Effects of three times daily milking on milk production and reproductive performance

Abstract

Proc. Aust. Soc. Anim. Prod. I996 Vol. 21 EFFECTS OF THREE TIMES DAILY MILKING ON MILK PRODUCTION AND REPRODUCTIVE PERFORMANCE P.J. GOODWIN, J. DRAPER, M.J. JOSEY and M. IMBEAH Dept of Animal Production, The University of Queensland, Gatton, Qld 4343 Milk production costs have risen dramatically in recent years and dairy producers are forced to find ways of increasing their net income. Methods most often used to increase milk production are to change herd size and to increase concentrate feeding (Amos et al. 1985). Changing the frequency of milking is another method that can be used to increase milk yield and thus increase income. A number of reports have suggested significantly higher milk yield with 3 times (3x) daily milking. There have also been reports of high milk yields adversely affecting reproductive performance of cows (Olds et al. 1979; Laben et al. 1982). Information on 3x milking under Australian conditions is lacking. Fifty four Holstein-Friesian cows paired on parity, milk production and stage of lactation were used to determine the effect of frequency of milking on milk production, milk composition, reproductive efficiency, body weight and condition score during a l0-week period. Milking times were 0500 hours, 1300 hours and 2100 hours for the 3 times daily milking group; 0600 hours and 1500 hours for the 2 times daily milking group. Condition score and body weight were measured at 6 weeks following the start of the trial and at the end of the 10-week period. Reproductive data - days to first heat and number of services to conception were recorded for all cows. All the cows were lot fed with haylage from a harvestore tower twice daily at levels close to ad libitum and a grain concentrate, rationed according to production and stage of lactation. All data was analysed statistically using GLM procedures of SAS (1988). Three times daily milking increased milk yield by 9.5% (P<O.O5) but did not affect milk composition (Table 1). Table 1. Effect of milking frequency on milk yield and milk composition Parameter Calving to first heat (days) No. of services to conception Body weight (kg) Condition score (l-8) 2x Daily milking 59.3 2.1 630 5.72 3x Daily milking 79.2 1.9 613 5.77 SEM 1.7 0.17 9.14 0.09 AMOS, H.E., KISER, T. and LOEWENSTEIN, M. (1985). J. Dairy Sci. 68: 732-9. LABEN, R.C., SHANKS, R., BERGER, P.J. and FREEMAN, A.E. (1982). J. Dairy Sci. 65: 1004-15. OLDS, D., COOPER, T. and THRIFT, F.A. (1979). J. Dairy Sci. 62: 1140-4. SAS (1988). SAS Users Guide, Statistics, (SAS Institute Inc: Cary, NC). 339