Influence of the age and lactation month of goats on the quantity and composition of milk as well as the number of somatic cells

The aim of this work was to examine the influence of the age and lactation month of goats on the quantity and composition of milk as well as the number of somatic cells. According to the data (on age of goats, time of kid bearing, quantity of milk) of goat farm and the data of the state enterprise “Pieno Tyrimai” (fatness as well as the quantity of crude proteins in milk, and somatic cells in milk), the influence of the age and lactation month of first year goats, second year goats, third year goats and older goats on the quantity and composition of milk as well as the number of somatic cells has been examined. The data of the goats of Zaanen breed has been used for the research. The influence of the age and lactation month of goats on the quantity and composition of their milk as well as the number of somatic cells has been examined. The data on the quantity of milk for the researches was taken during controlled milkings of the controlled goat flock. The controlled milking was done in the flocks of controlled goats each month according to the set schedule. During the control of productivity, the milk yield of the controlled animal was established (kg). During the controlled milking, the control samples of milk was taken for establishment of the quantity of fat (per cent), crude proteins (per cent) and number of somatic cells (thousand/ml). The milk samples have been examined in the accredited laboratory of milk testing, the state enterprise “Pieno Tyrimai” by applying the approved methods. In order to examine the influence of lactation and lactation stage on the quantity and composition of goat milk, the data on goat lactation, kid bearing and non-milking time during the period from 2004 to 2007 of the particular farm has been taken for the research. Having examined the influence of the age of goats on the milk productivity, it has been established that the most productive goats were those of the fourth lactation the milk yield of which per lactation was larger by 15.84 kg or 1.42 per cent (p>0.05) than that of the goats of the third lactation, by 5.31 kg or 0.47 per cent (p>0.05) than that of the goats of the fifth and older lactations. The richest milk was produced by the goats of the third lactation (3.88 ± 0.15 per cent) and the largest quantity of butterfat per lactation has been established (43.29±1.94 kg). The largest quantity of crude proteins has been established in the milk of the goats of the fifth and older lactations (3.00 ± 0.06 per cent), and the largest quantity of crude proteins in milk per lactation has been established (33.79 ± 1.8). It may be claimed that the quantity of crude proteins per lactation increases with the age of goats. Having examined the influence of the lactation month of goats on the milk productivity, it has been established that the most productive goats were those of the fifth month of lactation the milk yield of which was larger by 5.85 kg or 4.06 per cent (p>0.05) than during the fourth month of lactation, by 11.18 kg or 8.05 per cent (p<0.05) than during the sixth month of lactation and by 42.03 kg or 38.9 per cent (p