Abstract

The objective of this study was to compare the reproductive performance of herds milked once a day (OAD) for the whole season with that of herds milked twice a day (TAD) for the whole season. Herds were classified as OAD or TAD if they herd tested ≥ three times a season and >90% of animals had the same milking regime (OAD or TAD) at each test. Once the OAD herds were identified, the closest geographical TAD herd was identified and included in the dataset for the 2014 to 2016 seasons. Only herds with a Detailed InCalf Fertility Focus report were analysed (OAD n=75, TAD n=76). The means of five key reproduction measures were analysed and the means were significantly different for all measures (P<0.001). The OAD herds had a 7.7% higher mean herd 3-week submission rate (OAD=84.6%, TAD=76.9%), 7.9% higher mean conception rate (OAD=60.1%, TAD=52.2%), 10.4% higher mean 6-week in-calf rate (OAD=74.8%, TAD=64.4%), 4.8% lower mean not-in-calf rate (OAD=12.8%, TAD=17.6%), and 4.3% more of the herd calved by week six of calving (OAD=88.2%, TAD=83.9%) than TAD herds. These results indicate that herds milking OAD for the whole season have, on average, better reproductive performance than those milked TAD the whole season.

NV, Hemming, LR McNaughton, and C Couldrey

New Zealand Journal of Animal Science and Production, Volume 78, Lincoln, 170-172, 2018