Abstract:This study aims to clarify the effects of drinking warm water under fencing fattening modes on the growth performance of beef cattle in winter. A field experiment was carried out in the Zhangye area under the two modes: fencing fattening with warm water (average drinking water temperature: (20.58±0.91)℃), and house-fattening with cold water (average drinking water temperature: (7.20±1.70)℃). Some thermal parameters were measured, including the temperature- humidity index (THI), wind chill index (WCI), comprehensive climate index (CCI), and cold stress index (CSI). 140 fattening cattle were collected to divide into two groups, including a fence fattening with warm water group, and a house-fattening with cold water group. In the warm water group, 118 fattening cattle (average body weight at (513.23±39.78) kg) were divided into 6 repetitions with 15 to 20 fattening cattle each repetition, and the area of each repetition (fence) was 18 m × 18 m. In the cold water group, 22 fattening cattle (average body weight at (515.93±53.42) kg) were divided into 6 replicates with 3 to 4 fattening cattle in each replicate, and the area of each replicate (fence) was 20 m×4 m. The period of this experiment was last for 35 days. The total mixed ration (TMR) was mechanically fed at 8:30 and 14:30 every day, and the water was taken freely for each fattening cattle. Some parameters were measured and recorded at 8:30, 14:30, and 20:30 each day, including the air temperature, humidity, wind speed, carbon dioxide concentration, ammonia concentration, and the drinking water temperature. The fattening cattle were weighed in the morning before feeding on the 1st and 35th day of the experiment, where the feed was weighed and recorded each day. As such, the average daily gain, average daily feed intake, and feed conversion rate were calculated, according to the feed. The results showed that there were significantly lower air temperature, humidity, pollutant gas concentration, THI, WCI, and CCI of fencing-fattening with warm water (P<0.05), whereas, the wind speed and CSI index was significantly higher (P<0.05), compared with the cold water group. The average daily gain of the fencing fattening with warm water beef cattle was (1.40±0.39) kg/d, which was significantly higher than the (1.14±0.47) kg/d of the house-fattening with cold water beef cattle (P<0.05). The feed conversion ratio of the fencing fattening with warm water beef cattle was significantly lower (P<0.05) than that of house-fattening with cold water beef cattle. The construction cost of fencing fattening with warm water was 37.78% lower than that of in-house fattening with cold water. In conclusion, the fencing fattening with warm water mode in winter presented a lower environmental humidity and less harmful gas concentration, such as carbon dioxide and ammonia for fattening cattle, which was more conducive to the growth of beef cattle.