摘要
本试验旨在研究饲粮蛋白质水平对妊娠期云南半细毛羊氮平衡和氮、磷、钙排放的影响。选取50只体况良好、体重[(46.52±4.58)kg]相近、年龄一致、配种日期相同的经产2胎妊娠期云南半细毛羊,随机分为5组,每组10个重复,每个重复1只羊。5组试验羊在妊娠前期和中期饲喂蛋白质水平分别为6.65%(Ⅰ组)、9.02%(Ⅱ组)、10.97%(Ⅲ组)、12.43%(Ⅳ组)和13.95%(Ⅴ组)的试验饲粮,妊娠后期饲喂蛋白质水平分别为6.31%(Ⅰ组)、7.77%(Ⅱ组)、10.47%(Ⅲ组)、12.69%(Ⅳ组)和15.25%(Ⅴ组)的试验饲粮。从妊娠第46天算起,所有试验羊进行为期104 d的饲养试验,其中预试期14 d,正试期90 d。分别在妊娠前期(妊娠第71~75天)、中期(妊娠第101~105天)和后期(妊娠第131~135天)从各组选5只试验羊进行为期5 d的消化代谢试验。结果表明:1)在妊娠前期,饲粮蛋白质水平对粪干物质排放量、尿磷排放量、尿钙排放量的影响不显著(P>0.05);粪氮排放量、尿氮排放量和氮总排放量随着饲粮蛋白质水平的升高而增加;Ⅴ组的粪磷排放量、磷总排放量显著高于Ⅰ组(P<0.01);Ⅴ组的粪钙排放量、钙总排放量最高,而Ⅲ组最低。在妊娠中期,粪干物质排放量、尿磷排放量不受饲粮蛋白质水平的显著影响(P>0.05);尿氮排放量、氮总排放量、粪磷排放量、磷总排放量随着饲粮蛋白质水平的升高而增加,Ⅳ的粪氮排放量、粪钙排放量、钙总排放量最高,Ⅰ组的尿钙排放量显著高于其他各组(P<0.05)。在妊娠后期,饲粮蛋白质水平对粪干物质排放量、尿磷排放量的影响不显著(P>0.05);粪氮排放量、尿氮排放量、氮总排放量、粪磷排放量、磷总排放量、粪钙排放量随着饲粮蛋白质水平的升高而增加。2)妊娠前期和中期云南半细毛羊氮排放以粪中排放为主,而在妊娠后期,当采食氮较低时,氮排放仍然以粪中排放为主,但随着采食氮的增加,尿氮排放量大于粪氮排放量。妊娠期磷、钙排放量几乎都从粪中排放,粪磷占比和粪钙占比分别为98.52%~99.68%和96.22%~98.98%。3)妊娠期云南半细毛羊的采食氮随着饲粮蛋白质水平的升高而增加,妊娠前期和中期的沉积氮则呈先升高后降低趋势,在Ⅳ组最高;妊娠后期沉积氮与饲粮蛋白质水平变化一致,在Ⅴ组最高;整个妊娠期各组云南半细毛羊的氮平衡均为正。综合本试验的结果,以氮沉积率为标识,妊娠前期、中期和后期云南半细毛羊的最佳饲粮蛋白质水平分别为12.43%、12.43%、10.47%,此蛋白质水平时氮沉积效率最佳,粪尿中的氮、磷排放量较少,有利于降低环境污染。
This experiment aimed to study the effects of dietary protein level on nitrogen balance and nitrogen,phosphorus and calcium excretions of Yunnan semi-fine wool ewes during pregnancy.Fifty multiparous Yunnan semi-fine wool ewes with good body condition,similar body weight[(46.52±4.58)kg],the same age,and the same mating date were randomly divided into 5 groups with 10 replicates per group and 1 ewe per replicate.The experimental diets with the protein levels of 6.65%(groupⅠ),9.02%(groupⅡ),10.97%(groupⅢ),12.43%(groupⅣ)and 13.95%(groupⅤ)were fed in pre-and mid-pregnancy,and the experimental diets with the protein levels of 6.31%(groupⅠ),7.77%(groupⅡ),10.47%(groupⅢ),12.69%(groupⅣ)and 15.25%(groupⅤ)were fed in late-pregnancy.From the 46th day of pregnancy and lasted for 104 days,including 14 days preliminary period and 90 days formal period.Five sheep were selected from each group for a 5-day digestion and metabolism trail in pre-pregnancy(the 71st to 75th day of pregnancy),mid-pregnancy(the 101st to 105th day of pregnancy)and late-pregnancy(the 131st to 135th day of pregnancy).The results showed as follows:1)in pre-pregnancy,dietary protein level had no significant effects on fecal dry matter excretion,urinary phosphorus excretion and urinary calcium excretion(P>0.05);the fecal nitrogen excretion,urinary nitrogen excretion and total nitrogen excretion were increased with the increase of dietary protein level;the fecal phosphorus excretion and total phosphorus excretion of groupⅤwere significantly higher than groupⅠ(P<0.01);the fecal calcium excretion and total calcium excretion of groupⅤwere the highest and groupⅢwas the lowest.In mid-pregnancy,fecal dry matter excretion and urinary phosphorus excretion were not significantly affected by dietary protein level(P>0.05);the urinary nitrogen excretion,total nitrogen excretion,fecal phosphorus excretion and total phosphorus excretion were increased with the increase of dietary protein level.Fecal nitrogen excretion,fecal calcium excretion and total calcium excretion of groupⅣwere the highest,and urinary calcium excretion of groupⅠwas significantly higher than that of other groups(P<0.05).In late-pregnancy,dietary protein level had no significant effects on fecal dry matter excretion and urinary phosphorus excretion(P>0.05);the fecal nitrogen excretion,urinary nitrogen excretion,total nitrogen excretion,fecal phosphorus excretion,total phosphorus excretion and fecal calcium excretion were increased with the increase of dietary protein level.2)In pre-and mid-pregnancy,the nitrogen excretion of Yunnan semi-fine ewes was mainly in feces,while in late-pregnancy,nitrogen excretion was still mainly in feces when the intake of nitrogen was low,but with the increase of the intake of nitrogen,urinary nitrogen excretion was greater than fecal nitrogen excretion.Almost all phosphorus and calcium excretion in feces and urine were discharged from feces during pregnancy,accounting for 98.52%to 99.68%and 96.22%to 98.98%of total phosphorus excretion and total calcium excretion,respectively.3)The nitrogen intake of Yunnan semi-fine wool ewes during pregnancy was increased with the increase of dietary protein level,and the nitrogen deposition in pre-and mid-pregnancy increased firstly and then decreased,which was the highest in groupⅣ;the change of nitrogen deposition in late-pregnancy was consistent with the dietary protein level,which was the highest in groupⅤ;the nitrogen balance of Yunnan semi-fine wool ewes was positive during pregnancy.Based on the results of this experiment,taking the nitrogen deposition rate as the marker,the optimal dietary protein levels of Yunnan semi-fine wool ewes in pre-,mid-and late-pregnancy are 12.43%,12.43%and 10.47%,respectively.At this protein level,the nitrogen deposition efficiency is the best,and the excretions of nitrogen and phosphorus in feces and urine are less,which is conducive to reducing environmental pollution.
作者
赵小琪
王思宇
薛白
倪晓君
李银江
洪琼花
ZHAO Xiaoqi;WANG Siyu;XUE Bai;NI Xiaojun;LI Yinjiang;HONG Qionghua(Yunnan Animal Science and Veterinary Institute,Kunming 650224,China;Institute of Animal Nutrition,Sichuan Agricultural University,Chengdu 611130,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2022年第3期1709-1720,共12页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家绒毛用羊产业技术体系(CARS39-08)
云南省科技创新人才计划(2018HC017)
云南省科技人才和平台计划(2018IC108)。
关键词
云南半细毛羊
妊娠期
蛋白质
氮平衡
养分排放
Yunnan semi-fine wool ewes
pregnancy
protein
nitrogen balance
nutrient excretions
