不同饲料效率与绵羊瘤胃组织形态学关系

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张德印^,¹, 张小雪¹, 李发弟¹^,², 李冲¹^,², 李国泽¹, 张煜坤¹, 李晓龙¹, 宋其志¹, 赵源¹, 刘晓青¹, 马亮强¹, 王维民^,¹

¹甘肃农业大学动物科学技术学院,兰州 730030

²甘肃省肉羊繁育生物技术工程实验室,甘肃民勤 733300

Association of Rumen Histomorphology of Sheep with Different Feed Efficiencies

ZHANG DeYin^,¹, ZHANG XiaoXue¹, LI FaDi¹^,², LI Chong¹^,², LI GuoZe¹, ZHANG YuKun¹, LI XiaoLong¹, SONG QiZhi¹, ZHAO Yuan¹, LIU XiaoQing¹, MA LiangQiang¹, WANG WeiMin^,¹

¹College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070

²Engineering Laboratory of Sheep Breeding and Reproduction Biotechnology in Gansu Province, Minqin 733300

通讯作者: 王维民,E-mail： wangwm@gsau.edu.cn

责任编辑: 林鉴非
收稿日期:2020-01-2接受日期:2020-09-5网络出版日期:2020-12-16

基金资助:

国家自然科学基金.31560625
国家自然科学基金.31760651
国家畜禽良种联合攻关计划.125D0101
国家肉羊产业技术体系.CARS-38

Received:2020-01-2Accepted:2020-09-5Online:2020-12-16
作者简介 About authors
张德印,E-mail： 1547767138@qq.com。

摘要
【目的】利用单栏系统测定个体的饲料效率相关性状与瘤胃组织形态学指标,探讨绵羊饲料效率与瘤胃组织形态的关系,为解析绵羊饲料效率性状的影响因素研究提供基础数据。【方法】随机选取出生日龄相近、系谱信息详细、健康状况良好的187湖羊公羔,56 d断奶后转入单栏饲养,过渡期14 d,预饲期10 d,正试期100 d。正试期内所有羊只仅饲喂颗粒饲料,自由采食及饮水,并在80 d和180 d晨饲前空腹测定其体重（body weight,BW）和80—180 d间的采食量（feed intake,FI）,计算平均日增重（average daily gain,ADG）、中期代谢体重（metabolic body weight, MBW）、饲料转化率（feed conversion rate,FCR）和剩余采食量（residual feed intake,RFI）等饲料效率相关性状并对其进行描述性统计,于180 d饲养结束后屠宰采集瘤胃腹囊组织1 cm²保存于4%甲醛溶液中,用于制作组织切片并观测其瘤胃乳头长度、宽度和肌层厚度。最后将其与饲料效率相关性状进行相关分析和方差分析。【结果】饲料效率相关性状的变异系数均大于10%,且剩余采食量最大与最小的个体每天的剩余采食量之差达0.57 kg。饲料效率相关性状间的表型相关分析表明剩余采食量与饲料转化率（r= 0.68）和采食量（r= 0.48）呈极显著正相关（P<0.01）,与初始体重（r=0）、末期体重（r= -0.01）和平均日增重（r= -0.02）无显著相关（P>0.05）。饲料效率相关性状与瘤胃组织形态相关性分析发现,瘤胃乳头长度与平均日增重、采食量、初始体重和末期体重呈显著或极显著正相关（P<0.05或P<0.01）,肌层厚度与平均日增重、采食量和末期体重呈显著或极显著正相关（P<0.05或P<0.01）,而剩余采食量和饲料转化率与瘤胃组织形态无显著相关。不同RFI组羔羊采食量、饲料转化率和瘤胃肌层厚度存在显著或极显著差异（P<0.05或P<0.01）,瘤胃乳头长、宽无显著差异（P>0.05）,其中High-RFI组羔羊采食量和饲料转化率极显著高于Low-RFI组（P<0.01）,肌层厚度显著高于Medium-RFI组（P<0.05）;不同FCR组羔羊的剩余采食量、采食量、ADG、初始体重、末期体重和乳头长度存在显著或极显著差异（P<0.05或P<0.01）,肌层厚度和乳头宽度差异不显著（P>0.05）,其中High-FCR组羔羊剩余采食量、采食量、ADG、初始体重和末期体重均显著或极显著高于Low-FCR组（P<0.05或P<0.01）,Medium-FCR组羔羊乳头长度显著长于Low-FCR组（P<0.05）;除瘤胃乳头宽度外,不同FI组羔羊的上述指标均存在显著或极显著差异（P<0.05或P<0.01）,且High-FI组羔羊的剩余采食量、饲料转化率、ADG、初始体重、末期体重、肌层厚度和乳头长度均显著或极显著高于Low-FI组（P<0.05或P<0.01）;不同ADG组羔羊采食量、饲料转化率、初始体重、末期体重和肌层厚度均存在显著或极显著差异（P<0.05或P<0.01）,乳头长度和乳头宽度无显著差异（P>0.05）,其中High-ADG组羔羊采食量、剩余采食量、初始体重、末期体重和肌层厚度均显著或极显著高于Low-ADG组,饲料转化率则极显著低于Low-ADG组。【结论】剩余采食量与采食量和饲料转化率等饲料效率性状呈极显著正相关,表明其可作为衡量饲料效率的潜在指标。剩余采食量和饲料转化率与瘤胃组织形态学指标无显著相关,采食量和平均日增重与瘤胃乳头长度和肌层厚度呈显著正相关,表明羔羊瘤胃组织形态对采食量和增重有显著影响,但其进一步的作用机制有待深入研究。
关键词： 剩余采食量;饲料转化率;瘤胃;组织形态;湖羊

Abstract

【Objective】The individual pens was used to determine individual feed efficiency-related traits and rumen morphology indexes, and the association of feed efficiency of sheep and rumen histomorphology was discussed, so as to provide fundamental data for analyzing the influencing factors of sheep feed efficiency traits. 【Method】One hundred and eighty-seven Hu lambs with the similar birthday age, good growth and available pedigrees were selected randomly, and all lambs were transferred to the housed indoors in individual pens after weaning at 56 days, the lambs were subjected to a 14 days adaptation period. The pre-test period was 10 days and the experimental period was 100 days, during which all lambs were fed pellet feed and had free access to food and fresh drinking water. Lambs were weighed before feeding in the morning at 80 and 100 days, and feed intake (FI) were measured during 80-180 days. Average daily gain (ADG), metabolic body weight (MBW), feed conversion rate (FCR) and residual feed intake (RFI) were calculated and the descriptive statistics were carried out. The lambs were slaughtered at 180 days, and rumen abdominal sac tissue was collected, and stored in 4% formaldehyde solution for making tissue sections. The length, width and muscle thickness of the rumen papilla were observed. Finally, correlation analysis and variance analysis were carried out for the traits related to feed efficiency.【Result】The variation coefficients of feed efficiency-related traits were all greater than 10%, and the difference of the individuals with the largest and smallest residual feed intake was 0.57 kg per day. Phenotypic correlation analysis of feed efficiency-related traits showed that RFI was very significantly positively correlated with FCR (r= 0.68) and FI (r= 0.48) (P<0.01), there was no significant correlation with initial body weight (r=0) final body weight (r= -0.01) and average daily gain (r= -0.02) (P>0.05). The correlation analysis between feed efficiency and rumen histomorphology was found that the length of the rumen papilla was significantly or very significantly positively correlated with average daily gain, feed intake, initial body weight and final body weight (P<0.05 or P<0.01), while there were no significant differences in length and width of rumen papilla (P>0.05). The feed intake and feed conversion rate of lambs in the High-RFI group were significantly higher than those in the Low-RFI group (P<0.01), and the muscle thickness was significantly higher than that of the Medium-RFI group (P<0.05). There were significantly or extremely significantly differences in residual feed intake, feed intake, ADG, initial body weight, final body weight and the length of rumen in different FCR groups (P<0.05 or P<0.01), there was no significant difference between the rumen muscular thickness and the width of rumen papilla (P>0.05). Among them, the residual feed intake, feed intake, ADG, initial body weight and final body weight of the lambs in the High-FCR group were significantly or extremely significantly higher than those in the Low-FCR group (P<0.05 or P<0.01), The length of the rumen papilla in the medium-FCR group was significantly longer than that in the Low-FCR group (P<0.05). There were significant or extremely significant differences in the above indexes of the lambs in different FI groups (P<0.05 or P<0.01), and the residual feed intake, feed conversion rate, ADG, initial body weight, final body weight, muscle thickness and the length of the rumen papilla in the High-FI group were significantly or extremely significantly higher than those in the Low-FI group (P<0.05 or P<0.01). There were significant or extremely significant differences in feed intake, feed conversion rate, initial body weight, final body weight and muscle thickness in different ADG groups (P<0.05 or P<0.01), there was no significant difference between the length and the width of the rumen papilla (P>0.05), the feed intake, residual feed intake, initial body weight, final body weight and muscle thickness of the High-ADG group were significantly or extremely significantly higher than those of the Low-ADG group, and the feed conversion rate was significantly lower than that of the Low-ADG group.【Conclusion】There was a significant positive correlation between residual feed intake and the traits related to feed efficiency such as feed intake and feed conversion rate, indicating that it could be used as a potential index to measure feed efficiency. There was no significant correlation between the residual feed intake and feed conversion rate and the rumen histopathology. Feed intake and average daily gain were significantly positively correlated with the length of the rumen papilla and the muscular thickness, indicating that the morphology of the rumen tissue had significant effects on feed intake and body weight gain. However, the mechanism of action remains to be further studied.

Keywords：residual feed intake;feed conversion rate;rumen;histomorphology;Hu sheep

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本文引用格式
张德印, 张小雪, 李发弟, 李冲, 李国泽, 张煜坤, 李晓龙, 宋其志, 赵源, 刘晓青, 马亮强, 王维民. 不同饲料效率与绵羊瘤胃组织形态学关系[J]. 中国农业科学, 2020, 53(24): 5115-5124 doi:10.3864/j.issn.0578-1752.2020.24.014
ZHANG DeYin, ZHANG XiaoXue, LI FaDi, LI Chong, LI GuoZe, ZHANG YuKun, LI XiaoLong, SONG QiZhi, ZHAO Yuan, LIU XiaoQing, MA LiangQiang, WANG WeiMin. Association of Rumen Histomorphology of Sheep with Different Feed Efficiencies[J]. Scientia Acricultura Sinica, 2020, 53(24): 5115-5124 doi:10.3864/j.issn.0578-1752.2020.24.014

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0 引言

【研究意义】在肉羊生产实践中,饲草料成本约占总成本的65%—70%,因此提高饲料效率对经济具有重要的意义。在畜禽生产中,饲料效率通常被定义为动物将饲料转化为产品的相对能力,目前饲料转化率（feed conversion rate,FCR）和剩余采食量（residual feed intake,RFI）作为衡量饲料效率最常用的指标^[1,2,3],但剩余采食量仍处于探讨与研究的阶段,因此需要更进一步地评价其作为衡量饲料效率指标的科学性。【前人研究进展】1963年,KOCH等^[4]首次提出了剩余采食量（residual feed intake,RFI）作为估测畜禽饲料利用效率的指标,是指畜禽实际采食量与预期的根据生产性能（体增重、产奶量和产蛋数等）需要和维持体重需要的标准而计算得出的采食量之差。RFI反映的是畜禽本身由遗传背景决定的代谢差异而导致的饲料利用效率的差异^[5],其与畜禽的体型大小及生产性能,甚至是屠宰性能和肉品质等性状相互独立,计算过程中既考虑了畜禽的体增重,也校正了其代谢体重。在对RFI进行遗传改良的同时,不会对生长及生产性状造成不良影响或影响很小^[6,7]。因此,RFI可作为评价饲料效率的潜在育种指标。目前有关RFI的研究主要集中在猪^[8,9]、牛^[10,11]和禽^[12,13]上,有关绵羊RFI的研究较少。【本研究切入点】瘤胃是反刍动物特有的消化器官^[14],瘤胃乳头高和乳头宽等形态学结构,决定了瘤胃上皮对养分吸收和离子的转运能力^[15]。而养分吸收和利用的效率决定动物饲料效率的高低。目前有关瘤胃形态学的研究主要集中在不同生长时期^[16,17,18]、不同饲料类型和结构^[19]、以及不同断奶时间^[20]对瘤胃发育的影响,但不同饲料效率羔羊瘤胃组织形态与饲料效率的关系的研究报道较少。【拟解决的关键问题】本研究以湖羊公羔为研究对象,利用单栏系统测定个体的采食量、剩余采食量、饲料转化率、平均日增重（average daily gain,ADG）等饲料效率相关的性状,并观测瘤胃组织形态学指标,探讨绵羊饲料效率与瘤胃组织形态的关系,为解析绵羊饲料效率性状的影响因素研究提供基础数据。

1 材料与方法

1.1 试验群体与饲养管理

试验于2018年5—9月在甘肃民勤勤锋滩进行,所有试验羊只是从金昌中天羊业有限公司（甘肃,金昌）随机选取187只系谱信息详细、出生日期相近、身体健康、发育状态良好的湖羊公羔,56 d断奶后转于民勤县德福农业科技有限公司（甘肃,民勤）进行单栏饲养,每个栏位装有独立的水槽和料槽,在进行试验前按羊场常规程序对羊只进行免疫和驱虫,根据羊场饲喂方式,每天饲喂4次,试验羊只自由采食和饮水,并对羊舍每14 d进行一次消毒。试验期包括57—70 d的过渡期14 d,在过渡期间每天增加7.1%的全价颗粒饲料以代替羔羊料;71—80 d的预饲期,10 d;81—180 d的正试期,在正试期所有羊只均饲喂全价颗粒料。分别测定80—180 d期间的采食量、80 d和180 d体重,体重在晨饲前空腹测定。饲养试验结束后,立即屠宰采集瘤胃腹囊组织1 cm²保存于4%甲醛溶液中,用于后续制作组织切片。

1.2 试验方法

1.2.1 剩余采食量（residual feed intake,RFI）的计算本试验的预测采食量是通过试验羊只的实际日采食量（AFI）与平均日增重（ADG）和平均中期代谢体重（MBW）多元回归模型来计算,其中ADG和MBW被作为固定效应,所用计算方法参照莫负涛^[21]构建的回归模型：

ADG=(BW₁₈₀-BW₈₀₎/N,MBW=[1/2×(BW₁₈₀+ BW₈₀)]^0.75,Y_i=β₀+β₁(ADG_i)+β₂(MBW_i)+e_i,FCR=FI/（BW₁₈₀-BW₈₀）,其中,ADG为平均日增重,MBW为平均中期代谢体重（W^0.75）,BW₈₀为试验初始体重,BW₁₈₀为试验末期体重,FI为采食量,N为饲养天数,Y_i表示动物i的实际干物质采食量,β₀表示回归截距,β₁为固定值,表示ADG对采食量的影响程度,β₂表示MBW对采食量的影响程度,为定值。e_i表示第i只动物的随机误差,即RFI=实际采食量-预测采食量。

1.2.2 试验分组与统计分析根据个体RFI对试验群体进行排序,将试验群体按平均值和标准差分为High-RFI组（High>0.05）、Medium-RFI组（-0.05≤Medium≤0.05）和Low-RFI组（Low<-0.05）3组。

根据个体ADG对试验群体进行排序,将试验群体按平均值和标准差分为High-ADG组（High>0.29）、Medium-ADG组（0.26≤Medium≤0.29）和Low-ADG组（Low<0.26）3组。

根据个体FI对试验群体进行排序,将试验群体按平均值和标准差分为High-FI组（High>165.82）、Medium-FI组（144.98≤Medium≤165.82）和Low-FI组（Low<144.98）3组。

根据个体FCR对试验群体进行排序,将试验群体按平均值和标准差分为High-FCR组（High>6.06）、Medium-FCR组（5.48≤Medium≤6.06）和Low-FCR组（Low<5.48）3组。

1.2.3 切片制作与数据测定参考温蕾等^[22]的石蜡切片制作过程制作瘤胃组织切片。在进行石蜡包埋、切片、苏木精-伊红染色后,选择3—5张切片,每张选5个典型视野（组织完整）,采用Image-Pro Express 6.0图像分析系统软件分别测量瘤胃腹囊乳头长度和宽度以及瘤胃肌层的厚度。

1.3 数据处理

利用SPSS 16.0软件和R语言（版本3.6.1）对测得的数据进行分析,结果用平均值±标准差表示,采用Tukey法进行多重比较,统计结果以P<0.05为差异显著,P<0.01为差异极显著;对饲料效率相关性状及其与瘤胃组织形态进行皮尔逊相关性分析,并使用corrplot和pheatmap包作图。

2 结果

2.1 饲料效率相关性状描述性统计量

试验测定了试验羊只80—180 d期间的采食量和80 d体重和180 d体重,分别计算剩余采食量、饲料转化率、平均日增重等相关性状结果如表1所示。发现剩余采食量最高和最低个体每天的剩余采食量之差达0.57 kg,其次各性状的变异系数均大于10%,且初始体重的变异系数最大。

Table 1
表1
表1饲料效率相关性状的描述性统计
Table 1Descriptive statistics of feed efficiency traits

性状 Trait	均值 Mean	标准差 SD	变异系数 CV（%）	最大值 Max	最小值 Min
剩余采食量RFI (kg·d^-1)	0.00	0.10	-	0.30	-0.27
采食量FI (kg)	155.40	20.84	13.41	203.70	100.80
平均日增重ADG (g·d^-1)	270.12	34.04	12.60	350.00	177.00
饲料转化率FCR	5.77	0.58	10.05	8.55	4.24
初始体重Initial BW (kg)	18.99	3.79	19.96	27.80	10.04
末期体重Final BW (kg)	46.00	6.01	13.07	61.90	29.10

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2.2 饲料效率相关性状的相关性分析

相关性分析结果表明剩余采食量与平均日增重、初始体重和末始体重无显著相关,但与采食量（r=0.48）和饲料转化率（r=0.68）呈极显著正相关（P<0.01）,而且采食量与平均日增重（r = 0.73）、初始体重（r = 0.87）和末期体重（r = 0.73）高度相关,与饲料转化率（r = 0.45）呈中等相关（P<0.01）。饲料转化率与平均日增重呈极显著负相关（r=-0.28,P<0.01,图1）。

图1

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图1饲料效率相关性状的相关性分析

每个圆的大小表示相关系数的绝对值。蓝色和红色梯度分别表示正相关或负相关。**表示差异极显著（P<0.01）,*表示差异显著（P<0.05）
Fig. 1Correlation coefficient between feed efficiency traits

The size of each circular indicates the absolute value of the correlation coefficient. The blue and red gradients indicate positive or negative correlation, respectively. ** means very difference significantly (P<0.01), * means significantly difference (P<0.05)

2.3 羔羊瘤胃组织形态及其与饲料效率相关性状的相关性分析

由图2可知,不同饲料效率羔羊瘤胃的肌层厚度和乳头长度存在一定差异,并与饲料效率性状关联分析发现剩余采食量和饲料转化率与瘤胃乳头宽度、长度以及肌层厚度的相关程度不高,但平均日增重、采食量和末期体重与瘤胃乳头长度和肌层厚度呈显著正相关,而初始体重仅与乳头长度呈显著正相关（图3）。

图2

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图2不同饲料效率羔羊瘤胃组织形态

a：低饲料效率组;b：中饲料效率组;c：高饲料效率组
Fig. 2Rumen tissue morphology of lambs with different feed efficiency

a: Low feed efficiency group; b: Medium feed efficiency group; c: High feed efficiency group

图3

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图3饲料效率相关性状与羔羊瘤胃组织的相关性分析

蓝色和红色梯度分别表示正相关或负相关。**表示差异极显著（P<0.01）,*表示差异显著（P<0.05）
Fig. 3Correlation analysis between feed efficiency traits and rumen tissue of lambs

The blue and red gradients indicate positive or negative correlation, respectively. ** means very difference significantly (P<0.01), * means significantly difference (P<0.05)

2.4 不同剩余采食量羔羊瘤胃组织形态学

由表2可知,不同RFI组羔羊的平均日增重、初始体重、末期体重、乳头长度和乳头宽度均无显著差异（P>0.05）,但采食量、饲料转化率和瘤胃肌层厚度存在显著或极显著差异（P<0.05或P<0.01）,其中High-RFI组羔羊的采食量、饲料转化率极显著高Medium-RFI和Low-RFI组（P<0.01）,并且High-RFI组羔羊瘤胃腹囊组织肌层厚度显著高于Medium-RFI组羔羊（P<0.05）,但与Low-RFI组羔羊无显著差异（P>0.05）。

Table 2
表2
表2不同剩余采食量羔羊瘤胃组织形态
Table 2The morphological structure of rumen in different residual feed intake of lambs

组别 Groups	个数 Numbers	采食量 FI (kg)	平均日增重 ADG (g·d^-1)	饲料转化率 FCR	初始体重 Initial BW （kg）	末期体重 Final BW (kg)	肌层厚度 Muscular thickness (μm)	乳头长度 Papilla height (μm)	乳头宽度 Papilla width (μm)
High-RFI	56	168.63±15.73A	272.93±32.71	6.22±0.55A	19.16±3.01	46.45±4.73	766.87±163.98a	1138.59±396.27	245.83±33.41
Medium-RFI	71	153.48±19.03B	267.96±34.55	5.75±0.43B	18.61±4.02	45.41±6.33	687.90±186.95b	1096.72±461.15	245.72±44.83
Low-RFI	60	145.31±20.85C	270.07±35.01	5.39±0.46C	19.28±4.16	46.28±6.68	719.26±189.87ab	1048.59±353.14	241.18±46.01

同列中数值标注不同小写字母表示差异显著（P<0.01）;不同大写字母表示差异极显著（P<0.05）。下同
In the same column, different lowercase letters represent significant differences (P<0.05), different capital letters represent extremely significant differences (P<0.01). The same as below

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2.5 不同日增重羔羊瘤胃组织形态学

由表3可知,在不同日增重组羔羊中,采食量、饲料转化率、初始体重、末期体重和肌层厚度存在显著差异（P<0.05）,其他指标在3组间均无显著差异（P>0.05）,High-ADG组羔羊的采食量和末期体重极显著高于Medium-ADG和Low-ADG组（P<0.01）;High-ADG组羔羊的饲料转化率极显著低于Medium- ADG和Low-ADG组（P<0.01）;但High-ADG组羔羊瘤胃腹囊组织肌层厚度显著高于Low-ADG组羔羊（P<0.05）。

Table 3
表3
表3不同日增重羔羊瘤胃组织形态
Table 3The morphological structure of rumen in different average daily gain

组别 Groups	个数 Numbers		剩余采食量 RFI (kg·d^-1)	饲料转化率 FCR	初始体重 Initial BW (kg)	末期体重 Final BW (kg)	肌层厚度 Muscular thickness (μm)	乳头长度 Papilla height (μm)	乳头宽度 Papilla width (μm)
High-ADG	59	170.48±14.64A	-0.006±0.11	5.55±0.44B	20.21±3.64A	50.96±4.18A	765.01±195.82a	1126.10±438.54	245.58±43.93
Medium-ADG	75	157.47±13.87B	-0.005±0.09	5.84±0.53A	19.74±3.42A	46.74±3.56B	713.63±187.71ab	1124.63±367.61	245.42±42.04
Low-ADG	53	135.68±19.49C	0.005±0.11	5.94±0.71A	16.58±3.38B	39.44±4.34C	684.60±153.68b	1014.27±427.28	241.28±40.32

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2.6 不同采食量羔羊瘤胃组织形态学

由表4可知,与饲料效率相关的剩余采食量、饲料转化率、平均日增重、初始体重和末期体重在不同采食量组中均存在极显著差异（P<0.01）,且High-FI组极显著高于Medium-FI和Low-FI组。在不同采食量羔羊瘤胃组织形态学中,High-FI组羔羊瘤胃腹囊组织肌层厚度显著高于Low-FI组羔羊（P<0.05）,High-FI和Medium-FI组羔羊瘤胃腹囊组织乳头长度极显著高于Low-FI组羔羊（P<0.01）,但乳头宽度无显著差异（P>0.05）。

Table 4
表4
表4不同采食量羔羊瘤胃组织形态
Table 4The morphological structure of rumen in different feed intake

组别 Groups	个数 Numbers	剩余采食量 RFI (kg·d^-1)	饲料转化率 FCR	平均日增重 ADG (g·d^-1)	初始体重 Initial BW (kg)	末期体重 Final BW (kg)	肌层厚度 Muscular thickness (μm)	乳头长度 Papilla height (μm)	乳头宽度 Papilla width (μm)
High-FI	59	0.049±0.10A	6.05±0.56A	295.79±26.80A	22.08±3.08A	51.66±3.63A	761.15±202.61a	1161.56±419.86A	239.28±33.94
Medium-FI	77	-0.004±0.09B	5.79±0.52B	271.10±23.52B	19.03±2.64B	46.14±3.16B	722.19±185.29ab	1155.08±414.32A	252.09±41.84
Low-FI	51	-0.061±0.08C	5.42±0.51C	238.98±29.47C	15.35±2.63C	39.25±4.39C	674.99±145.26b	922.96±340.51B	238.34±48.99

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2.7 不同饲料转化率羔羊瘤胃组织形态学

由表5可知,不同饲料转化率组羔羊的剩余采食量、采食量、平均日增重、初始体重、末期体重以及瘤胃腹囊组织乳头长度存在显著差异（P<0.05）,肌层厚度和乳头宽度无显著差异（P>0.05）。其中,High- FCR组羔羊的RFI、FI、Initial BW极显著高于Medium-和Low-FCR组羔羊（P<0.01）;Medium-和Low-FCR组羔羊的平均日增重极显著高于High-FCR组（P<0.01）;并且Medium-FCR组羔羊的末期体重和瘤胃腹囊组织乳头长度显著长于Low-FCR组羔羊（P<0.05）。

Table 5
表5
表5不同饲料转化率羔羊瘤胃组织形态
Table 5The morphological structure of rumen in different feed conversion rate

组别 Groups	个数 Numbers	剩余采食量 RFI (kg·d^-1)	采食量 FI (kg)	平均日增重 ADG (g·d^-1)	初始体重 Initial BW (kg)	末期体重 Final BW (kg)	肌层厚度 Muscular thickness (μm)	乳头长度 Papilla height (μm)	乳头宽度 Papilla width (μm)
High-FCR	53	0.078±0.09A	165.51±17.72A	256.58±28.56B	21.11±3.48A	46.77±5.42a	709.28±147.02	1094.28±402.16ab	248.13±41.56
Medium-FCR	75	0.003±0.07B	158.22±18.37B	274.16±33.76A	19.32±3.09B	46.73±5.79a	741.11±220.29	1181.26±450.19a	238.19±32.44
Low-FCR	59	-0.083±0.07C	142.72±20.33C	277.15±35.92A	16.66±3.63C	44.38±6.53b	707.90±160.05	982.25±332.19b	248.62±41.98

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3 讨论

饲料效率是衡量饲料利用率的主要指标,当饲料效率较低时,会使饲养成本增加,因此提高饲料效率显得尤为重要。并且瘤胃是反刍动物特有的消化器官^[23,24],在动物机体的消化代谢过程中具有极其重要的作用,是反刍动物健康生长的基础。在瘤胃形态学研究中,瘤胃乳头长度是最重要的指标,其次是瘤胃乳头宽度和肌层厚度^[25]。剩余采食量是一个具有中等遗传力的负向选择性状,遗传力为0.18—0.43^[26,27],是衡量饲料利用效率的一个重要指标。有****对畜禽剩余采食量的研究中,发现剩余采食量与采食量、消化率、体组织代谢、活动量、体温调节等生理因素有密切关系^[28,29]。本研究对不同饲料效率羔羊瘤胃组织形态的研究结果显示,按RFI值分组后,发现在同样的饲喂条件下Low-RFI组羔羊的FI和FCR极显著低于Medium-RFI和High-RFI组,且不同组间的生长性能如ADG、初始体重、末期体重均无显著差异,这与莫负涛^[21]和MCGEE等^[30]的研究结果相一致。其次发现High-RFI组羔羊瘤胃腹囊组织肌层厚度显著高于Medium-RFI组羔羊,但瘤胃乳头长度和宽度在不同组间也无显著差异这与梁玉生^[31]的研究结果相一致。表明对RFI的选择不会影响瘤胃乳头的发育,进而不会影响个体的生长性能。此外,本研究按平均日增重(ADG)、采食量（FI）、饲料转化率(FCR)等影响饲料效率的重要性状对试验群体进行分组,结果表明不同ADG羔羊的采食量、饲料转化率、初始体重、末期体重、瘤胃肌层厚度存在显著差异,其中High-ADG组羔羊的饲料转化率极显著低于Medium-ADG和Low-ADG组,但High-ADG组羔羊瘤胃肌层厚度显著高于Low-ADG组羔羊,表明瘤胃肌层厚度可能会影响饲料效率。饲料相关性状在不同FI组均存在极显著差异,并且High-FI羔羊瘤胃肌层厚度和乳头长度均显著高于Low-FI羔羊,可能与采食量的增多可提高瘤胃的运动水平,从而促进瘤胃肌层厚度的发育有关,这与朱文涛等^[32]等的研究表明饲料的物理刺激是影响瘤胃肌层发育的主要因素相符;不同FCR组羔羊瘤胃乳头长度以及饲料效率相关的性状均存在显著差异,其中Medium-FCR组羔羊瘤胃乳头长度显著高于Low-FCR组羔羊,与High-FCR组无显著差异,但Medium-和Low-FCR组羔羊的平均日增重极显著高于High-FCR组;表明羔羊瘤胃组织形态的发育有利于提高饲料效率,特别是瘤胃乳头长度和肌层厚度,但其进一步作用机理还有待深入研究。

4 结论

本研究结果表明剩余采食量与生长性状无显著相关,与采食量和饲料转化率呈显著正相关,且Low-RFI组羔羊饲料转化率极显著低于High-RFI组,表明RFI可作为评价饲料效率的潜在指标;剩余采食量和饲料转化率与瘤胃组织形态学指标无显著相关,采食量和平均日增重与瘤胃乳头长度和肌层厚度呈显著正相关,表明羔羊瘤胃组织形态对采食量和增重有显著影响,但其进一步的作用机制有待深入研究。

参考文献原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子

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Journal of Animal Science, 2006,84(1):145-153.

DOI:10.2527/2006.841145x URLPMID:16361501 [本文引用: 1]

Residual feed intake (RFI) is the difference between the actual and expected feed intake of an animal based on its BW and growth rate over a specified period. The biological mechanisms underlying the variation in feed efficiency in animals with similar BW and growth rate are not well understood. This study determined the relationship of feedlot feed efficiency, performance, and feeding behavior with digestion and energy partitioning of 27 steers. The steers were selected from a total of 306 animals based on their RFI following feedlot tests at the University of Alberta Kinsella Research Station. Selected steers were ranked into high RFI (RFI > 0.5 SD above the mean, n = 11), medium RFI (RFI +/- 0.5 SD above and below the mean, n = 8), and low RFI (RFI < -0.5 SD below the mean, n = 8). The respective BW +/- SD for the RFI groups were 495.6 +/- 12.7, 529.1 +/- 18.6, and 501.2 +/- 15.5 kg. Digestibility and calorimetry trials were performed on a corn-or barley-based concentrate diet in yr 1 and 2, respectively, at 2.5 x maintenance requirements. Mean DMI (g/kg of BW(0.75)) during the measurements for high-, medium-, and low-RFI groups, respectively, were 82.7 +/- 2.0, 78.8 +/- 2.6, and 81.8 +/- 2.5 and did not differ (P > 0.10). Residual feed intake was correlated with daily methane production and energy lost as methane (r = 0.44; P < 0.05). Methane production was 28 and 24% less in low-RFI animals compared with high- and medium-RFI animals, respectively. Residual feed intake tended to be associated (P < 0.10) with apparent digestibilities of DM (r = -0.33) and CP (r = -0.34). The RFI of steers was correlated with DE (r = -0.41; P < 0.05), ME (r = -0.44; P < 0.05), heat production (HP; r = 0.68; P < 0.001), and retained energy (RE; r = -0.67; P < 0.001; energy values are expressed in kcal/kg of BW(0.75)). Feedlot partial efficiency of growth was correlated (P < 0.01) with methane production (r = -0.55), DE (r = 0.46), ME (r = 0.49), HP (r = -0.50), and RE (r = 0.62). With the exception of HP (r = 0.37; P < 0.05), feed conversion ratio was unrelated to the traits considered in the study. Feeding duration was correlated (P < 0.01) with apparent digestibility of DM (r = -0.55), CP (r = -0.47), methane production (r = 0.51), DE (r = -0.52), ME (r = -0.55), and RE (r = -0.60). These results have practical implications for the selection of animals that eat less at a similar BW and growth rate and for the environmental sustainability of beef production.

[8]

ONTERU S

, GORBACH D

, YOUNG J

. Whole genome association studies of residual feed intake and related traits in the pig
PLoS One, 2013,8(6):e61756.

DOI:10.1371/journal.pone.0061756 URLPMID:23840294 [本文引用: 1]

BACKGROUND: Residual feed intake (RFI), a measure of feed efficiency, is the difference between observed feed intake and the expected feed requirement predicted from growth and maintenance. Pigs with low RFI have reduced feed costs without compromising their growth. Identification of genes or genetic markers associated with RFI will be useful for marker-assisted selection at an early age of animals with improved feed efficiency. METHODOLOGY/PRINCIPAL FINDINGS: Whole genome association studies (WGAS) for RFI, average daily feed intake (ADFI), average daily gain (ADG), back fat (BF) and loin muscle area (LMA) were performed on 1,400 pigs from the divergently selected ISU-RFI lines, using the Illumina PorcineSNP60 BeadChip. Various statistical methods were applied to find SNPs and genomic regions associated with the traits, including a Bayesian approach using GenSel software, and frequentist approaches such as allele frequency differences between lines, single SNP and haplotype analyses using PLINK software. Single SNP and haplotype analyses showed no significant associations (except for LMA) after genomic control and FDR. Bayesian analyses found at least 2 associations for each trait at a false positive probability of 0.5. At generation 8, the RFI selection lines mainly differed in allele frequencies for SNPs near (<0.05 Mb) genes that regulate insulin release and leptin functions. The Bayesian approach identified associations of genomic regions containing insulin release genes (e.g., GLP1R, CDKAL, SGMS1) with RFI and ADFI, of regions with energy homeostasis (e.g., MC4R, PGM1, GPR81) and muscle growth related genes (e.g., TGFB1) with ADG, and of fat metabolism genes (e.g., ACOXL, AEBP1) with BF. Specifically, a very highly significantly associated QTL for LMA on SSC7 with skeletal myogenesis genes (e.g., KLHL31) was identified for subsequent fine mapping. CONCLUSIONS/SIGNIFICANCE: Important genomic regions associated with RFI related traits were identified for future validation studies prior to their incorporation in marker-assisted selection programs.

[9]

DO D

, STRATHE A

, OSTERSEN

, PANT D

, KADARMIDEEN N

. Genome-wide association and pathway analysis of feed efficiency in pigs reveal candidate genes and pathways for residual feed intake
Frontiers in Genetics, 2014,5:307.

DOI:10.3389/fgene.2014.00307 URLPMID:25250046 [本文引用: 1]

Residual feed intake (RFI) is a complex trait that is economically important for livestock production; however, the genetic and biological mechanisms regulating RFI are largely unknown in pigs. Therefore, the study aimed to identify single nucleotide polymorphisms (SNPs), candidate genes and biological pathways involved in regulating RFI using Genome-wide association (GWA) and pathway analyses. A total of 596 Yorkshire boars with phenotypes for two different measures of RFI (RFI1 and 2) and 60k genotypic data was used. GWA analysis was performed using a univariate mixed model and 12 and 7 SNPs were found to be significantly associated with RFI1 and RFI2, respectively. Several genes such as xin actin-binding repeat-containing protein 2 (XIRP2),tetratricopeptide repeat domain 29 (TTC29),suppressor of glucose, autophagy associated 1 (SOGA1),MAS1,G-protein-coupled receptor (GPCR) kinase 5 (GRK5),prospero-homeobox protein 1 (PROX1),GPCR 155 (GPR155), and FYVE domain containing the 26 (ZFYVE26) were identified as putative candidates for RFI based on their genomic location in the vicinity of these SNPs. Genes located within 50 kbp of SNPs significantly associated with RFI and RFI2 (q-value
[10]

SANTANA M

, UTSUNOMIYA Y

, NEVES H

, GOMES C

, GARCIA F

, FUKUMASU

, SILVA L

, JUNIOR O

, ALEXANDRE P

, LEME R

, BRASSALOTI A

, COUTINHO L

, LOPES G

, MEIRELLES V

, ELER P

, JOSé B

. Genome-wide association analysis of feed intake and residual feed intake in Nellore cattle
BMC Genetics, 2014,15(1):21.

DOI:10.1186/1471-2156-15-21 URL [本文引用: 1]

[11]

GUAN L

, NKRUMAH J

, BASARAB J

, MOORE S

. Linkage of microbial ecology to phenotype: correlation of rumen microbial ecology to cattle's feed efficiency
FEMS Microbiology Letters, 2008,288(1):85-91.

DOI:10.1111/j.1574-6968.2008.01343.x URLPMID:18785930 [本文引用: 1]

Linkage of rumen microbial structure to host phenotypical traits may enhance the understanding of host-microbial interactions in livestock species. This study used culture-independent PCR-denaturing gradient gel electrophoresis (PCR-DGGE) to investigate the microbial profiles in the rumen of cattle differing in feed efficiency. The analysis of detectable bacterial PCR-DGGE profiles showed that the profiles generated from efficient steers clustered together and were clearly separated from those obtained from inefficient steers, indicating that specific bacterial groups may only inhabit in efficient steers. In addition, the bacterial profiles were more likely clustered within a certain breed, suggesting that host genetics may play an important role in rumen microbial structure. The correlations between the concentrations of volatile fatty acids and feed efficiency traits were also observed. Significantly higher concentrations of butyrate (P < 0.001) and valerate (P = 0.006) were detected in the efficient steers. Our results revealed potential associations between the detectable rumen microbiota and its fermentation parameters with the feed efficiency of cattle.

[12]

YUAN

, WANG

, YI

, MA

, DOU

, SUN C

, QU L

, SHEN

, QU

, YANG

. Genome-wide association studies for feed intake and efficiency in two laying periods of chickens
Genetics Selection Evolution, 2015,47(1):82.

DOI:10.1186/s12711-015-0161-1 URL [本文引用: 1]

[13]

TIANFEI

, CHENGLONG

, JIE

, DINGMING

, SAND L

. Assessment of the genomic prediction accuracy for feed efficiency traits in meat-type chickens
PLoS One, 2017,12(3):e0173620.

DOI:10.1371/journal.pone.0173620 URLPMID:28278209 [本文引用: 1]

Feed represents the major cost of chicken production. Selection for improving feed utilization is a feasible way to reduce feed cost and greenhouse gas emissions. The objectives of this study were to investigate the efficiency of genomic prediction for feed conversion ratio (FCR), residual feed intake (RFI), average daily gain (ADG) and average daily feed intake (ADFI) and to assess the impact of selection for feed efficiency traits FCR and RFI on eviscerating percentage (EP), breast muscle percentage (BMP) and leg muscle percentage (LMP) in meat-type chickens. Genomic prediction was assessed using a 4-fold cross-validation for two validation scenarios. The first scenario was a random family sampling validation (CVF), and the second scenario was a random individual sampling validation (CVR). Variance components were estimated based on the genomic relationship built with single nucleotide polymorphism markers. Genomic estimated breeding values (GEBV) were predicted using a genomic best linear unbiased prediction model. The accuracies of GEBV were evaluated in two ways: the correlation between GEBV and corrected phenotypic value divided by the square root of heritability, i.e., the correlation-based accuracy, and model-based theoretical accuracy. Breeding values were also predicted using a conventional pedigree-based best linear unbiased prediction model in order to compare accuracies of genomic and conventional predictions. The heritability estimates of FCR and RFI were 0.29 and 0.50, respectively. The heritability estimates of ADG, ADFI, EP, BMP and LMP ranged from 0.34 to 0.53. In the CVF scenario, the correlation-based accuracy and the theoretical accuracy of genomic prediction for FCR were slightly higher than those for RFI. The correlation-based accuracies for FCR, RFI, ADG and ADFI were 0.360, 0.284, 0.574 and 0.520, respectively, and the model-based theoretical accuracies were 0.420, 0.414, 0.401 and 0.382, respectively. In the CVR scenario, the correlation-based accuracy and the theoretical accuracy of genomic prediction for FCR was lower than RFI, which was different from the CVF scenario. The correlation-based accuracies for FCR, RFI, ADG and ADFI were 0.449, 0.593, 0.581 and 0.627, respectively, and the model-based theoretical accuracies were 0.577, 0.629, 0.631 and 0.638, respectively. The accuracies of genomic predictions were 0.371 and 0.322 higher than the conventional pedigree-based predictions for the CVF and CVR scenarios, respectively. The genetic correlations of FCR with EP, BMP and LMP were -0.427, -0.156 and -0.338, respectively. The correlations between RFI and the three carcass traits were -0.320, -0.404 and -0.353, respectively. These results indicate that RFI and FCR have a moderate accuracy of genomic prediction. Improving RFI and FCR could be favourable for EP, BMP and LMP. Compared with FCR, which can be improved by selection for ADG in typical meat-type chicken breeding programs, selection for RFI could lead to extra improvement in feed efficiency.

[14]

王彩莲, 郝正里, 李发弟, 余洋, 郎侠, 马友记, 年芳, 郭江鹏. 0-56日龄放牧羔羊消化道的解剖特点和瘤胃功能变化
畜牧兽医学报, 2010(4):38-45.

[本文引用: 1]

WANG C

, HAO Z

, LI F

, YU

, LANG

, MA Y

, NIAN

, GUO J

. Anatomical changes of digestive tract and rumen functional development in grazing lamb at the age of 0-56 d
Acta Veterinaria et Zootechnica Sinica, 2010,41(4):38-45. (in Chinese)

[本文引用: 1]

[15]

张彩英, 胡国良, 曹华斌. 反刍动物瘤胃内环境的特点及调控措施
中国畜牧兽医, 2010,37(4):18-20.

URL [本文引用: 1]

瘤胃是反刍动物的一个极其重要的消化器官，瘤胃微生物在反刍动物营养物质代谢方面尤其是粗饲料利用方面起着举足轻重的作用，而瘤胃内环境的稳定是保证瘤胃微生物正常发酵性消化的前提条件。因此，了解瘤胃内环境的特点，对瘤胃内环境实施有效调控，使营养物质的利用率达到最优化，具有非常大的经济效益。

ZHANG C

, HU G

, CAO H

. Characteristics and control measures of rumen environment in ruminants
China Animal Husbandry and Veterinary Science, 2010,37(4):18-20. (in Chinese)

URL [本文引用: 1]

瘤胃是反刍动物的一个极其重要的消化器官，瘤胃微生物在反刍动物营养物质代谢方面尤其是粗饲料利用方面起着举足轻重的作用，而瘤胃内环境的稳定是保证瘤胃微生物正常发酵性消化的前提条件。因此，了解瘤胃内环境的特点，对瘤胃内环境实施有效调控，使营养物质的利用率达到最优化，具有非常大的经济效益。

[16]

丁莉. 关中奶山羊周岁前消化系统发育规律的研究
[D]. 西北农林科技大学, 2007.

[本文引用: 1]

DING

. The study on development of digestive system in Guanzhong dairy goat before oneyear old
[D]. Yangling: Northwest A & F University, 2007. (in Chinese)

[本文引用: 1]

[17]

冯如龙, 赵文嘉, 张锐, 陈国龙, 姜兴佳, 陈绍淑. 不同日龄舍饲绵羊瘤胃形态学变化
畜牧与饲料科学, 2016,37(4):29-32.

[本文引用: 1]

FENG R

, ZHAO W

, ZHANG

, CHEN G

, JIANG X

, CHEN S

. The morphological changes of confined sheep rumen at different age in days
Animal Husbandry and Feed Science, 2016,37(4):29-32. (in Chinese)

[本文引用: 1]

[18]

刘婷, 李发弟, 王维民, 汪晓娟, 李冲, 李飞, 郑琛, 莫负涛, 王芳彬, 喇永富, 李宝胜. 不同日龄补饲开食料对湖羊羔羊瘤胃形态及表皮生长相关基因表达的影
畜牧兽医学报, 2016,47(12):2441-2449.

DOI:10.11843/j.issn.0366-6964.2016.12.014 URL [本文引用: 1]

The objective of this study was to investigate the effects of starter age on Hu lamb genes expression involved in cellular growth in rumen papilla and rumen morphology.Two factor design (starter age and age of lambs) was adopted in this study.A total of 78 male Hu lambs with similar born body weight （(3.41±0.27) kg） were selected.Of which，six were slaughtered immediately after birth and the remaining 72 were equally divided into 2 groups，a group fed by starter diet 1 at d 7 and a group fed by starter diet 1 at d 42，and lambs from both groups were weaned at d 56 and transacted to starter diet 2 at d 60.The transition period lasted 10 d.Six lambs from each group were slaughtered at d 14，28，42，56，70 and 84，respectively.The ventral sac of the rumen was collected，rumen papilla height，width and muscular thickness were measured，and total RNA was extracted.Real-time qPCR was used to analyze the expression of genes related to rumen papilla growth.Tissue sections were prepared to observe rumen development.The results revealed that rumen papilla width of 7 d-starter group was higher (P<0.05) than that of 42 d-starter group，however，rumen muscular thickness in 7 d-starter group was lower (P<0.05) than that in 42 d-starter group.The IGFBP3 expression of rumen tissue in 7 d-starter group were lower (P<0.05) than that in 42 d-starter group.In contrast，IGFBP5 expression in 7 d-starter group were higher (P<0.05) than that in 42 d-starter group.In 7 d-starter group，rumen papilla height and width were positively correlated with expression of TGFβ1 and IGFBP3 (R=0.507，P<0.001；R=0.444，P<0.001；R=0.465，P<0.001；R=0.299，P=0.011)，while were negatively correlated with expression of IGFBP6 (R=－0.443，P<0.001；R=－0.477，P<0.001).In 42 d-starter group，rumen papilla height was positively correlated with expression of IGFBP5 (R=0.227，P=0.018)，additionally，rumen papilla width were positively correlated with expression of IGFBP3 and IGFBP5 (R=0.338，P=0.005；R=0.293，P=0.002).In conclusion，this study result indicate that starter feeding for lambs at day 7 can improve rumen morphology，and the expression levels of genes involved in cellular growth in ruminal epithelium can regulate rumen development.

LIU

, LI F

, WANG W

, WANG X

, LI

, ZHEN

, MO F

, WANG F

, LA Y

, LI B

. Effects of starter feeding on rumen papilla gene expression involved in cellular growth and morphology in hu lamb at different ages
Acta Veterinaria et Zootechnica Sinica, 2016,47(12):2441-2449. (in Chinese)

DOI:10.11843/j.issn.0366-6964.2016.12.014 URL [本文引用: 1]

汪晓娟, 刘婷, 李发弟, 李冲, 王维民, 唐德富, 李宝胜, 马志远, 潘香羽. 开食料补饲日龄对湖羊羔羊生长性能和胃发育的影响
畜牧兽医学报, 2016,47(2):305-314.

DOI:10.11843/j.issn.0366-6964.2016.02.013 URL [本文引用: 1]

This study aimed to investigate the effect of different starter supplying ages on growth performance and stomach development of Hu sheep lamb.Seventy-two Hu male lambs (twin，the average weight of birth (3.51±0.51)kg) were randomly divided into 2 groups with starter supplying on 7-day-old(7 d group) or 42-day-old (42 d group)，respectively.Six lambs of each group were killed，sampled and measured the weight and volume of stomach and intestinal tract at the age of 14，28，42，56，70 and 84 d.The results showed that the body weight of lambs after the 42-day-old (besides 70-day-old) in 7-day-old group were significantly higher than 42-day-old group (P<0.05)，the average daily gain (ADG) of lambs at the age of 21-28 d and 35-42 d in 7-day-old group were also significantly higher than 42-day-old group (P<0.05)，the feed intake of lambs in each group were increased with the increasing of age.There was a difference on weight and volume of forestomach at the age of 28 or 42 d between 7- and 42-day-old groups.The weight of ruminoreticulum and associated relative weight (%，live weight)，the weight of forestomach and associated relative weight (%，stomach weight) of lambs at the age of 28 d in 7-day-old group trended to be higher than 42-day-old group (0.05<P<0.1)，the weight and volume of ruminoreticulum and associated relative weight (%，live weight)，the weight and volume of omasum，the weight of forestomach and associated relative weight (%，live weight)，the weight and volume of abomasum and associated relative weight (%，live weight) of lambs at the age of 42 d in 7-day-old group were significantly higher than 42-day-old group (P<0.05).The starter supplying could stimulate the growth performance and development of stomach of lambs，furthermore，starter supplement at the 7-day-old was better than 42-day-old.Starter supplying at the age of 7 d with the weaning age of 35 d and starter supplying at the age of 42 d with the weaning age of 56 d were feasible.

WANG X

, LIU

, LI F

, LI

, WANG W

, TANG D

, LI B

, MA Z

, PAN X

. Effect of starter supply age on the morphology of the rumen and small intestine in lamb
Acta Veterinaria et Zootechnica Sinica, 2016,47(2):305-314. (in Chinese)

DOI:10.11843/j.issn.0366-6964.2016.02.013 URL [本文引用: 1]

BALDWIN R

, MCLEOD K

, KLOTZ J

. Rumen development, intestinal growth and hepatic metabolism in the pre- and postweaning ruminant
Journal of Dairy Science, 2004,87(1):E55-E65.

DOI:10.3168/jds.S0022-0302(04)70061-2 URL [本文引用: 1]

[21]

莫负涛. 不同RFI育肥羔羊生产性能和体组成及消化代谢研究
[D]. 兰州: 甘肃农业大学, 2016.

[本文引用: 2]

MO F

. Study on production performance, body composition traits, digestion metabolism of lambs by different RFI
[D]. LanZhou: GanSu Agricultural University, 2016. (in Chinese)

[本文引用: 2]

[22]

温蕾, 陈肇源, 陈桂霞, 袁镜乐. 石蜡切片的制作及其免疫组化染色技术
畜牧兽医科技信息, 2018,5(36):497.

[本文引用: 1]

WEN

, CHEN Q

, CHEN G

, YUAN

J L

. preparation of paraffin sections and immunohistochemical staining technique
Chinese Journal of Animal Husbandry and Veterinary Medicine, 2018,5(36):497. (in Chinese)

[本文引用: 1]

[23]

金鑫, 张丽, 何林波, 肖先灿, 曹忻. 瘤胃发育研究进展
[J]. 湖南畜牧兽医, 2019(4):52-54.

[本文引用: 1]

JIN

, ZHANG

, HE L

, XIAO X

, CAO

. Advance in ruminal development
Hunan Journal of Animal Science & Veterinary Medicine, 2019(4):52-54. (in Chinese)

[本文引用: 1]

[24]

祁敏丽, 刁其玉, 张乃锋. 羔羊瘤胃发育及其影响因素研究进展
中国畜牧杂志, 2015,51(09):77-81.

[本文引用: 1]

, DIAO Q

, ZHANG N

. Advance in ruminal development and its influencing factors in lambs
Chinese Journal of Animal Husbandry, 2015,51(09):77-81. (in Chinese)

[本文引用: 1]

[25]

刘婷, 李发弟, 李冲, 王维民, 汪晓娟, 李飞, 郑琛, 莫负涛, 王芳彬, 喇永富, 李宝胜. 断奶时间对不同日龄湖羊羔羊瘤胃形态及表皮生长相关基因表达的影响
动物营养学报, 2016,28(5):1384-1393.

[本文引用: 1]

LIU

, LI F

, LI

, WANG W

, WANG X

, LI

, ZHENG

, MO F

, WANG F

, LA Y

, LI B

. Effects of weaner time on rumen morphology and gene expressions involved in rumen epidermis growth of Hu Lambs at different days of age
Chinese Journal of Animal Nutrition, 2016,28(5):1384-1393. (in Chinese)

[本文引用: 1]

[26]

CROWLEY J

, MCGEE

, KENNY D

, CREWS D

, EVANS R

, BERRY D

. Phenotypic and genetic parameters for different measures of feed efficiency in different breeds of Irish performance-tested beef bulls
Journal of Animal Science, 2010,88(3):885-894.

DOI:10.2527/jas.2009-1852 URLPMID:19966161 [本文引用: 1]

No genetic parameters for performance and feed efficiency traits are available for Irish performance-tested bulls. The objective of this study was to determine the phenotypic and genetic variation for feed intake, BW, ADG, and measures of feed efficiency including feed conversion ratio (FCR), relative growth rate, Kleiber ratio, residual BW gain (RG), and residual feed intake (RFI). Observations were available on up to 2,605 bulls for each trait from one test station across 24 yr; breeds included in the analyses were Aberdeen Angus (AN), Charolais (CH), Hereford, Limousin (LI), and Simmental. The test period was at least 70 d. Bulls were individually offered concentrates ad libitum, with a restricted forage allowance. Differences in performance and feed efficiency existed among breeds. For example, AN, on average, ate 0.04 kg of DM/d more than CH but had ADG of 0.14 kg/d less over the 70-d test period. Results showed LI and CH were the most efficient breeds when efficiency was defined as FCR or RFI. When animals were partitioned into groups based on high, medium, or low RFI, the low RFI (i.e., most efficient) group were also the more efficient as defined by RG and FCR. The low RFI group had the same ADG as the medium group and a greater ADG (P < 0.01) than the high group (1.67 vs. 1.66 and 1.63 kg/d); yet they ate 0.67 kg of DM/d less (P < 0.001) than the medium RFI group and 1.22 kg of DM/d less (P < 0.001) than the high RFI (i.e., least efficient) group. Genetic parameters for all performance and efficiency measures were estimated across breeds using linear animal mixed models; heritability estimates for feed efficiency traits ranged from 0.28 +/- 0.06 (RG) to 0.45 +/- 0.06 (RFI). An additional series of analyses included a maternal component in the model; maternal heritability estimates for feed efficiency traits ranged from 0.05 +/- 0.03 (RG) to 0.11 +/- 0.05 (relative growth rate). Genetic correlations between most of the different feed efficiency measures were strong. Results from this study indicate significant genetic differences in performance and some measures of feed efficiency among performance-tested beef bulls.

[27]

SAMUEL E

, FERNANDO G

, ROMDHANE

. Association of SNPs with components of residual feed intake parameters in a meat-type chicken population
[C]// 10th World Congress on Genetics Applied to Livestock Production. 2014.

[本文引用: 1]

[28]

张小雪. 不同剩余采食量羔羊生产性能和瘤胃微生物区系及肝脏转录组研究
[D]. 兰州: 兰州大学, 2019.

[本文引用: 1]

ZHANG X

. Study on production performance, rumen microflora and liver transcriptome of lambs with different residual feed intake
[D]. Lanzhou: Lanzhou University, 2019. (in Chinese)

[本文引用: 1]

[29]

石风华, 周振明, 任丽萍, 孟庆翔. 肉牛剩余采食量的概念和实践应用
饲料工业, 2010(S2):138-141.

[本文引用: 1]

SHI F

, ZHOU Z

, REN L

, MENG Q

. Residual feed intake of beef cattle: the concept and it's application
Feed Industry, 2010(S2):138-141. (in Chinese)

[本文引用: 1]

[30]

MCGEE

, WELCH C

, RAMIREZ J

, CARSTENS G

, PRICE

, Hall

JB 4

, Hill

. Relationships of feeding behaviors with average daily gain, dry matter intake, and residual feed intake in Red Angus-sired cattle
Journal of Animal Science, 2014,92(11):5214-5221.

DOI:10.2527/jas2014-8036 URL [本文引用: 1]

Feeding behavior has the potential to enhance prediction of feed intake and to improve understanding of the relationships between behavior, DMI, ADG, and residual feed intake (RFI) in beef cattle. Two cohorts, born in 2009 and 2010, the progeny of Red Angus bulls (n = 58 heifers and n = 53 steers), were evaluated during the growing phase, and the latter group of steers was also evaluated during the finishing phase. All behavior analyses were based on 7 feeding behavior traits (bunk visit frequency, bunk visit duration [BVDUR], feed bout frequency, feed bout duration, meal frequency, meal duration, and average meal intake) and their relationships with ADG, DMI, and RFI. During the growing phase, feeding duration traits were most indicative of DMI with positive correlations between BVDUR and DMI for cohort 1 steers, growing phase (n = 28, r = 0.52, P = 0.00); cohort 2 steers, growing phase (n = 25, r = 0.44, P = 0.01); and cohort 2 heifers, growing phase (n = 29, r = 0.28 P = 0.05). There were similar trends toward correlation of BVDUR and RFI for both steer groups and cohort 1 heifers, growing phase (C1HG; n = 29; r = 0.27, P = 0.06; r = 0.30, P = 0.07; and r = 0.26, P = 0.08, respectively). Feed bout frequency was correlated with ADG in C1HG and in cohort 2 steers, finishing phase (r = -0.31, P = 0.04, and r = 0.43, P = 0.01, respectively). Feed bout duration was correlated with ADG in heifer groups (r = 0.29 and r = 0.28, P = 0.05 for both groups) and DMI for all growing phase animals (r = 0.29 to 0.55, P <= 0.05 for all groups). Evaluation of growing vs. finishing phase steer groups suggests that all behaviors, RFI, and DMI, but not ADG, are correlated through the growing and finishing phases (P = 0.01 for all variables excluding ADG), implying that feeding behaviors determined during the growing phase are strong predictors of DMI in either life stage. Sire maintenance energy EPD effects (measured as high or low groups) on progeny feeding behaviors revealed a difference in meal duration with a tendency to differ in average meal intake (P = 0.01 and P = 0.07, respectively). Feeding behavior duration traits may be useful predictors of DMI in Red Angus cattle.

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