Milk yield, milk composition and somatic cell count of dairy goats given n-3 unsaturated fatty acids diet supplement.

摘要

Research of the effects of n-3 unsaturated fatty acids (PUFA, particularly eicosapentaenoic acid-EPA; alpha -linoleic acid-ALA; docosahexaenoic acid-DHA) on goat's milk production (daily milk yield; daily fat, protein and lactose content) and somatic cell count and the persistence of this effect after terminated supplementation was conducted on 62 machine-milked Alpine breed goats kept at an indoor Alpine farm. After adoption period the animals were randomly allocated according to supplement addition into control group (G-4) with no added supplement and test groups (G-1; G-2; G-3) where a supplement containing PUFA was added over a period of five days. Measurements of milk yield and sampling (70 mL) for analysis of milk composition during the adoption period, supplementation period and first five days after supplementation were done every day at each milking (morning and evening). From the 5th to the 50th day of the after supplementation period, measurements and sampling occurred every fifth day. Based on the obtained results it could be concluded that the PUFA dietary addition alters the quantity and the quality of produced milk. DHA and EPA supplementation increase daily milk yield, while ALA supplementation induces a decrease of milk yield. When milk content is taken into consideration, the effects are contrary. Regarding somatic cell count, the highest effect on reduction was determined when ALA supplement was added. The mentioned effects persisted after the dietary supplement was withdrawn. The obtained results could be used in dietary supplementation planning in respect to the desired effects. Further research with the aim of determining the fatty acid composition of milk fat is needed.