Characterization of functional traits with focus on udder health in heifers with divergent paternally inherited haplotypes on BTA18

Abstract

Background A major challenge in modern medicine and animal husbandry is the issue of antimicrobial resistance. One approach to solving this potential medical hazard is the selection of farm animals with less susceptibility to infectious diseases. Recent advances in functional genome analysis and quantitative genetics have opened the horizon to apply genetic marker information for efficiently identifying animals with preferential predisposition regarding health traits. The current study characterizes functional traits with a focus on udder health in dairy heifers. The animals were selected for having inherited alternative paternal haplotypes for a genomic region on Bos taurus chromosome (BTA) 18 genetically associated with divergent susceptibility to longevity and animal health, particularly mastitis. Results In the first weeks of lactation, the q heifers which had inherited the unfavorable (q) paternal haplotype displayed a significantly higher number of udder quarters with very low somatic cell count (< 10,000 cells / ml) compared to their paternal half-sib sisters with the favorable (Q) paternal haplotype. This might result in impaired mammary gland sentinel function towards invading pathogens. Furthermore, across the course of the first lactation, there was indication that q half-sib heifers showed higher somatic cell counts, a surrogate trait for udder health, in whole milkings compared to their paternal half-sib sisters with the favorable (Q) paternal haplotype. Moreover, heifers with the haplotype Q had a higher feed intake and higher milk yield compared to those with the q haplotype. Results of this study indicate that differences in milk production and calculated energy balance per se are not the main drivers of the genetically determined differences between the BTA18 Q and q groups of heifers. Conclusions The paternally inherited haplotype from a targeted BTA18 genomic region affect somatic cell count in udder quarters during the early postpartum period and might also contribute to further aspects of animal’s health and performance traits due to indirect effects on feed intake and metabolism. Electronic supplementary material The online version of this article (10.1186/s12917-019-1988-4) contains supplementary material, which is available to authorized users.

Genetic selection for bovine chromosome 18 haplotypes associated with divergent somatic cell score affects postpartum reproductive and metabolic performance

“…This difference could originate in the differing feed intake capacities of the 2 haplotypes. For technical reasons, it was not possible to record the DMI of the animals in the present study, but a parallel long-term experiment with 6 animals (3 Q and 3 q) showed significantly higher feed intake in Q-heifers (Heimes et al, 2019).…”

“…P < 0.05 was considered significant, and P < 0.1 was considered a statistical tendency. lower milk yield of up to 7.6 (Q) or 6.7 (q) kg of ECM compared with their sisters housed in a conventional loose stall barn fed a high-energy TMR (Heimes et al, 2019). Based on studies in organic farming, it is known that a reduced-energy diet results in reduced milk yield despite similar genetic merit (Langford et al, 2009).…”

In vivo model to study the impact of genetic variation on clinical outcome of mastitis in uniparous dairy cows

“…In cattle, recently, several association studies revealed consistent results concerning BTA 18 and genetic modulation of functional traits [26][27][28][29]. Data from our work group obtained from the postpartum period of the divergent haplotype uniparous cows [37] and from a parallel long-term trial [38] indicate that although SCC served as a target criterion during the selection process, the metabolic adaption capacity of the uniparous cows seems to play a fundamental role in paving the way for adequate immune response patterns towards immunological challenges.…”

“…SCC served as a surrogate trait for mastitis susceptibility, indicating low (Q) or high (q) mastitis susceptibility. At the start of the experiment, no significant differences regarding udder-specific parameters were found between the two haplotypes, although Quniparous cows had shown a lower incidence of metritis, lower blood concentrations of betahydroxbutyrate compared to q-uniparous cows, numerical lower incidence of CM and SCM in the postpartum period and significant differences in SCC as recently published [37][38][39].…”

“…The experiment included 36 Holstein Friesian uniparous cows that were genetically selected for favorable (Q) and unfavorable (q) paternal chromosome-18-haplotypes for somatic cell count (SCC), as previously described [37][38][39]. The SCC served as a surrogate trait for mastitis susceptibility; therefore, low SCC was assumed to represent low mastitis susceptibility (Q), and high SCC was assumed to represent high mastitis susceptibility (q).…”