This experiment was conducted to study the effects of dietary protein level on nitrogen deposition and nutrient emissions of non-pregnant Yunnan semi-fine wool ewes,in order to provide a theoretical reference for non-pregnant Yunnan semi-fine wool ewes diet proportion and environmental load reduction.Fifty health non-pregnant Yunnan semi-fine wool ewes with similar body weight and at the age of 38 months were randomly divided into 5 groups with 10 ewes per group.Ewes in the 5 groups were fed diets with different proteins levels [7.60%(group 1),9.49%(group 2),11.29%(group 3),11.56%(group 4) and 14.96%(group 5),respectively] and the same other nutrient levels.All the tested sheep were reared for 19 days,including 14 days of pre-test and 5 days of formal trial.During the formal trial period,five sheep were selected from each group for digestion and metabolism test.The test sheep were raised in a single cage in a metabolic cage.The feces and urine were collected continuously for 5 days,and diet samples were collected.The results showed as follows: 1) dietary protein level had no significant effects on dry matter intake and fecal dry matter emission of non-pregnant Yunnan semi-fine wool ewes ( P >0.05).2) With the increase of dietary protein level,nitrogen intake was increased significantly ( P <0.05 or P <0.01);nitrogen deposition rate in group 3 was significantly higher than that in group 1 ( P <0.05),but there was no significant difference among other groups ( P >0.05).3) With the increase of dietary protein level,fecal nitrogen emission was gradually increased,there was no significant difference between group 2 and groups 1 and 3 ( P >0.05),but there was significant difference among other groups ( P <0.01);fecal calcium emission in group 3 was the lowest (5.04 g/d),which was significantly lower than that in group 5 ( P <0.01);fecal phosphorus emission was gradually increased with the increase of dietary protein level,and it in group 5 was significantly higher than that in other groups ( P <0.05 or P <0.01 ).4) Wit
CHINESE JOURNAL OF ANIMAL NUTRITION
dietary protein level
Yunnan semi-fine wool ewes
李卫娟(1976—),女,云南罗平人,副研究员,硕士,从事草食动物营养与饲料研究。E-mail: firstname.lastname@example.org;通信作者:洪琼花,研究员,硕士生导师,E-mail: email@example.com.