@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}
}
