New evaluation of reproduction parameters of sows and its economic relation

Abstract

In pig breeding the question often comes up how long we should keep sows in breeding, when sorting out is needed to be made on the basis of decisions considering biological and economic respects. When analysing the two kinds of production we can state that in nucleus-herds it is breeding-biology while in stock-farms it is economy that is determinant. This complex problem directed our attention to determining the longevity and the time of sorting out the sows. We collected data from a Large White nucleus-herd in Keszthely. We evaluated the reproduction and piglet-growing performances, the number of lifedays of sows per one piglet, the piglet-gain per sow- lifeday, the age as well as the reproduction index „SZFTV” of the random selected 100 sows per farrowing. In our economic evaluation we used the expense-minimising index „Dobos ” and, built on it, we worked out a method of our own. We have established as the results of our investigation that the reproduction performance of the investigated sows reaches its maximum at the 4th farrowing. The reproduction and piglet-growing performances per one lifeday do not show considerable changes after the 6-7th farrowing. Besides the following statement can be made: there is medium, occassionally close connection between index „SZFTV” and parameters per lifeday, which makes the qualification of sows possible either jointly or separately. According to the analysis completed by model „Dobos (1980)”, the expense- minimum falling to unit end-product, can be found at the 5-6th farrowing. The results of our model show that in the case of evaluated sows the expense-minimum per unit end- product is formed at the 6-7th farrowing. During our work we have compared the substitutability of two kinds of model and found close correlation between them (r=0,9314). On the basis of this relation we have proved that the method worked out by us is suitable for the estimation of sows ’performance in the same way as model „Dobos”.