The feeding trial was conducted at

The feeding trial was conducted at Fuchuan sheep farm, Bayannaoer city, Inner Mongolia, China (40°59′47″ N latitude and 107°34′50″ E longitude). The experiment lasted for 120 days, beginning on May 28, 2013 and ending on September 24, 2013. The climate of the location is classified as temperate continental monsoon climate. Maximum environmental temperatures registered throughout the experiment varied from 22°C to 36°C. The experiment was approved by the Institutional Animal Care Committee of China Agricultural University with the criteria in the Guide for the Care of Laboratory Animals (Beijing, China).Animals and dietsTwenty-eight Bamei male lambs (a meat-type sheep developed in 2007) with average age of 3 months±10 days, an average initial live weight of 19.34±2.21 kg and the same genetic background were equally assigned, on the basis of body weight, into 4 dietary treatments of 7 animals each. All animals were kept in individual pens (2.5×1 m2) with sand bedding in an open-side barn, with a roof but without walls. All lambs were placed on the sunny side of shed in a line across the lateral direction and they were allowed visual contact with each other and had ad libitum

The feeding trial was conducted at Fuchuan sheep farm, Bayannaoer city, Inner Mongolia, China (40 ° 59'47 "N latitude and 107 ° 34'50" E longitude). The experiment lasted for 120 days, beginning on May 28, 2013 and ending on September 24, 2013. The climate of the location is classified as temperate continental monsoon climate. Maximum environmental temperatures registered throughout the experiment varied from 22 ° C to 36 ° C. The experiment was Approved by the Institutional Animal Care Committee of China Agricultural University with the criteria in the Guide for the Care of Laboratory Animals (Beijing, China).
Animals and diets
Twenty-Eight Bamei male Lambs (a Meat-Type Sheep developed in 2007. ) with average age of 3 months ± 10 days, an average initial live weight of 19.34 ± 2.21 kg and the same genetic background were equally assigned, on the basis of body weight, into 4 dietary treatments of 7 animals each. All animals were kept in individual pens (2.5 × 1 m2) with sand bedding in an open-side barn, with a roof but without walls. All lambs were placed on the sunny side of shed in a line across the lateral direction and they were allowed visual contact with each other and had ad libitum.