In pig production, within-batch variation in bodyweight gain of piglets during the nursery period (up to 10 weeks of age) can be high and is of high economic importance, according to S.P. Paredes and colleagues at Nutreco Research and Development at Boxmeer in the Netherlands.

They report in a paper in a recent issue of Journal of Animal Science that homogeneity of bodyweight within batches of animals is important as it influences the efficiency of use of the grower and finisher facilities, and provides an extra value for the fattening farms.

In their study, factors for a low bodyweight at the end of the nursery period were determined by analysing data-sets from three different Swine Research Centres in the Netherlands and France. The entire dataset contained information on 77,868 individual piglets born in the period between 2005 and 2010. Bodyweight was determined at different time points over the pre- and post-weaning phase, and sex, season of birth; litter information (litter size at day of birth and after cross-fostering, number of piglets born alive per litter, number of total born litter-mates, sow parity number); cross-fostered animals (yes or no), and pen group size over the post-weaning period were recorded.

A risk factor analysis approach was used to analyse the data-sets to determine factors that predict piglet bodyweight at the end of the nursery period.

Bodyweight at the end of the nursery period corrected for age was mainly determined by season (P<0.001), sex (P<0.001), birth weight (P<0.001), weaning weight (P<0.001) and bodyweight at six weeks of age (P<0.001). These variables were consistent among data-sets and explained approximately 70 per cent of the overall variation in bodyweight at the end of the nursery period.

Litter information did not significantly (P>0.05) contribute to explaining the bodyweight at the end of the nursery period.

To discard the possibility of intrauterine growth-retarded piglets being the reason for the influence of birth weight as an explanatory factor in the regression model, a further analysis was performed on the effect of this category of piglets on the results of the regression analysis.

Overall, Paredes and colleagues concluded that piglet bodyweight at the end of the nursery phase is mainly determined by season, sex, birth and weaning weight and bodyweight at six weeks of age. Piglets with a birthweight higher than the mean birthweight minus 2.5 times the SD have the potential to compensate during the subsequent phases of growth.

Reference

Paredes S.P., A.J. Jansman, M.W. Verstegen, A. Awati, W. Buist, L.A. den Hartog, H.M. van Hees, N. Quiniou, W.H. Hendriks and W.J. Gerrits. 2012. Analysis of factors to predict piglet body weight at the end of the nursery phase. J. Anim. Sci., May 14. [Epub ahead of print]

Further Reading

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