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 days, index-supplemented diets were provided to the gestating and lactating sows. Feces were collected at 24-h intervals for 9 and 7 days 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 day 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 day 5 to 7. In conclusion, at least 8 days of adaptation period are required for gestating sows to determine total tract digestibility using Cr as the indigestible index method whereas 5 days of adaptation period are required for gestating sows. An insufficient adaptation period results in lower digestibility values.

中文翻译：

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采用指数法评估总消化道消化率时，饲喂量有限的妊娠母猪在收集粪便前需要比哺乳母猪更长的适应期


本实验的目的是使用不消化指数法确定妊娠期和哺乳期母猪全消化道消化率实验的最短适应期。使用 5 头妊娠母猪和 5 头泌乳母猪，胎次为 3 至 5 头。在以玉米和豆粕为主的饮食中添加了难消化指数为 0.5% 的氧化铬。妊娠母猪日饲喂量为2公斤，并为母猪提供2次等量膳食。哺乳母猪每天饲喂饲料6公斤，分3次等量饲喂。在饲喂不添加氧化铬的日粮 5 天后，向妊娠母猪和哺乳母猪提供指数补充日粮。分别在 9 天和 7 天的时间内，每隔 24 小时收集妊娠母猪和哺乳母猪的粪便。妊娠期和哺乳期母猪的粪便 Cr 浓度随收集时间呈线性 (P < 0.001) 和二次方 (P < 0.001) 增加。最短适应期通过单斜率折线模型估计。妊娠母猪粪便中 Cr 浓度的临界点分别为第 7.2 天 (SE = 0.3)，泌乳母猪粪便中 Cr 浓度的临界点为第 4.2 天 (SE = 0.2)。对于饲喂实验日粮和 2 公斤饲料津贴的妊娠母猪，第 4 天干物质、有机物质和能量的表观总消化道消化率 (P < 0.001) 低于第 8 至 9 天。在饲喂 6 公斤饲料用量的实验日粮的泌乳母猪中，第 3 天干物质、有机物质和能量的表观总消化道消化率低于第 5 至 7 天 (P < 0.05)。 ，以Cr为不消化指数法测定总消化道消化率时，妊娠母猪至少需要8天的适应期，而妊娠母猪则需要5天的适应期。 适应期不足会导致消化率值较低。