Effect of genetic and environmental factors on the phenotype characteristics of lambs

Abstract

The aim of this study was to determine the influence of environmental factors affecting body weight variability of lambs in two crossbreed groups: Pirot x Württemberg and Sjenica x Württemberg. Both populations were managed under the same farm conditions. The data were analyzed to determine the effect of age of the dam, weight of dam, birth type, sex, year and season, on the birth weight and weaning weight of crossbreed lambs. Statistical analysis was performed by GLM procedure using the SPSS statistical package program. The average birth weight of Pirot x Württemberg lambs was 3.56 kg while Sjenica x Württemberg lambs was slightly higher at 3.69 kg. The difference on birth weight between the two crosses was not statistically significant (P>0.05). The average weaning weight of Pirot x Württemberg lambs was 23.54 kg while Sjenica x Württemberg lambs had higher weight at 24.37 kg. The difference of 0.83 kg on weaning weight was statistically significant (P (lt) 0.05). Body weight, depending on the environmental factors, ranged from 3.17 to 3.96 kg at birth and from 22.12 to 24.18 kg at weaning in Pirot x Württemberg lambs. Body weight of Sjenica x Württemberg lambs ranged from 3.39 to 3.99 kg at birth and from 22.69 to 25.44 kg at weaning. Statistical analysis showed that the differences were statistically significant (P (lt) 0.05) and highly significant (P (lt) 0.01).

Cilj ovog istraživanja je bio da se utvrdi uticaj faktora životne sredine na varijabilnost telesne težine jagnjadi u dve grupe meleza: pirotska x virtemberg I sjenička x virtemberg. Obe populacije su držane pod istim uslovima na farmi. Podaci su analizirani da se utvrdi uticaj starosti majke, njene težine, tipa rođenja, pola, godine i sezone, na težinu na rođenju i odbijanju jagnjadi meleza. Statistička analiza je izvedena pomoću GLM procedure, koristeći SPSS statistički program paket. Prosečna telesna masa meleza pirotska x virtemberg je 3,56 kg, dok sjenička x virtemberg jagnjad bila nešto veća - 3,69 kg. Razlika u težini na rođenju između dve grupe meleza nije bila statistički značajna (P>0,05). Prosečna težina na odbijanju jagnjadi meleza pirotska x virtemberg je bila 23,54 kg, dok su jagnjad melezi sjenička x virtemberg imala veću težinu - 24,37 kg. Razlika težine na zalučenju od 0,83 kg je statistički značajna (P (lt) 0,05). Telesna masa, u zavisnosti od faktora sredine, kretala se u rasponu od 3,17 do 3,96 kg na rođenju i od 22,12 do 24,18 kg na odbijanju u jagnjadi pirotska x virtemberg. Telesna masa jagnjadi sjenička x virtemberg kretala se u rasponu od 3,39 do 3,99 kg na rođenju i od 22,69 do 25,44 kg na odbijanju. Statistička analiza pokazala je da su razlike statistički značajne (P (lt) 0,05) i visoko značajne (P (lt) 0,01).