@article {3672, title = {Regression of traits-other-than-production phenotypes for cows milked once a day on estimated breeding values obtained from cows milked twice a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {140-143}, address = {Palmerston North}, abstract = {The use of traits other than production (TOP) to aid selection for conformation fit-for-purpose offspring becomes more important as once-a-day (OAD) milking for whole or part season becomes more common. In 2013 Massey University Dairy 1 farm transitioned their mixed-breed herd milked twice a day (TAD) to an OAD spring-calving system. All cows on the farm were scored for 14 inspector TOP traits and four farmer-scored traits for a total of 1,163 records over five seasons (168 to 254 cows per year). The scores were adjusted for age of the cow and season. The adjusted phenotypes for all cows for each trait were then regressed on their corresponding nationally-produced TAD estimated breeding values (EBV), which had been calculated without using these phenotypes. The four farmer-scored traits had the lowest relationships with EBV. Estimates of regression coefficients near one were observed for the udder traits (udder support, rear udder, front teats, udder overall), dairy conformation and body capacity. This supports the use of national EBVs in OAD herds derived mostly from records on daughters in TAD herds. }, issn = {1176-5283}, author = {Sneddon NW and Lopez-villalobos N and Garrick DJ and Rocha JF and Donaghy DJ} } @conference {3672, title = {Culling reasons in once-a-day milking cows and differences in production and type traits between retained and culled cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {200-204}, address = {Rotorua}, abstract = {The aim of this study was to investigate the culling reasons in cows milked once-a-day (OAD), evaluating the differences of production, fertility and traits other than production (TOP) between retained and culled cows. Cows in different lactations from Massey University Dairy 1 were scored for 18 TOP for three consecutive seasons from 2013 to 2015. Herd-test records were used to estimate milk yield (MY), fat yield (FY), protein yield (PY) and somatic cell score (SCS). Low fertility, poor udder conforma-tion and low production were the main reasons for culling in all seasons. Overall, culled cows had a lower MY (3534{\textpm}56 kg), FY (173.5{\textpm}2.8 kg), PY (138.5{\textpm}2.1 kg) and higher SCS (6.41{\textpm}0.09) than retained cows (MY = 4006{\textpm}41 kg; FY = 204.7{\textpm}1.9 kg; PY = 160.6{\textpm}1.5; SCS = 6.19{\textpm}0.06). Culled cows had a poorer adaptability to milking (7.02 {\textpm} 0.04) and poorer farmer{\textquoteright}s overall opin-ion (7.62{\textpm}0.06) than retained cows (7.23{\textpm}0.03 and 7.89{\textpm}0.04, respectively). Moreover, culled cows had a weaker udder support (5.56), weaker front udder (5.48) and lower rear udder (6.01) than retained cows (6.19, 5.85 and 6.25, respectively). These traits might have a higher influence on the culling decisions of OAD dairy farms than the age and production worth of cows.}, issn = {1176-5283}, author = {Rocha JF and Lopez-Villalobos N and Burke JL} }