Department of Animal Science and Technology, Konkuk University, Seoul 05029, Republic of Korea.
Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae228.
The objective of the present experiment was to determine the minimum adaptation period for total tract digestibility experiments in gestating and lactating sows using the indigestible index method. Five gestating and 5 lactating sows at parities 3 to 5 were used. An indigestible index of 0.5% chromic oxide was supplemented to a diet based on corn and soybean meal. The daily feed allowance for gestating sows was 2 kg and 2 equal meals were provided to the sows. Lactating sows were fed 6 kg of feed per day in 3 equal meals. After feeding a diet without supplemental chromic oxide for 5 d, index-supplemented diets were provided to the gestating and lactating sows. Feces were collected at 24-h intervals for 9 and 7 d from gestating and lactating sows, respectively. Fecal Cr concentrations increased linearly (P < 0.001) and quadratically (P < 0.001) with collection time in both gestating and lactating sows. Minimum adaptation periods were estimated by one-slope broken-line model. The break point of Cr concentrations in feces was day 7.2 (SE = 0.3) in the gestating sows and day 4.2 (SE = 0.2) in the lactating sows, respectively. Apparent total tract digestibility of dry matter, organic matter, and energy on day 4 was less (P < 0.001) than that on days 8 to 9 in gestating sows fed the experimental diet with a 2-kg feed allowance. In lactating sows fed the experimental diets with a 6-kg feed allowance, the apparent total tract digestibility of dry matter, organic matter, and energy on day 3 was less (P < 0.05) than that on days 5 to 7. In conclusion, at least 8 d of adaptation period are required for gestating sows to determine total tract digestibility using Cr as the indigestible index method whereas 5 d of adaptation period are required for lactating sows. An insufficient adaptation period results in lower digestibility values.
本实验旨在通过不消化指数法确定妊娠和泌乳母猪进行全肠道消化率实验的最小适应期。选用 5 头初产至 5 胎的妊娠母猪和 5 头泌乳母猪。日粮以玉米和豆粕为基础，添加 0.5%的铬氧化合物不消化指数。妊娠母猪的日采食量为 2kg，每天饲喂 2 次。泌乳母猪每天饲喂 6kg 饲料，分 3 次饲喂。在饲喂不含铬氧化合物日粮 5d 后，向妊娠和泌乳母猪提供添加指数的日粮。妊娠和泌乳母猪分别在 9d 和 7d 内，每 24h 收集一次粪便。妊娠和泌乳母猪粪便中 Cr 浓度随收集时间呈线性（P<0.001）和二次曲线（P<0.001）增加。最小适应期通过单斜率折线模型估计。Cr 浓度在粪便中的转折点分别为妊娠母猪的第 7.2 天（SE=0.3）和泌乳母猪的第 4.2 天（SE=0.2）。妊娠母猪在采食试验日粮且日采食量为 2kg 时，第 4 天的干物质、有机物和能量的表观全肠道消化率显著低于第 8 至 9 天（P<0.001）。泌乳母猪在采食试验日粮且日采食量为 6kg 时，第 3 天的干物质、有机物和能量的表观全肠道消化率显著低于第 5 至 7 天（P<0.05）。总之，用 Cr 作为不消化指数法确定妊娠母猪的全肠道消化率需要至少 8d 的适应期，而泌乳母猪则需要 5d 的适应期。适应期不足会导致消化率值降低。
