Variation in yields of milk and milk solids in Holstein cows induced to calve prematurely

Jaques, S. A., Macmillan, K. L., Anderson, G. A. and Morton, J. M. (2006). Variation in yields of milk and milk solids in Holstein cows induced to calve prematurely. In: Proceedings of the New Zealand Society of Animal Production. NZSAP 2006 Proceedings. New Zealand Society of Animal Production Conference 2006, Hamilton, (344-349). 2006.

Author Jaques, S. A.
Macmillan, K. L.
Anderson, G. A.
Morton, J. M.
Title of paper Variation in yields of milk and milk solids in Holstein cows induced to calve prematurely
Conference name New Zealand Society of Animal Production Conference 2006
Conference location Hamilton
Conference dates 2006
Proceedings title Proceedings of the New Zealand Society of Animal Production. NZSAP 2006 Proceedings
Place of Publication Hamilton, New Zealand
Publisher New Zealand Society of Animal Production
Publication Year 2006
Sub-type Fully published paper
ISSN 0370-2731
1175-7434
1176-5283
Volume 66
Start page 344
End page 349
Total pages 6
Language eng
Abstract/Summary Milk production was compared between multiparous Holstein cows that were induced to calve and herdmates that calved spontaneously at approximately the same time in 88 dairy herds from Victoria and Tasmania. Yield averages for each herd were calculated for induced and spontaneously calving cows for milk volume, milkfat and protein during the first 120 days of lactation and for 305 days. Associations between induced and spontaneously calving groups for 305-day yields were described using linear equations. Slopes ranged from 0.82 (for milk yield) to 0.87 (for protein yield) and R2 values ranged from 0.84 to 0.88 (P<0.001). The average reduction in milk yield over the 88 herds was 366 litres (7%). The estimated milk yield reduction for induced groups in herds where spontaneously calving contemporaries averaged only 3500 litres per 305 days was 40 litres (1.1%) compared to an average estimated reduction of 915 litres (11%) in herds averaging 8500 litres. Similar proportional reductions were calculated for 305-day yields of milkfat and protein. Collectively these results show that yield reductions following induced premature parturition are substantially higher in absolute as well as proportional terms in herds with higher milk yields.
Subjects 070206 Animal Reproduction
0702 Animal Production
Keyword NZSAPAB
Induced parturition
Holstein
Milk yield
Q-Index Code E1
Q-Index Status Provisional Code
Institutional Status Unknown

 
Versions
Version Filter Type
Citation counts: Google Scholar Search Google Scholar
Created: Thu, 09 Apr 2009, 15:40:24 EST by Ms Lynette Adams on behalf of Faculty Of Nat Resources, Agric & Veterinary Sc