Scientia Agricultura Sinica ›› 2019, Vol. 52 ›› Issue (19): 3460-3470.doi: 10.3864/j.issn.0578-1752.2019.19.015

• ANIMAL SCIENCE·VETERINARY SCIENCE·RESOURCE INSECT • Previous Articles     Next Articles

Effects of Weaning Age and Dietary Nutritional Levels on Intestinal Morphology and Activity of Digestive Enzymes in 6-Month-Old Shaanbei White Cashmere Goats

QU XingMei1,XUE FuLai2,HUANG XiaoYu1,ZHANG Yu1,XING XiaoNan1,ZHANG EnPing1()   

  1. 1 College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi
    2 Zhucheng Animal Husbandry and Veterinary Administration of Shandong Province, Zhucheng 262200, Shandong
  • Received:2018-10-10 Accepted:2019-07-22 Online:2019-10-01 Published:2019-10-11
  • Contact: EnPing ZHANG E-mail:zhangenping@nwsuaf.edu.cn

Abstract:

【Objective】 This study aimed to investigate the effects of weaning age and dietary nutritional levels on intestinal morphology and activity of major digestive enzymes of 6-month-old Shaanbei white Cashmere goats.【Method】 Fifty-four Shaanbei White Cashmere female goats aged 54 days (live body weight was (10.73±1.03)kg) were randomly assigned to 6 groups, with 3 replications per group and 3 goats per replication. Group I, II, and III were fed standard diets, and the weaning age was 90 d, 75 d and 60 d, respectively. Goats in group IV, V and VI were all weaned at 60 d, and were fed diet with 85%, 115%, 130% digestive energy and protein levels of the standard diets, resptectively. Goats were fed to 6-month-old. At the end of the trial period, 1 goat were randomly selected from each replicate for slaughter (no fasting before slaughter), and 2 cm 2 tissue samples were collected from upper middle section of duodenum, middle jejunum and distal ileum, respectively. Paraffin sections of sampling tissues were made to observe the morphology of the small intestine. Chyme from each segment of the small intestine was collected for the determination of the enzymes activity of trypsin, chymotrypsin, lipase, alpha-amylase, sucrase and maltase.【Result】 The results showed that: (1) Weaning age affected growth performance of lamb in 4-6 month. The lamb average daily gain of group Ⅲ was significantly greater than that of groupⅠ(P<0.05). (2) Weaning age affected small intestine histological morphology of 6- month-old lambs. Muscular layer thickness of duodenum and villi surface area of jejunum of group Ⅲ was significantly greater than that of group I or group II (P<0.05);the villi width of duodenum and the villi width of ileum groupII and group III was significantly higher than that of group I (P<0.05). (3) weaning age affected the activity of digestive enzymes in small intestine. The activity of lipase in duodenum and ileum, the activity of chymotrypsin in jejunum and ileum, group III was significantly higher than that of groupI or group II (P<0.05). (4) Nutrient level of diets affected small intestine histological morphology of 6-month-old lambs. The villi height, villi width, muscle layer thickness and villi surface area of duodenum, and the villi height, muscle layer thickness of jejunum, and the villi height, ratio of V/C, groupV and group VI was significantly higher than that of group III and group IV (P<0.01). (5) Nutrient level of diets affected the activity of digestive enzymes in small intestine. The activity of chymotrypsin and trypsase in jejunum of group V and group VI was significantly higher than that of group III and group IV (P<0.05); the activity of chymotrypsin in jejunum and the activity of trypsase in ileum of group V was significantly higher than that of each other group (P<0.05). 【Conclusion】 In this study, in terms of growth performance, small intestine morphology and activity of main digestive enzymes in Shaanbei white Cashmere goat, the best weaning time of lamb was at 60 d, and the optimum dietary energy and protein level was recommended to use 1.15 times the setting standard.

Key words: Shaanbei White Cashmere goat, nutritional level, weaning age, small intestinal morphology, activity of digestive enzymes

Table 1

The composition and nutrient levels of experimental diets (air-dry basis,%)"

项目
Item
第一阶段 Diet 1 第二阶段 Diet 2
基础日粮 Base 85% 115% 130% 基础日粮 Base 85% 115% 130%
原料成分 Ingredient
玉米 Corn 35.00 28.00 47.00 56.50 23.60 4.00 27.67 32.00
小麦麸 Wheat bran 5.00 4.00 1.50 0.00 6.00 28.00 0.00 0.00
豆油 Soybean oil 1.50 0.00 2.50 3.00 0.00 0.00 2.00 3.00
大豆粕 Soybean meal 2.00 2.00 2.50 4.00 2.96 0.00 8.53 5.00
棉籽粕 Cottonseed meal 0.00 1.00 0.00 1.00 0.56 2.00 0.00 0.00
菜籽粕 Rapeseed meal 0.00 1.00 0.00 2.00 5.00 2.25 0.00 0.00
碳酸钙 CaCO3 0.00 0.00 0.00 0.00 0.09 0.75 0.00 0.00
磷酸氢钙 CaHPO4 0.30 0.50 0.00 0.00 0.30 0.00 0.30 0.30
食盐(饲料级)NaCl 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
复合预混料1) Premix 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
苜蓿草粉 Alfalfa meal 24.00 7.62 34.50 32.00 10.00 0.00 25.00 49.00
玉米秸秆 Corn straw 30.70 54.38 10.50 0.00 50.00 61.50 35.00 9.20
合计Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
干物质 DM 89.10 91.60 90.90 87.30 91.30 88.80 88.80 89.70
总能GE (MJ·kg-1) 16.66 16.38 16.79 16.89 17.45 17.35 17.68 17.96
消化能2) DE (MJ·kg-1) 10.45 8.87 11.97 13.50 9.03 8.06 10.26 11.51
粗蛋白CP 10.06 8.85 11.70 13.01 10.38 9.10 11.78 13.47
粗脂肪 EE 2.79 2.31 2.41 2.58 2.37 2.31 2.84 3.84
中性洗涤纤维 NDF 39.56 43.13 37.01 35.63 42.38 43.33 41.69 38.25
酸性洗涤纤维 ADF 24.95 26.33 17.13 15.14 23.13 27.69 21.15 18.95
钙 Ca 0.59 0.50 0.59 0.55 0.47 0.55 0.65 0.70
总磷 TP 0.32 0.34 0.26 0.30 0.35 0.38 0.36 0.38

Table 2

Effects of weaning days and dietary nutrition level on growth performance of weaned lambs in Shaanbei White Cashmere goats"

项目
Items
组别 Groups SEM P
P value
I II III IV V VI
初始体重(54 d) Initial BW (kg) 10.80 10.55 10.40 10.85 10.97 10.82 1.57 0.92
结束体重 (180 d) Final BW (kg) 22.32B 23.10B 23.45B 21.57C 25.58A 24.22AB 1.10 0.01
平均日增重 ADG (g·d-1) 95.97c 104.58bc 108.75b 89.30d 121.80a 111.67ab 4.59 0.02
干物质采食量 DMI (g·d-1) 716.06C 767.25B 775.40B 726.58C 830.15A 779.72B 10.55 <0.001
耗料增重比F/G 7.45b 7.34b 7.15b 8.16a 6.81c 6.98c 0.23 0.04

Table 3

Effects of weaning age on the development of intestinal morphology of weaned lambs in Shaanbei White Cashmere goats"

项目
Item
组别 Group SEM P
P value
I(90 d) II(75 d) III(60 d)
十二指肠 Duodenum
绒毛高度Villus height (μm) 563.93B 724.58A 543.18B 24.03 <0.001
绒毛宽度Villus width (μm) 70.72b 80.82a 83.51a 2.20 0.046
隐窝深度Crypt depth (μm) 259.20B 372.88A 275.55B 13.85 <0.001
肌层厚度Muscular thickness 115.90C 182.14B 242.20A 13.79 <0.001
绒毛高度/隐窝深度V/C 2.17 1.95 1.97 0.05 0.11
表面积Surface area (μm2) 39813.37B 58593.92A 45237.72B 2430.22 <0.001
空肠Ileum
绒毛高度Villus height (μm) 557.55 531.58 582.76 14.11 0.33
绒毛宽度Villus width (μm) 80.07 83.71 90.19 3.07 0.43
隐窝深度Crypt depth (μm) 340.08 309.74 316.58 8.78 0.38
肌层厚度Muscular thickness (μm) 173.49 205.65 236.60 11.85 0.06
绒毛高度/隐窝深度V/C 1.64 1.72 1.86 0.05 0.22
表面积 Surface area (μm2) 44467.55b 44883.99b 52444.75a 2133.90 0.03
回肠Jejunum
绒毛高度Villus height (μm) 664.13 679.51 653.89 20.69 0.88
绒毛宽度Villus width (μm) 88.82b 105.84a 104.77a 3.01 0.04
隐窝深度Crypt depth (μm) 384.75 343.51 367.68 17.15 0.66
肌层厚度Muscular thickness (μm) 202.18 196.71 170.01 13.37 0.60
绒毛高度/隐窝深度V/C 1.73 2.11 1.78 0.08 0.11
表面积Surface area (μm2) 59145.10 73566.13 68485.03 3867.20 0.36

Table 4

Effects of weaning age on activity of intestinal digestive enzymes of 6 month-old Shaanbei White Cashmere goats"

项目
Item
组别 Group SEM P
P value
I(90 d) II(75 d) III(60 d)
α-淀粉酶 α-Amylase (U/mg) 十二指肠Duodenum 0.11a 0.07c 0.09b 0.01 0.02
空肠Jejunum 0.14a 0.08b 0.09b 0.01 0.03
回肠Ileum 0.06 0.07 0.08 0.01 0.10
脂肪酶 Lipase (U/mg) 十二指肠Duodenum 9.17b 8.71b 9.95a 0.23 0.05
空肠Jejunum 7.82 8.39 8.07 0.31 0.21
回肠Ileum 7.47B 7.23B 8.87A 1.33 0.01
蔗糖酶 Invertase (U/mg) 十二指肠Duodenum 23.05 22.26 21.95 0.45 0.64
空肠Jejunum 31.01 28.81 26.23 1.50 0.49
回肠Ileum 24.58 23.43 27.58 1.54 0.59
麦芽糖酶 Maltase (U/mg) 十二指肠Duodenum 8.96 8.77 9.67 0.31 0.52
空肠Jejunum 13.63 9.46 10.73 1.02 0.26
回肠Ileum 13.39 8.14 7.66 1.32 0.12
糜蛋白酶 Chympotrypsin (U/mg) 十二指肠Duodenum 8.53 8.87 8.05 0.57 0.06
空肠Jejunum 9.51b 9.14b 10.74a 0.31 0.03
回肠Ileum 5.34c 6.49b 6.89a 0.26 0.02
胰蛋白酶 Trypsin (U/mg) 十二指肠Duodenum 3.80 3.63 3.57 0.03 0.06
空肠Jejunum 3.61B 4.19A 3.65B 0.11 0.01
回肠Ileum 3.51 3.57 3.52 0.02 0.40

Table 5

Effects of dietary nutrition levels on the development of intestinal morphology of 6 month-old Shaanbei White Cashmere goats"

项目
Item
组别 Group SEM P
P value
III (100%) IV (85%) V (115%) VI (130%)
十二指肠 Duodenum
绒毛高度Villus height (μm) 543.18B 498.69B 643.52A 713.82A 20.75 <0.001
绒毛宽度Villus width (μm) 83.51B 70.43C 93.83A 87.35A 2.43 0.001
隐窝深度Crypt depth (μm) 275.55B 276.85B 250.40B 333.78A 9.05 0.002
肌层厚度Muscular thickness (μm) 242.20B 198.11C 301.16A 272.10A 10.76 0.001
绒毛高度/隐窝深度V/C 1.97BC 1.81C 2.60A 2.15B 0.07 <0.001
表面积Surface area (μm2) 45237.72B 35137.95C 60451.23A 62454.37A 2809.58 <0.001
空肠Ileum
绒毛高度Villus height (μm) 582.76B 515.79C 621.48A 674.15A 14.32 <0.001
绒毛宽度Villus width (μm) 90.19 89.94 91.80 100.43 2.34 0.372
隐窝深度Crypt depth (μm) 316.58a 294.78a 285.84a 251.06b 7.17 0.011
肌层厚度Muscular thickness (μm) 236.60B 183.05C 243.51A 255.68A 7.93 <0.001
绒毛高度/隐窝深度V/C 1.86C 1.75C 2.18B 2.69A 0.09 <0.001
表面积μm2 Surface area (μm2) 52444.75B 46426.49C 57020.80AB 67775.10A 2244.59 0.002
回肠Jejunum
绒毛高度Villus height (μm) 653.89B 617.89B 752.46A 781.61A 14.60 <0.001
绒毛宽度Villus width (μm) 104.77B 90.79C 107.30B 188.25A 8.30 <0.001
隐窝深度Crypt depth (μm) 367.68A 339.43B 330.03B 300.12C 7.96 0.014
肌层厚度Muscular thickness (μm) 170.01C 156.60C 323.53A 214.46B 13.51 <0.001
绒毛高度/隐窝深度V/C 1.78B 1.82B 2.34A 2.63A 0.08 <0.001
表面积Surface area (μm2) 68485.03C 56119.59D 80726.33B 147524.51A 7560.46 <0.001

Table 6

Effects of dietary nutrition levels on activity of small intestine main digestive enzymes of 6 month-old Shaanbei White Cashmere goats"

项目
Item
组别 Group SEM P
P value
α-淀粉酶 α-Amylase (U/mg) 十二指肠Duodenum 0.09A 0.05B 0.08A 0.08A 0.01 <0.001
空肠Jejunum 0.09b 0.05c 0.10a 0.11a 0.01 0.01
回肠Ileum 0.08 0.07 0.06 0.06 0.01 0.40
脂肪酶Lipase (U/mg) 十二指肠Duodenum 9.95 8.45 9.93 7.82 0.62 0.63
空肠Jejunum 8.07 7.68 8.45 7.30 0.52 0.40
回肠Ileum 8.87 8.00 9.73 8.42 0.33 0.28
蔗糖酶Invertase (U/mg) 十二指肠Duodenum 21.95b 23.99a 19.93c 21.73b 0.52 0.02
空肠Jejunum 26.23 32.48 29.28 30.44 1.31 0.45
回肠Ileum 27.58 23.68 23.90 23.82 1.22 0.67
麦芽糖酶Maltase (U/mg) 十二指肠Duodenum 9.67 10.42 8.72 10.79 0.32 0.09
空肠Jejunum 10.73 12.24 9.12 10.31 0.68 0.50
回肠Ileum 7.66 14.13 12.35 11.52 1.00 0.07
糜蛋白酶 Chympotrypsin (U/mg) 十二指肠Duodenum 8.05b 6.52c 9.48a 10.89a 0.62 0.04
空肠Jejunum 10.74B 8.40C 15.50A 11.83B 0.88 0.01
回肠Ileum 6.89 6.29 5.83 5.71 0.30 0.57
胰蛋白酶Trypsin (U/mg) 十二指肠Duodenum 3.57b 3.60b 3.74a 3.80a 0.03 0.04
空肠Jejunum 3.65 3.79 3.79 3.81 0.04 0.07
回肠Ileum 3.52b 3.53b 3.82a 3.59b 0.07 0.03
[1] 刘月琴, 王宝山, 张英杰, 甄二英, 孙洪新 . 日粮类型对小尾寒羊小肠消化酶活性影响的研究. 中国草食动物, 2004(S1):131-134.
LIU Y Q, WANG B S, ZHANG Y J, ZHEN E Y, SUN H X . Effects of dietary types on digestive enzyme activity in small intestine of Small Tail Han Sheep. China Herbivores, 2004(S1):131-134. (in Chinese)
[2] DUNSFORD B, KNABE D A, HAENSLY W E . Effect of dietary soybean meal on the microscopic anatomy of the small intestine in the early-weaned pig. Journal of Animal Science, 1989,67(7):1855-1863.
[3] 李辉 . 蛋白水平与来源对早期断奶犊牛消化代谢及胃肠道结构的影响[D]. 北京: 中国农业科学院, 2008.
LI H . Effects of protein level and source on nutritent utilization and gastrointestinal characteristics in early weaning calves[D]. Beijing: Chinese Academy of Agricultural Sciences, 2008. ( in Chinese)
[4] 郭江鹏, 王俊, 李发弟, 张元兴, 杨宇泽, 郝正里 . 断奶日龄对舍饲羔羊小肠内容物中主要消化酶活性的影响. 中国畜牧兽医, 2017,44(09):2603-2612.
GUO J P, WANG J, LI F D, ZHANG Y X, YANG Y Z, HAO Z L . Effect of different weaning ages on main digestive enzymes activities in the small intestinal contents of lamb. Chinese Animal Husbandry and Veterinary Medicine, 2017,44(09):2603-2612. (in Chinese)
[5] 张宏福, 顾宪红 . 仔猪营养生理与饲料配制技术研究. 北京: 中国农业科技出版社, 2001.
ZHANG H F, GU X H. Study on Nutritional Physiology and Feed Preparation Technology of Piglets. Beijing: China Agricultural Science and Technology Press, 2001. ( in Chinese)
[6] 孟庆蕊 . 陕北白绒山羊羔羊培育试验及生长发育指标监测[D]. 杨凌: 西北农林科技大学, 2017.
MENG Q R . Effect of broken breast age on growth performance and gastrointestinal development of lambs[D]. Yangling: Northwest A&F University, 2017. ( in Chinese)
[7] 马仲华 . 家畜解剖学及组织胚胎学. 3版. 北京: 中国农业出版社, 2003.
MA Z H. Anatomy and Histology and Embryology of Domestic Animals( The Third Edition) . Beijing: China Agriculture Press, 2003. ( in Chinese)
[8] WANG Y H, XU M, WANG F N, YU Z P, YAO G H, ZAN L S . Effect of dietary starch on rumen and small intestine morphology and digesta pH in goats. Livestock Science,2010, 122(1):48-52.
[9] 施特而马赫B . 酶的测定方法. 钱嘉渊译. 北京: 中国轻工业出版社, 1992.
STERMACHER B. Method for Measuring Enzyme. QIAN J Y Translation. Beijing: China Light Industry Press, 1992. ( in Chinese)
[10] 李建武 . 生物化学实验原理与方法. 北京: 北京大学出版社, 1994.
LI J W. Principles and Methods of Biochemistry Experiment. Beijing: Peking University Press, 1994. ( in Chinese)
[11] 徐永平, 李淑英, 布莱恩·米恩 . 哺乳期补料对仔猪胃肠道发育和生产性能的影响. 饲料研究, 2001(02):6-8.
XU Y P, LI S Y, MILNE B . Effect of lactation feeding on gastrointestinal development and production performance of piglets. Feed Research, 2001(02):6-8. (in Chinese)
[12] 曲星梅, 阚博文, 刘素趁, 李碧波, 张恩平 . 断奶日龄和日粮营养水平对4~6月龄陕北白绒山羊消化代谢的影响. 畜牧兽医学报, 2019,50(01):94-104.
QU X M, KAN B W, LIU S C, LI B B, ZHANG E P . Effect of weaning age and dietary nutrition level on major nutrients digestibility and metabolism in aged 4 to 6 months Shaanbei white cashmere goats. Acta Veterinaria et Zootechnica Sinica, 2019,50(01):94-104. (in Chinese)
[13] 宋代军, 张家骅, 杨游, 乔艳芳, 田茂春 . 羔羊不同断奶日龄对小肠黏膜形态的影响. 动物营养学报, 2007(04):344-349.
SONG D J, ZHANG J Y, YANG Y, QIAO Y F, TIAN M C . Effects of lamb weaning age on morphology of small intestinal mucosa in lamb. Chinese Journal of Animal Nutrition, 2007(04):344-349. (in Chinese)
[14] 陈鼎 . 小尾寒羊和滩羊肠道发育及其主要消化酶活性变化规律研究[D]. 杨凌:西北农林科技大学. 2008.
CHEN D . Regulation of intestine and its digestive enzymes activities between small-tailed han sheep and tan sheep[D].Yangling: Northwest A&F University. 2008. ( in Chinese)
[15] LINDVALL H, NEVSTEN P, STROM K . A novel hormone-sensitive lipase isoform expressed in pancreatic beta-cells. Journal of Biology Chemistry, 2004,279(5):3828-3836.
[16] 张庆丽 . 早期能量与蛋白限制饲养对1月龄断奶羔羊胃肠道发育的影响[D]. 杨凌:西北农林科技大学, 2010.
ZHANG Q L . Effect of early energy and protein restricted feeding on gastrointestinal development of weaned lambs at the age of 1 month[D]. Yangling: Northwest A&F University, 2010. ( in Chinese)
[17] POND W G, Ellis K J, Mersmann H J, Heath J P, Krook L P, Burrin D G . Severe protein deficiency and repletion alter body and brain composition and organ weights in infant pigs. Journal of Nutrition, 1996, 126(1):290-302.
[18] GUIRALDES E, HAMILTON J R . Effect of chronic malnutrition on intestinal structure, epithelial renewal, and enzymes in suckling rats. Pediatric Research, 1981,15(6):930-934.
[19] 任文 . 不同直/支链淀粉比对肥羔胃肠道发育及其相关基因mRNA表达量的影响[D]. 大庆:黑龙江八一农垦大学, 2014.
REN W . Effects of different amylose/amylopectin ratios on the development of gastrointestinal tract and mRNA expression of related genes in fattening in fattening lambs[D]. Daqing: Heilongjiang Bayi Agricultural University, 2014. ( in Chinese)
[20] 丁莉 . 关中奶山羊周岁前消化系统发育规律的研究[D]. 杨凌:西北农林科技大学, 2007.
DING L . The study on development of digestive system in Guanzhong dairy goats before one year old[D]. Yangling: Northwest A&F University, 2007. ( in Chinese)
[21] 吕凯, 侯生珍, 王志有, 郭远玉, 梁晓兵 . 饲粮蛋白质水平及赖氨酸/蛋氨酸对早期断奶藏羔羊生长性能及胃肠道组织形态的影响. 动物营养学报, 2013,25(04):743-751.
LV K, HOU S Z, WANG Z Y, GUO Y Y, LIANG X B . Dietary Protein level and Lys/Met affect growth performance and gastrointestinal morphology of early-weaner Tibetan lambs. Chinese Journal of Animal Nutrition, 2013,25(04):743-751. (in Chinese)
[22] VELAZQUES O C, LEDERER H M, RONBEAU J L . Butyrate and the colonocyte. Implications for neoplasia. Digestive Diseases and Sciences, 1996, 41:727-739.
[23] 祁敏丽, 柴建民, 王波, 孟春花, 陶晓箐, 张蓉, 刁其玉, 张乃锋 . 饲粮营养限制对早期断奶湖羊羔羊生长性能以及内脏器官发育的影响. 动物营养学报, 2016,28(02):444-454.
QI M L, CHAI J M, W B, MENG C H, TAO X Q, ZHANG R, DIAO Q Y, ZHANG N F . Effects of dietary nutrient restriction on growth performance and visceral organ development of early weaned Hu sheep lambs. Chinese Journal of Animal Nutrition, 2016, 28(02):444-454. (in Chinese)
[24] HIBBARD B, PETER J P, SHEN R Y W, CHESTER S T . Effect of recombinant porcine somatotropin and dietary protein on pancreatic digestive enzyme in the pig. Journal of Animal Science, 1992, 70:2188-2194.
[25] KREIKEMIER K K, HARMO D L . Influence of dietary forage and feed intake on carbohydrase activities and small intestinal morphology of calves. Journal of Animal Science, 1990,68:2916-2929.
[26] WANG X B, OGAWA T, SUDA S, TANIGUCHI K, UIKE H, KUMAGAI H . Effects of nutritional level on digestive enzyme activities in the pancreas and intestine of calves slaughtered at same body weight. Asian-Australian Journal of Animal Science, 1998, 11(4):375-380.
[27] KREIKEMIER K K, HAMMON D L . Influence of dietary forage and feed intake on carbohydrase activities and small intestinal morphology of calves. Journal of Animal Science, 1990,68:2916-2929.
[28] GORRILL A D, SCHINGOETHE D J, THOMAS J W . Proteolytic activity and in vitro enzyme stability in small intestinal contents from ruminants and non ruminants at different ages. Journal of Nutrition, 1968,96(3):342-348.
[29] 佟莉蓉 . 0-6月龄犊牛胰腺和小肠主要消化酶发育规律的研究[D]. 太谷: 山西农业大学, 2001.
TONG L R . Study on the development of main digestive enzymes in pancreas and small intestine of 0-6 month old calves[D]. Taigu: Shanxi Agricultural University, 2001. ( in Chinese)
[30] 张振斌, 蒋宗勇, 林映才, 郑黎 . 早期断奶仔猪的消化生理与日粮配制. 中国饲料, 2000(10):4-5.
ZHANG Z B, JIANG Z Y, LIN Y C, ZHENG L . Digestive physiology and diet formulation of early weaned piglets. Chinese Feed, 2000(10):4-5. (in Chinese)
[31] MCDONALD P, EDWARDS R A, GREENHALGH J F D . Animal Nutrition (Sixth Edition). Pearson Education Limited, 2007.
[32] 张英杰, 刘月琴, 冯仰廉 . 日粮对肉牛小肠pH值及胰蛋白酶活性的影响. 中国草食动物, 2000,20(1):8-9.
ZHANG Y J, LIU Y Q, FENG Y L . Effect of diet on pH and trypsin activity in beef cattle. China Herbivores, 2000,20(1):8-9.(in Chinese)
[33] 周韶, 李树聪 . 不同精料水平对肉牛瘤胃和小肠pH值的影响. 饲料工业, 2003,24(5):27-29.
ZHOU S, LI S C . Effects of different concentrate levels on rumen and intestinal pH of beef cattle. Feed Industry, 2003,24(5):27-29. (in Chinese)
[1] CHAI Jian-min, WANG Hai-chao, DIAO Qi-yu, QI Min-li, GUO Feng, WANG Hai-chao*, ZHANG Nai-feng. Effects of Weaning Stress on Growth Performance, Organ Development and Serological Parameters in Lambs [J]. Scientia Agricultura Sinica, 2015, 48(24): 4979-4988.
[2] YING Shi-Jia, NIE Hai-Tao, ZHANG Guo-Min, WU Yong-Cong, WANG Zi-Yu, PANG Xun-Sheng, WANG Chang-Long, HE Dong-Yang, JIA Ruo-Xin, WANG Feng. Effects of Different Levels of Diet on Plasma Physiochemical Indexes and Folliculogenesis in Hu Sheep During the Luteal Phase [J]. Scientia Agricultura Sinica, 2012, 45(8): 1606-1612.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!