Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 30 for “"Beef Heifers"”.
-
Calf shape and pelvic dimensions affecting dystocia in beef heifers
Typescript (photocopy).
-
The Vaginal Microbiome Related to Reproductive Traits in Beef Heifers
… greatest impact on profitability of a commercial beef operation is reproduction. In the human vaginal microbiome, dominance by Lactobacillus is a sign of reproductive health and fitness. In other species (non-human primates and ewes), Lactobacillus is found in low amounts and dominators of these …
-
Prediction of Fertility of Virginia Beef Heifers Using Expert Systems Technology
An expert system to predict the fertility of beef heifers was developed using the A.I. Toolkit KAPPA-PC 2.33. The knowledge base was developed from scientific literature and from a beef cattle reproduction expert. The expert system computes an evaluation age, age both at the start and end of the …
-
The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers
… determine the effects of handling peri-puberal heifers for 2 h each week on in-chute behavior, isolation behavior, and the time required for each heifer to leave the testing area; and to determine if the location of the facial hair whorl was associated with any of the behavior scores or social …
-
Supplemental Trace Minerals (Zn, Cu, and Mn) as Sulfates or Hydroxy Trace Mineral Sources for Beef Heifers
<p>Crossbred heifers (n = 286, 255 ± 4.5 kg initial BW, 295 ± 16.5 d of age) were used over a 2-yr period to determine the effects of mineral source on beef heifer development at 2 locations (n = 71 and n = 72, Fayetteville, blocks 1 and 4; n = 72 in each of 2 breeding groups, Batesville, blocks 2 …
-
Assessing the reliability of plant-wax markers to delineate diet choice and feed efficiency in beef heifers
… composition of test diets, and diet choices in beef cattle, and provided opportunities to evaluate efficiency in growing heifers. To test estimation of botanical composition, samples of red clover and fescue hay were mixed to form test diets containing 0-100% of either forage. To test estimation …
-
The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers
… systems that facilitate timed insemination in beef cattle. However, synchronization systems utilizing a single fixed-time artificial insemination (FTAI) frequently result in 25-40% non-pregnant heifers. The purpose of this study was to determine the effectiveness and define economic parameters …
-
Effect of Timing of Insemination and Synchronization of Estrus Method on Artificial Insemination (AI) Pregnancy Rates in Beef Heifers
… insert (CIDR) plus PG on AI pregnancy rate in beef heifers (n = 662) during Fall or Spring. Fall heifers (n = 349) received MGA-PG (MGA for 14 d followed by PG on d 18) or CIDR-PG (CIDR for 7 d, PG administered 1 d before CIDR removal). Estrus was monitored by HeatWatch® (n = 200) or visually …
-
Influence of Prepubertal Dietary Protein and Age at First Calving on the Performance, Reproduction and Lactation of Replacement Beef Heifers
… reproduction and lactation of replacement beef heifers. Dietary protein levels ranging from 11.7% to 22.6% CP were tested in six experiments using several nutritional management systems. Heifers were managed to calve first at 18 or 24 months of age. The effects of prebreeding protein and …
-
Effect of delaying time of AI based on Estrotect patch status on pregnancy rates of beef heifers and nursing beef cows
… 2 was conducted to evaluate delayed TAI on 1,682 heifers across 3 locations. The objective was to evaluate the use of Estrotect patch status at various recommended and delayed insemination times for a TAI protocol. Experiment 2a was implemented with 1,159 Bos taurus heifers synchronized using a 14 …
-
Physiological and immune responses to endophyte-infected tall fescue exposure in beef heifers: impacts on performance, metabolism, and immune cell transcriptomics
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-08-01
-
Fetal programming in cattle: the effects of varying maternal protein intake in adolescent beef heifers on fetal and postnatal growth and development of the calf
… gestation is common in extensive grass-fed beef production systems. In the northern Australian rangelands, protein, rather than energy, is the major limiting nutrient for cattle in dry-season pastures with protein supplementation of breeding heifers an animal husbandry requirement. Few …
-
Effects of prenatal androgenization on hormones of growth and reproduction in cattle
… androgenization was evaluated in 15 pregnant beef heifers. Fifteen additional heifers were used as controls. During the 84-day blood collection period, treatment with Synovex$\sp\circler$H resulted in greater (P $<$.001) serum concentrations of testosterone, similar serum estradiol …
-
Evaluation of long-term CIDR-based estrus synchronization protocols in primiparous two-year-old beef cows
Reproductive management of two-year-old beef cows presents a unique challenge in managing a beef herd, since this age group of females typically experiences the highest incidence of reproductive failure. Strategic management of replacement beef heifers and primiparous cows is necessary to ensure …
-
The effects of extended-release eprinomectin on heifer performance and fescue toxicity and an evaluation of parasite resistance
… to mitigate fescue toxicity in fall-born beef heifers grazing endophyte-infected tall fescue. Only one extended-release anthelmintic is currently on the market for ruminants and only limited data exist relative to parasite resistance. Therefore, the objective of this experiment was to …
-
Utilization of early weaning and intrafollicular insemination as methods to improve the reproductive performance of cattle
Optimization of reproductive efficiency of both beef and dairy herds is critical for sustainability and profitability. Two separate experiments were performed to test the reproductive outcomes following early weaning of beef heifers and intrafollicular insemination in dairy cows. Early weaning is a …
-
Strategies to improve fertility of Bos taurus beef females enrolled in estrous synchronization protocols
… (ES) protocols enhances profitability of beef cow-calf operations by improving percentage of cows pregnant early in the breeding season and increasing kg of calf weaned per cow exposed. Many factors, however, influence the fertility of cattle enrolled to ES protocols. The overall goal of …
-
Associations Among Beef Cattle Genotypes, Neospora Caninum Infection, and Reproductive Performance
… crucial for sustained financial success in the beef cattle industry. This dissertation includes a population study that quantified the incidence of Neospora caninum infections in the central region of the United States and tested its relationship with reproductive performance in beef cattle. …
-
Effects of ovarian steroids on bovine mammary epithelial cells: in vitro and in viro evidence of indirect stimulation of proliferation
… (P), or E+P were administered to prepubertal beef heifers and biopsied mammary parenchyma taken before and following treatment were compared for growth by evaluation of histoautoradiographic incorporation of thymidine. Estrogen increased epithelial cell growth by 24 h, and fibroblasts to a …
-
Use of Nutrition and Precision Technology to Improve Health, Performance, and Alleviate Stress of Beef Cattle
Concerns about beef production are growing among consumers, questioning the use of antibiotics, hormones, and metaphylactic treatments, as well as its environmental footprint. Therefore, beef production systems need to be more efficient to increase productivity while using less resources to become …
Page 1 of 2