Influence of housing conditions, number of farrowing and number of pigs in litter on weight loss in sows during lactation

The objective of this work was to investigate the influence of housing conditions, number of farrowing and number of pigs in litter on weight loss in sows during lactation. The experiment included 60 sows, half breed developed by cross breeding of Big Yorkshire and Swedish Landrace in lactation. Body weight of the sows (kg) was determined 2nd, 7th, 14th, 21st and 28th day after farrowing. On the basis of the obtained values, there was calculated the difference in body weight between two consecutive investigation periods. The sows were divided into two groups and held in different housing conditions: 30 of them were held in extensive, and other 30 sows in intensive way of farming. In regard to number of farrowing, the sows were divided into three groups: sows with one or two farrowing (group P1, n=20), with three or four farrowing (group P2, n=20), and sows that farrowed five or more times (P3,n=20). In regard to number of pigs in litter, the sows were divided into two groups: the first (Group I, n=30) with sows that had up to eight pigs, and the second (Group II, n=30) with sows that had nine or more pigs in litter. The obtained results showed that in all perids of the investigation during lactation, body weight in sows held in extensive farming conditions was statistically significantly higher compared to those from intensive farming conditions. On the other hand, the loss of body weight during lactation was significantly higher in sows from extensive in regard to intensive farming conditions in the first two weeks of lactation. The sows with bigger number of farrowing had greater body weight, compared to those with smaller number of farrowing. There was no statistically significant difference in body weight loss during lactation, between sows with different number of farrowing, but considering that the sows with less farrowings had significantly lower body weight, they consequently lost more weight in percentage. The sows with greater number of pigs had significantly smaller body weight in the end of lactation, that is on 21st and 28th day of lactation. The results of this investigation point out to the fact that mainly housing conditions, that is nutrition influence body weight loss, and after that comes the number of pigs in litter