Considerable variation in the percentage of Y-chromosome bearing spermatozoa (%Y-CBS) between ejaculates in the same male has been reported. Collection regime has been speculated to influence the degree of variation in %Y-CBS in bull ejaculates (Chandler et al., 1998). Experiments were designed to evaluate the effects of two collection regimes on %Y-CBS. Conventional PCR combined with gel electrophoresis and image analysis was employed to determine %Y-CBS in ejaculates from two bulls collected on 7-day intervals and two bulls on 21-day intervals. Real-time PCR technology was used to quantify %Y-CBS in the same ejaculates. Boar ejaculates were also analyzed with both techniques and compared to the percent male piglets in litters resulting from the assayed ejaculates. Collection day (P<0.0001) significantly affected %Y-CBS as determined by both PCR methods. Ejaculate nested within bull (P<0.07) was significant in the conventional PCR study and collection frequency (P<0.0001) in the realtime PCR trial. Ejaculate nested within boar was highly significant (P<0.0001) for both technologies. Boar was significant (P<0.002) in the conventional PCR study. Predicted %Y-CBS determined by real-time PCR was significantly correlated (0.52, P=0.004) to percent male piglets. Both PCR techniques were effective in quantifying the variation in %Y-CBS in bull and boar ejaculates. Manipulation of %Y-CBS via collection regime may prove valuable for altering the secondary sex ratio in animal agriculture.

Mastitis in prepartum dairy heifers has been recognized as a significant economic problem for the dairy industry. Intramammary infusion of cephapirin sodium was completed in 20 treatment animals and the results were compared to 25 non-treated control animals. Bacteriological data from the quarter milk samples were used to determine and compare initial infection rates and cure rates following calving between treatment and control groups. Comparisons were also made between groups for differences in reproductive performance, milk yield, somatic cell count and milk ketone concentration. Milk yield did not differ between groups for either DHIA monthly average kg/day, 305 day actual milk yield or 305 day mature equivalent yield (305ME). The average weekly milk weights (kg/d) between groups were different (P<.0001). Reproductive performance between groups was not significantly different. Milk ketone concentration did not differ at weeks 1 or 2. Somatic cell count score (SCS) at 200 days in milk were not different between groups, but the treatment group exhibited a trend towards lower cell counts (P<.10). SCS in the treatment group tended to be lower (P<.09) during the average of the first 3 DHIA test periods. Prepartum treatment of dairy heifers significantly improved cure rates in the treatment group (P<.003), moderately reduced SCC throughout lactation, and did not affect milk yield. While there were no significant differences between treatment groups in milk ketone concentration, evidence suggests that infections caused by major mastitis pathogens may increase metabolic stress on primiparous heifers. Further research in the use of prepartum lactating cow antibiotics in heifers is needed.

Eight weaned Holstein steers approximately 4 mo of age (mean BW = 119.47 ± 2.65 kg) were used in a replicated 4 x 4 Latin square designed experiment to study the effects of protein source and level on performance and anabolic hormonal status of weaned dairy calves. Treatments consisted of two diets containing either 16 or 20 % crude protein (CP) with or without fish meal (FM). Experimental diets were corn silage based with soybean meal (SBM) as the source of ruminal degradable protein and FM as the source of ruminal undegradable protein. The animals were fed their respective diets twice daily at ad libitum levels during each 10-d adjustment period and 4-d sample collection period. Animals were housed in individual stalls for 10 d and in metabolism crates for 4 d for each experimental period. Feed intake was recorded daily. Total fecal and urine output were collected, weighed and subsampled during the 4-d sample collection period for laboratory analysis of nitrogen. On d 4 of the sample collection period, animals were fitted with indwelling jugular catheters. Blood samples were collected for 6 h at 15-min intervals for analysis of growth hormone (GH) and 30-min intervals for analysis of insulin (INS) and insulin-like growth factor-1 (IGF-1). An initial blood sample was taken at the beginning of the 6-h blood sample period for analysis of plasma urea nitrogen (PUN) and thyroxine (T4). On d 14 of the each experimental period, body weight, wither height, hip height, and body length were measured. Treatment did not affect (P > 0.10) dry matter intake, any of the growth parameters measured, or nitrogen balance. Steers consuming diets containing 20% CP diets tended to have higher plasma INS concentrations (P = 0.07) whereas steers consuming SBM as the protein source tended to have higher mean GH levels (P= 0.07). Thyroxine, IGF-1, and PUN concentrations were not effected by protein level or source (P > 0.10). It is concluded that feeding diets greater than 16% CP with or without FM does not improve performance in weaned dairy calves.

The experiments described herein are designed to elucidate many metabolic changes that occur to regulate the partitioning of nutrients between production and animal maintenance with particular regard to glucose metabolism and insulin sensitivity. The onset of milk production and parturition causes dramatic stress to the cow. The challenge of improving metabolism during this period is being addressed by nutritional management with the possibility of the addition of supplements. The use of Ca-propionate as a supplement did not affect glucose metabolism in transition cows. The data revealed that insulin sensitivity was low during the transition period, but the tissue responses to insulin and the acute insulin response to a glucose infusion increased slightly after calving as compared to late gestation. Glucagon and nonesterified fatty acid concentrations increased throughout the transition period, while glucose, insulin, and thyroxine concentrations decreased. A need for a relatively easy and inexpensive test for evaluating glucose metabolism has been indicated, and it was shown that the Minimal Model computer analysis of the frequently sampled glucose tolerance test was adequate in assessing insulin sensitivity in dairy cattle. The acute hyperinsulinemia induced by the insulin tolerance test or by the hyperinsulinemic euglycemic test did not affect plasma leptin concentrations.

Six non-lactating Holstein cows with ruminal and duodenal cannulas were used in a replicated 3x3 Latin square design experiment to investigate the effects of supplemental protein source on ruminal and total tract nutrient digestibility. Supplemental protein was provided from soybean meal (SBM), expeller processed soybean meal (EXP), or menhaden fish meal (FM). Basal diets consisted of (DM basis) 33% corn silage, 20% bermudagrass hay, 27% ground corn, and 2% minerals and vitamins. Supplemental protein was provided as (DM % of total diet) 18% soybean meal (SOY), 17% soybean meal and 1% fish meal (FM), or 12% soybean meal and 6% expeller processed soybean meal (EXP). Period length was 14 d. Flow of digesta was estimated using Cr₂O₃ as an external marker. Due to factors unrelated to the trial, one cow died during the first period of the study and was not replaced. Dry matter intake averaged 9.5 kg/d and was not affected by treatment. Apparent ruminal dry matter digestibility was not affected by source of supplemental protein. Source of supplemental protein did not affect apparent total tract dry matter digestibility. Feeding low ruminal degradable protein to non-lactating cows resulted in no appreciable impact on feed intake or apparent diet digestibility.

Thirty-nine ejaculates from 8 Holstein bulls were collected. Straws of semen (n=750) were distributed among dairies in three states. Ten straws per ejaculate were sent to Louisiana State University (LSU) Dairy Improvement Center for conventional polymerase chain reaction (PCR) analysis. Spermatozoal DNA was extracted and PCR analysis was done using one primer set amplifying a single copy 125 base pair (bp) section of the Bos taurus factor IX (Christmas factor) precursor (found on the X chromosome) and another primer set amplifying a single copy section of the Bos taurus sex determining region Y protein (SRY) gene (found on the Y chromosome). A 294 bp product from the Bos taurus glyceraldehydes-phosphate-dehydrogenase (GAPDH) was amplified as an internal control. Standard curves were designed using PCR products in known ratios. Gel electrophoresis and image analysis allowed for determination of predicted % Y chromosome-bearing spermatozoa (predicted % Y spermatozoa). Calf sex was reported and % male calves was determined between bull, ejaculate within bull, state, and location within state. Predicted % Y spermatozoa and % male calves showed significant correlation to each other. No significant variance between bull was found in predicted % Y spermatozoa or % male calves, but significant variance was found between ejaculate within bull for both. PCR technology used for determining the % Y spermatozoa in ejaculates was shown to be an adequate method to determine semen sex ratio.

Folic acid plays an important role in the prevention of neural tube defects such as spina bifida and anencephaly, heart defects, facial clefts, urinary abnormalities and limb deficiencies. Milk and milk products serve as a potential source for folic acid fortification due to the presence of folate binding proteins which seem to be involved in the folate bioavailability. Though milk is a not a good source of folic acid, fortification could help in the prevention of the above mentioned defects. The objective of this study was to examine the physico-chemical characteristics of reduced fat milks fortified with folic acid. Reduced fat milks were prepared using 25, 50, 75 and 100% of the recommended dietary allowance of 400 micrograms of folic acid. Treatments included addition of folic acid at these levels before and after pasteurization. Color, pH, fat, protein, viscosity, folic acid concentration, folate binding protein concentration, folate binding protein profile, standard plate count and coliform counts were determined on days 1, 7, 14 and 21. A consumer acceptance test was conducted on day 7. Data from the consumer panel was analyzed using analysis of variance (PROC GLM) with means separation to determine the differences among treatments. Data obtained from the color, pH, fat, protein, viscosity, folic acid concentration, folate binding protein concentration, standard plate count and coliform counts were analyzed using the General Linear Model with a repeated measure in time by the Statistical Analysis System. Significant differences were determined at P<0.05 using Tukeys Studentized Range Test. There were no differences in the electrophoretic mobility of folate binding protein in the samples. The concentration of folic acid was significantly higher in reduced fat milks fortified with folic acid after pasteurization compared to the treatments to which folic acid was added before pasteurization. The consumer panelists did not find any significant differences in flavor, appearance and texture of folic acid fortified reduced fat milks compared to that of the control. Fortification of reduced fat milks with folic acid can be accomplished with out adversely affecting the product characteristics.

It has been proposed that Bos indicus when compared with Bos taurus embryos are more sensitive to cryopreservation procedures due to higher intracellular lipid content of the embryos. With cyropreservation of Bos indicus embryos increasing for export, it is essential to improve the viability of these cryopreserved embryos. In Experiment I, M-II oocytes from mice, pigs and cows were subjected to two different procedures to evaluate lipid content. The lipid content present in pig oocytes was significantly (P<0.05) higher when compared with mouse and cow oocytes. Pig oocytes had a lower settling point in the sucrose buoyant density gradient and higher Nile Red units, which indicated higher lipids present in the oocytes. In Experiment II, it was determined that M-II oocytes aspirated from superstimulated Brahman donors were significantly higher (P<0.05) in lipid content compared with English breed donors. The lipid content present in Brahman oocytes was higher when compared with English breeds when tested with a sucrose buoyant density gradient and Nile Red staining. In addition, donor females with higher body condition scores were significantly (P<0.05) higher in oocyte lipid content when compared with donor females of lower body condition scores. Furthermore, animal body condition scores, cholesterol and triglyceride levels prior to oocyte aspiration may be indicators of intracellular lipids in the oocytes and embryos. To our knowledge, this is the first report that evaluated intracellular lipid content of M-II oocytes of different beef breed types using a sucrose buoyant density gradient and Nile Red staining.

Health benefits of Lactobacillus acidophilus include providing immune support for infections or cancer, providing a healthy replacement of good bacteria in the intestinal tract following antibiotic therapy, reducing occurrence of diarrhea in humans, aiding in lowering cholesterol and improving the symptoms of lactose intolerance. Consumer demand exists for new dairy products. There are several types of yogurt like stir curd, set curd and drinkable yogurt and they all need to be refrigerated. Moreover there are very few dairy products that can be stored at room temperature and not many dairy foods are finger foods. A novel yogurt product like a yogurt jerkey with L.acidophilus could be a dairy product that is a finger food, which can be stored at room temperature and have health benefits. The objectives of the research were to study the effects of 0, 1, 10 and 100g of Lactobacillus acidophilus /gal of novel yogurt product on L. acidophilus, yogurt bacteria, coliform, yeast and mold counts and TPA (Texture Profile Analysis) hardness, springiness, chewiness, cohesiveness, and adhesiveness over 0, 1, 2 and 3 months of storage of the novel yogurt product at room temperature. The interaction effect of treatment and time was significant for all attributes studied except adhesiveness. Yogurt bacterial counts were significantly higher in all treatments at month 3 compared to control. With the use of 10g and 100g/gal addition of L.acidophilus there was a significant decrease in L.acidophilus counts at month 2 and month 3 when compared to month 0. Hardness of product with L.acidophilus use at 100g/gal was significantly lower when compared to the control and treatments 1, 10g/ gal over months 1, 2 and 3. Springiness and chewiness of all treated samples at month 2 were significantly higher than control. Cohesiveness was significantly higher with all levels of L.acidophilus compared to control. Use of probiotics favorably affected some characteristic of the novel yogurt product. Use of probiotic L.acidophilus at 100g/gal can be recommended in the manufacture of a healthy novel yogurt product such as a yogurt jerkey or bite sized chewable yogurt capable of being stored at room temperature.

Forty-eight calves (heifers n=20, bulls n=28) were randomly assigned one of four dietary treatments which included no additive (C); the yeast culture Saccharomyces cerevisiae (YC); the probiotics Bacillus lichenformis and Bacillus subtilis (P); and both yeast culture and probiotics (YCP). Calves were administered treatments from day 2 to 56 in starter and from day 57 to 84 in grower diets. Body weights were measured at birth and weekly thereafter until day 112 of age. Wither and hip heights were measured weekly. Feed intake, water intake, and fecal scores were recorded twice daily until day 56. Rumen fluid was collected on days 14, 28, 42, 56, 70, 84, and 112 for analysis of pH, VFA, and NH3. Blood was collected on d 28, 42, 56, 84, and 112 for analysis of BHBA concentrations. There was a sex*treatment interaction (P < 0.01) for starter intake. Males receiving P consumed less than other calves. Females consuming C ate less than males on the same diet. Females consuming YC ate more than males consuming YC. There was a tendency (P = 0.06) for calves receiving YC to consume more than calves not fed YC. Calves consuming P drank less water than all other calves (P = 0.01). There was a sex*time*treatment interaction for body weight (P < 0.05). Females consuming C and males consuming P showed a decreased body weight over time (P < 0.05). Calves consuming YC showed an increased body weight at week 6 and 8 (P < 0.05). There were no differences among treatment groups for hip and wither height (P > 0.1). Calves consuming YC had higher fecal scores than those with no YC (P < 0.05). There were no differences among treatments on pH, NH3, BHBA, butyrate, and propionate (P > 0.1). A sex*treatment*week interaction occurred for acetate (P < 0.05). Calves consuming P had an increase in acetate, with females showing a greater increase over males. Incorporating YC into starter may result in an increase in growth. However, this effect did not continue after weaning. Rumen development remains unaffected by addition of YC and P to grain diets.