本试验旨在探讨饲粮钙、磷水平对泌乳期伊犁母马体重、胸围、营养物质表观消化率和代谢以及血浆生理生化指标的影响，为确定泌乳期伊犁母马钙、磷适宜需要量提供参考。选取年龄（11~14周岁）、体重[（371±21） kg]和胎次（4~6胎）接近的处于第2泌乳月的伊犁母马25匹，随机分为5组，每组5匹。第3泌乳月Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组母马钙饲喂水平分别为45.03、48.50、51.96、55.43和58.89 g/d，磷饲喂水平分别为30.05、32.03、34.01、35.99和37.97 g/d；第4和第5泌乳月Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组母马钙饲喂水平分别为43.60、46.42、49.25、52.07和54.92 g/d，磷饲喂水平分别为27.63、29.24、30.86、32.47和34.12 g/d。试验为期90 d，每30 d为1个试验周期。结果显示：饲粮钙、磷水平对母马体重和胸围以及干物质、有机物和中性洗涤纤维的表观消化率均无显著影响（P>0.05）。Ⅴ组的粗蛋白质表观消化率最高，分别比Ⅱ、Ⅲ和Ⅳ组提高12.26%、12.37%和18.28%（P<0.05）；Ⅰ组的总能表观消化率最高，分别比Ⅱ、Ⅲ和Ⅳ组提高8.32%、7.19%和11.24%（P<0.05）；Ⅰ和Ⅲ组的钙表观消化率分别较Ⅳ组提高17.74%和14.49%（P<0.05）；Ⅲ组的磷表观消化率最高，比Ⅱ组提高35.39%（P<0.05）。饲粮钙、磷水平对母马氮和钙代谢均无显著影响（P>0.05）。Ⅰ组的代谢能较Ⅱ和Ⅳ组分别增加7.95%和11.33%（P<0.05）；Ⅰ组的能量沉积率较Ⅱ、Ⅲ和Ⅳ组分别提高9.30%、8.50%和12.10%（P<0.05）；Ⅰ、Ⅲ和Ⅴ组的磷沉积量显著高于Ⅱ组（P<0.05），其中Ⅲ组在各组中最高，比Ⅱ组提高42.59%；Ⅰ和Ⅲ组的磷沉积率显著高于Ⅱ和Ⅳ组（P<0.05），其中Ⅰ组在各组中最高，分别比Ⅱ和Ⅳ组提高49.67%和46.32%；Ⅰ、Ⅲ和Ⅴ组的磷利用率显著高于Ⅱ组（P<0.05），分别比Ⅱ组提高17.74%、18.80%和16.79%。饲粮钙、磷水平对血浆中离子钙、磷、降钙素、骨钙素、胎盘催乳素、垂体泌乳素、雌二醇、孕酮和雌酮水平均无显著影响（P>0.05）。Ⅲ组的血浆中甲状旁腺素水平显著高于Ⅳ和Ⅴ组（P<0.05），分别提高70.61%和47.58%。由此得出，Ⅰ组饲粮（在第3泌乳月钙、磷饲喂水平分别为45.03和30.05 g/d，第4和第5泌乳月钙、磷饲喂水平分别为43.60和27.63 g/d）即可满足伊犁母马泌乳期的钙、磷需要。适宜的饲粮钙、磷水平有助于维持较高水平的能量和钙的表观消化率以及能量和磷的沉积和利用。

In order to provide references for confirming requirement of calcium (Ca) and phosphorus (P) for Yili mares during lactation period, the effects of dietary Ca and P levels on body weight, heart girth, nutrient apparent digestibility and metabolism and plasma physiological-biochemical indices were examined. Twenty-five Yili mares in their end of the 2nd lactation month with similar age (11 to 14 years old), body weight [(371±21) kg] and parity (4 to 6 parities) were selected, and allocated to five groups of 5 animals each. In the 3rd lactation month, the Ca feed level of mares in groups Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ was 45.03, 48.50, 51.96, 55.43 and 58.89 g/d, and the P feed level was 30.05, 32.03, 34.01, 35.99 and 37.97 g/d, respectively. In the 4th and 5th lactation month, the Ca feed level of mares in groups Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ was 43.60, 46.42, 49.25, 52.07 and 54.92 g/d, and the P feed level was 27.63, 29.24, 30.86, 32.47 and 34.12 g/d, respectively. The trial lasted for 90 days, and every 30 days for a test cycle. The results showed as follows: dietary Ca and P levels had no significant effects on body weight, heart girth and the apparent digestibility of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) (P>0.05). The apparent digestibility of crude protein (CP) of group Ⅴ was the highest, and increased by 12.26%, 12.37% and 18.28% (P<0.05) as compared with group Ⅱ, Ⅲ and Ⅳ, respectively. The apparent digestibility of gross energy (GE) of group Ⅰ was the highest, and increased by 8.32%, 7.19% and 11.24% (P<0.05) as compared with group Ⅱ, Ⅲ and Ⅳ, respectively. The apparent digestibility of Ca of groups Ⅰ and Ⅲ was higher than that of group Ⅳ, and increased by 17.74% and 14.49% (P<0.05), respectively. The apparent digestibility of P of group Ⅲ was the highest, and increased by 35.39% (P<0.05) as compared with group Ⅱ. Dietary Ca and P levels had no significant effects on nitrogen and Ca metabolism (P>0.05). The metabolic energy (ME) of group Ⅰ was higher than that of groups Ⅱ and Ⅳ, and increased by 7.95% and 11.33% (P<0.05), respectively. The energy retention rate of group Ⅰ was higher than that of groups Ⅱ, Ⅲ and Ⅳ, and increased by 9.30%, 8.50% and 12.10% (P<0.05), respectively. The P retention of groups Ⅰ, Ⅲ, Ⅴ was significantly higher than that of group Ⅱ (P<0.05), and group Ⅲ was the highest among groups which increased by 42.59% (P<0.05) as compared with group Ⅱ. The P retention rate of groups Ⅰ and Ⅲ was significantly higher than that of groups Ⅱ and Ⅳ, and group Ⅰ was the highest among groups which increased by 49.67% and 46.32% (P<0.05) as compared with groups Ⅱ and Ⅳ, respectively. The P utilization rate of groups Ⅰ, Ⅲ and Ⅴ was significantly higher than that of group Ⅱ (P<0.05), and increased by 17.74%, 18.80% and 16.79% as compared with group Ⅱ, respectively. The levels of plasma ionized calcium (Ca²⁺), P, calcitonin, bone gla protein, placental prolactin, pituitary prolactin, estradiol, progesterone and estrone showed no significant difference (P>0.05) when mares fed with different levels of dietary Ca and P. Moreover, the level of plasma parathyroid hormone of group Ⅲ was significantly higher than that of groups Ⅳ and Ⅴ with an increase of 70.61% and 47.58% (P<0.05). In conclusion, diet Ⅰ (the Ca and P feed levels in the 3rd lactation month are 45.03 and 30.05 g/d and those in the 4th and 5th lactation month are 43.60 and 27.63 g/d, respectively) can meet the Ca and P requirements of Yili mares during lactation period. Suitable dietary Ca and P levels are beneficial to maintain higher apparent digestibility of gross energy and Ca, retention and utilization of P and energy.