Izvorni znanstveni članak
THE EFFECT OF PARITY, STAGE OF LACTATION, LITTER SIZE, LAMBING SEASON, AND HERD ON MILK YIELD TRAITS OF PAG SHEEP
Zdravko Barać
; Hrvatska poljoprivredna agencija, Ilica 101, Zagreb, Hrvatska
Marija Špehar
; Hrvatska poljoprivredna agencija, Ilica 101, Zagreb, Hrvatska
Boro Mioč
; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Sažetak
The objective of this study was to determine the effect of parity, stage of lactation, litter size, lambing season, and herd on daily milk, fat and protein yield in Pag sheep. Data included 21.033 test-day records of 2.332 ewes reared in 32 herds. Daily milk yield and milk components were recorded using AT4 method for the period from 2003 to 2008. Parity had statistically significant effect on the daily milk yield (P<0.05), daily fat and protein yield. Daily milk, fat, and protein yield was the lowest in the first parity. Ewes in later parities produced more milk, fat, and protein per day than ewes in the first parity and at the same stage of lactation. The highest daily fat and protein yield was in the fourth parity, while the ewes in the fifth parity had the highest daily milk yield. The stage of lactation, described by Ali and Schaeffer lactation curve nested within parity, had significant effect (P<0.0001) on all milk traits. The peak of production was achieved around the 10th day of lactation for the ewes in the first parity. In the second and later parities, the peak occurred around the 20th day of lactation. Daily milk, fat, and protein yield decreased towards the end of lactation. Litter size, lambing season, and flock had statistically significant effect on all milk traits (P<0.0001). The results obtained in the study indicate significant impact of environmental effects on milk production traits in Pag sheep. Furthermore, the results also indicate the possibility for breeders to improve herd management and consequently increase milk production and profitability.
Ključne riječi
Pag sheep; milk yield traits; parity and stage of lactation; litter size; lambing season; herd
Hrčak ID:
89925
URI
Datum izdavanja:
25.5.2012.
Posjeta: 1.084 *