Abstract

Once-a-day (OAD) milking has been increasing in popularity in New Zealand, while housing cows is being advocated as one means of minimising environmental impacts of dairying. The present study aimed to investigate health treatments under four different farming systems: OAD, and three twice-a-day (TAD) systems (housed, standard and commercial). There were health records from 377 cows milked OAD and 878 cows milked TAD, over the dairy seasons 2013-14, 2014-15 and 2015-16. Data were analysed assuming binomial distributions for the dependent variables with a generalised linear model that included the effects of season, system (OAD, TAD systems), breed and lactation number. In 2014-15, cows milked OAD were treated less often for mas-titis than cows milked TAD (12% and 25% respectively; P<0.05). Cows milked OAD had fewer reproductive treatments compared to cows milked TAD (standard) in 2014-15 and 2015-16 (1% vs 39% and 2% vs 40% respectively; P<0.01). These results support the advice to farmers that milking OAD does not have a major impact on the risk of mastitis but may provide benefits in terms of reproductive performance. In addition, cows milked TAD (housed) had 13% of the cows treated for lameness compared to 7% of cows milked TAD (standard) (P<0.01).

P, Van Der Spek, NW Sneddon, N Lopez-Villalobos, DJ Donaghy, RA Laven, KR Mueller, J Amoore, and H Doohan

Proceedings of the New Zealand Society of Animal Production, Volume 77, Rotorua, 211-215, 2017