Back to Search Start Over

Modelling impacts of performance on the probability of reproducing, and thereby on productive lifespan, allow prediction of lifetime efficiency in dairy cows

Authors :
H.N. Phuong
P. Blavy
O. Martin
P. Schmidely
N.C. Friggens
Source :
Animal, Vol 10, Iss 1, Pp 106-116 (2016)
Publication Year :
2016
Publisher :
Elsevier, 2016.

Abstract

Reproductive success is a key component of lifetime efficiency – which is the ratio of energy in milk (MJ) to energy intake (MJ) over the lifespan, of cows. At the animal level, breeding and feeding management can substantially impact milk yield, body condition and energy balance of cows, which are known as major contributors to reproductive failure in dairy cattle. This study extended an existing lifetime performance model to incorporate the impacts that performance changes due to changing breeding and feeding strategies have on the probability of reproducing and thereby on the productive lifespan, and thus allow the prediction of a cow’s lifetime efficiency. The model is dynamic and stochastic, with an individual cow being the unit modelled and one day being the unit of time. To evaluate the model, data from a French study including Holstein and Normande cows fed high-concentrate diets and data from a Scottish study including Holstein cows selected for high and average genetic merit for fat plus protein that were fed high- v. low-concentrate diets were used. Generally, the model consistently simulated productive and reproductive performance of various genotypes of cows across feeding systems. In the French data, the model adequately simulated the reproductive performance of Holsteins but significantly under-predicted that of Normande cows. In the Scottish data, conception to first service was comparably simulated, whereas interval traits were slightly under-predicted. Selection for greater milk production impaired the reproductive performance and lifespan but not lifetime efficiency. The definition of lifetime efficiency used in this model did not include associated costs or herd-level effects. Further works should include such economic indicators to allow more accurate simulation of lifetime profitability in different production scenarios.

Details

Language :
English
ISSN :
17517311
Volume :
10
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Animal
Publication Type :
Academic Journal
Accession number :
edsdoj.23f285eed6ba4e4e9bf4f48e9b3890b9
Document Type :
article
Full Text :
https://doi.org/10.1017/S1751731115001718