The effect of breeding area, stage of lactation and herd on milk yield traits of Pag sheep

The objective of this study was to determine the effect of different breeding areas (south-west and north-east part of the island of Pag) on daily milk, fat and protein yield in Pag sheep. The aim of thisstudy was also to determine the shape of lactation curves as well as the herd effect on Pag sheep milk traits. Research was conducted on 32 herds reared in the south-western (23) and north-eastern (9) part of the island of Pag. Data included 21.033 test-day records of 2.332 ewes. Daily milk yield and milk components were recorded using AT4 method for the period from 2004 to 2008. The rearing area had statistically significant effect on the daily milk yield (P<0.001), daily fat and protein yield. Ewes reared on the south-western part of the island had larger average daily production than ewes reared on its north-eastern part. The stage of lactation, described by Ali and Schaeffer lactation curve nested within rearing area, had significant effect (P<0.0001) on all milk traits. The peak of lactation production was achieved around the 20th day of lactation in both areas and was somewhat higher for ewes kept in the south-western compared to the north-eastern part of the island. Flock nested within rearing area had statistically significant effect on all milk traits (P<0.0001). Results obtained in the study showed potential possibilities for breeders to enlarge milk production and consequently economically benefit through improved herd management of Pag sheep.