| It is of vital importance to improve utilization level of elite sheep breeds and genetically impove available breeds for sheep industry,which is one of the pillar industries of animal husbandry in Tianzhu County.In this study,Hu sheep was introduced to Songshan Town,Tianzhu County(altitude 2800 m),and the physiological and biochemical indexes and production performance and reproductive performance were measured to evaluate the adaptability of Hu sheep in high altitude and cold area.In addition,the growth performance of F1 hybrid progeny of Hu sheep(?)with Texel,Dorper,Australian White and Small Tail Han sheep(?)was compared with purebreeding Hu sheep.The current research will supply basic theoretical foundation for introduction of Hu sheep to high altitude and cold areas in Northwstern China and heterosis utilization in sheep industry.The results are as follows:1.In summer,the body temperatures of rams were significantly higher than ewes at 24 months age(P < 0.05).No significant differences of blood physiological indexes between males and females were observed in addition to mean hemoglobin contentration of red blood cells(MCHC)at 6 months age(P < 0.01)and mean platelet volume(MPV)at 24 months age(P < 0.05),which both indicated that rams were significantly higher than ewes.The individuals with different ages showed huge variations in blood physiological indexes,while all of them were in a normal range.Overall,the blood biochemical indexes of Hu sheep at 3 and 6 months age were higher than those at 12 and 24 months age.2.Of physiological indexes investigated,the yearling Hu sheep showed significantly higher body temperature in summer than that in winter(P <0.05).There was no significant difference in the blood physiological indexes of males and females between summer and winter(P>0.05).The lactate dehydrogenase(LDH)(P < 0.05)and alanine aminotransferase(ALT)(P < 0.01)of blood biochemical indexes for ram were significantly higher in winter than that in summer,while ewes' ALT in winter was significantly higher than that in summer(P < 0.05);alkaline phosphatase(ALP)of ram and ewes in winter was very significantly higher than that in summer(P <0.01);total protein(TP)of ram and ewes was very significantly higher in summer than in winter(P <0.01).3.In the current study,the body weight of one yearling male Hu sheep was 35.39±6.54 kg,which was slightly higher than the original counterpart(34.84 kg).Its reproduction fertility is 234.57 % and the rate of litter size of 2 or 3 is 79.56 % which was also slightly higher than the original one(229% and 79.56 %).The birth weight of F1 generation of different crosses of Hu sheep was higher than that of pure Hu sheep.The body weight of yearling Hu rams and was 35.39 ± 6.54 kg and 33.22 ± 4.40 kg respectively,which was significantly lower than yearling Texel×Hu sheep F1 rams(44.70±4.99 kg)and ewes(44.26±7.90 kg)(P <0.01).The cumulative growth from four to twelve months Texel sheep×Hu sheep F1 generation was also very significantly higher(P <0.01)than that of Hu sheep.The weight gain trend of F1 generation of Dorper×Hu sheep and Australian White×Hu sheep from five to six months was significantly decreased,absolute growth(4.32±72.63 g/d)and relative growth(0.04±7.14 %)of 5-6 months Dorper×Hu sheep F1 generation rams were negative,and this period is in the winter of Tianzhu area.Therefore,attention should be paid such as keeping warm,strengthening nutrition and management in the lamb production in winter in Tianzhu area,to avoid lamb weight losing.In summary,both the physiological and the biochemical indexes of Hu sheep were in the normal range and its growth and reproductive performance were similar with the one from the original place,which indicated that Hu sheep could adapt to the natural environment in the area of northwest alpine relatively well.Different kinds of hybridized combination showed a certain heterosis as well.Hu sheep showed good adaptability to the natural environment and production pattern in the northwest alpine region.So it is feasible to introduce and popularize Hu sheep in northwest alpine region. |
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