Animal Sciences Commons^™

Identifying Early-Life Behavior To Predict Mothering Ability In Swine Utilizing Nutrack System, Savannah Millburn

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

Early recognition of indicator traits for swine reproduction and longevity supports economical selection decision making. Gilt activity is a key variable impacting a sow’s herd life and productivity. The purpose of this study was to examine early- life behaviors contributing to farrowing traits including gestation length (GL), number born alive (NBA), number weaned (NW), and herd life (HL). Herd life was a binary trait representing if a gilt was culled after one parity. Beginning at approximately 20 weeks of age, video recordings were taken on 480 gilts for 7 consecutive days and processed using the NUtrack system. Activity traits include …

Quantification And Repeated Measurements Of Conformation Traits In Replacement Females To Optimize Sow Longevity, Melanie D. Trenhaile Grannemann

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

The objectives were to 1) assess the reliability of objective conformation trait measurements between evaluators, 2) evaluate effects of dietary energy and lysine during development and housing system during first gestation on longevity, reproductive performance, and conformation, 3) characterize conformation changes throughout life, 4) identify phenotypic associations between conformation and longevity, 5) estimate heritability of conformation traits, and 6) assess genetic relationships between conformation traits measured throughout life in sows. Sows (n = 622) were fed a standard, energy restricted, or standard energy with increased lysine diet during gilt development and housed in either a group pen or stall during …

Surveillance And Evaluation Of Manure Treatment Practices For Mitigation Of The Porcine Epidemic Diarrhea Virus (Pedv) In A Commercial Swine Farm Setting, Erin Boyles

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

The emergence of the porcine epidemic diarrhea virus (PEDv) in the United States in 2013 resulted in billions of dollars in annual losses for the U.S. swine industry. Infection with PEDv causes severe diarrhea and vomiting in pigs, spreads rapidly through ingestion of infected manure, and produces nearly 100% mortality in pre-weaned piglets. Because swine manure slurry is a valuable crop nutrient source, concerns about virus persistence in stored manure remain a major barrier to proper manure management. Proper manure handling and application practices are necessary to control the risk of pathogen re-infection at affected production sites or infecting new …

Genomic Analysis Of Sow Reproductive Traits: Identification Of Selective Sweeps, Major Genes, And Genotype By Diet Interactions, Melanie D. Trenhaile

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

Reproductive traits, such as litter size and reproductive longevity, are economically important. However, selection for these traits is difficult due to low heritability, polygenic nature, sex-limited expression, and expression late in life. Marker-assisted selection may provide an alternative to increase genetic progress.

Nebraska Index Line (NIL) has been selected for litter size related traits since 1981. It is one of the main contributing lines to the UNL reproductive longevity resource population (n > 1,500), which was genotyped for 60,000 SNPs, phenotyped for age at puberty (AP), lifetime number of parities (LTNP), litter size traits, and other reproductive traits, and fed either …

Genomic Predictions For Age At Puberty And Reproductive Longevity In Sows Using Bayesian Methods, Katherine L. Lucot

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

Including marker-assisted selection in breeding programs is potentially more efficient than traditional selection for improving traits that are expensive or difficult to measure. One of the challenges of genomics is the lack of robustness of marker effects across populations and over time (generations) and the cost to commercial producers of high-density arrays. The objective of this study was to analyze differences in the proportion of phenotypic variation explained by different fractions of major 1 Mb windows and SNPs. Using a population of Nebraska Index Line and commercial Large White x Landrace females (n = 1,234) generated in 11 batches, we …

The Effect Of Dam Parity On Progeny Growth Performance, Passive Immunity, And Gastrointestinal Microbiota, Erin E. Hinkle

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

Previous research has shown that parity (P) 4 progeny have greater weaning weights and decreased microbial diversity compared to P1 progeny. Three experiments were conducted to evaluate litter performance, passive immunity, and fecal microbiota among P1 and P3 dams and their progeny. In experiment 1, 56 P1 and 49 P3 dams and their progeny’s litter and growth performance, immunoglobulin (IgG and IgA) concentrations, and gut microbiota were evaluated. In experiment 2, 48 pigs per P were selected to determine growth performance, immunoglobulin (IgG and IgA) concentrations, and gut microbiota. In experiment 3, 8 dams per P were selected. At birth, …

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 …