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Uniform monthly milk production in Israel by planned breeding of replacement heifers: results of a simulation study

Published online by Cambridge University Press:  02 September 2010

H. E. Kahn  and
A. R. Lehrer
H. E. Kahn
Affiliation:
Institute of Animal Science, ARO, Bet Dagan 50 250, Israel
A. R. Lehrer
Affiliation:
Institute of Animal Science, ARO, Bet Dagan 50 250, Israel
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Abstract

Both milk production (MP) and conception rate (CR) of primi- and multiparous cows (P+M) in Israel are characterized by the same summer-autumn trough and winter-spring peak. Although there is no causal link between CR and MP (a simulation-model study explained the connection), monthly CR determines the number of dry cows 7 months later, at 2 months pre-calving. Inevitably, when the number of dry cows is low, MP is high, and vice versa.

Replacement heifers (RH) in Israel have a consistently high (64%) CR throughout the year. The same simulation model was used to investigate the effect of manipulated RH breeding on the herd MP pattern. When RH breeding was confined to the 3-month July to September (J-S) period during which CR is lowest for post-partum P+Ms, the monthly MP pattern in an otherwise year-round breeding dairy herd was the diametric opposite of the one produced by all-year RH breeding. When a uniform monthly quota was set for RH and P+M conceptions, and monthly RH conceptions were restricted to complement monthly P+M conceptions, the herd MP pattern became almost level. There did not appear to be any economic penalty attached to the planned RH conception system.

In practice it will not be possible to adhere to a strict monthly quota of conceptions, since there is a 1 to 2 month lag between insemination and confirmed conception. Estimates of individual farm monthly CR could be used, where available. Alternatively, if 40% of all RH inseminations were performed in J-S, the MP curve would be much flatter than under the present non-planned system of RH insemination.

Keywords

conception ratemilk productionreplacement rateseasonal fluctuationssimulation model
Type
Research Article
Information
Animal Production , Volume 54 , Issue 1 , February 1992 , pp. 1 - 6
Copyright
Copyright © British Society of Animal Science 1992

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References

Bar-Anan, R. and Genizi, A. 1981. The effects of lactation, pregnancy and calendar month on milk records. Animal Production 33:281–290.Google Scholar
Israel Dairy Board. 1989. [1988 year-book] (ed. Dror, J.). P.O.B. 20035, Tel Aviv, Israel, (in Hebrew).Google Scholar
Kahn, H. E. 1991. The effect of summer decline in conception rate on the monthly milk production pattern in Israel. Animal Production 53:127–131.Google Scholar
Haemek, Meida. 1990. [The replacer: cow ratio.] Meshek Habakar Ve'hechalav 229: 31. (in Hebrew).Google Scholar
Ron, M., Bar-Anan, R. and Wiggans, G. R. 1984. Factors affecting conception rate of Israeli Holstein cattle. Journal of Dairy Science 67: 854–860.CrossRefGoogle ScholarPubMed