哺乳期
动物科学
化学
直肠温度
乳房
内科学
生物
医学
怀孕
遗传学
微生物学
乳腺炎
作者
Nathalie Quiniou,Jean Noblet
标识
DOI:10.2527/1999.7782124x
摘要
Multiparous Large White sows (n = 63) were used to investigate the effects of five ambient temperatures (18, 22, 25, 27, and 29°C) and two dietary protein contents on their lactation performance. At each temperature treatment, ambient temperature was maintained constant over the 21-d lactation period. Dietary protein content was either 14 or 17% with essential amino acids levels calculated not to be limiting. The animals had ad libitum access to feed between the seventh and the 19th day of lactation. Diet composition did not influence lactation performance. Over the 21-d lactation, feed intake decreased from 5.67 to 3.08 kg/d between 18 and 29°C. Between d 7 and 19, the corresponding values were 7.16 and 3.48 kg/d, respectively. This decrease was curvilinear; an equation to predict voluntary feed intake (VFI) from temperature (T, °C) and body weight (BW, kg) is proposed: VFI = −49,052 + 1,213 T − 31.5 T2 + 330 BW − .61 BW2 (residual standard deviation: 1,018). Skin temperature increased regularly with increased ambient temperature (34.6 to 37.4°C between 18 and 29°C), whereas udder temperature reached a plateau at 25°C (38.3°C). The gradient of temperature between skin and rectum was minimal (2°C ) at 27°C and remained constant at 29°C. This constancy coincides with the marked reduction of feed intake. The respiratory rate increased from 26 to 124 breaths/min between 18 and 29°C, and this indicates that the evaporative critical temperature was below 22°C. The BW loss increased from 23 to 35 kg between 18 and 29°C, but its estimated chemical composition remained constant. Pig growth rate was almost constant between 18 and 25°C (241 g/d) and was reduced above 25°C (212 and 189 g/d at 27 and 29°C, respectively). In conclusion, temperatures above 25°C seem to be critical for lactating sows in order to maintain their performance.
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