THE EFFECTS OF AGE AND PREGNANCY TYPE IN COLOURED ENHANCED GOATS ON PRODUCTIVITY AND COMPOSITION OF MILK

The aim of this work was to evaluate the effects of age and pregnancy type in coloured enhanced goats on productivity and composition of milk. Research material consisted of 552 colour enhanced goats from a productive flock based in Kujawsko-Pomorskie district in 2004-2007. Milk productivity in goats and chemical composition of milk were evaluated on the basis of monthly morning and evening control milkings from both teats during lactation period, according to the A4 method used in the National Centre of Animal Breeding. The age of goats had a statistically significant effect on the litter size. Goats pregnant for the first time produced a greater number of a single offspring litters and a smaller number of twin and triple litters than older goats. The most numerous litters were produced by the three and four-year-old goats. Goats in their second and third lactation had longer lactation time and higher milk productivity, as well as higher fat and protein contents. Goats producing twins and triplets had longer lactation time and greater milk productivity in comparison to goats with a single offspring litters. The differences were confirmed statistically.