Life Sciences Commons^™

Effect Of Supplementation Prior To Artificial Insemination And During Gestation In Beef Females, Landon Tadich

Department of Animal Science: Dissertations, Theses, and Student Research

Objectives of Experiment 1 was to evaluate the impact of increased energy prior to AI on BW, ADG, and reproductive efficiency in heifers developed on range or in a dry lot. During the winter development period (131 ± 3.5 d/yr) heifers (n= 100/yr) were assigned to either upland range (RANGE) or fed a dry lot diet in two pens that either remained constant (DLLO) or increased in energy prior to AI (DLHI). Heifers developed on RANGE grazed upland winter range until 38 d prior to AI where they then received the DLLO diet. Pre-breeding BW was greater (P £ …

Changes In Whole Blood Parameters In Beef Heifers May Contribute To Delayed Pubertal Attainment, Jessica A. Keane

Department of Animal Science: Dissertations, Theses, and Student Research

Pubertal development in beef heifers is a transient period that has many contributing factors. Previously in our lab, progesterone (P4) concentrations collected from heifers at weaning (Oct) to breeding (May) were used to identify four distinct pubertal groups: Typical, Early, Start-Stop, and Non-Cycling. There is limited research on heifers and the impacts of whole blood cell populations, particularly WBCs, during pubertal development; however, girls with differing puberty onset displayed altered concentrations of hematocrit, white blood cells (WBC), and hemoglobin concentrations. Thus, our hypothesis was that heifer pubertal groups with delayed or precocious puberty may have increased white blood cells or …

Effects Of Pubertal Status And Number Of Estrous Cycles Prior To Breeding In Beef Heifers, Average Daily Gain On Reproductive Performance And Comparison Of Two Fixed Time Ai Estrus Synchronization Protocols, Rebecca Vraspir

Department of Animal Science: Dissertations, Theses, and Student Research

Reproductive success is the most important factor in beef cattle production and is affected by timing of pubertal onset in heifers, and reproductive biotechnologies utilized. Three studies were conducted to evaluate the effects of pubertal status, ADG, and 2 fixed time AI protocols on reproductive success in beef heifers.

In the first study, heifers that were pubertal prior to breeding had a greater AI and overall pregnancy rate; produced more calves born within the first 21 d of the calving season; and weaned older, heavier calves than non-pubertal heifers. Additionally, heifers that had ≥2 estrous cycles, prior to the first …

Analysis Of Long-Term Selection (28 Generations) For Reproduction, Growth, And Carcass Traits In Swine, Wan-Ling Hsu

Department of Animal Science: Dissertations, Theses, and Student Research

The objectives were 1) to estimate responses from 28 generations of selection for increased pigs born alive (BA) with additional selection for increased 180 d weight (WT) and longissimus muscle area (LMA) and decreased backfat (BF) in the last eight generations, 2) to estimate genetic parameters for an array of traits, and 3) to investigate whether a plateau in response for BA has occurred. All lines were derived from the same Large White/Landrace composite population. Index selection for ovulation rate and embryo survival (G0-11) was initiated in L2 in 1981; L1 was selected randomly control line for L2 (G0-23). L2 …

Alteration Of Vascular Endothelial Growth Factor A (Vegfa) Isoform Expression Results In Abnormal Gonadal Function, Ningxia Lu

Department of Animal Science: Dissertations, Theses, and Student Research

In the female, vascular endothelial growth factor A (VEGFA) isoforms regulate follicle development and affect the initial primordial follicle pool. In male rodent testes, they are involved in the development of vasculature and seminiferous cords. The objective of the current study was to evaluate effects of Sertoli and Granulosa cellspecific production of VEGFA isoforms on vascular development and gonadal morphogenesis. We used a DMRT1-cre crossed to a floxed VEGFA mouse to determine potential phenotypes in male Sertoli-cell (VEGFA-DSertG) and female Granulosa-cell (VEGFA-DGranG) specific knockouts. In females, we found smaller ovarian weight, fewer corpus luteums (CLs) with some abnormal CL morphology, …