Location: Genetics and Animal BreedingTitle: Genetic factors associated with changes in feeding behavior due to elevated temperature
|CROSS, AMANDA - Dna Research Institute|
|CASSADY, JOSEPH - South Dakota State University|
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/4/2018
Publication Date: N/A
Technical Abstract: Heat stress has negative impacts on pork production, particularly in the grow-finish phase. During heat stress events, feeding behavior of pigs is altered to reduce heat production. However, not all animals respond similarly to elevated ambient temperatures. To determine if genetic factors were associated with differences in feeding behavior at different environmental temperatures, feeding behavior was studied year-round in a barn containing 6 pens of 40 pigs/pen. Pigs were placed in the barn at 8 weeks of age and removed after 12 weeks on study. All pigs (n = 1653) were produced by sows from a common population (Landrace-Duroc-Yorkshire composite) and sired by Duroc, Landrace or Yorkshire boars. Pen assignments ensured uniform numbers of male and female pen mates for each breed of sire. Days were partitioned into categories based on their maximum temperature humidity index (THI): “Normal” (THI < 23.33°C), “Alert” (23.33°C < THI < 26.11°C), “Danger” (26.11°C < THI < 28.88°C) and “Emergency” (THI > 28.88°C). Females had a greater reduction in feeding time due to elevated temperature than males. Breed of sire differences were also observed as Duroc-sired pigs were marginally affected, Landrace-sired pigs were severely affected, and Yorkshire-sired pigs were intermediately affected by elevated temperatures. To avoid population stratification effects in genome-wide association studies (GWAS), phenotypic data were adjusted for breed of sire and sex prior to conducting a GWAS using genotypic data from ~60,000 SNP markers in GenSel. Candidate genes within regions identified by the GWAS include heat shock proteins and immune function. Genetics differences in feeding behavior of grow-finish pigs due to increased temperatures were observed. Selection targeting these genetic differences can produce pigs that are more tolerant to elevated ambient temperature and genetic markers will expedite this selection response.