESSING WASTEWATER

OBJECTIVES: 1. To determine the chemical and biochemical parameters of dairy processing wastewater following biological oxidation in a lagoon system. 2. To determine the effectiveness of an aerobic sequencing batch reactor (SBR) for treatment of dairy processing wastes. 3. To evaluate the use of adenosine triphosphate and heterotrophic plate count as indicators of biological activity in a lagoon system and SBR.

APPROACH: Studies will be conducted utilizing an operational 3-stage lagoon system at a cheese plant, Sequencing batch reactor at a fluid milk processing plant and a pilot scale batch reactor. Wastewater samples will be collected from each waste treatment system and analyzed for biochemical oxygen demand, chemical oxygen demand, total solids, total suspended solids adenosine triphosphate, heterotrophic plate count and pH. The efficiency of the wastewater treatment systems can be determined by reduction in pollution parameters. Adenosine triphosphate and heterotrophic plate count will be used to ascertain biological activity in all areas of the wastewater systems as well as determine proper loading ratio and retention time.

PROGRESS: 1998/01 TO 1998/12
The efficiency of a sequencing bath reactor (SBR) wastewater treatment system of a dairy processing plant is based on a viable biomass that will result in a breakdown of solids with a separation of the decant and sludge. We established a system to measure the viable biomass in a SBR system by means of a heterotrophic bacterial plate count (HPC) and a relative light unit (RLU) measurement based on an adenosine triphosphate bioluminescence procedure utilizing a dip wand method. In stage 2 of the system, which is the sequencing batch reactor phase, an average HPC of 3.8 x 10E7 CFU/ml was found along with an RLU bioluminescence measure of 2.6 x 10E6. The final effluent wastewater stage had an average HPC of 6.9 x 10E5 CFU/ml with a corresponding average RLU value of 1.1 x 10E4. When the log values of all HPC and RLU values in the three stage system were considered, a resulting R-square of 0.60 was determined for HPC vs. RLU (wand method). This indicates that the viable biomass of such a system can be measured with the rapid dip wand method of bioluminescence and provide wastewater treatment information to the operator. Other parameters that were analyzed in the system were chemical oxygen demand (COD), total solids (TS) and total suspended solids (TSS). Based on prior research on this wastewater system, these parameters can be used to predict biochemical oxygen demand (BOD) which is used as a major indicator of pollution strength. The COD, TS and TSS reduction through this system was 96, 52 and 98% respectively. With an operational pH of 7.4-7.8, the wastewater system operated within the permitted pH levels of 6-9.

PROGRESS: 2000/01 TO 2000/12
Processing wastewater from a dairy plant sequencing batch reactor system was used as a substrate for evaluation of several filtration media for primary treatment. Wastewater from the same source was analyzed for microbial load by use of heterotrophic plate count (HPC) and adenosine triphosphate (ATP) bioluminescence. The wastewater used in the study had the following parameters: chemical oxygen demand, 940 mg per liter; total solids, 1163 mg per liter and total suspended solids, 535 mg per liter. The effectiveness of filtration media in the primary treatment of dairy processing wastewater was investigated in laboratory studies. Zeolite, crushed coral, charcoal, and a combination of sand and glass beads as well as sand and crushed coral were studied. The effectiveness of the various filtration media was determined by testing the parameters of chemical oxygen demand, total solids and total suspended solids. Sand in combination with glass beads or crushed coral was found to be the most effective media with an average reduction of 93% in chemical oxygen demand; 51% in total solids and 99% in total suspended solids. Microbial load in the wastewater from the dairy plant was evaluated. Prior research on the react tank in a sequencing batch reactor using dairy plant wastewater revealed that a heterotrophic plate count and a dip wand procedure for ATP bioluminescence could be used to determine viable biomass. A study was initiated using the same parameters to evaluate untreated wastewater from a dairy plant. A biocounter was used to determine ATP while microbial load was determined by using HPC. Regressive analyses revealed a linear relationship between log 10 transformed HPC and ATP measured in relative light units (RLU). The R square from this data was 0.87 with a correlation coefficient of 0.93. The results indicate that this ATP method can be a good method for rapid estimation of bacteria in wastewater samples.

IMPACT: 2000/01 TO 2000/12
Dairy plant management must have information on levels of pollution parameters, primary wastewater treatment and laboratory tests that can be used to evaluate pollution strengths to properly manage and dispose of dairy plant waste. Proper evaluation of waste degradation or filtration must be quantified and used to make operational decisions on loading rates, type of treatment and adherence to state and federal regulations. Results of this study could be used as part of the information required to make management decisions on a sequencing batch reactor waste disposal system.

PUBLICATIONS: 2000/01 TO 2000/12
1. Gough, R. H., P. J. Samkutty, P. McGrew, J. Arauz and R. W. Adkinson. 2000. Prediction of effluent biochemical oxygen demand in a dairy plant SBR wastewater system. J. Environ. Sci. Health. 35:2.
2. Samkutty, P. J., R. H. Gough and P. McGrew. 2000. Effects of pure bacterial culture isolates on the operational efficiency of a sequencing batch reactor wastewater treatment system. Proc. La. Academy of Sciences. V.63.
 

PROJ NO: LAB03307 AGENCY: SAES LA.B
PROJ TYPE: STATE PROJ STATUS: NEW
START: 01 JAN 1998 TERM: 31 DEC 2002 FY: 2000

INVESTIGATOR: Hay, G. M.; Jenny, B. F.

PERFORMING INSTITUTION:DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

DAIRY CATTLE IMPROVEMENT THROUGH DHI

OBJECTIVES: To provide support for a DHI program that will 1) provide Louisiana producers with data for improving efficiency of operations and 2) provide data for use in research and educational programs.

APPROACH: The DHI program in Louisiana is run as a cooperative effort between the Department of Dairy Science, Dairy Extension, and the Louisiana DHIA. The state program is part of a national program involving the National DHIA and the USDA. A certified DHIA supervisor obtains individual cow milk samples and appropriate management data on a regular basis from participating herds. Results from milk analysis are compiled with farm data through a centralized computer system. A complete set of records is returned to the producer for use in decision making. Records are also made available to the Department of Dairy Science, Dairy Extension and the USDA for use in research and educational programs.

PROGRESS: 2000/01 TO 2000/12
The primary objective of the DHI program is to provide Louisiana producers with accurate records for improved decision making and efficiency of operation. Louisiana had 146 herds with 19,632 total cows participating in the DHI program at the end of 2000 giving an average herd size of 138 cows/herd. Although total herds decreased by 8 during 2000, herd size remained relatively constant for the year. Thirty-two producers are utilizing the pcdart program and one producer is using the new pocket dairy program. Three consultants have started to utilize pcdart. Herds enrolled in the DHI program produce over 4000 pounds more milk per cow per year than non DHI herds. The increased revenue from the added milk produced more than justifies the cost of the program which is about $22 per cow per year.

IMPACT: 2000/01 TO 2000/12
The DHI program provides an accurate records program on both individual cow and herd bases. A dairy enterprise, like any other business, must have accurate records if it is to be managed in an efficient business like manner.

INVESTIGATOR: Jenny

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

DAIRY PLANT OPERATIONAL SUPPORT

OBJECTIVES: To provide operational and technical support for all research, public service, and teaching activities related to dairy foods technology.

APPROACH: A functional dairy processing plant and dairy store are maintained in the Dairy Science Building on the Louisiana State University campus. The dairy plant occupies about 7,700 square feet of space with facilities for receiving raw milk, fluid milk processing, and manufacture of ice cream, various cheeses, and other frozen and cultured dairy products. All raw milk required for research, teaching, and manufacture of frozen and cultured products is obtained from the LSU dairy farm. The dairy store occupies about 320 square feet of space and serves as a retail outlet for products produced in the dairy plant. Operation of the dairy plant and store is under the direction of a instructor with a appointment of 60% reseaarch and 40% teaching. A full time classified position assists with operation of the dairy store. The remaining labor force consists of part time student labor. This unit provides the technical and operational support for all research, public service, and teaching activities related to dairy foods technology.

NON-TECHNICAL SUMMARY: A functional dairy processing facility is central to maintaining comprehensive research, public service, and teaching programs in dairy foods technology. The purpose of this project is to provide the technical and operationl support needed to conduct research, public service and teaching programs in dairy foods technology

INVESTIGATOR: C. C. Williams

PERFORMING INSTITUTION: DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

REGULATION OF THE SOMATOTROPIC AXIS BY DIETARY PROTEIN IN GROWING RUMINANTS

PROGRESS:A study was conducted to determine effects of dietary protein and weaning age on growth and hormonal status in neonatal dairy calves.  Thirty-seven Holstein calves were assigned to one of 4 dietary treatments:  (1) 4 week weaning age, 16% CP calf starter (n=10); (2) 4 week weaning age, 22% CP calf starter (n=9); (3) 8 week weaning age, 16% CP calf starter (n=9); (4) 8 week weaning age, 22% calf starter (n=9).  Individual feed intake and fecal scores were recorded daily.  Body weight, hip height, wither height, and body length measurements were recorded weekly.  Blood samples were collected weekly from 6 calves per treatment prior to and 2 hours after morning feeding.  Samples are currently being analyzed for hormones and metabolites including IGF-I, insulin, glucagon, glucose, and blood urea nitrogen.  At two week intervals, blood samples were collected from the same 6 calves per treatment every 15 minutes for determination of GH.  After a 6.5 hour collection period, arginine (.5g/kg BW) was administered intravenously to induce GH release, and 4 additional blood samples were collected at 15 minute intervals.  Hormone analysis is currently in progress on these samples.   Statistical analysis is being conducted on data from the growth portion of the trial.

SIGNIFICANCE: This study should provide useful information for improving the nutritional management of dairy
calves.  If the higher protein starter diets result in an increased production of anabolic hormones and increased growth, then perhaps calves can be successfully weaned at an earlier age without significant losses in growth.

INVESTIGATOR: Williams, C. C.

PERFORMING INSTITUTION:DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

MANAGEMENT SYSTEMS FOR IMPROVED DECISION MAKING AND PROFITABILITY OF DAIRY HERDS

OBJECTIVES: 1. Develop and integrate decision support systems to promote efficient, environmentally sound, and economically viable management systems for dairy youngstock. 2 Develop and integrate decision support systems to optimize productive and economic efficiencies for lactating and dry cow management systems.

APPROACH: The effects of dietary protein and ruminally undegradable protein on growth of weaned dairy heifers will be studied. Holstein heifer calves, approximately 4 months of age, will be assigned to one of four dietary treatments consisting of two grain supplements containing either 16 or 20% crude protein with or without a source of rumen escape protein. Body weight and height will be monitored. Anabolic hormone (growth hormone, IGF-I, insulin) status will also be assessed in order to determine whether increasing levels of protein and/or post-ruminal supply of amino acids will improve growth through increasing the concentrations of these hormones.

PROGRESS: 2000/01 TO 2000/12
Two projects were conducted with neonatal dairy calves to study effects of nutritional management on growth and performance. In the first project,18 Holstein and 15 Jersey heifer calves were fed milk replacer either once or twice daily to determine effects on weight gain, starter intake, and glucose metabolism during the neonatal period. Calves were fed milk replacer at 10% of birth weight. The fluid volume of water used in the replacer fed 1x was reduced to 70% of that used in the replacer fed 2x. However, total dry milk replacer fed was the same for both treatments. Calves were allowed free access to a calf starter and water throughout the study and were weaned at 6 weeks. Individual feed intakes and fecal scores were recorded daily. Body weights were measured from birth to 8 wk and at 12 wk to determine long-term differences in feeding systems. Blood samples were collected at weeks 1 through 6 from all calves immediately prior to and at 30, 60, 90, 120 and 180 min after the morning feeding. These samples were analyzed for glucose and insulin. Feeding frequency did not affect starter intake or body weight. Mean plasma insulin concentrations were higher in calves fed 1x whereas glucose concentrations were not, indicating that insulin was effective in maintaining plasma glucose levels in calves fed 1x. The second experiment investigated the effects of supplemental vitamin E with or without lasalocid on growth and health of calves challenged with coccidiosis. Thirty-two male Holstein calves were fed one of four treatments consisting of either 0 or 180 IU supplemental vitamin E with or without lasalocid (1 mg/kg body weight). Calves were fed colostrum for 3 days then switched to milk replacer fed at 10% of birth weight until weaning at 5 weeks. Individual feed intake and fecal scores were monitored daily, and fecal samples were collected weekly. Fecal oocyst counts did not differ among treatments. Fecal scores were lower in calves fed lasalocid and higher in calves fed vitamin E. Body weights and starter intake were greater in calves fed lasalocid, and calves fed both lasalocid and vitamin E had the greatest increase in body weight.

IMPACT: 2000/01 TO 2000/12
The data in the first experiment suggest that feeding calves milk replacer once daily did not deleteriously affect health, weight gain, or glucose metabolism. By feeding calves milk replacer once daily, expenses can be reduced by decreasing the labor input for calf rearing. The second experiment indicated that lasalocid is effective in prevention of coccidiosis. Additionally, lasalocid with supplemental vitamin E improved growth and health in neonatal calves infected with coccidiosis.

PUBLICATIONS: 2000/01 TO 2000/12
1. Goodier, G. E. and C. C. Williams. 2000. The transfer of passive immunity to neonatal calves. Lousiana Dairy Report. pp. 7-8.
2. Cheatham, C., C. C. Williams, and B. F. Jenny. 2000. When can calves be weaned? Louisiana Dairy Report. pp. 9-10.

PROJ NO: LAB03372 AGENCY: CSREES LA.B
PROJ TYPE: HATCH PROJ STATUS: NEW
START: 01 NOV 1998 TERM: 01 NOV 2001 FY: 2000

INVESTIGATOR: Williams

PERFORMING INSTITUTION:DAIRY SCIENCE
LOUISIANA STATE UNIVERSITY
BATON ROUGE, LOUISIANA 70893

REGULATION OF THE SOMATOTROPIC AXIS BY DIETARY PROTEIN IN GROWING RUMINANTS

OBJECTIVES: 1. To determine the effects of dietary protein level and pattern of weaning on growth and anabolic hormone status in neonatal dairy calves; 2. To determine the effects of dietary protein level and rumen degradability on growth and hormonal status in weaned dairy calves.

APPROACH: A study will be performed to determine whether weaning age (4 vs. 8 weeks) and calf starter crude protein level (16 vs. 22%)influence anabolic hormone levels and growth in pre-ruminant dairy calves. Feed intake, water intake, and health status of the animals will be recorded daily. Body weight gain and skeletal growth (wither height, hip height) will be measured. Blood samples will be collected and analyzed for growth hormone, insulin-like growth factor-I, insulin-like growth factor binding proteins, insulin, glucagon, and blood urea nitrogen. A second study will be conducted to investigate the effects of ruminally undegradable protein (RUP vs. no RUP) and dietary protein level (16 vs. 20%) on hormonal status and growth in weaned calves from 4 to 6 months of age. Measurements will include body weight gain and skeletal growth. Blood samples will be collected and analyzed for growth hormone, insulin-like growth factor-I, insulin-like growth factor binding proteins, insulin, glucagon, and blood urea nitrogen.

PROGRESS: 2000/01 TO 2000/12
While early weaning may be utilized to lower costs of raising replacements, calves may experience growth slumps that offset the economic benefits of these programs. The objective of this study was to determine the effects of weaning age and calf starter crude protein (CP) level on growth parameters in neonatal dairy calves. Thirty-seven Holstein calves were assigned to one of four treatments in a 2 x 2 factorial arrangement consisting of 2 weaning ages (4 vs. 8 weeks) and 2 isocaloric calf starters (16 vs 22% CP, as-fed basis). Calves received colostrum for 3 days and then milk replacer (22% CP, 15% fat) until weaning. Milk replacer was fed at 10% of birth weight divided into 2 feedings daily until 2 weeks prior to weaning. Then replacer was reduced to 75% of original amount one time per day and further reduced to 50% of original amount one week prior to weaning. Beginning on day 4 calves were allowed free access to one of the 2 calf starters. Individual feed intake, water intake, and fecal scores were recorded daily throughout the 10 week study. Body weight, hip height, wither height, and body length were recorded weekly through week 10. Starter CP did not affect starter intake, body weight, or skeletal growth. Starter intake was greater from wk 4 through week 10 in calves weaned at 4 weeks of age. Additionally, starter intake was greater in male calves regardless of treatment. There were no effects of treatment on water intake. Fecal scores were lower throughout the study in calves fed 16% CP and were not affected by weaning age. Body weights were greater in calves weaned at 8 weeks; however, calves weaned at week 4 did not experience weight losses after weaning. Hip heights and wither heights were greater in calves weaned at 8 weeks. These data indicate that despite slight increases in growth in calves weaned at 8 weeks, dairy calves can be weaned successfully at 4 weeks of age. Increasing the protein level in calf starter did not improve intake or growth in these early weaned calves.

IMPACT: 2000/01 TO 2000/12
These data indicate that despite slight increases in growth in calves weaned at 8 weeks, dairy calves can be weaned successfully at 4 weeks of age. Furthermore, increasing the protein level in calf starter did not improve intake or growth in early weaned calves. This is economically beneficial to the dairy producer, since liquid feeds and high protein starters are more expensive sources of nutrients for the young calf.

PUBLICATIONS: 2000/01 TO 2000/12
Williams, C. 2000. Raising dairy replacement heifers: what are the options? Louisiana Dairy Report. pp. 11-13.