本试验旨在研究饲喂不同钙、磷水平饲粮对伊犁马妊娠后期营养物质消化代谢和血浆生理生化指标的影响,为明确伊犁马在妊娠后期对钙、磷的适宜需要量提供参考。试验选取年龄、胎次、体重相近且无亲缘关系、处于妊娠后期的伊犁母马25匹,按照体重随机分为5组,每组5匹。饲粮钙和磷饲喂量分别为36.00和26.30 g/d(饲粮Ⅰ组)、39.00和28.30 g/d(饲粮Ⅱ组)、42.00和30.30 g/d(饲粮Ⅲ组)、45.00和32.30 g/d(饲粮Ⅳ组)以及48.00和34.30 g/d(饲粮Ⅴ组)。饲养试验为期30 d,其中预试期10 d,正试期20 d。试验期间采集各组饲粮、剩料、粪便和尿液样本用于测定常规营养成分含量,试验结束后采集空腹血样以测定血浆生理生化指标。结果表明:饲粮钙、磷水平对各营养物质的表观消化率均无显著影响(P>0.05),对总能、氮、钙、磷的保留率及可消化能、可消化氮、可消化磷的利用率均无显著影响(P>0.05),对血浆中离子钙、甲状旁腺素、骨钙素、胎盘催乳素、垂体泌乳素、孕酮、甲状腺素、三碘甲状腺氨酸和胰岛素样生长因子-Ⅰ水平亦无显著影响(P>0.05)。此外,饲粮钙、磷水平对血浆中肌酐、尿素氮、甘油三酯和游离脂肪酸的水平也无显著影响(P>0.05)。饲粮Ⅰ、饲粮Ⅱ和饲粮Ⅲ组可消化钙利用率显著高于饲粮Ⅴ组(P<0.05),当饲粮钙、磷水平分别超过42.00和30.30 g/d时,可消化钙的利用率逐渐下降。饲粮Ⅱ和饲粮Ⅴ组母马血浆中磷水平显著高于饲粮Ⅳ组(P<0.05)。除饲粮Ⅴ组外,随着饲粮钙、磷水平的增加,血浆中降钙素水平有升高的趋势(P<0.10)。饲粮Ⅱ和饲粮Ⅳ组血浆中雌二醇水平显著低于饲粮Ⅰ组(P<0.05),饲粮Ⅲ组则显著低于饲粮Ⅰ和饲粮Ⅴ组(P<0.05)。血浆中雌酮水平的变化规律与雌二醇一致。此外,提高饲粮钙、磷水平可增加血浆中生长激素的水平,除饲粮Ⅲ组外,其他各组血浆中生长激素水平均显著高于饲粮Ⅰ组(P<0.05)。由此可见,当饲粮钙水平在36.00~48.00 g/d、磷水平在26.30~34.30 g/d之间时,增加饲粮钙、磷水平不影响妊娠后期伊犁马营养物质的消化代谢,但血浆中雌二醇和雌酮水平降低,而生长激素水平增加。
关键词:
伊犁马; 妊娠后期; 钙; 磷; 消化; 代谢; 激素
The aim of this experiment was to investigate the effects of feeding different levels of calcium (Ca) and phosphorus (P) diets on nutrient digestion and metabolism, plasma physiological-biochemical indices of Yili mares during late pregnancy, and to provide references for exploring the requirements of Ca and P of Yili mares during late pregnancy. Twenty-five unrelated Yili mares during late pregnancy with similar age, body weight (BW) and parity were selected, which randomly divided into five groups according to the BW, and each group had 5 mares. The daily feeding amounts of Ca and P of five groups were 36.00 and 26.30 g/d (diet Ⅰ group), 39.00 and 28.30 g/d (diet Ⅱ group), 42.00 and 30.30 g/d (diet Ⅲ group), 4.50 and 32.30 g/d (diet Ⅳ group), and 48.00 and 34.30 g/d (diet Ⅴ group), respectively. The feeding trial period lasted for 30 days including 10 days for preliminary trial and 20 days for formal trial. Samples of diets, feces and urine were collected during the experimental period for measuring the contents of nutrients, and the fasting blood samples were collected at the end of the trial to determine the contents of plasma physiological-biochemical indices. The results showed that dietary Ca and P levels had no significant effect on the apparent digestibility of nutrients (P>0.05), and had no significant effects on the retention rates of gross energy, nitrogen, Ca and P and the availabilities of digestible energy, digestible nitrogen and digestible P (P>0.05). Meanwhile, the levels of plasma Ca2+, parathyroid hormone (PTH), calcitonin (CT), placental lactogen (PL), pituitary prolactin (PRL), progesterone (PROG), thyroxine (T4), triiodothyronine thyroxin (T3) and insulin like growth factor-Ⅰ(IGF-Ⅰ) showed no significant difference within the five groups (P>0.05). In addition, there were no significant effects of dietary Ca and P levels on the levels of plasma creatinine (CREA), urea nitrogen (UN), triglyceride (TG) and free fatty acid (FFA) (P>0.05). The availability of digestible Ca of the diet Ⅰ, Ⅱ and Ⅲ groups was significantly higher than that of diet Ⅴ group (P<0.05), and the availability of digestible Ca was decreased when dietary Ca and P levels exceeded 42.00 and 30.30 g/d, respectively. The level of plasma P of diet Ⅱ and Ⅴ groups was significantly higher than that of diet Ⅳ group (P<0.05). With the increase of dietary Ca and P levels, plasma CT level had a increasing tendency except the diet Ⅴ group (P<0.01). The level of plasma oestradiol (E2) of diet Ⅳ and Ⅱ groups was significantly lower than that of the diet Ⅰ group (P<0.05), and that of diet Ⅲ group was significantly lower than that of diet Ⅰ and Ⅴ groups (P<0.05). The variation tendency of plasma estrone (E1) level was consistent with E2. In addition, increasing the dietary Ca and P levels could increased the level of plasma growth hormone (GH), and that in diet Ⅰ group was significantly lower than that of other groups except diet Ⅲ group (P<0.05). In summary, when the dietary Ca level between 36.00 to 48.00 g/d and P level between 26.30 to 34.30 g/d, increasing dietary Ca and P levels do not affect the nutrient digestion and metabolism of Yili mares during late pregnancy, but decrease plasma E1 and E2 levels, and increase GH level.
[1] 国家科学研究委员会.奶牛营养需要[M].7版.孟庆祥,译.北京:中国农业大学出版社,2002.
[2] NRC.Nutrient requirements of horses[S].6th rev ed.Washington,D.C.:National Academies Press,2007:1-300.
[3] 彭健.饲料分析与检测技术[M].北京:科学出版社,2008.
[4] 傅启高,雒秋江.用邻-甲酚酞比色法测定饲料中钙含量的研究[J].动物营养学报,1996,8(3):25-30.
[5] 郭望山,孟庆翔.杜马斯燃烧法与凯氏法测定饲料含氮量的比较研究[J].畜牧兽医学报,2006,37(5):464-468.
[6] 初汉平.不同泌乳阶段对荷斯坦牛干物质采食量和钙磷消化率的影响[J].饲料工业,2011,32(5):39-41.
[7] VAN DOORN D A,VAN DER SPEK M E,EVERTS H,et al.The influence of calcium intake on phosphorus digestibility in mature ponies[J].Journal of Animal Physiology and Animal Nutrition,2004,88(11/12):412-418.
[8] VAN DOORN D A,EVERTS H,WOUTERSE H,et al.Influence of high phosphorus intake on salivary and plasma concentrations,and urinary phosphorus excretion in mature ponies[J].Journal of Animal Physiology and Animal Nutrition,2011,95(2):154-160.
[9] 王宗元,曹光辛,胡在朝,等.动物矿物质营养代谢与疾病[M].上海:上海科学技术出版社,1995:8-52.
[10] 魏炳栋,张力,周学辉,等.不同季节牧草钙磷含量对放牧绵羊血清骨钙素的影响[J].甘肃农业大学学报,2005,40(4):452-456.
[11] PHIRI E C J H,NKYA R,PEREKA A E,et al.The effects of calcium,phosphorus and zinc supplementation on reproductive performance of crossbred dairy cows in Tanzania[J].Tropical Animal Health and Production,2007,39(5):317-323.
[12] 李善,葛立宏,高翠林,等.妊娠期低钙饮食摄入对大鼠出产率的影响[J].实验动物科学与管理,2000,17(4):15-18.
[13] JONSSON N N.The effects of subclinical hypocalcaemia on postpartum fertility[J].Cattle Practice,1999,7(3):255-260.
[14] CALL J W,BUTCHER J E,SHUPE J L,et al.Dietary phosphorus for beef cows[J].American Journal of Veterinary Research,1986,47(2):475-481.
[15] 章世元,俞路,王雅倩,等.饲粮钙磷水平对新扬州鸡生产性能、蛋壳质量及骨代谢的影响[J].江苏农业学报,2008,24(4):460-466.
[16] PREDA C,BUDICA C,DOJANA N.Effect of various levels of dietary calcium on blood calcium concentration and hormonal status in white Cornish and white Leghorn hens[J].Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca,2014,71(1):182-186.
[17] NAPOLI N,THOMPSON J,CIVITELLI R,et al.Effects of dietary calcium compared with calcium supplements on estrogen metabolism and bone mineral density[J].American Journal of Clinical Nutrition,2007,85(5):1428-1433.
[18] 吴卓宇,冯艳玉,刘春庆.甲状腺切除患者甲状旁腺功能减退影响因素及低钙血症的防治[J].现代医学,2016(1):37-41.
[19] AMADI K,SABO M A,ADELAIYE A B,et al.Dependence of calcium on thyroid hormone for the regulation of cellular functions[J].Nigerian Journal of Physiological Sciences: Official Publication of the Physiological Society of Nigeria,2005,20(1/2):95-100.
[20] CHANDRA A K,GOSWAMI H,SENGUPTA P.Dietary calcium induced cytological and biochemical changes in thyroid[J].Environmental Toxicology and Pharmacology,2012,34(2):454-465.
[21] HARVEY S,HUYBRECHTS L M,SCANES C G.Growth hormone secretion in chicks during dietary calcium deficiency[J].Domestic Animal Endocrinology,1984,1(4):269-277.
[22] SOMMERVILLE B A,HARVEY S.The effect of low levels of dietary protein and calcium on growth rate,growth hormone,and vitamin D metabolism in the chick[J].General and Comparative Endocrinology,1988,71(1):93-96.
[23] 孙长颢,于新凤,李颖,等.膳食钙对高脂膳食大鼠血糖、血脂及激素的影响[J].卫生研究,2004,33(2):164-166.
[24] ZHANG Q M,WASTNEY M E,ROSEN C J,et al.Insulin-like growth factor-1 increases bone calcium accumulation only during rapid growth in female rats[J].Journal of Nutrition,2011,141(11):2010-2016.
[25] SHIDFAR F,MOGHAYEDI M,KERMAN S R J,et al.Effects of a calcium supplement on serum lipoproteins,apolipoprotein B,and blood pressure in overweight men[J].International Journal of Endocrinology and Metabolism,2010,8(4):194-200.
[26] CARRUTH B R,SKINNER J D.The role of dietary calcium and other nutrients in moderating body fat in preschool children[J].International Journal of Obesity,2001,25(4):559-566.
[27] ZEMEL M B.Proposed role of calcium and dairy food components in weight management and metabolic health[J].The Physician and Sportsmedicine,2009,37(2):29-39.