A series of experiments was conducted to: 1) investigate how feeding cattle with different amounts of different-sized seeds affects seed passage rate through the digestive tract, and the germinability of passed seeds; 2) examine how the location of seeds in dungpats of different thicknesses influences seedling emergence , development, and survival in cattle dungpats; and 3) characterize seedling emergence in naturally and artificially deposited cattle dungpats . Three perennial , cool-season grasses, bluebunch wheatgrass [Psuedoroegneria spicata (Pursh) A. Love], Sandberg bluegrass (Poa secunda Presl.), and 'Hycrest' crested wheatgrass [Agropyron desertorum (Fisch. ex Link) X A. cristatum (L.) Gaert.], were used as representative revegetation species for the Intermountain West region. When cattle were fed 60,000, 30,000, 15,000, and 7,500 seeds of bluebunch wheatgrass and Sandberg bluegrass, the recovery of passed seeds for both species declined as seed feeding levels decreased from 60,000 to 7,500 seeds per animal and as time after seed ingestion increased from 1 to 4 days. Sandberg bluegrass seeds had greater germinability than bluebunch wheatgrass seeds at all seed feeding levels and collection dates. In complementary greenhouse studies, artificially prepared cattle dungpats (20 cm diameter) with different thicknesses (1, 2, and 4 cm) were placed on a sandy loam soil (initially at field capacity) in large plastic containers. Pre-germinated seeds of blue bunch wheatgrass, Sandberg bluegrass, and/or Hycrest crested wheatgrass were planted separately in the center and periphery of dungpats at heights (from bottom of dungpats) of 0.5 cm for 1-cm-thick dungpats, 0.5 and 1.5 cm for 2-cm-thick dungpats , and 0.5, 2.0, and 3.5 cm for 4-cm -thick dungpats. Half of the dungpat treatments received no supplemental water while the other half received additional water simulating a wet spring . After 60 days, seedling emergence, development , and survival for all species were greatest at the 0.5 cm planting height , regardless of dungpat thickness , and greatest in 1 cm-thick dungpats , regardless of planting height. Seedling emergence , development , and survival were greatest for Hycrest crested wheatgrass, followed by bluebunch wheatgrass and Sandberg bluegrass. In a field study, cattle dung containing passed seeds of blue bunch wheatgrass, Hycrest crested wheatgrass, and Sandberg bluegrass was formed into artificial dungpats (2 kg in mass) with thicknesses of 1, 2, and 4 cm, and respective diameters of 40, 28, and 20 cm, and deposited on bare soil. Cattle also deposited natural dungpats varying in mass, thickness, and diameter. Seedling emergence for all species decreased as artificial dungpat thickness increased from 1 to 4 cm, and was lowest in natural dungpats. Seedling emergence for all dungpat types was greatest for Hycrest crested wheatgrass, followed by Sandberg bluegrass and bluebunch wheatgrass. These studies indicate that: 1) cattle should be fed about 60,000 seeds ( of these grass species) per animal to pass sufficient germinable seed to establish at least one seedling in a dungpat; and 2) seedling emergence, development, and survival in cattle dungpats are greatly influenced by plant species (seeds) ingested, thickness of dungpats, seed location in dungpats, and moisture content of the soil underlying dungpats.

In two lactation studies reported in this dissertation, it was hypothesized that feeding 35% brown midrib corn silage (BMRCS) and 25% alfalfa hay (dry matter basis) would result in increased dry matter intake (DMI) around peak lactation compared with feeding conventional corn silage (CCS), causing longer peak milk production, and that feeding dairy cows in early lactation a 16% crude protein diet with fair quality alfalfa hay (FAH) in BMR-based diets would maintain milk production, reduce urinary N excretion, and improve N efficiency compared to those fed high quality alfalfa hay (HAH) in CCS- or BMR-based diets. A third experiment was conducted to assess in situ degradation kinetics of BMRCS harvested prior to or at maturity. The first lactation study was performed to determine the long-term effects of feeding BMRCS fed with a high dietary concentration of good quality alfalfa hay in a high-forage lactation diet on productive performance of Holstein dairy cows for the first 180 d of lactation. Feeding BMRCS-based diet did not affect milk production through peak lactation compared with a CCS-based diet; however, cows fed the BMRCS-based diet maintained heavier body weight through peak lactation and longer peak milk production, which resulted in increased milk yield post peak lactation, leading to greater overall milk production and milk protein yield. A second lactation experiment was performed to investigate if early lactating dairy cows fed with the FAH in BMRCS-based diets would reduce urinary N excretion and improve N efficiency compared to those fed the HAH in CCS- or BMR-based diets. Feeding BMR and HAH had better N utilization by decreasing concentrations of urea in blood, milk, and urine. In addition, feeding BMR-based diets decreased urinary N-to-fecal N ratio, and it was further reduced by feeding the HAH, which can represent an environmental advantage over traditional sources of forages in lactation dairy diets. A third experiment assessed in situ DM and neutral detergent fiber degradation kinetics for two new pre-matured BMR varieties (pmBMR1 and pmBMR2) that can be double-cropped by harvesting at tassel, compared with a sole crop mature BMR (mBMR) and CCS harvested at maturity in dry and lactating Holstein dairy cows. The potentially degradable NDF fraction was greater for BMR hybrids compared with CCS with the exception of the pmBMR2, which had the lowest potentially degradable NDF fraction in dry cows. Estimates of ruminal degradability of NDF were greatest for pmBMR1 in both dry and lactating cows. Feeding BMRCS exerted nutritive and environmental benefits when fed with typical Intermountain West lactation dairy diets. Further research is needed to understand interactive aspects of nutrient utilization with other dietary ingredients under different physiological conditions to take full potential benefits of BMRCS.

One of t he largest problems facing the successful dairyman of today is selection of proper sires to mate to his high producing cows. Many breeders and dairymen have the impression that proven sires will give the same increase in production regardless of the dam's production or the level of environment present. Even though sires come from high producing herds, some as high as 600 pounds of butterfat, the average production of all cows in the state of Utah remains at a much lower figure. The average for all cows in Utah is about 250 pounds of butterfat and the average in 1958 of cows on Dairy Herd Improvement test was 403 pounds. This difference in level of production may be attributed to either genetic or environmental factors and possibly an interaction of the two. Most workers agree that the heritability estimates for milk production and fat yield are from .2 to .3. This means t hat about 25 per cent of the variance in milk yield is due to inheritance, and the other 75 per cent is due to management or environment. Therefore, there is a need to study daughters of the same sire at various levels of production to determine the amount of increase or decrease found at these levels. This thesis presents a study of daughters of Holstein sires used in artificial breeding. Sires in artificial breeding were used because they have a larger number of daughters, and their daughters come from a wide range of production and management levels.

Six nonlactating Holstein cows fitted with rumen and duodenal cannula were used to determine the efficacy of pH sensitive fatty acid polymer encapsulation as a means protecting amino acids from rumen fermentation and as a post-ruminal amino acid delivery system. The cows were arranged in a 2 x 2 factorial in a latin square design. Treatments were 1) the basal ration, and 2) basal ration plus rumen-protected lysine, methionine, and threonine at 10 g each per day. Rumen parameters measured were pH, ammonia, volatile fatty acids, protozoa, liquid, and dry matter rate of passage, total viable bacteria, and viable cellulolytic bacteria. Duodenal parameters measured were crude protein, ammonia, and amino acid concentrations. Total tract apparent digestibility of nutrients was measured. In addition, rumen degradation of the three amino acid products was measured by loss from nylon bags, in the rumen. Loss of product from nylon bags suggested the lysine and threonine products had no significant rumen protection, but that the methionine product had > 50% protection at 12 h in the rumen. None of the rumen parameters measured differed (P>.05) due to treatment. Duodenal crude protein and ammonia concentrations did not differ due to treatment. Duodenal amino acid concentrations were numerically higher for the amino acid supplemented treatment, but the differences were nonsignificant and thought to be confounded by failure of the lysine and threonine products. Total tract apparent nutrient digestibility was not affected by treatment. A second experiment was conducted using 40 post-parturient Holstein cows, and different rumen-protected amino acid products from the first trial. Cows were nesteMwby treatment (control vs rumen-protected methionine 46 g and lysine 22 g) and parity (primiparous vs multiparous). Dry matter intake and milk production were monitored daily, body weight weekly, and milk composition bi-weekly. Total tract apparent nutrient digestibility was measured during the last week of the 10-week trial. There was no significant (P<.05) effect of supplemental rumen-protected lysine and methionine among primiparous animals. Multiparous animals receiving supplemental amino acids had lower dry matter intakes and yield of milk components than control animals.

Free radicals are short-lived molecules that can cause decreased embryonic development in vitro. Antioxidants are molecules that block free radical formation or guard against their harmful effects. Many studies have linked exposure of media to light and culturing of embryos in high (20%) oxygen concentrations to free radical production. Some of the antioxidants used in culture media are superoxide dismutase (SOD), catalase, zinc (II), ethylenedinitrilo tetraacetic acid (EDTA), mannitol, vitamin E, dimethyl sulfide, and taurine. Most research involving antioxidants and embryonic development has been conducted on non-farm animals, particularly mouse and rabbit. Studies have shown that antioxidants in vitro culture improved embryo development to the blastocyst stage. In this study, we evaluated the effects of SOD and catalase on bovine embryo development. Four concentrations of SOD (0, 1500, 3000, 6000 IU/ml) and catalase (0, 75, 100, 125 μg/ml) and combinations of the two antioxidants were evaluated through maturation, fertilization, and culture. SOD and catalase were first reconstituted in water and then diluted to their final concentrations. Oocytes were matured in M-199 plus 0.5 μg/ml LH, 5 μg/ml FSH, and 10% FBS at 39°C in 5% CO2 for 24 hours. They were then placed in fertilization-TALP with heparin and 1 x 106/ml sperm. Embryos were cultured in CR2 medium supplemented with alanine, glycine, and 3 mg/ml of fatty-acid free bovine serum albumin in modular incubators with 5% CO2, 5% O2, and 90% N2. Embryo development was evaluated on day 8. Three replicates with approximately 50 embryos per treatment were used to evaluate the effects of SOD and catalase. The control had better embryo development than all treatments. The treatment that was most similar to the control was treatment 2, which consisted of no SOD and 75 μg/ml catalase. Based on these observations, levels of both SOD and catalase were lowered to 0, 100, 250, and 500 IU/ml and 0, 10, 25, and 50 μg/ml, respectively. Although these levels appeared to improve embryo development, there were no statistical differences. Based on the culture system and media currently used along with the precautions against light and oxygen concentration, we did not find any beneficial effects of supplementing medium with SOD or catalase.

Lactose in milk has relatively low variation regardless of season, breed, or country. The study of lactose concentration and correlation among other milk components is limited. Furthermore, dairy farmers have limited access to the lactose data and are not familiar with it. This study was conducted to: 1) investigate the phenotypic correlation between lactose and other milk components; and 2) determine the importance of lactose for dairy herds. Monthly DHIA records from Utah (DHIA), Dairy Herd Performance Test (DHTP) records from Ibaraki, Japan, and California herd average data (CHAD) covering 27 states were used to analyze the relationships between milk lactose concentrations and parameters related to milk production. Record spans for each data sets for DHIA, DHTP and CHAD were 7 consecutive years ending August 2017, 12 consecutive years ending August 2017, and 9 consecutive years ending August 2017 respectively. Means for the DHIA records were 187.9 days in milk, 34.6 kg/d milk yield, 4.08% lactose, 3.88% fat, 3.15% protein, 8.86% SNF, 14.4 mg/dl MUN, 256,000 SCC, and 2.4 parity. A negative correlation was observed between lactose concentration and parity (r = -0.27). Positive phenotypic correlations between lactose percentage and milk yield (r = 0.28), and negative correlations with fat (r = -0.17), protein (r = -0.21) and SCC (r = -0.30) were observed. No seasonal fluctuations of milk lactose concentrations were observed. Mean for the DHTP records were 4.55% lactose, 3.95% fat, 3.29% protein, 8.74% SNF, 283 mOsm/kg osmotic pressure, 19,600 bacteria count, and 222,000 SCC. A seasonality in the lactose concentrations were observed, with the lowest concentrations of lactose observed in late summer and fall. There were no phenotypic correlations between lactose concentrations and protein, but a negative correlation with fat (r = -0.12) was observed. A significant negative correlation with SCC (r = -0.28) was also observed. Based on the CHAD records, cows with lower lactose concentrations showed a higher culling rate, which indicates that the milk lactose concentration could be a potential indicator of problems in a dairy herd. This study suggest that lactose level could be an indicator for managing dairy farms. Dairy farmers should be able to access lactose data, and these data should be provided by DHIA.

The economics of ranches in the Zimbabwe Midlands, generating income from cattle, or wildlife, or both, were compared during 1989/90 to test the claim that wildlife ranching can generate greater profits than cattle ranching on semi-arid African savannas. Both financial (market) prices and economic prices (opportunity cost) were used. Financial data were obtained from 15 cattle, 7 wildlife and 13 mixed ranches in four areas with wildlife and from 15 cattle ranches in two areas with sparse wildlife. Estimates of economic prices were obtained from official data. In the first paper, gross revenues, costs, net revenues, and capital investments of each ranch type were compared. Cattle ranches in the areas with sparse wildlife provided the greatest net revenues while only mixed ranches were financially profitable in areas with abundant wildlife. Wildlife ranches had the least capital investments. In the second paper a policy analysis matrix was used to compare financial and economic profitability. Excluding policy interventions, cattle ranches in areas with sparse wildlife were most profitable. Negative financial-economic profit differences showed that all ranchers faced production disincentives, but cattle ranchers were affected the most. In the third paper an attempt was made to quantify the cost of lost rangeland productivity due to overstocking. Carrying capacities and stocking rates were estimated and a range of overstocking costs was used. Cattle ranches appeared to be overstocked while wildlife ranches were not. Thus the larger economic profit of cattle versus wildlife ranches decreased when range productivity loss increased. The last paper compared the relative efficiency of cattle, wildlife, and mixed ranches from the financial perspective (using the private cost ratio) and from the national perspective (using the domestic resource cost). While few ranches were financially efficient, cattle ranches with sparse wildlife and mixed and wildlife operations were found to be economically efficient when overstocking costs were not charged. With increased rangeland sensitivity to overstocking, the probability of economic inefficiency increased more for cattle than mixed or wildlife ranches. This study did not corroborate the claim that wildlife ranching is more profitable or efficient than cattle ranching in semi-arid African savannas.

The Shiras moose, Alces alces shirasi, and its winter habitat on the north slopes of the Uinta Mountains in Utah were studied from August, 1969, to July, 1971 to determine the food requirement for moose, the key browse species during the winter months, the acreage, density and utilization of the key browse species, and their carrying capacity for moose. It was determined that an average adult moose had a daily food requirement of 19,133 kilocalories. The key browse species for moose were Salix drummondiana and S. geyeriana. These two species accounted for 92.0 and 4.7 percent respectively of all feeding occurrences on browse species recorded. According to density analyses, S. drummondiana made up 59 percent of the vegetation and S. geyeriana 31 percent. The caloric capacity of the key browse species for moose body maintenance was slightly more than 1.5 billion kilocalories. The moose carrying capacity of the key browse species on the winter range was 80,030 moose days or 445 adult animals for a period of six months. Specifically, the carrying capacity, based on a weighted caloric requirement and annual classification counts, would be 115 bulls, 250 cows, and 156 calves for a period of six months on the winter range.

A diagnostic test for bovine leukosis was developed using the polymerase chain reaction (PCR) to amplify a 375 base pair region in the gag gene of the proviral genome. Blood samples were collected from 3 adult Holstein cows shown to be infected with bovine leukosis virus (BLV) by the agar-gel immunodiffusion (AGID) technique. The 3 samples were mixed and the composite blood was used to inoculate 10 cows. Five of the cows were inoculated with 0.1 ml of blood, and the other cows were inoculated with 1 ml of blood. Five of the cows were negative for BLV by AGID and PCR on the day of inoculation, and the other five cows were positive for BLV on the day of inoculation. The 10 cows were bled on day 1 (day 0 being the day of inoculation) and day 7 post-inoculation, and every 2 weeks subsequently until 3 months post-inoculation. Samples were stored until the end of the study, at which time the AGID and PCR tests were performed. Three cows became AGID-positive 3 weeks post-inoculation, and two cows seroconverted 5 weeks post-inoculation. The time of seroconversion did not correlate with the volume of viral inoculum. In comparison, the PCR consistently detected infection sooner than the AGID: by day 7 post-inoculation all 5 cows were BLV-positive as determined with the PCR test, and remained positive until the end of the study. The results indicate that under the experimental conditions, bovine leukemia virus infection in cattle can be detected as much as 2 to 4 weeks earlier by PCR than by AGID.

During spermatogenesis, histones are largely replaced by transition proteins and protamines in normal stallions. Incomplete nucleoprotein exchange results in the abnormal retention of histones and transition proteins, which is an indicator of poor sperm quality. Equine nucleoprotein exchange has not previously been investigated in detail, so that equine sperm chromatin quality problems, which are often responsible for poor breeding performance of stallions, are not well understood. In order to characterize chromatin remodeling events in stallion spermatogenesis and to identify proteins indicative of sperm chromatin defects, such as excessive amounts of histones, we identified antibodies that recognize equine testis-specific proteins of interest. Immunoblotting of testis and sperm protein lysates and immunofluorescence staining of histological tissue sections were used to identify candidate marker proteins of incomplete sperm chromatin maturation. Results of the study, which represents the first comprehensive characterization of the nucleoprotein exchange during spermatogenesis in the stallion, challenge the paradigm that the main function of histone H4 lysine (hyper-) acetylation (concomitant H4K5 and H4K8 acetylation) is to facilitate nucleosome ejection during spermatid nuclear elongation to allow for transition protein and protamine insertion into the chromatin. That paradigm was based on observations in mice and rats where H4 acetylation in several lysine residues occurs just prior to or during nuclear elongation. In contrast, the equine data presented here show strong acetylation of H4 in K5, K8 and K12 positions immediately after meiosis in round spermatids, independent of nuclear transition protein 1 deposition. Furthermore, results of H4K16 acetylation analyses underline the importance of this mark, which is likely mediated by DNA damage signaling pathways, emphasizing the importance of DNA repair processes for the exchange of nucleoprotein exchange in spermiogenesis and therefore, in extension, for male fertility. In addition, a revised description of the equine spermatogenic cycle is proposed here that is better aligned with human, mouse and rat spermatogenesis. Finally, the testis-specific histone variant TH2B was identified as a potential quantitative marker of equine sperm quality.