Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI53706, USA.
Br J Nutr. 2022 Aug 14;128(3):377-388. doi: 10.1017/S0007114521003421. Epub 2021 Sep 6.
Phosphorus requirements of reproducing sows were estimated using 24-h urinary P excretion. Thirty-six multiparous sows were fed one of six maize-soybean meal-based diets with total P ranging from 0·40 to 0·80 % in 0·08 % increments with a constant Ca:total P ratio (1·25:1). Diets were fed from day 7·5 ± 1 after breeding until the end of lactation (day 26 ± 1). Urine samples were collected in mid and late gestation (days 77·1 ± 2 and 112·4 ± 1) and early and late lactation (days 4·5 ± 1 and 18·2 ± 1). Phosphorus requirements were estimated using linear and nonlinear regression models. Based on a single 24-h urinary P excretion, estimated daily dietary total P requirements in mid and late gestation were 10·3 g (6·0 g standardised total tract digestible P, STTD P), and estimates for early and late lactation were 31·1 g (16·6 g STTD P) and 40·3 g (22·1 g STTD P), respectively. Plasma P and Ca concentrations were maintained within normal ranges at the estimated levels of P requirements. No differences among treatments were observed for plasma parathyroid hormone ( ≥ 0·06) and bone formation marker ( ≥ 0·16). In lactation, bone resorption marker decreased ( ≤ 0·001) as sows consumed more P. Among the analysed variables, urinary P was the most sensitive response to changes in dietary P intake. Urinary P excretion offers a practical method to estimate P requirements in sows. Our recommended daily total P requirements are 10·3 g for gestation and 35·7 g for lactation.
采用 24 小时尿液磷排泄量估计繁殖母猪的磷需要量。36 头经产母猪饲喂 6 种基于玉米-豆粕的日粮，日粮总磷水平从 0.40%到 0.80%，每隔 0.08%递增，钙与总磷比例（1.25:1）保持不变。从配种后第 7.5 ± 1 天到哺乳期结束（第 26 ± 1 天），母猪每天饲喂不同的日粮。在妊娠中期（第 77.1 ± 2 天和第 112.4 ± 1 天）和泌乳早期（第 4.5 ± 1 天和第 18.2 ± 1 天）及泌乳晚期（第 4.5 ± 1 天和第 18.2 ± 1 天）采集尿液样本。采用线性和非线性回归模型估计磷需要量。根据单次 24 小时尿液磷排泄量，妊娠中期和晚期的每日总日粮磷需要量估计值分别为 10.3 g（6.0 g 标准总肠道可消化磷，STTD P），泌乳早期和晚期的估计值分别为 31.1 g（16.6 g STTD P）和 40.3 g（22.1 g STTD P）。在估计的磷需要量水平下，母猪的血浆磷和钙浓度保持在正常范围内。在不同处理组间，血浆甲状旁腺激素（≥0.06）和骨形成标志物（≥0.16）无差异。在泌乳期，随着母猪摄入更多的磷，骨吸收标志物降低（≤0.001）。在分析的变量中，尿液磷对日粮磷摄入量变化最敏感。尿液磷排泄量为估计母猪磷需要量提供了一种实用方法。我们推荐的妊娠母猪总磷日需要量为 10.3 g，泌乳母猪为 35.7 g。
