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DID DROUGHT AFFECT SOME FERTILITY TRAITS AND LAMB BIRTH WEIGHT OF SLOVENIAN AUTOCHTHONOUS SHEEP BREEDS?
Vesna Gantner
; Poljoprivredni fakultet Sveučilišta u Osijeku, Osijek, Hrvatska
Sonja Jovanovac
; Poljoprivredni fakultet Sveučilišta u Osijeku, Osijek, Hrvatska
D. Kompan
; Univerza v Ljubljani, Biotehniška fakulteta, Domžale, Slovenia
Sažetak
The aim of this research was to determine effect of extreme environmental conditions such as drought and high temperatures during the vegetation period on some fertility traits and birth weight of lambs. The data used in this study were 46,434 records of fertility and birth weight collected on 14,562 sheep of Slovenian autochthonous breeds. Sheep lambed from January 2002 to December 2006 on 247 family farms in Slovenia. Records are from central data base of Selection Service, Biotechnical Faculty, Department for Animal Science. 34,35% represented the Jezersko-Solcava sheep (JS), 52.41% the Improved Jezersko-Solcava sheep (OJS), while 13.24% of sheep belonged to the Bovec Sheep (B). According to flock size, farms were divided into three classes, S (<_ 50 sheep), M (50 – 100 sheep) and L (>_ 100 sheep). Nonparametric analysis was used for estimation of lambing year fixed effect in relation to breed on fertility parameters (number of born and liveborn lambs in litter, and number of lambing per year). For estimation of breed, flock size and lambing year effect on birth weight of lambs fixed effect linear model was used. Lambing year statistically significantly (P< 0.05) influenced the litter size, number of born and liveborn lambs in litter of the Jezersko-Solcava sheep, the Improved Jezersko-Solcava sheep and the Bovec sheep breed, respectively. Lambing year statistically significantly (P< 0.05) influenced the number of lambing per year in the Jezersko-Solcava sheep and the Improved Jezersko-Solcava sheep breed, while in the Bovec sheep the lambing year had no statistically significant
(P > 0.05) effect. Breed, flock size and lambing year statistically highly significantly (P < 0.001) influencedthe average birth weight of lambs. Extremely high temperatures and drought during year 2003 probably caused a decrease of litter size in all analysed breeds in year 2004 when compared to year 2003. In addition, the number of lambing per year in the Jezersko-Solcava Sheep and the Improved Jezersko-Solcava sheep breed decreased in year 2004 when compared to year 2003 probably as the result of extreme drought in 2003. Variation in average lamb birth weight of all analysed breeds was probably the consequence of climate conditions in the research period. In conclusion, the determined decrease of fertility parameters (litter size and number of lambing per year) and variation in average birth weight per lambing year can probably be attributed to feeding problems due to extreme climate conditions, particularly expressed in year 2003.
Ključne riječi
Slovenian Autochthonous Sheep Breeds; drought; fertility parameters; lamb birth weight
Hrčak ID:
26522
URI
Datum izdavanja:
28.6.2007.
Posjeta: 1.061 *