Postpartum anoestrous intervals and reproductive performance of
three genotypes of Holstein-Friesian dairy cattle managed in a seasonal
pasture-based dairy system
L.R. McNAUGHTON, G.A. VERKERK, T.J. PARKINSON, K.A. MACDONALD
AND C.W. HOLMES
Institute of Veterinary, Animal and Biomedical Sciences, Massey
University, Private Bag 11 222, Palmerston North, New Zealand
E-Mail:
NZSAP 2003 Abstract No. 20
Proceedings of the New Zealand Society of Animal Production
63: 77-81
An extended postpartum anovulatory interval (PPAI) is the major
form of infertility in New Zealand (NZ) dairy cattle. Recently, Holstein
cows, originating from North American genetic strains (Overseas; OS),
have been widely used in NZ. Worldwide, there is concern over an
apparent decline in the fertility of Holstein-Friesian dairy cattle.
This study determined whether differences existed in PPAI, BCS and
parameters of reproductive performance between NZ and OS
Holstein-Friesians. One hundred and forty-six records from 88 NZ animals
of high genetic merit for milk production (NZH), 81 records from 48 NZ
animals of low genetic merit (NZL), and 137 records from 88 OS high
genetic merit animals that calved in Years 1 (all two-year-olds) and 2
(two- and three-year-olds) were included. Over both years PPAI in
two-year-olds were significantly shorter in OS (20 days shorter) and NZL
(12 days shorter) than in NZH animals (P<0.05). Body condition score
at calving, and BCS loss from calving to four weeks postpartum were not
different between strains. In Year 1 of the study significantly more NZH
than NZL or OS 2-year-olds were treated for anoestrus prior to the start
of mating (P=0.001). Other measures of reproductive performance did not
differ significantly between strains. The differences in PPAI require
further investigation.
Keywords: NZSAPAB;
Holstein-Friesian; calving; conception rate; postpartum
anovulatory interval
Last Updated 8/07/2004
