Mljekarstvo (Dec 2008)
Factors affecting goat milk yield and composition
Abstract
The aim of this paper was to study the effects of breed, stage of lactation, season of kidding and parity on goat milk yield and composition. A total of 25255 records of daily milk production and 25065 records of fat percentage, 25382 records of protein percentage and 24810 records of lactose percentage were obtained, at approximately monthly intervals, from 3702 Alpine and 411 Saanen goats in Croatia. The analysed data were recorded during 2006. Saanen breed had significantly (P<0.01) higher lactation and daily milk yield than Alpine breed (720 kg and 2.63 kg/day versus 577 kg and 2.08 kg/day, respectively). The contents of protein and lactose were similar between investigated breeds, while Alpine goats had significantly higher (P<0.05) milk fat content than Saanen goats (3.47 % versus 3.25 %, respectively). Least square analyses showed significant effects of stage of lactation, season of kidding and parity on almost all variables. Milk lactose content tended to decline as the lactation period progressed and milk yield decreased. Milk protein content tended to increase with the lactation period. The lowest content of milk fat was established in the mid stage of lactation, whereas the highest fat content was recorded at the end of lactation. The effect of parity on total lactation and daily milk yield shows an almost steady growing trend from first to fourth lactation. Goats kidding early in the year had better milking performances (longer lactation period, higher milk yield, higher content of milk fat) than goats kidding in the spring. In order to improve lactation performances of their animals, the goat farmers should apply earlier mating season and use the appropriate breeding programmes.
