Dynamics of forage supplement and nutrition requirements of grazing sheep in alpine grasslands

Abstract

Abstract: The dynamics of forage supply and nutrition requirements of sheep were monitored for a whole year under alpine grassland conditions in Sunan County,Gansu Province.The digestion and metabolism of grazed sheep were determined in different seasons. The results showed that the DE(9.76MJ),CP(21.53%) and the ratio of crude protein to digestible energy (22.06g稭J^-1) of forage were the highest in Spring,while the herbage dry matter yield and dry matter intake (60.51?3.42 g稺 0.75 kg^-1穌^-1) by grazed sheep were the lowest.Supplementary DMespecially in energy should be provided. The ratio of crude protein to digestible energy was 17.62g稭J^-1 in Summer,and was somewhat higher. The nitrogen utility of the forage would be improved,if energy feed was supplemented. Both the quality and quantity of forage produced in grasslands in Autumn could meet the sheep requirement. Whereas during Winter, neither forage yield nor nutritive value was sufficient for sheep, and the contents of the DEand CPof forage were the lowest in the year, which were 4.30MJand 4.63%, respectively. The nitrogen metabolism of sheep was negative. Therefore, DM,especially DEand CP,should be supplemented. To improve the conditions, it was necessary to develop seasonal animal husbandry,and combine the subsystems into coupling systems.

Key words: Alpine grassland, Grazing sheep, Nutrition, ¹³C labeling, plant-soil system, photosynthate, rice, elevated CO₂

CLC Number:

S826.43

XIAO Jinyu, HOU Fujiang, GUO Zhenggang, LI Juncheng, WANG Qing ; AN Yufeng . Dynamics of forage supplement and nutrition requirements of grazing sheep in alpine grasslands[J]. Chinese Journal of Applied Ecology, 2002, (8): 967-970.

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