Chinese Journal of Animal Nutrition >

2023 , Vol. 35 >Issue 9: 5837 - 5848

DOI: https://doi.org/10.12418/CJAN2023.537

RESEARCH PAPER

Effects of Replacing Corn Straw and Caragana korshinskii with Different Proportions of Reed Grass on Growth Performance, Nitrogen Metabolism, Slaughter Performance and Meat Quality of Tan Sheep

  • WANG Tian , 1 ,
  • LI Qingmin 1 ,
  • TIAN Xiaoyu 1 ,
  • LI Xuemei 1 ,
  • LI Fei 2 ,
  • WEN Hongrui 1 ,
  • ZHOU Yuxiang , 1, ** ,
  • LIU Wenmao 3
Expand
  • 1 Agricultural College of Ningxia University, Yinchuan 750021, China
  • 2 Xiji County Animal Husbandry and Aquatic Technology Extension Service Center, Xiji 756299, China
  • 3 Ningxia Zhongning Wenmao Ecological Feed Co., Ltd., Zhongning 755100, China
** professor, E-mail:

*Contributed equally

Received date: 2023-04-07

  Online published: 2023-09-13

Fold

Abstract

The aim of this experiment was to investigate the effects of different proportions of reed grass replacing corn straw and Caragana korshinskii on growth performance, nitrogen metabolism, slaughter performance and meat quality of Tan sheep. Thirty-two male lambs of Ningxia Tan sheep in good body condition, healthy and similar body weight were randomly divided into four groups with eight lambs in each group. Tan sheep in the four groups were fed pelleted total mixed rations (TMR) which contained 0 (control group), 7% (trial group Ⅰ), 14% (trial group Ⅱ) and 21% (trial group Ⅲ) yellow reed grass. The pretest lasted for 15 days and the test lasted for 85 days. The results showed that: 1) the average daily gain of trial groups Ⅰ, Ⅱ and Ⅲ was extremely significantly lower than that of control group (P<0.01), while the feed to gain ratio was extremely significantly higher than that of control group (P<0.01). With the increase of the additive proportion of reed grass, the average daily gain of Tan sheep showed a gradually decreasing trend, and the feed to gain ratio showed a gradually increasing trend. The addition of reed grass reduced the growth performance and economic efficiency of Tan sheep. However, the average daily gain and net profit of Tan sheep in the trial groups were still at high levels, they were 210.54 to 224.80 g/d and 3.91 to 4.32 CNY/(sheep·d), respectively. 2) The deposition and utilization efficiency of nitrogen of Tan sheep decrease gradually with the increase of the additive proportion of reed grass, and the lowest total excretion of nitrogen was found when the additive proportion of reed grass was 7%. Compared with the control group, the apparent digestibility of acid detergent fiber was significantly reduced when the additive proportions of reed grass were 14% and 21% (P<0.05). 3) The addition of reed grass reduced the slaughter performance, tail fat deposition, muscle cooked meat rate and water retention capacity of Tan sheep, and did not cause adverse effects on the lamb nutritional composition of Tan sheep. Compared with the control group, the additive proportion of reed grass at 14% significantly improved the muscle brightness (L*) value (P<0.05). In summary, under the conditions of this experiment, the growth performance, slaughter performance, meat quality, deposition and utilization efficiency of nitrogen and economic efficiency of Tan sheep decrease gradually with the increase of the additive proportion of reed grass, but the total excretion of nitrogen is the lowest when the additive proportion of reed grass is 7%. Considering that the net profit and average daily gain of Tan sheep are at high levels, reed grass can be used as a substitute when there is a shortage of corn straw, and the reed grass additive proportion no more than 7% is preferable.

Key words： reed grass; Tan sheep; performance; meat quality

Cite this article

WANG Tian , LI Qingmin , TIAN Xiaoyu , LI Xuemei , LI Fei , WEN Hongrui , ZHOU Yuxiang , LIU Wenmao . Effects of Replacing Corn Straw and Caragana korshinskii with Different Proportions of Reed Grass on Growth Performance, Nitrogen Metabolism, Slaughter Performance and Meat Quality of Tan Sheep[J]. Chinese Journal of Animal Nutrition, 2023 , 35(9) : 5837 -5848 . DOI: 10.12418/CJAN2023.537

芦苇草(Phragmites australis)属于禾本科芦苇属,该属在全球范围内分布有10余种,我国有芦苇、卡开芦和日本苇3个种[1-2]。芦苇草有多种用途,可作为生物燃料、土壤肥料等,对不同pH、酸碱度、含重金属离子的土壤具有修复作用[3]。有研究表明,嫩芦苇茎叶干物质中含代谢能9.21 MJ/kg,粗蛋白质12.2%,粗纤维26.8%,钙0.4%,磷0.3%,其营养成分高于一般牧草,具有潜在的饲料原料开发价值。嫩芦苇草还含有丰富的维生素,这些维生素在机体代谢中起着重要作用,同时可增强机体免疫力[4];它还起到益菌素的功能,能维持消化道微生物生态平衡,促进共生微生物的生长,增强胃肠蠕动,增加采食量[4]。有研究表明,饲粮中添加20%和40%芦苇草组和田羊的干物质采食量显著高于对照组,且添加20%芦苇草组的日增重也显著高于对照组[5]。目前,在饲粮组成不同的情况下,芦苇草的添加量对滩羊的饲喂效果及经济效益的影响尚未见报道。因此,本试验旨在探讨添加芦苇草替代玉米秸秆和柠条对滩羊生长性能、屠宰性能和肉品质的影响,同时确定滩羊饲粮中芦苇草的适宜添加量,以期为滩羊科学养殖及芦苇草饲用化提供理论依据和参考。

1 材料与方法

1.1 试验时间与地点

饲养试验和试验样品的采集于2021年5—9月在宁夏回族自治区中宁县文茂生态饲料有限公司进行,样品分析于2021年10—12月在宁夏大学农学院动物营养实验室完成。

1.2 试验动物及试验设计

选用健康、平均体重为(23.36±2.67) kg的4月龄宁夏滩羊公羔32只,随机分为4组,每组8只。4组试验羊分别每日饲喂含有0(对照组)、7%(试验Ⅰ组)、14%(试验Ⅱ组)、21%(试验Ⅲ组)枯黄期芦苇草的颗粒化全混合日粮(TMR)。试验期100 d,其中预试期15 d,正试期85 d。试验开始前对圈舍进行消毒通风,对试验羊进行驱虫等常规防疫。每日饲喂2次,自由饮水。

1.3 试验饲粮

试验饲粮参照我国《肉羊饲养标准》(NY/T 816—2004)并结合实际生产配制,以满足每日滩羊的营养需要量,并制成颗粒化TMR。试验饲粮黄曲霉毒素B1含量<20 μg/kg,呕吐毒素含量<500 μg/kg,玉米赤霉烯酮含量<100 μg/kg,符合我国《饲料卫生标准》(GB 13078—2017)。采用四分法采集每组的颗粒化TMR,65 ℃烘48 h后分别参照GB/T 6435—2014、GB/T 6436—2018、GB/T 6437—2018测定干物质、钙、总磷含量,粗蛋白质含量使用全自动凯氏定氮仪(K9860,济南海能仪器有限公司)测定,中性洗涤纤维和酸性洗涤纤维含量使用纤维分析仪(ANKOM A200i型半自动纤维分析仪,Ankom公司,美国)进行测定。试验饲粮组成及营养水平见表1。
表1 试验饲粮组成及营养水平(干物质基础)

Table 1 Composition and nutrient levels of experimental diets (DM basis)%

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ
原料 Ingredients
玉米 Corn 25.95 25.95 25.95 25.95
豆粕 Soybean meal 5.40 5.40 5.40 9.15
胡麻饼 Flax cake 8.25 8.25 8.25 4.50
麸皮 Wheat bran 3.40 3.40 3.40 3.40
枸杞渣 Lycium barbarum residue 5.00 5.00 5.00 5.00
南瓜子仁皮 Pumpkin seed peel 11.00 11.00 11.00 11.00
南瓜子皮 Pumpkin seed 8.00 8.00 8.00 8.00
南瓜子壳外皮 Pumpkin seed shell 1.00 1.00 1.00 1.00
玉米秸秆 Corn straw 17.00 10.80 4.20
柠条 Caragana korshinskii 9.00 8.20 7.80 5.00
苦豆子 Bitter beans 2.00 2.00 2.00 2.00
枣渣 Jujube residue 1.00 1.00 1.00 1.00
葵花头 Sunflower head 1.00 1.00 1.00 1.00
芦苇草 Reed grass 7.00 14.00 21.00
食盐 NaCl 0.20 0.20 0.20 0.20
石粉 Limestone 0.60 0.60 0.60 0.60
小苏打 NaHCO3 0.20 0.20 0.20 0.20
预混料 Premix1) 1.00 1.00 1.00 1.00
合计 Total 100.00 100.00 100.00 100.00
营养水平 Nutrient levels2)
代谢能 ME/(MJ/kg) 10.46 10.50 10.52 10.54
粗蛋白质 CP 15.00 14.86 14.89 14.92
中性洗涤纤维 NDF 56.85 56.10 55.99 57.07
酸洗洗涤纤维 ADF 24.65 25.97 24.59 23.99
钙 Ca 0.51 0.63 0.57 0.67
总磷 TP 0.34 0.34 0.32 0.31

1)每千克预混料含有 One kilogram of premix contained the following: VA 250 000 IU,VE 375 IU,VD 3 100 000 IU,Fe 18 750 mg,Cu 875 mg,Zn 3 750 mg,Mn 3 750 mg,Se 125 mg,I 250 mg, Co 50 mg。

2)代谢能为计算值,其余为实测值。ME was a calculated value, while the others were measured values.

1.4 指标检测

1.4.1 生长性能指标

试验开始前和结束后,对试验羊进行空腹称量初始体重、终末体重,称量时间为07: 00,称量3次,并测量体高、体斜长、胸围,记录采食量,计算平均日干物质采食量、平均日增重和料重比。计算公式为:
平均日干物质采食量=总干物质耗料量/试验天数;
平均日增重=(终末体重-初始体重)/试验天数;
料重比=平均日采食量(以干物质计)/平均日增重。

1.4.2 氮代谢指标

采用全收粪尿法,在饲养试验中期从每个组随机选择4只体重相近的健康滩羊于特制的消化代谢笼中,试验期为12 d,其中预试期7 d,正试期5 d。正试期每天记录试验羊的采食量、排粪量、排尿量。对每天的总粪量进行称重,混匀后按总重的10%进行取样,每100 g新鲜粪便加入10 mL 10%的稀硫酸溶液固氮,用于粪氮的测定;对每天的总尿量体积进行记录,在混匀后取50 mL,装入试验用的取样瓶内并标号,按每毫升10%~20%的量加入10%的稀硫酸溶液固氮,用于尿氮的测定。氮代谢指标及营养物质表观消化率的计算公式参见文献[6]。氮生物学价值采用如下公式计算:
氮生物学价值(%)=[沉积氮/(食入氮-粪氮)]×100。

1.4.3 屠宰性能及肉品质指标

在饲养试验结束后,每组随机屠宰4只试验羊,进行肉品质的测定及羊肉常规营养成分的分析,宰前禁水2 h、禁食24 h。宰前活重、胴体重、净肉重、屠宰率、净肉率、骨重、骨肉比、胴体净肉率、胴体脂肪重和眼肌面积参考《绵、山羊生产性能测定技术规范》(NY/T 1236—2006)进行测定;GR值是用游标卡尺量取第12与第13肋骨之间距背脊中线11 cm处的肉组织厚度。羊肉pH45 min、滴水损失、失水率、剪切力、肉色和熟肉率的测定参照侯鹏霞[7]的方法进行;羊肉大理石纹评分参照NY/T 2781—2015 《羊胴体等级规格评定规范》进行测定;羊肉水分、粗灰分、粗脂肪、粗蛋白质等常规营养成分含量的测定参考AOAC(1990)[8]的方法测定。

1.5 数据统计与分析

使用Excel 2007对试验数据进行记录并作简单处理,采用SAS 8.2软件进行单因素方差分析,并采用LSD多重比较法进行差异显著性分析,结果用平均值±标准差表示,P<0.05为差异显著,P<0.01为差异极显著,P>0.05为差异不显著。

2 结果与分析

2.1 不同比例芦苇草替代玉米秸秆和柠条对滩羊生长性能及经济效益的影响

由表2可知,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组的平均日增重均极显著低于对照组(P<0.01),分别较对照组降低9.59%、11.30%、15.32%,且随着芦苇草添加比例的增加,试验羊的平均日增重呈逐渐降低的趋势;此外,3个试验组的料重比较对照组均有极显著的升高(P<0.01)。滩羊的初始体重、终末体重、平均日干物质采食量、体高增长量、体长增长量、胸围增长量各组间均无显著差异(P>0.05)。随着芦苇添加比例的增加,饲料成本逐渐降低,但增重收益和纯利润也呈现降低趋势。
表2 不同比例芦苇草替代玉米秸秆和柠条对滩羊生长性能及经济效益的影响

Table 2 Effects of replacing corn straw and Caragana korshinskii with different proportions of reed grass on growth performance and economic benefit of Tan sheep

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ		 P值
P-value
生长性能 Growth performance1)
初始体重 Initial body weight/kg 23.36±2.67 23.85±1.91 23.75±3.05 23.71±3.98 0.996
终末体重 Final body weight/kg 48.48±2.96 46.56±2.19 46.03±3.98 44.94±3.93 0.527
平均日增重 ADG/(g/d) 248.64±3.53Aa 224.80±5.62Bb 220.54±17.66Bb 210.54±3.53Bb 0.008
平均日干物质采食量 ADMI/(kg/d) 1.47±0.44 1.44±0.42 1.43±0.41 1.44±0.40 0.999
料重比 F/G 5.91±0.08Bb 6.55±0.16Aa 6.70±0.51Aa 6.99±0.12Aa 0.008
体高增长量 Increase in body height/cm 5.20±2.17 6.00±3.00 4.80±2.39 6.40±3.91 0.820
体长增长量 Increase in body length/cm 6.60±1.52 6.00±1.73 5.60±2.30 6.00±1.87 0.866
胸围增长量
Increase in chest circumference/cm		 20.00±10.84 15.20±3.83 15.80±4.21 15.40±3.05 0.593
经济效益 Economic benefit/[元/(只·d)]2)
饲料成本 Feed cost 3.16 3.05 3.01 2.96
人工成本 Labor cost 0.50 0.50 0.50 0.50
增重收益 Weight gain profit 8.70 7.87 7.72 7.37
纯利润 Net profit 5.04 4.32 4.21 3.91

1)同行数据肩标不同小写字母表示差异显著(P<0.05),不同大写字母表示差异极显著(P<0.01),相同字母或无字母表示差异不显著(P>0.05)。下表同。Values in the same row with different small letter superscripts mean significant difference (P<0.05), and with different capital letter superscripts mean extremely significant difference (P<0.01), while with no letter or the same letter superscripts mean no significant difference (P>0.05). The same as below.

2)滩羊活羊价格按2021年市场价35元/kg计算。The live sheep price of Tan sheep is 35 CNY/kg, which is the market price in 2021.

2.2 不同比例芦苇草替代玉米秸秆和柠条对滩羊氮代谢的影响

由表3可知,3个试验组的尿氮均较对照组有所降低(P>0.05),其中以试验Ⅲ组最低,为4.55 g/d,而对照组的粪氮则低于3个试验组(P>0.05),为13.63 g/d。试验Ⅰ组的总排出氮低于其他3组,但无显著差异(P>0.05)。3个试验组的沉积氮和氮利用率均较对照组有所降低,但差异不显著(P>0.05)。
表3 不同比例芦苇草替代玉米秸秆和柠条对滩羊氮代谢的影响

Table 3 Effects of replacing corn straw and Caragana korshinskii with different proportions of reed grass on nitrogen metabolism of Tan sheep

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ		 P值
P-value
进食氮 Intake nitrogen/(g/d) 39.66±1.98 37.53±2.91 37.48±0.10 37.69±2.59 0.347
尿氮 Urine nitrogen/(g/d) 5.09±0.27 4.72±0.64 4.87±0.35 4.55±0.36 0.502
粪氮 Fecal nitrogen/(g/d) 13.63±1.33 13.64±2.36 14.06±0.55 14.88±1.58 0.569
总排出氮
Total excretion of nitrogen/(g/d)		 18.72±1.36 18.36±1.82 18.93±0.24 19.43±1.46 0.523
沉积氮 Retention nitrogen/(g/d) 20.94±2.14 19.17±4.64 18.55±0.31 18.26±2.14 0.642
氮利用率
Utilization efficiency of nitrogen/%		 52.80±3.64 51.08±8.38 49.49±0.67 48.45±3.42 0.756
氮生物学价值
Biological value of nitrogen/%		 80.45±1.04 80.24±1.89 79.21±0.90 80.05±0.66 0.822

2.3 不同比例芦苇草替代玉米秸秆和柠条对滩羊营养物质表观消化率的影响

由表4可知,3个试验组的酸性洗涤纤维表观消化率均低于对照组,其中试验Ⅲ组最低,为28.07%,较对照组降低了32.26%,差异显著(P<0.05)。中性洗涤纤维和干物质表观消化率各组间均无显著差异(P>0.05),但以对照组最高,分别为62.35%和56.31%。
表4 不同比例芦苇草替代玉米秸秆和柠条对滩羊营养物质表观消化率的影响

Table 4 Effects of replacing corn straw and Caragana korshinskii with different proportions of reed grass on apparent digestibility of nutrients of Tan sheep%

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ		 P值
P-value
干物质 DM 56.31±2.09 55.55±11.89 53.21±2.61 53.59±4.60 0.923
中性洗涤纤维 NDF 62.35±3.65 58.90±4.80 56.46±1.93 56.49±4.36 0.271
酸性洗涤纤维 ADF 41.44±3.84a 36.99±5.84ab 31.19±3.11b 28.07±6.43b 0.045

2.4 不同比例芦苇草替代玉米秸秆和柠条对滩羊屠宰性能的影响

由表5可知,3个试验组滩羊的胴体重、净肉重、屠宰率及皮下脂肪厚与对照组相比有不同程度降低,其中试验Ⅲ组最低,胴体重和净肉重较对照组分别降低了13.83%和15.98%(P<0.05),屠宰率和皮下脂肪厚较对照组分别降低了7.59%和20.64%(P<0.05)。胴体净肉率、骨重、骨肉比、GR值、眼肌面积各组间均无显著差异(P>0.05)。骨重占胴体重比例、胴体脂肪重占胴体重比例及尾重占胴体重比例各组间均无显著差异(P>0.05),其中骨重占胴体重比例3个试验组均高于对照组。
表5 不同比例芦苇草替代玉米秸秆和柠条对滩羊屠宰性能的影响

Table 5 Effects of replacing corn straw and Caragana korshinskii with different proportions of reed grass on slaughter performance of Tan sheep

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ		 P值
P-value
胴体重 Carcass weight/kg 25.95±0.37a 23.86±1.75ab 23.42±2.96ab 22.36±0.40b 0.045
净肉重 Net meat weight/kg 22.71±0.52a 20.67±2.13ab 19.97±2.80ab 19.08±0.44b 0.047
胴体净肉率 Carcass net meat rate/% 87.52±0.92 86.46±2.86 85.19±1.45 85.35±1.26 0.268
骨重 Bone weight/kg 3.24±0.21 3.20±0.48 3.44±0.25 3.28±0.29 0.733
骨重占胴体重比例
Percentage of bone weight to
carcass weight/%		 12.48±0.92 13.54±2.86 14.81±1.45 14.65±1.26 0.268
胴体脂肪重占胴体重比例
Percentage of carcass fat
weight to carcass weight/%		 25.55±2.56 24.09±2.53 24.92±2.18 24.91±1.96 0.848
尾重占胴体重比例
Percentage of tail weight to
carcass weight/%		 8.32±1.90 6.87±1.11 6.80±2.20 6.36±1.06 0.398
骨肉比 Bone/meat ratio 0.14±0.01 0.16±0.04 0.18±0.02 0.17±0.02 0.216
屠宰率 Dressing percentage/% 57.55±1.26a 55.98±3.23ab 54.74±3.06ab 53.18±2.77b 0.041
GR值GR value/mm 22.95±1.88 24.77±1.82 24.66±2.39 22.67±1.99 0.358
皮下脂肪厚
Thick of subcutaneous fat/mm		 15.55±2.28a 14.59±1.81ab 14.63±2.25ab 12.34±0.48b 0.037
眼肌面积 Loin eye area/cm2 24.24±5.71 20.03±5.67 25.47±2.89 20.72±6.39 0.433

2.5 不同比例芦苇草替代玉米秸秆和柠条对滩羊非胴体性能的影响

由表6可知,试验Ⅰ组的蹄重显著低于对照组(P<0.05),较对照组降低了12.36%,蹄重占宰前活重的比例最低,为1.82%。宰前活重各组间无显著差异(P>0.05)。试验Ⅱ组的头重及头重占宰前活重比例较其他3组高(P>0.05)。皮重、皮重占宰前活重比例、睾丸重、睾丸占宰前活重比例各组间差异均不显著(P>0.05)。
表6 不同比例芦苇草替代玉米秸秆和柠条对滩羊非胴体性能的影响

Table 6 Effects of replacing corn straw and Caragana korshinskii with different proportions of reed grass on non-carcass performance of Tan sheep

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ		 P值
P-value
宰前活重 Live weight before slaughter/kg 45.10±0.91 42.63±1.78 42.65±3.05 42.10±1.56 0.194
头重 Head weight/kg 2.90±0.33 2.95±0.27 2.98±0.26 2.86±0.11 0.925
头重占宰前活重比例
Percentage of head weight to live
weight before slaughter/%		 6.43±0.64 6.92±0.57 7.00±0.71 6.80±0.13 0.510
蹄重 Hoof weight/kg 0.89±0.09a 0.78±0.05b 0.85±0.04ab 0.79±0.09ab 0.049
蹄重占宰前活重比例
Percentage of hoof weight to live
weight before slaughter/%		 1.97±0.17 1.82±0.16 2.00±0.12 1.88±0.28 0.562
皮重 Fur weight/kg 3.73±0.47 3.58±0.38 3.65±0.12 3.56±0.21 0.886
皮重占宰前活重比例
Percentage of fur weight to live weight/%		 8.27±1.22 8.37±0.59 8.60±0.83 8.47±0.56 0.945
睾丸重 Testicular weight/kg 0.47±0.08 0.44±0.14 0.39±0.07 0.45±0.08 0.650
睾丸重占宰前活重比例
Percentage of testicular
weight to live weight/%		 1.05±0.19 1.02±0.30 0.90±0.16 1.05±0.16 0.724

2.6 不同比例芦苇草替代玉米秸秆和柠条对滩羊肉理化性质的影响

由表7可知,3个试验组的羊肉pH45 min和失水率均高于对照组,其中试验Ⅱ组、试验Ⅲ组与对照组间差异显著(P<0.05)。试验Ⅲ组的滴水损失比对照组提高了60.31%(P<0.05),试验Ⅰ组和试验Ⅱ组则与对照组无显著差异(P>0.05)。肌肉红度(a*)值试验Ⅱ组与试验Ⅰ组间差异极显著(P<0.01),以试验Ⅱ组最高,为21.45。肌肉亮度(L*)值试验Ⅱ组、试验Ⅲ组与对照组间差异极显著(P<0.01),试验Ⅰ组与对照组间无显著差异(P>0.05),以试验Ⅲ组最高,为42.30。脂肪a*值试验Ⅲ组与试验Ⅰ组、对照组间差异极显著(P<0.01),以试验Ⅲ组最高,为6.53。此外,剪切力、熟肉率、大理石纹评分、肌肉黄度(b*)值及脂肪b*值和L*值各组间无显著差异(P>0.05)。滩羊肉营养成分中水分、粗蛋白质、粗脂肪、粗灰分含量各组间均无显著差异(P>0.05),其中试验Ⅰ组的粗脂肪含量最高。
表7 不同比例芦苇草替代玉米秸秆和柠条对滩羊肉理化性质的影响

Table 7 Effects of replacing corn straw and Caragana korshinskii with different proportions of reed grass on physicochemical properties of Tan sheep meat

项目
Items		 对照组
Control group		 试验Ⅰ组
Trial group Ⅰ		 试验Ⅱ组
Trial group Ⅱ		 试验Ⅲ组
Trial group Ⅲ		 P值
P-value
pH45 min 6.37±0.04b 6.45±0.05ab 6.52±0.09a 6.53±0.13a 0.046
失水率 Water loss rate/% 40.00±1.96b 42.78±4.39ab 42.96±4.13a 43.64±2.77a 0.032
滴水损失 Drip loss/% 1.99±0.82b 2.02±0.52ab 2.68±1.02ab 3.21±0.64a 0.032
剪切力 Shear force/N 38.18±5.47 37.45±3.43 36.43±4.67 44.34±6.68 0.187
熟肉率 Cooked meat rate/% 53.39±1.30 53.13±1.37 53.03±1.16 52.91±1.20 0.954
红度 a* 18.99±1.01ABab 17.80±0.86Bb 21.45±2.43Aa 20.52±1.06ABab 0.001

肌肉颜色		 黄度 b* 7.84±0.29 7.61±0.78 8.35±1.71 9.06±0.36 0.207

Muscle color		 亮度 L* 35.75±1.21Bb 39.31±3.97ABab 41.18±1.50Aa 42.30±1.47Aa 0.009
红度 a* 4.68±1.40Bb 4.30±0.45Bb 5.42±0.40ABab 6.53±0.76Aa 0.001
脂肪颜色 黄度 b* 9.24±1.98 7.23±1.12 7.73±1.68 8.57±1.45 0.331
Fat color 亮度 L* 78.24±3.89 83.73±5.90 84.17±2.86 85.12±5.56 0.214
大理石纹评分 Marbling score 4 4 4 4 0.285
水分 Moisture 75.35±0.44 74.88±0.51 74.78±0.56 75.11±0.33 0.485
粗蛋白质 CP 19.94±1.31 19.72±0.44 20.12±0.72 19.75±0.40 0.932
粗脂肪 EE 3.33±0.31 4.01±0.87 3.82±0.80 3.60±0.09 0.591
粗灰分 Ash 1.38±0.26 1.39±0.20 1.28±0.29 1.54±0.54 0.830

3 讨论

3.1 不同比例芦苇草替代玉米秸秆和柠条对滩羊生长性能的影响

影响动物生长发育的因素主要有遗传因素和营养因素,其中营养因素包括饲粮的营养成分、适口性和状态等[9]。平均日增重是体现动物生长性能和对饲料消化利用率的重要指标[10]。陈宁等[11]在研究不同饲粮组成下新疆芦苇在断奶初期奶公犊瘤胃内动态降解时发现,精粗比为60:40的饲粮有利于新疆芦苇草在断奶期奶公犊瘤胃内的消化吸收及快速育肥。本试验中,3个试验组的滩羊平均日增重均极显著低于对照组,分别为224.80、220.54、210.54 g/d,并随芦苇草添加比例的增加呈逐渐降低的趋势,与Zaki等[12]和Farghaly等[13]的研究结果不同。其原因可能是,收获后期干枯芦苇草纤维含量高、蛋白质含量低、适口性差,导致动物自愿采食力下降,降低了滩羊的干物质采食量,从而影响了平均日增重[14⇓⇓-17]。本试验使用的芦苇草是生长后期收获的干枯芦苇草,滩羊平均日增重在210.54~224.80 g/d,仍属于较高水平。芦苇草饲喂滩羊并未影响其正常的生长发育和健康,故在粗饲料资源短缺情况下可以考虑用芦苇草来代替部分玉米秸秆饲喂滩羊。

3.2 不同比例芦苇草替代玉米秸秆和柠条对滩羊氮代谢的影响

蛋白质是动物机体维持健康、保持高效生产性能的重要营养物质。动物饲粮中蛋白质水平过高会引起氮的浪费,蛋白质水平过低则不利于动物的生长发育。大量研究表明,畜禽饲粮中粗蛋白质相对含量每减少1个百分点相应地可减少8%~10%的氮排泄[18]。研究报道,饲粮蛋白质水平是影响羊氮采食量、粪氮和尿氮排放量最直接的因素[19]。郭凯等[20]研究发现,当滩羊每日氮摄入量超出机体需要量时,多余的氮会以粪氮和尿氮的形式排出体外。本试验中,饲粮蛋白质在相近水平时,试验Ⅱ组总排出氮较其他组有降低的趋势。若在粗饲料短缺时,以芦苇草来代替部分玉米秸秆饲喂滩羊,其氮排放量较低,但随着芦苇草添加比例的增加,其氮排放量逐渐增高,综合来看,以添加7%和14%芦苇草较宜。

3.3 不同比例芦苇草替代玉米秸秆和柠条对滩羊营养物质表观消化率的影响

消化率是衡量饲料的可消化性和动物对饲料的消化能力这2个方面的统一指标。饲粮某营养成分的表观消化率高低受饲料的可消化性、动物采食量的多少、瘤胃微生物组成以及营养物质在瘤胃内停留时间等因素的影响。本试验中,试验Ⅱ组、试验Ⅲ组的酸性洗涤纤维表观消化率显著低于对照组,较对照组分别降低了24.73%和32.26%,这与袁芳等[5]的研究结果不同。其一方面可能与芦苇草的添加比例不同有关;另一方面可能是由于本试验中芦苇草的收获时间较晚,品质较低,其纤维含量较青绿时增加,过高的纤维含量加快了营养物质通过瘤胃的速度,使营养物质难以充分消化利用,从而降低了其对酸性洗涤纤维的表观消化率。干物质表观消化率代表了动物对饲料的平均消化能力。本试验中干物质表观消化率各组间差异均不显著,这与齐大胜[9]的研究结果相同。

3.4 不同比例芦苇草替代玉米秸秆和柠条对滩羊屠宰性能的影响

屠宰性能是判断动物发育的重要指标之一[21],其主要包括胴体重、净肉重、屠宰率、皮下脂肪厚、GR值、眼肌面积等指标,且都与牧场的经济效益密切相关。本研究发现,3个试验组滩羊的胴体重、净肉重、屠宰率及皮下脂肪厚与对照组相比逐渐降低,其中试验Ⅲ组最低,胴体重和净肉重较对照组分别降低了13.83%和15.98%,屠宰率和皮下脂肪厚较对照组分别降低了7.59%和20.64%。结合本试验前文研究结果分析,可能是芦苇草的添加降低了滩羊对蛋白质的沉积率和利用率,且使酸性洗涤纤维等营养物质的表观消化率下降,从而使滩羊对营养物质的利用率降低,影响了其屠宰性能。骨重占胴体重比例、胴体脂肪重占胴体重比例、尾重占胴体重比例各组间均无显著差异,其中尾重占胴体重比例3个试验组均低于对照组,表明芦苇草的添加可一定程度上降低滩羊尾脂的沉积。

3.5 不同比例芦苇草替代玉米秸秆和柠条对滩羊肉理化性质的影响

肉品质包括两部分,一部分是肉的感官品质,另一部分是营养组成[22]。羊肉pH反映了试验动物屠宰后肌肉糖原酵解速率和水平[23],试验动物屠宰后肌肉的pH应在6.0~7.0,若pH的下降速度过快会破坏水和蛋白质的结合,影响肌肉组织的蛋白质特性[24]。本试验中,各组羊肉pH45 min均在正常范围内,对照组pH45 min低于3个试验组,且与试验Ⅱ组、试验Ⅲ组间差异显著,这可能与对照组滩羊肌肉糖原酵解速率较快有关。有研究发现,滴水损失与肌肉失水率呈高度正相关[25],体现了肌肉的系水能力。本试验中,3个试验组滩羊肌肉的滴水损失和失水率均高于对照组,表明芦苇草的添加降低了滩羊肌肉的系水能力。肉的颜色是确保客户吸引力的关键,并对产品的价值做出了重大的贡献[26]。其中肌肉的L*值和b*值越低,a*值越高,则肉色越好[27-28]。此外,优质的脂肪是白色且有光泽的,若颜色发黄则会影响其品质[29]。有研究表明,用芦苇草和田菁饲喂生长羔羊,芦苇草组羔羊的肌肉b*值和L*值显著提高,脂肪a*值显著降低[13]。本试验中,试验Ⅱ组、试验Ⅲ组肌肉L*值显著提高,与以上研究结果一致,而试验Ⅱ组的肌肉a*值极显著高于试验Ⅰ组,试验Ⅲ组脂肪a*值较对照组极显著升高,这与以上研究结果不同。分析原因可能与饲粮种类、形态及芦苇草添加比例不同有关,还可能是由于芦苇草降低了羊肉脂肪和胶原蛋白含量,增加了肉的嫩度,使肌肉和脂肪颜色得到了改变[13]。羊肉熟肉率越高代表蒸煮损失越小,肉品质越高[30]。本试验中,3个试验组的熟肉率均低于对照组,说明芦苇草的添加对羊肉的熟肉率有一定的影响。
羊肉的营养成分对羊肉的口感和风味有重要意义,是评价肉品质的重要营养指标之一[31]。有研究报道,滩羊羊肉的水分含量在77%左右[32]、粗脂肪含量在3.4%~4.5%时,羊肉的味道最好[33]。本试验中羊肉的水分和粗脂肪含量在以上范围内。此外,Murphy等[34]研究发现,饲草比例对羊肉的水分、蛋白质、脂肪、灰分含量无显著影响。本试验中芦苇草不同添加比例下羊肉的水分、粗蛋白质、粗脂肪、粗灰分含量均无显著差异,这与Murphy等[35]的结果相符,表明芦苇草的添加对滩羊肉营养成分未产生不良影响。

4 结论

本试验条件下,随着芦苇草添加比例的增加,滩羊对氮的沉积和利用率呈逐渐降低趋势,添加比例为7%时总排出氮最低。芦苇草添加比例为14%和21%时显著降低了滩羊对酸性洗涤纤维的表观消化率。随着芦苇草添加比例的增加,滩羊的生长性能、屠宰性能、肉品质及经济效益均有降低趋势。考虑到滩羊的纯利润和平均日增重处于较高水平下,故在玉米秸秆出现短缺的情况下可以用芦苇草来代替,芦苇草添加比例以不超过7%较宜。

References

Publishing order | Descend order by publishing year | Descend order by cited within
[1]
中国科学院中国植物志编辑委员会. 中国植物志 (第九卷) 第二分册[M]. 北京: 科学出版社, 2002.

Editorial Committee of the Flora of China,Chinese Academy of Sciences. Flora Reipublicae Popularis Sinicae[M]. Beijing: Science Press, 2002. (in Chinese)

[2]
李建国, 李贵宝, 刘芳, 等. 白洋淀芦苇资源及其生态功能与利用[J]. 南水北调与水利科技, 2004, 2(5):37-40.

LI J G, LI G B, LIU F, et al. Reed resource and its ecological function&utilization in Baiyangdian lake[J]. South-to-North Water Transfers and Water Science&Technology, 2004, 2(5):37-40. (in Chinese)

[3]
ALSHAAL T, ELHAWAT N, DOMOKOS-SZABOLCSY É, et al. Giant reed (Arundo donax L.):a green technology for clean environment[M]//ANSARI A A,GILL S S,GILL R,et al.Phytoremediation. Cham: Springer, 2015:3-20.

[4]
张淑荣. 嫩芦苇草饲喂獭兔的效果试验[J]. 中国草食动物, 2002, 22(5):39.

ZHANG S R. Experiment on the effect of feeding young reed grass to otters[J]. China Herbivore Science, 2002, 22(5):39. (in Chinese)

[5]
袁芳, 郭同军, 张俊瑜, 等. 日粮中添加芦苇对育肥期和田羊生长性能及表观消化率的影响[J]. 中国畜牧兽医, 2017, 44(6):1701-1706.

YUAN F, GUO T J, ZHANG J Y, et al. Effect of adding reed to diet on growth performance and apparent digestibility in fattening Hetian sheep[J]. China Animal Husbandry & Veterinary Medicine, 2017, 44(6):1701-1706. (in Chinese)

[6]
王之盛, 李胜利. 反刍动物营养学[M]. 北京: 中国农业出版社, 2016:134.

WANG Z S, LI S L. Ruminant nutrition[M]. Beijing: China Agriculture Press, 2016:134. (in Chinese)

[7]
侯鹏霞. 滩羊羔羊早期补饲以及不同体重阶段羊肉品质的研究[D].硕士学位论文. 银川: 宁夏大学, 2014.

HOU P X. Studies on the early supplement of lamb and mutton quality of different stages of weight in Tan sheep[D].Master’s Thesis. Yinchuan: Ningxia University, 2014. (in Chinese)

[8]
AOAC. Official methods of Analysis of the Association of Official Analytical Chemists[S].15th ed. Washington,D.C.: AOAC,

[9]
齐大胜. 四种非常规粗饲料在家兔上的营养价值评定[D].硕士学位论文. 保定: 河北农业大学, 2014.

QI D S. Study on nutritional value in four kinds of unconventional roughagefeed for rabbits[D].Master’s Thesis. Baoding: Agricultural University of Hebei, 2014. (in Chinese)

[10]
郭雪峰, 刘俊峰, 张苏江, 等. 妊娠后期限饲对策勒黑羊母羊分娩后血液中激素水平的影响研究[J]. 饲料研究, 2015(8):38-41.

GUO X F, LIU J F, ZHANG S J, et al. Study on the effect of post-pregnancy period feeding on blood hormone levels in ewes of black sheep after delivery[J]. Feed Research, 2015(8):38-41. (in Chinese)

[11]
陈宁, 尹君亮, 李国庆, 等. 不同日粮组成下新疆芦苇在断奶初期奶公犊瘤胃内动态降解的研究[J]. 饲料博览, 2006(5):4-7.

CHEN N, YIN J L, LI G Q, et al. Study on dynamic degradation in rumen of the initial stage of weaning calf to Xinjiang reed within different composition diets[J]. Feed Review, 2006(5):4-7. (in Chinese)

[12]
ZAKI A, OSMAN A, IBRAHIM F, et al. Effect of using Sesbania sesban and its mixtures with some summer fresh grasses on lambs productive performance in new reclaimed soil[J]. Journal of Animal,Poultry and Fish Production, 2015, 3(1):7-16.

DOI

[13]
FARGHALY M M, YOUSSEF I M I, RADWAN M A, et al. Effect of feeding Sesbania sesban and reed grass on growth performance,blood parameters,and meat quality of growing lambs[J]. Tropical Animal Health and Production, 2021, 54(1):3.

DOI

[14]
MOKHTARPOUR A, JAHANTIGH M. Effect of supplementing common reed (Phragmites australis) with urea on intake,apparent digestibility and blood metabolites of Baluchi sheep[J]. Iranian Journal of Applied Animal Science, 2018, 8(4):623-628.

[15]
SHEHATA E I, AHMED M E, AMMOU F F A, et al. Comparison of feeding reed as hay or silage with feeding berseem hay or maize silage to dairy Zaraibi goat[J]. Egyptian Journal of Sheep,Goat and Desert Animal Sciences, 2006, 1(1):233.

[16]
AHMED M E, ABDEL-GAWAD A M, SHEHATA E I, et al. Influence of using reed forage in different forms as fresh,silage and hay on blood profile and carcass quality of growing Rahmani sheep[J]. Egyptian Journal of Sheep and Goat Sciences, 2011, 6(2):25.

[17]
AHMED M E, EL-ZALAKY O A, AIAD K M, et al. Response of small ruminants to diets containing reed forage either as fresh,silage or hay versus berseem hay[J]. Egyptian Journal of Sheep and Goat Sciences, 2011, 6(1):15-26.

[18]
张相鑫. 低蛋白质日粮添加二氯乙酸钠对大足黑山羊氮平衡、物质代谢及消化道微生物区系的影响研究[D].硕士学位论文. 重庆: 西南大学, 2019.

ZHANG X X. Study for effects of supplementing low-protein diets with sodium dichloroacetate on nitrogen balance,nutrient metabolism and gastrointestinal microbial community of Dazu black goats[D].Master’s Thesis. Chongqing: Southwest University, 2019. (in Chinese)

[19]
赵小琪, 王思宇, 薛白, 等. 饲粮蛋白质水平对妊娠期云南半细毛羊氮平衡和养分排放的影响[J]. 动物营养学报, 2022, 34(3):1709-1720.

DOI

ZHAO X Q, WANG S Y, XUE B, et al. Effects of dietary crude protein level on nitrogen balance and nutrient excretions of Yunnan semi-fine wool ewes during pregnancy[J]. Chinese Journal of Animal Nutrition, 2022, 34(3):1709-1720. (in Chinese)

[20]
郭凯, 王栋, 霍倩倩, 等. 不同蛋白水平饲粮对荷斯坦公犊牛生长性能、氮消化代谢和血清指标的影响[J]. 饲料工业, 2019, 40(9):52-58.

GUO K, WANG D, HUO Q Q, et al. Effects of diets with different protein level on growth performance,nitrogen digestion and metabolism and serum indexes of Holstein male calves[J]. Feed Industry, 2019, 40(9):52-58. (in Chinese)

[21]
朱凯, 周瑞, 徐红伟, 等. 尾菜发酵饲料对绵羊生长性能、屠宰性能及肉品质的影响[J]. 现代畜牧兽医, 2021(12):32-35.

ZHU K, ZHOU R, XU H W, et al. Effect of vegetable residue fermented feed on growth performance,slaughtering performance and meat quality of sheep[J]. Modern Journal of Animal Husbandry and Veterinary Medicine, 2021(12):32-35. (in Chinese)

[22]
BERRI C, DEBUT M, SANTÉ-LHOUTELLIER V, et al. Variations in chicken breast meat quality:implications of struggle and muscle glycogen content at death[J]. British Poultry Science, 2005, 46(5):572-579.

DOI

[23]
孙冰, 侯艳茹, 徐丽媛, 等. 不同饲养方式下苏尼特羊肌纤维组成和羊肉品质的比较研究[J]. 食品工业科技, 2022, 43(11):96-103.

SUN B, HOU Y R, XU L Y, et al. Effects of different feeding patterns on muscle fiber type composition and mutton quality of Sunit sheep[J]. Science and Technology of Food Industry, 2022, 43(11):96-103. (in Chinese)

[24]
李文博. 饲养方式对苏尼特羊宰后肌原纤维蛋白与肉品质的影响[D].硕士学位论文. 呼和浩特: 内蒙古农业大学, 2020.

LI W B. Effects of feeding regimen on myofibrillar protein and meat quality after Sunit sheep slaughter[D].Master’s Thesis. Hohhot: Inner Mongolia Agricultural University, 2020. (in Chinese)

[25]
张艳梅. 复合化学处理稻草日粮中添加过瘤胃氨基酸对滩羊生产性能及肉品质的影响[D].硕士学位论文. 银川: 宁夏大学, 2019.

ZHANG Y M. The effects of rumen protected amino acids added in complex chemical straw diet on production performance and meat quality of Tan sheep[D].Master’s Thesis. Yinchuan: NingXia University, 2019. (in Chinese)

[26]
CALNAN H B, JACOB R H, PETHICK D W, et al. Factors affecting the colour of lamb meat from the longissimus muscle during display:the influence of muscle weight and muscle oxidative capacity[J]. Meat Science, 2014, 96(2):1049-1057.

DOI

[27]
DING H, LIU W, AO C, et al. PSIX-17 effects of dietary Allium mongolicum Regel leaves or probiotic complexes on mutton eating quality and antioxidant activities of Duhan sheep[J]. Journal of Animal Science, 2018, 96(S3):279-280.

[28]
KHLIJI S, VAN DE VEN R, LAMB T A, et al. Relationship between consumer ranking of lamb colour and objective measures of colour[J]. Meat Science, 2010, 85(2):224-229.

DOI PMID

[29]
杨桂林. 影响羊肉品质的饲料因素及营养调控措施[J]. 现代畜牧科技, 2017(3):49.

YANG G L. Feed factors and nutritional control measures affecting the quality of lamb meat[J]. Modern Animal Husbandry Science & Technology, 2017(3):49. (in Chinese)

[30]
吴爽, 周玉香, 贾柔, 等. 纤维素酶处理荞麦秸秆对其纤维结构和滩羊肉品质的影响[J]. 草业学报, 2021, 30(1):170-180.

DOI

WU S, ZHOU Y X, JIA R, et al. Effects of cellulase treatment of buckwheat straw on fiber structure and meat quality of Tan sheep[J]. Acta Prataculturae Sinica, 2021, 30(1):170-180. (in Chinese)

[31]
欧慧敏, 张小丽, 谭支良, 等. 呼伦贝尔羔羊不同部位肌肉品质评价及营养组成分析[J]. 动物营养学报, 2022, 34(1):467-477.

DOI

OU H M, ZHANG X L, TAN Z L, et al. Evaluation of muscle quality and analysis of nutrient composition in different parts of Hulun Buir lambs[J]. Chinese Journal of Animal Nutrition, 2022, 34(1):467-477. (in Chinese)

[32]
杨树猛, 郭淑珍, 格桂花, 等. 甘南藏羊与滩羊等羊羊肉营养成分分析[J]. 中国草食动物, 2009, 29(2):61-62.

YANG S M, GUO S Z, GE G H, et al. Nutrient composition analysis of sheep and goat meat of Gannan Tibetan sheep and Tan sheep[J]. China Herbivore Science, 2009, 29(2):61-62. (in Chinese)

[33]
SAÑUDO C, ENSER M E, CAMPO M M, et al. Fatty acid composition and sensory characteristics of lamb carcasses from Britain and Spain[J]. Meat Science, 2000, 54(4):339-346.

PMID

[34]
MURPHY T A, LOERCH S C, MCCLURE K E, et al. Effects of restricted feeding on growth performance and carcass composition of lambs[J]. Journal of Animal Science, 1994, 72(12):3131-3137.

PMID

Options
Outlines

/

〈 〉

京ICP备17050989号-2
Copyright © Chinese Journal of Animal Nutrition, All Rights Reserved.
Tel: 010－62817823　E-mail: cjan@vip.163.com
Powered by Beijing Magtech Co., Ltd.