Investigating the effects of fish oil supplementation as an omega-3 fatty acid source during late gestation: milk yield and composition of does and growth performance of their offspring

Abstract

The aim of the study was to evaluate the effects of fish oil as an Omega-3 source during late pregnancy of does on pregnancy and lactation performance, as well as on the growth performance of kids. Thirty German Fawn x Hair crossbreed does were used. On the 76th day of pregnancy, the does were separated into two groups and fed a total mixed ration (TMR) including 2.8% (as-fed) fish oil (n = 17) or protected fat (n = 13) until kidding. The does and kids were subjected to a standard feeding regimen between kidding and 60 days of lactation. Feed intake was monitored on a weekly basis. Milk production was recorded every two weeks, with samples analyzed for total solids, fat, protein, casein, lactose, and urea levels. Additionally, the feed intake and individual body weights of the kids were measured biweekly. The use of fish oil in the diet during the last period of pregnancy did not affect live weight except on the 128th day of pregnancy. Similarly, the duration of pregnancy, milk yield, and milk composition were not affected by fish oil. However, feed intake increased during pregnancy, while it caused a decline during the lactation period. The kids born to does fed with fish oil TMRs consumed less feed. In conclusion, the use of 2.8% fish oil in the rations of does in late pregnancy did not affect the live weight of the dam and offspring. Fish oil increased feed intake during pregnancy. In lactation, feed intake decreased in dams and kids of dams receiving fish oil during pregnancy. The length of pregnancy and the protein and casein levels in the milk may also be influenced by the type of delivery. These findings suggest that while fish oil supplementation can alter feed intake patterns, it does not adversely affect key performance metrics such as live weight and milk production. Further research could explore the underlying mechanisms and long-term effects of fish oil supplementation in the diets of pregnant does.