Feedlot and carcass data from 1,533 weanling steers consigned to the Louisiana Calf-to-Carcass program from 1992 to 1998 were used to evaluate the influence of feeder calf grade, sire breed, and initial feedlot weight on growth and carcass traits. Each October, spring born calves were delivered to Clinton, Ruston, or Lake Charles loadout sites. Steers were identified by sire breed, tagged, weighed, assigned a feeder calf grade. Forty-six, 18, 26, and 10 percent of the steers graded large frame-thick muscle, large frame-moderate muscle, medium frame-thick muscle, and medium frame-moderate muscle, respectively. Steers were trucked to a commercial feedlot and sorted into pen lots based on predicted harvest weight and grade. Steers were harvested at approximately 1 cm fat thickness. Steers were grouped by breed of sire origin into American (Beefmaster, Braford, Brahman, Brangus, Gelbray, Red Brangus, Simbrah), English (Angus, Hereford, Red Poll), and European (Braunvieh, Charolais, Gelbvieh, Limousin, Salers, Simmental) sire breed groups. Growth and carcass traits were analyzed with a linear mixed model that included year-location as random and feeder calf grade, sire breed group, and feeder calf grade x sire breed group as fixed sources of variation. Large frame steers had .05 ± .02 kg greater feedlot average daily gain, 21 ± 4 and 10 ± 3 kg heavier harvest and hot carcass weights, 3.3 ±.8 cm² larger ribeye areas and lower yield and quality grades than medium frame steers (P <.01). Thick muscled steers were similar to moderate muscle steers for most traits. European-sired steers had larger ribeye area (P < .05), larger ribeye area per 100 kg of carcass (P < .05), lower yield grade (P < .05), and less fat thickness (P < .05) than English- and American-sired steers. English-sired steers had higher marbling score (P < .05) than American- and European-sired steers. Light weight steers had lower harvest weight (P < .05) and smaller ribeye area (P <.05) than moderate and heavy weight steers. Generally, large frame steers and European-sired steers produced higher yielding carcasses and medium frame steers and English-sired steers produced carcasses with higher quality grade.

Calpastatin activity at 24 h postmortem is inversely proportional to postmortem tenderization and accounts for a greater proportion of the variation in beef tenderness. Tenderness was determined by measurement of 24 h postmortem longissimus muscle calpastatin activity (CA) and Warner-Bratzler shear force after 7 and 14 d of steak aging. The quantitative inheritance of tenderness in Brahman steers was investigated phenotypically by Multiple Trait Derivative-Free Restricted Maximum Likelihood (MTDFREML) procedures and genotypically by using restriction fragment length polymorphisms (RFLP), a microsatellite marker, and DNA sequence analyses. In experiment 1, MTDFREML was used to obtain the genetic parameters of tenderness traits and their genetic and phenotypic correlations with carcass traits such as fat thickness, hot carcass weight, rib eye area, marbling score, and hump height. Contemporary group (CG) was defined as members that were exposed to the same environmental conditions with respect to year of birth and slaughter group. The statistical model included fixed effects of CG, random effects for animal, and residual effects with the covariable of slaughter age. Heritability estimates were 0.44 ± 0.17, 0.30 ± 0.14, and 0.21 ± 0.11 for calpastatin activity, d-7 shear force, and d-14 shear force, respectively. High heritability and additive genetic correlation estimates for CA and shear force indicated that genetic factors made a large contribution to the variation in tenderness and, therefore, tenderness traits would be reliable predictors not only for the rate of tenderization during the beef aging process but also for carcass characteristics. In experiment 2, DNA samples were extracted for RFLP, microsatellite marker, and DNA sequence analyses from the CG of Brahman steers. No DNA polymorphisms were detected in a RFLP procedure conducted for a region between inhibitory domain I and inhibitory domain II of the calpastatin gene. However, microsatellite marker and DNA sequence analyses conducted on the calpastatin promoter region and a region within the L-domain, respectively, revealed distinctive genetic polymorphisms within the calpastatin gene. These findings indicate that the polymorphic sites identified may reveal specific allelic diversity and such alleles may be used as a marker of tenderness for Brahman steer breeding.

Generalized mixed model methodology and MCMC simulations were used to estimate genetic parameters for calving rate and calf survival with the normal, probit, and logistic models. Calving rate and calf survival were defined as 0 each time a cow failed to calf or a calf failed to survive to weaning age, otherwise they were set to 1. Data were available on 1,458 cows and on 5,015 calves. Cows produced a total of 4,808 records over 4 discrete generations of rotational crosses between Angus, Brahman, Charolais, and Hereford from 1977 to 1995. The heritability of calving rate and calf survival, the EPDs of sires, and mean performance for calving rate and calf survival for various rotational crossbreeding systems were computed. The probit model and the logistic model each failed a lack of fit test based on the scaled deviance for calf survival. Spearmen correlations measured potential change in the ranking of bull EPDs across models. The normal model estimate of heritability for calving rate and calf survival was 0.062 ± 0.023 and 0.038 ± 0.019, respectively. Heritability estimates from the other models were slightly larger when adjusted, but smaller than 20%. Spearman rank correlations were larger than 0.98 indicating a minimal change in the ranking of bull EPDs. The H-B two-breed rotation cows had a higher calving rate than A-B or C-B two-breed rotation cows. The best mating system for calving rate was the A-H two-breed rotation system (0.93 ± 0.07), and the best system for calf survival was the A-B-H three-breed rotation system (0.98 ± 0.03). Three- and four-breed rotation systems were similar to two-breed rotation cows for calving rate. The differences between three-breed and four-breed rotation systems were minimal. Heritability estimates found in this study for calving rate and calf survival were similar to the literature estimates. Sire EPD range varied among models but was less for the normal model. Predicted performance for mating systems is possible with estimates of genetic effects.

Forty-one (10 primiparous and 31 multiparous) Holstein cows were used in an experiment to determine the effects of prepartum dietary energy (PDE) and supplemental Ca-propionate on the incidence of ketosis in transition dairy cows and to evaluate the usefulness of urine pH as a predictor for ketosis. Treatment factors were prepartum dietary energy concentration (normal vs. high) with or without 113.5g Ca-Propionate/day (Nutro Cal®, Kemin Industries, Inc., Des Moines, IA). All cows were fed the same basal diet postpartum. Ca-propionate supplementation continued postpartum. Cows were individually fed and dry matter intakes (DMI) were measured daily. Milk production was measured and sampled at each milking for 3 weeks postpartum and analyzed for % fat, % protein, and SCC (somatic cell count). Blood samples were collected prior to the afternoon milking 3x/ wk and analyzed for β-hydroxybutyrate (BHBA) and glucose concentrations. Urine was collected 3x/ wk and analyzed for pH, acetoacetate, and BHBA. Treatment did not affect mean DMI, milk yield, milk component production or percentage, 4% FCM, SCCS, BWT, urine pH, urine acetoacetate, urine BHBA, plasma BHBA, or plasma glucose. There was a statistical interaction of Ca-propionate supplementation and week for urine pH and BHBA. Correlation coefficients between urine BHBA, urine pH, and urine acetoacetate were not useful for prediction of ketosis across all cows. However, they were numerically higher when restricted to data from an individual cow. Correlation coefficients between BHBA and acetoacetate concentrations in urine were significant. These data suggest that PDE and Ca-propionate supplementation had no effect on the incidence of ketosis, however Ca-propionate supplementation allowed cows to recover faster from ketosis postpartum. The use of urine pH was not a useful tool for the prediction of ketosis across a herd, but may be a useful indicator of ketosis when compared within an individual animal. Due to factors unrelated to treatment diets, there was a high incidence of health disorders such as retained fetal membranes, metritis, displaced abomasums, and laminitis were observed during this trial that probably affected any observed treatment responses.

The postpartum period has been the focus of numerous studies; however, there is no information available relating to oocyte production in early postpartum cows. Ovaries of early postpartum cows were stimulated with FSH to produce follicular development and oocytes. The objectives of these studies were: (1) to evaluate the use of FSH for oocyte production in early postpartum beef cows, (2) to evaluate follicular response and oocyte quality of beef cows treated with FSH shortly after calving, (3) to evaluate FSH for oocyte production in early postpartum dairy cows, (4) to evaluate responses of FSH-treated, early postpartum beef cows in a transvaginal ultrasound-guided oocyte aspiration (TUGA) experiment using polyvinylpyrrolidone as the vehicle for FSH in a single dose plus energy supplementation and/or bovine somatotropin treatment, and (5) to evaluate if a single dose of GnRH could modify LH secretion in beef cows at day 5 and day 30 postpartum. In each of 4 experiments, TUGA was used to harvest oocytes from the FSH-stimulated donor cow ovaries. It was demonstrated that early postpartum cows did respond to exogenous FSH treatment with good follicular development and produced quality oocytes shortly after parturition. Harvested oocytes were subjected to IVF procedures. The number of follicles (>5 mm) aspirated, number of oocytes, recovery rate, number that cleaved, number of blastocysts developing from cleaved embryos, and blastocyst production rate per donor was: 19.4, 8.8, 64%, 4.3, 1.4 and 32.3%, respectively, for cows treated with FSH and oocytes harvested between day 5 and 20 postpartum. The number of follicles aspirated per donor at day 25 and 35 postpartum was 20.4 for the FSH-treated group, resulting in 12.9 oocytes (recovery rate, 63%). It was determined that a single FSH injection could stimulate the ovaries of the early postpartum cow as early as day 10 postpartum with a follicular response of 17.5 follicles and 11 oocytes recovered per cow (recovery rate, 69%). Furthermore, live calves were obtained from harvested oocytes from FSH-treated cows in the early postpartum period. In summary, TUGA should be considered as an alternative tool for obtaining oocytes for embryo production from early postpartum cows.

The low efficiency of the nuclear transfer (NT) procedure requires large number of oocytes to produce embryos and live offspring. A series of experiments were conducted to evaluate the ability of the bovine cytoplast to reprogram nuclei from horses and llamas. In a preliminary study, equine oocytes from small (<20mm diameter) follicles were either pretreated with roscovitine or placed in maturation (IVM only) prior to NT. Roscovitine pretreatment did not improve nuclear maturation rates (roscovitine pretreatment 57% vs. IVM only 66%) and no fusion was obtained from roscovitine-pretreated oocytes after NT. Another preliminary study was conducted with the objective to produce llama NT embryos and to compare their development in two in vitro culture conditions (G1.2® vs. CR1aa). No difference was found in the number of embryos cleaved after 2 d of culture. This resulted in the first scientific report of somatic cell NT, in vitro culture and transfer of NT embryos in the llama. In the next experiment, adult horse and llama fibroblasts were injected into enucleated cow oocytes. The results showed the cow cytoplasm is capable of partially reprogramming nuclei from other species and support mitotic divisions. However, this study also showed a consistent embryonic developmental arrest at the 8- to 16- cell stage when horse or llama donor cells were used as donor nuclei. When a more closely related species of donor cell (banteng) and recipient oocyte (domestic cattle) were used for NT, no embryonic developmental arrest was found. Embryos progressed to achieve high blastocyst rates (banteng male cell line 28% vs. banteng female cell line 15%). Two banteng interspecies NT pregnancies were established and subsequently lost from the banteng male cell line. In the final study, the effect of a mixed mitochondrial population (heteroplasmy) on early embryonic development was investigated. Ooplasmic transfer performed in combination with NT procedure indicated presence of foreign mitochondria clustered in a small portion of the cytoplasm in early stages of embryo development. When goat ooplasm was transferred into interspecies (cow oocyte-goat donor cell) NT embryos, fusion and cleave rates were reduced suggesting an increased level of heteroplasmy or nuclear-ooplasmic incompatibilities.

The interest in preserving endangered species has increased the amount of attention lent to the recovery of functional sperm from the epididymides of deceased males (Foote, 2000). Postmortem specimens have a finite time period before decomposition affects functionality. Determination of this window of opportunity to harvest and preserve epididymal sperm would be beneficial for further research in sperm preservation and assisted reproductive technologies. The objective of these studies was to determine 1) the window of opportunity to collect viable rat, caprine, equine and bovine epididymal sperm, 2) if epididymal sperm collected could be cryopreserved, 3) to test two common cryoprotectants for efficacy of sperm preservation, 4) to determine if bovine samples could be used to produce in vitro fertilization (IVF) embryos and 5) to establish if sperm subjected to a series of freeze-thaw cycles can maintain motility. Epididymal sperm collected from rat, caprine, equine and bovine males all maintained some level of acrosomal membrane integrity up to 96 hours postmortem. The bovine, caprine and equine sperm survived cryopreservation and exhibited greater preservation with milk-based extenders. In vitro fertilization with cryopreserved bovine epididymal sperm was not efficient but development of embryos proved limited usefulness. Finally, subjecting the bovine sperm to repeated freeze-thaw cycles proved extremely damaging and should be practiced only when absolutely necessary. Rat sperm exhibited a difference from 24 to 48 hour with a percent progressive motility (PPM) of 46 to 28%. Caprine sperm PPM and percent intact acrosomes (PIA) declined after 24 hours from 68 and 66% to 56 and 55% at 48 hours, respectively. Equine sperm exhibited a drop in PPM and PIA at 48 hour of 42 and 71% to 34 and 68% at 72 hours, respectively. Bovine sperm PPM dropped initially from 65 to 49% at 24 to 48 hours and again from 46 to 30% at 72 to 96 hours. The difference in PIA only appears between 24 and 48 hours of 77 to 65%. As stated previously, the epididymal sperm collected from the rat, caprine, equine and bovine males maintained acceptable levels of PPM and PIA up to 96 hours postmortem.

This research was conducted to determine the non-phosphorus effects of phytase in diets for swine and poultry. An experiment was conducted to determine the effect of phytase addition on energy availability and protein and fat deposition in growing pigs. Results from this experiment indicated that phytase had small positive effects on energy availability, protein deposition, and fat deposition. In this study, 23 of 29 response variables were at least numerically increased with phytase addition. Two experiments were conducted to determine the accuracy of the energy and amino acid matrix values for Natuphos 1200 in broilers from 0 to 21 or 0 to 42 d posthatching. Results from these experiments indicated that the nutrient matrix values for phytase are accurate, and that they can be used in diet formulations for broilers. Experiments also were conducted to determine the effect of phytase addition to diets with or without the trace mineral premix in nursery, growing, and finishing pigs and in commercial broilers. Results indicated that phytase can replace the trace mineral premix in swine diets. Phytase addition had no negative effect on growth performance or pork quality, and it had minimal effects on carcass traits. In broilers, removing the trace mineral premix had no effect on growth performance but decreased bone breaking strength, and adding phytase did not reverse this response. This research indicates that phytase addition has little effect on carcass traits or meat quality in swine and poultry. When formulating swine diets with phytase, the trace mineral premix can be removed with no negative effects on growth performance or pork quality. However, more research is needed to determine the effect of phytase addition in diets without the trace mineral premix in broilers, because the addition of phytase did not overcome the decrease in bone breaking strength.

The objective of Experiment 1 was to determine the effect of bovine follicular fluid (bFF) on nuclear maturation. Treatment A (Control) oocytes were stained with Hoechst-33342 immediately after aspiration from follicles, whereas, oocytes in Treatment B were held in bFF for 12 hours at 38¢ªC and then stained to determine nuclear status. No significant difference was detected between treatment groups. Results indicate that bFF inhibits resumption of meiosis. The objective of Experiment 2 was to determine the effect of bFF on embryonic development. Oocytes in Treatment A (Control) were placed into in vitro maturation (IVM) for 22 hours followed by in vitro fertilization (IVF). Oocytes in Treatment B were held in bFF for 12 hours at 22¢ªC, followed by IVM and then subjected to IVF. Significantly more (P<0.0001) oocytes cleaved, developed into blastocysts and hatched in Treatment A compared with Treatment B. Results indicate that a 12-hour holding period in bFF does not promote normal embryonic development. The objective of Experiment 3 was to determine the effect of decreased time and concentration of bFF on embryonic development. Treatment A (Control) oocytes were placed into IVM followed by IVF. Oocytes in Treatment B were held in bFF, oocytes in Treatment C were held in Lactated Ringer¡¯s Solution (LRS) and oocytes in Treatment D were held in a combination of bFF and LRS for 6 hours at 22¢ªC, followed by IVM then by IVF. No significant difference was detected between Treatments A and B when analyzing cleavage, blastocyst formation and hatching rates. However, significantly fewer (P<0.0001) embryos reached these stages of development in Treatments C and D. Nevertheless, there were significantly more embryos that developed to the blastocyst stage in Treatment D compared with Treatment C. Decreasing the amount of time that oocytes were held in bFF proved to be beneficial in supporting in vitro embryo production (IVP). These findings could be advantageous when attempting to rescue valuable gametes from deceased females.

Bakso is a finely comminuted boiled Indonesian meat product that is traditionally made of starch, salt and emulsified prerigor or early postmortem meat and often sold from street vendors. Recently processors have begun to commercially manufacture bakso. This research was conducted to investigate the substitution of early postmortem meat with postrigor meat to allow more efficient manufacturing and raw material procurement. The first experiment was to determine the properties of bakso with three tapioca starch concentrations added to early or late postmortem beef. No differences (p<0.05) were observed in bakso properties of composition and texture, though bakso made of post-rigor meat had slightly less elasticity, strength and shear. These disadvantages were compensated by incorporating 15% starch concentration, indicating that the replacement of early postmortem meat with postrigor meat was applicable in industrial mass production of bakso. The second phase of experiments was to investigate the properties of bakso with different frozen storage times of raw postrigor meat and after different times of frozen storage for bakso made from postrigor and early postmortem meat. Postrigor meat substitution for early postmortem meat in bakso with 15% tapioca starch resulted in minimum composition and textural differences (p>0.05). Meat stored frozen for 2 and 4 months was still suitable as raw material for bakso production. The decreased oxidative stability in bakso made from postrigor meat after frozen storage of 2 and 4 months should be addressed with antioxidant ingredients or procedures to minimize potential off-flavors of the precooked bakso products stored frozen.