Genetic selection for bovine chromosome 18 haplotypes associated with divergent somatic cell score affects postpartum reproductive and metabolic performance.
The susceptibility of animals to periparturient diseases has a great effect on the economic efficiency of dairy industries, on the frequency of antibiotic treatment, and on animal welfare. The use of selection for breeding cows with reduced susceptibility to diseases offers a sustainable tool to improve dairy cattle farming. Several studies have focused on the association of distinct bovine chromosome 18 genotypes or haplotypes with performance traits. The aim of this study was to test whether selection of Holstein Friesian heifers via SNP genotyping for alternative paternal chromosome 18 haplotypes associated with favorable (Q) or unfavorable (q) somatic cell scores influences postpartum reproductive and metabolic diseases. Thirty-six heifers (18 Q and 18 q) were monitored from 3 wk before calving until necropsy on d 39 (± 4 d) after calving. Health status and rectal temperature were measured daily, and body condition score and body weight were assessed once per week. Blood samples were drawn twice weekly, and levels of insulin, nonesterified fatty acids, insulin-like growth factor-I, growth hormone, and β-hydroxybutyrate were measured. Comparisons between the groups were performed using Fisher's exact test, chi-squared test, and the GLIMMIX procedure in SAS. Results showed that Q-heifers had reduced incidence of metritis compared with q-heifers and were less likely to develop fever. Serum concentrations of β-hydroxybutyrate were lower and insulin-like growth factor-I plasma concentrations were higher in Q- compared with q-heifers. However, the body condition score and withers height were comparable between haplotypes, but weight loss tended to be lower in Q-heifers compared with q-heifers. No differences between the groups were detected concerning retained fetal membranes, uterine involution, or onset of cyclicity. In conclusion, selection of chromosome 18 haplotypes associated with a reduced somatic cell score resulted in a decreased incidence of postpartum reproductive and metabolic diseases in this study. The presented data add to the existing knowledge aimed at avoiding negative consequences of genetic selection strategies in dairy cattle farming. The underlying causal mechanisms modulated by haplotypes in the targeted genomic region and immune competence necessitate further investigation.
['Meyerholz|M M|MM|', 'Rohmeier|L|L|', 'Eickhoff|T|T|', 'Hülsebusch|A|A|', 'Jander|S|S|', 'Linden|M|M|', 'Macias|L|L|', 'Koy|M|M|', 'Heimes|A|A|', 'Gorríz-Martín|L|L|', 'Segelke|D|D|', 'Engelmann|S|S|', 'Schmicke|M|M|', 'Hoedemaker|M|M|', 'Petzl|W|W|', 'Zerbe|H|H|', 'Schuberth|H-J|HJ|', 'Kühn|Ch|C|']
D020155:3-Hydroxybutyric Acid D000818:Animals D001835:Body Weight D002417:Cattle D002418:Cattle Diseases D033481:Chromosomes, Mammalian D003612:Dairying D005230:Fatty Acids, Nonesterified D005260:Female D013006:Growth Hormone D006239:Haplotypes D007328:Insulin D007774:Lactation D018457:Placenta, Retained D020641:Polymorphism, Single Nucleotide D049590:Postpartum Period D011247:Pregnancy D012098:Reproduction D012641:Selection, Genetic
somatic cell score insulin-like growth factor-I metritis BTA18