南京农业大学学报  2018, Vol. 41 Issue (3): 511-518   PDF    
http://dx.doi.org/10.7685/jnau.201710002
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文章信息

王雨雨, 刘强, 王保哲, 范程瑞, 黎佳颖, 庄苏
WANG Yuyu, LIU Qiang, WANG Baozhe, FAN Chengrui, LI Jiaying, ZHUANG Su
凹凸棒石黏土对饲料颗粒质量及樱桃谷肉鸭生长性能、屠宰性能、肌肉品质和抗氧化性能的影响
Effect of different levels of palygorskite supplementation on pellet quality, growth performance, slaughter performance, meat quality and antioxidant ability in Cherry Valley ducks
南京农业大学学报, 2018, 41(3): 511-518
Journal of Nanjing Agricultural University, 2018, 41(3): 511-518.
http://dx.doi.org/10.7685/jnau.201710002

文章历史

收稿日期: 2017-10-09
凹凸棒石黏土对饲料颗粒质量及樱桃谷肉鸭生长性能、屠宰性能、肌肉品质和抗氧化性能的影响
王雨雨 , 刘强 , 王保哲 , 范程瑞 , 黎佳颖 , 庄苏     
南京农业大学动物科技学院, 江苏 南京 210095
摘要[目的]本试验旨在研究日粮中添加不同水平的凹凸棒石黏土(凹土)对饲料颗粒质量及樱桃谷肉鸭生长性能、屠宰性能、肌肉品质和抗氧化性能的影响。[方法]按照随机区组试验设计,将720只1日龄的樱桃谷肉鸭随机分为4个处理组,每组6个重复,每个重复30只。分别饲喂基础日粮(对照组)及添加5、10和20 g·kg-1凹土的试验日粮。试验期42 d,1~14 d为前期,15~42 d为后期。试验结束时,每重复随机抽取1只公鸭屠宰,用于各项指标测定。[结果]与对照组相比,添加3种不同水平凹土均显著提高肉鸭前期饲料颗粒硬度以及降低前期饲料的含粉率(P < 0.05),添加20 g·kg-1凹土使后期饲料的颗粒硬度显著提高(P < 0.05),但其他凹土添加水平对后期饲料的颗粒硬度及含粉率无显著影响(P>0.05)。与对照组相比,添加3种不同水平的凹土对樱桃谷肉鸭的终末体质量、平均日采食量、平均日增重和料重比均无显著影响。与对照组相比,日粮中添加10 g·kg-1凹土显著提高胸肌率、腿肌率与瘦肉率,添加20 g·kg-1凹土显著提高腿肌率与瘦肉率,但对胸肌率没有影响(P>0.05),其中,就腿肌率而言,10 g·kg-1凹土添加水平较20 g·kg-1凹土添加水平提高显著。与对照组相比,添加3种水平凹土均显著降低胸肌的滴水损失,添加20 g·kg-1凹土显著降低胸肌的蒸煮损失,添加10 g·kg-1凹土显著降低胸肌的红度值(a*)和腿肌的滴水损失。与对照组相比,日粮中添加10和20 g·kg-1凹土均显著提高胸肌的超氧化物歧化酶(SOD)活性,添加5 g·kg-1凹土显著提高胸肌的谷胱甘肽过氧化物酶(GSH-Px)活性;添加10 g·kg-1凹土显著提高腿肌SOD活性,添加3种水平凹土均显著降低腿肌中丙二醛(MDA)含量。[结论]在本试验条件下,基础日粮中添加凹土能改善饲料颗粒质量,提高樱桃谷肉鸭的屠宰性能,改善肌肉品质,提高肌肉的抗氧化能力,对肉鸭的生长性能无显著不利影响,其最佳添加水平为10 g·kg-1
关键词凹凸棒石黏土   樱桃谷肉鸭   屠宰性能   肌肉品质   抗氧化性能   
Effect of different levels of palygorskite supplementation on pellet quality, growth performance, slaughter performance, meat quality and antioxidant ability in Cherry Valley ducks
WANG Yuyu, LIU Qiang, WANG Baozhe, FAN Chengrui, LI Jiaying, ZHUANG Su    
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Abstract: [Objectives] This study was conducted to investigate the effect of different levels of dietary palygorskite supplementation on pellet quality, growth performance, slaughter performance, meat quality and antioxidant ability in Cherry Valley ducks. [Methods] According to the randomized block design, a total of 720 one-day-old Cherry Valley ducks were randomly divided into 4 dietary treatment groups with 6 replicates of 30 ducks per replicate, and fed a basal diet supplemented with 0(control group), 5, 10 and 20 g·kg-1 palygorskite. The experiment period was 42 days, which consisted of the starter period(1 to 14 days)and grower period(15 to 42 days). At the end of the experiment, 1 male duck per replicate was randomly selected for measuring the relevant indexes. [Results] Compared with the control group, three levels palygorskite supplementation increased the hardness and decreased the fines percentage of pellet during starter period(P < 0.05). The inclusion of 20 g·kg-1 palygorskite increased the pellet hardness of pellet during grower period(P < 0.05), and other levels palygorskite supplementation did not affect the pellet hardness and the fines percentage of pellet during grower period(P>0.05). Palygorskite supplementation, regardless of levels, did not affect the final body weight, average daily feed intake, average daily weight gain and the ratio of feed intake to gain(F/G)of ducks. However, the percentage of breast muscle, leg muscle and lean muscle increased when supplementing 10 g·kg-1 palygorskite(P < 0.05), and the inclusion of 20 g·kg-1 palygorskite increased the percentage of leg muscle and lean muscle(P < 0.05), but had no effect on the percentage of breast muscle(P>0.05). 10 g·kg-1 palygorskite supplementation showed higher leg muscle percentage than 20 g·kg-1 palygorskite supplementation(P < 0.05). In addition, three levels palygorskite supplementation all significantly decreased the drip loss of breast muscle(P < 0.05). The inclusion of 20 g·kg-1 palygorskite decreased the cooking loss of breast muscle(P < 0.05). Similarly, the redness(a*)of breast muscle and the drip loss of leg muscle decreased significantly(P < 0.05)when the palygorskite inclusion dosage was 10 g·kg-1. 10 and 20 g·kg-1 palygorskite supplementation all significantly increased the superoxide dismutase(SOD)activity of breast muscle(P < 0.05), and 5 g·kg-1 palygorskite supplementation increased the glutathione peroxidase(GSH-Px)activity of breast muscle(P < 0.05). The inclusion of 10 g·kg-1 palygorskite supplementation increased the superoxide dismutase activity of leg muscle. Whereas the malonaldehyde(MDA)contents of leg muscle decreased significantly(P < 0.05)by three levels palygorskite supplementation. [Conclusions] The basic dietary palygorskite supplementation could improve the feed pellet quality, enhance slaughter performance and meat quality, and increase antioxidant ability, and had no disadvantageous effect on the growth performance of Cherry Valley ducks. In addition, the optimal level of supplemented palygorsskite in the pellet diets of ducks was 10 g·kg-1.
Key words: palygorskite    Cherry Valley ducks    slaughter performance    meat quality    antioxidant ability   

凹凸棒石黏土(简称凹土)是一种具有层链状和纤维晶体结构的镁铝硅酸盐矿物质, 广泛存在于自然界, 其表面具有活性—OH基团[1-2]。凹土独特的链式分层晶体结构赋予其良好的吸附性、离子交换性、脱色性、黏合性等理化特性[3-4]。凹土作为黏结剂、脱色剂等已广泛用于石油、化工、建材与造纸行业[5]。近年来的研究发现凹土亦可作为营养物质增强剂、有害物质吸附剂等应用于饲料工业中[4, 6]。研究表明肉鸡饲料中添加凹土可提高饲料颗粒硬度, 改善饲料颗粒质量[2]。断奶仔猪饲料中添加适量凹土可提高养分利用效率及生产性能[7]。此外, 凹土可吸附细菌、病毒及其产生的毒素[8-10], 以及消化道中生成的氨等有害物质, 保证动物消化道内良好的生理环境, 从而提高动物的抗氧化和抗病能力。Chen等[11]研究表明在生长期肉鸡日粮中添加适量凹土能显著降低血浆中二胺氧化酶活性。凹土能改善肉鸡肌肉品质与肌肉氧化还原状态[12]。但是, 目前有关凹土在肉鸭饲料中应用尤其是凹土对肉鸭肌肉品质及抗氧化性能影响的研究尚未见报道。为此, 本试验在肉鸭饲料中添加不同水平的凹土, 研究其对饲料颗粒质量, 樱桃谷肉鸭生长性能、屠宰性能、肌肉品质和抗氧化能力的影响, 为凹土在肉鸭饲料中的合理应用提供理论依据。

1 材料与方法 1.1 试验材料

试验所用凹土由江苏神力特生物科技有限公司提供, 粉碎过180 μm筛。

1.2 试验设计与日粮组成

选取1日龄平均体质量为(50±1.2)g的樱桃谷肉鸭720只, 按照随机区组试验设计随机分成4组, 每组6个重复, 每个重复30只鸭, 分别饲喂基础日粮中添加0(对照组)、5、10和20 g·kg-1凹土的试验日粮。基础日粮组成及营养水平见表 1

表 1 基础日粮组成及营养水平(风干基础) Table 1 Ingredients and nutrient levels of the diets(air-dry basis)
组成Composition试验时间/d
Test time
1~1415~42
原料组成/% Ingredients composition
  玉米Corn50.0052.00
  小麦Wheat3.0010.00
  次粉Wheat middling11.008.00
  棉粕Cottonseed meal5.006.00
  豆粕Soybean meal8.005.00
  玉米蛋白粉Corn gluten meal10.007.00
  肉骨粉Meat and born meal3.003.00
  米糠Rice bran6.505.10
  赖氨酸Lysine0.150.20
  蛋氨酸Methionine0.150.20
  石粉Limestone1.401.20
  磷酸氢钙CaHPO40.501.00
  食盐NaCl0.300.30
  预混料1 Premix1.001.00
营养组成/% Nutrition composition
  代谢能2/(MJ·kg-1) Metabolizable energy(ME)12.1312.34
  粗蛋白Crude protein19.3817.19
  钙Calcium0.951.00
  总磷Total phosphorus0.660.70
  赖氨酸Lysine1.100.78
  蛋氨酸Methionine0.450.43
注: 1)预混料可为每千克日粮提供:维生素A 10 000 IU, 维生素D 2 000 IU, 维生素E 20 mg, 维生素K 0.5 mg, 烟酸60 mg, 泛酸钙11 mg, 吡哆醇2.5 mg, 核黄素4.0 mg, 生物素0.2 mg, 叶酸0.6 mg, 硫胺素3 mg, 铜8 mg, 铁80 mg, 锰80 mg, 锌60 mg, 硒0.20 mg; 2)代谢能为计算值, 其余为实测值。
Notes: 1)The premix provides following for per kilogram diet:vitamin A 10 000 IU, vitamin D 2 000 IU, vitamin E 20 mg, vitamin K 0.5 mg, nicotinic acid 60 mg, calcium pantothenate 11 mg, pyridoxine 2.5 mg, riboflavin 4.0 mg, biotin 0.2 mg, folic acid 0.6 mg, thiamine 3 mg, Cu 8 mg, Fe 80 mg, Mn 80 mg, Zn 60 mg, Se 0.20 mg; 2)Metabolizable energy was calculated value according to ingredients energy, while others were measured values.
1.3 饲养地点及管理

试验在徐州恒杰饲料厂樱桃谷肉鸭养殖场进行, 整个试验期为42 d, 分为前、后两期, 前期为1~14 d, 后期为15~42 d。试验鸭采用网上平养, 按常规程序进行疫苗接种, 饲喂颗粒饲料, 自由采食和饮水, 24 h连续光照, 每天记录各组试验鸭采食量与死亡数。

1.4 样品采集与指标测定 1.4.1 饲料颗粒质量

饲料颗粒硬度:从各组颗粒饲料样品中用四分法选取长度基本相同并且大于6 mm(以颗粒两头最凹处计算)的饲料颗粒60粒, 每20粒作为1组中的1个重复进行颗粒硬度测定。将GW-1谷物硬度计(上海华岩仪器设备有限公司, 测定压力范围:0~200 N)的压力指针调整至零点, 用镊子将饲料颗粒置于压杆下方载物台上, 转动手轮, 使压杆下降, 速度中等、均匀, 待颗粒破碎后读取压力计数值(kg), 计算每重复的平均值。

含粉率:含粉率测定方法参照文献[13], 每组称取样品100 g(m1), 置于验粉筛粉化仪(JJSF-2型, 上海精密仪器厂)内振动10 min, 其筛下物(2.0 mm筛下物)的质量(m2, g)作为样品的含粉量, 每组颗粒饲料重复测定6次, 含粉率(Q)按公式(1)计算。

(1)
1.4.2 生长性能

在试验开始时, 测定试验鸭初始体质量。在试验42 d结束时, 对所有试验鸭禁食12 h后测定试验鸭活体质量, 用于计算平均体质量、平均日采食量、平均日增重与料重比。

1.4.3 屠宰性能

试验结束后, 从每个重复中随机选取与该重复平均体质量相近的公鸭1只, 每组共6只, 颈静脉放血后屠宰、去羽, 按照文献[14]方法计算屠宰率、半净膛率、全净膛率、胸肌率、腿肌率、瘦肉率和腹脂率。

1.4.4 肌肉品质

采集屠宰鸭左侧胸肌、腿肌用于测定pH值、肌肉色泽, 采集右侧胸肌、腿肌用于滴水损失及蒸煮损失的测定。余下样品贮存于-20 ℃冰箱中待用。

肌肉pH值:在室温下, 利用数显pH计HI9025(HANNA instruments, Italy), 分别在左侧胸肌、腿肌同一部位测定宰后45 min、24 h的pH值, 测定时将电极完全包埋在肉样中, 待数值稳定后读数, 每个样本重复测定3次, 取平均值。

肌肉色泽:宰后45 min, 在正常室内光线条件下用色差仪(Konica Minolta Sensing, Japan)测定左侧胸肌和腿肌的亮度值(L*)、红度值(a*)与黄度值(b*); 分别从每个样品的上、中、下部位各取1块肉样, 取出切取新鲜横切面, 测定不同区域的肉色, 最后求平均值。

滴水损失:屠宰后从胸肌、腿肌固定位置取下10 g左右的肉块, 去除肉样表面的结缔组织和脂肪组织, 称其初始质量(m1, g)后放入塑料袋中沿肌纤维方向倒挂于4 ℃冰箱, 放置24 h后取出, 用吸水纸擦拭去其表面汁液后称量其末质量(m2, g)。肉样滴水损失按公式(2)计算[12], 单位为g·kg-1

(2)

蒸煮损失:取10 g左右的胸肌和腿肌称质量(m1, g)后置于自封袋内, 排除自封袋内的空气, 使肉样与自封袋紧贴。再将装有样品的自封袋放置在80 ℃的水浴锅中蒸煮, 当样品中心温度达到75 ℃时, 取出肌肉, 用吸水纸擦干肉样表面水分, 称蒸煮后质量(m2, g)。肉样烹饪损失按公式(3)计算[12], 单位为g·kg-1

(3)
1.4.5 肌肉抗氧化性能

采集每只鸭相同部位的胸肌和腿肌(去除脂肪和结缔组织)0.5 g左右, 剪碎后放入试管中按质量(g)、体积(mL)比为1:9的比例加入9倍体积生理盐水, 在冰水浴条件下用匀浆机(T 10 basic ULTRA-TURRAX)进行匀浆, 匀浆后在4 ℃以3 000 r·min-1离心10 min, 取上清液用于测定超氧化歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量。SOD酶活性定义为每毫克组织蛋白在反应液中的抑制率达50%时所对应的量为一个酶活性单位(U·mg-1)。GSH-Px酶活性定义为每毫克组织蛋白每分钟扣除非酶反应的作用使反应体系中GSH浓度降低1 μmol·L-1为一个酶活性单位(U·mg-1)。组织中SOD与GSH-Px活性和MDA含量测定所用试剂盒均购于南京建成生物工程研究所。

1.5 数据统计分析

数据经Excel 2010进行初步处理后, 结果均以“平均数±标准误”( ±SE)表示。用SPSS 21.0软件进行单因素方差分析(one-way analysis of variance), 用邓肯氏(Duncan ’ s)法进行多重比较。

2 结果与分析 2.1 凹土对饲料颗粒质量的影响

表 2可知:与对照组相比, 日粮中添加凹土显著提高前期饲料的颗粒硬度(P < 0.05), 并显著降低前期饲料的含粉率; 添加20 g·kg-1凹土可显著提高后期饲料的颗粒硬度, 但添加凹土对后期料的含粉率无显著影响(P>0.05)。

表 2 凹土对饲料颗粒硬度及含粉率的影响 Table 2 Effects of palygorskite on the pellet hardness and fines percentage
指标Items凹土添加水平/(g·kg-1)Added palygorskite levels
051020
1~14 d
  颗粒硬度/kg Pellet hardness2.66±0.16a4.02±0.27b5.02±0.14c5.16±0.05c
  含粉率/% Fines percentage3.34±0.42c2.06±0.32b1.34±0.09ab0.87±0.05a
15~42 d
  颗粒硬度/kg Pellet hardness2.04±0.13a1.91±0.08a2.06±0.07a2.39±0.02b
  含粉率/% Fines percentage1.98±0.241.68±0.311.38±0.061.32±0.18
注:同行数据肩标不同字母表示差异显著(P < 0.05)。下同。
Note:The different superscript letters in the same row mean significant difference at 0.05 level. The same as the follows.
2.2 凹土对樱桃谷肉鸭生长性能的影响

表 3可知:与对照组相比, 日粮中添加凹土对樱桃谷肉鸭的终末体质量、平均日采食量、平均日增体质量及料重比均无显著影响。日粮中添加5与10 g·kg-1的凹土使樱桃谷肉鸭的终末体质量及平均日增体质量升高, 但无统计学的意义。

表 3 凹土对樱桃谷肉鸭生长性能的影响 Table 3 Effects of palygorskite on growth performance in Cherry Valley ducks
指标Items凹土添加水平/(g·kg-1)Added palygorskite levels
051020
初始体质量/g Initial body weight49.22±0.4051.50±0.3648.60±0.2350.62±0.22
终末体质量/g Final body weight2 952.36±14.792 965.90±33.562 973.72±7.922 911.17±14.52
平均日采食量/g Average daily feed intake135.93±3.55135.26±1.06137.30±2.61134.93±1.78
平均日增体质量/(g·d-1) Average daily weight gain69.12±0.3669.39±0.8269.65±0.1968.11±0.35
料重比Feed/gain1.96±0.061.95±0.021.97±0.031.98±0.03
2.3 凹土对樱桃谷肉鸭屠宰性能的影响

表 4可知:日粮中添加凹土并不影响肉鸭屠宰率、半净膛率、全净膛率(P>0.05)。10 g·kg-1凹土添加组肉鸭的胸肌率、腿肌率以及瘦肉率显著高于对照组与5 g·kg-1凹土添加组(P < 0.05), 腿肌率高于20 g·kg-1凹土添加组; 20 g·kg-1凹土添加组肉鸭的腿肌率和瘦肉率显著高于对照组, 瘦肉率高于5 g·kg-1凹土添加组(P < 0.05);而5 g·kg-1凹土添加组胸肌率、腿肌率、瘦肉率与对照组间无显著差异。日粮中添加凹土对肉鸭腹脂率无显著影响。

表 4 凹土对樱桃谷肉鸭屠宰性能的影响 Table 4 Effects of palygorskite on slaughter performance in Cherry Valley ducks
指标Items凹土添加水平/(g·kg-1)Added palygorskite levels
051020
屠宰率/%Dressing percentage89.07±0.2489.31±0.2089.43±0.1889.10±0.34
半净膛率/% Half-eviscerated yield percentage83.00±0.3883.10±0.3483.16±0.6083.21±0.25
全净膛率/% Eviscerated yield percentage76.38±0.1676.43±0.3576.72±0.5276.38±0.50
胸肌率/% Breast muscle percentage13.10±0.35a13.16±0.36a14.49±0.43b14.13±0.48ab
腿肌率/% Leg muscle percentage9.41±0.16a9.62±0.07ab10.45±0.16c9.88±0.16b
瘦肉率/% Lean muscle percentage22.51±0.29a22.78±0.40a24.93±0.33b24.01±0.35b
腹脂率/% Abdominal fat percentage1.74±0.061.62±0.041.73±0.141.53±0.05
2.4 凹土对樱桃谷肉鸭肌肉品质的影响

表 5可知:与其他各组相比, 日粮中添加10 g·kg-1凹土显著降低了胸肌的红度(a*)值(P < 0.05);而各组间胸肌亮度(L*)与黄度(b*)值的差异不显著。日粮中添加凹土对胸肌pH45 min和pH24 h值并无影响, 各组间差异不显著。与对照组相比, 日粮中添加凹土显著降低了胸肌滴水损失; 20 g·kg-1凹土添加组胸肌蒸煮损失显著低于对照组, 但各凹土添加组间胸肌滴水损失与蒸煮损失差异未达显著水平。

表 5 凹土对樱桃谷肉鸭胸肌和腿肌肌肉品质的影响 Table 5 Effects of palygorskite on the meet quality of breast and leg muscle in Cherry Valley ducks
指标Items凹土添加水平/(g·kg-1)Added palygorskite levels
051020
胸肌reast muscle
  亮度L* Lightness38.96±0.8938.04±0.5239.39±0.8037.46±0.29
  红度a* Redness19.10±0.82b19.28±0.40b17.27±0.62a18.69±0.41b
  黄度b* Yellowness7.53±0.436.93±0.986.67±0.547.09±0.31
  pH45 min6.12±0.096.02±0.036.07±0.486.03±0.04
  pH24 h5.90±0.035.90±0.035.90±0.035.88±0.03
  滴水损失/(g·kg-1)Drip loss113.63±6.37b93.26±6.17a91.34±4.32a82.60±5.27a
  蒸煮损失/(g·kg-1)Cooking loss310.11±5.03b295.77±9.85ab292.32±3.22ab284.90±6.01a
腿肌Leg muscle
  亮度L* Lightness40.73±0.6640.73±0.8141.26±0.3140.07±0.48
  红度a* Redness18.37±0.4518.40±0.3318.31±0.4418.74±0.76
  黄度b* Yellowness9.03±0.529.01±0.507.95±0.497.95±0.38
  pH45 min6.26±0.076.18±0.066.17±0.056.14±0.04
  pH24 h6.03±0.055.92±0.035.93±0.056.04±0.02
  滴水损失/(g·kg-1)Drip loss146.59±5.36b155.77±7.16b123.07±7.93a146.62±7.93b
  蒸煮损失/(g·kg-1)Cooking loss258.36±16.97246.63±11.49246.95±11.66246.96±6.05

日粮中添加凹土不影响肉鸭腿肌L*a*b*值与腿肌pH45 min、pH24 h值(P>0.05)。添加10 g·kg-1凹土组腿肌的滴水损失显著低于其他各组。凹土添加组腿肌蒸煮损失低于对照组(P>0.05)。

2.5 凹土对樱桃谷肉鸭肌肉抗氧化性能的影响

表 6可知:与对照组相比, 日粮中添加10和20 g·kg-1凹土均显著提高肉鸭胸肌的SOD活性(P < 0.05), 分别提高了32.10%与30.83%。5 g·kg-1凹土添加组胸肌中GSH-Px活性显著高于对照组和10、20 g·kg-1凹土添加组(P < 0.05)。日粮中添加凹土对胸肌中的MDA含量无显著影响。

表 6 凹土对樱桃谷肉鸭肌肉抗氧化性能的影响 Table 6 Effects of palygorskite on antioxidant capacity of breast and leg muscle in Cherry Valley ducks
指标Items凹土添加水平/(g·kg-1)Added palygorskite levels
051020
胸肌Breast muscle
  SOD活性/(U·mg-1)SOD activity21.15±1.29a24.47±1.42ab27.94±1.23b27.67±1.83b
  GSH-Px活性/(U·mg-1)GSH-Px activity9.36±0.39a10.92±0.52b9.39±0.14a9.43±0.56a
  MDA含量/(nmol·mg-1)MDA content2.54±0.102.35±0.192.26±0.162.23±0.14
腿肌Leg muscle
  SOD活性/(U·mg-1)SOD activity47.15±1.66a52.35±1.85a58.05±1.66b48.47±1.79a
  GSH-Px活性/(U·mg-1)GSH-Px activity7.72±0.148.24±0.258.92±0.598.57±0.66
  MDA含量/(nmol·mg-1)MDA content0.34±0.03b0.16±0.03a0.19±0.01a0.23±0.04a

腿肌抗氧化指标显示, 10 g·kg-1凹土添加组腿肌中SOD活性显著高于其他各组。与对照组相比, 日粮中添加3种不同水平的凹土并不影响腿肌肉中GSH-Px活性(P>0.05), 但显著降低腿肌中MDA含量。

3 讨论 3.1 凹土对饲料颗粒质量的影响

饲料的物理性状(粉状料、颗粒料)是影响家禽产肉量的关键因素之一[15-17]。已有研究表明, 与粉状料相比, 颗粒料可以提高肉鸡的生长性能[17-18]。颗粒饲料具有减少组分分级、提高消化率、减少致病生物的侵袭、提高淀粉糊化度等特点[19]。颗粒饲料必须在减少含粉率的前提下才可确保提高家禽的生长性能[20-21]。本试验发现添加凹土显著提高前期饲料的颗粒硬度, 降低饲料的含粉率, 添加20 g·kg-1凹土显著提高后期饲料的颗粒硬度。Angulo等[22]报道, 日粮中添加海泡石(一种类似凹土结构的镁硅酸盐黏土)可以提高颗粒饲料的质量, 尤其在高脂肪和高纤维含量日粮中作用效果更加明显[23]。Pappas等[2]发现, 日粮中添加1.0%凹土可以显著改善饲料颗粒质量。因此, 本试验结果与前人研究结果基本一致。引起饲料颗粒硬度增加及含粉率降低的原因主要归结于凹土特殊的吸附性和胶体流变性质。凹土中微孔和通道的存在以及细小的颗粒与纤维状特征赋予其拥有庞大的表面积[24-25], 可吸收极性液体并形成胶体, 进而促进固体与固体间相互作用, 最终改善饲料的颗粒硬度及降低颗粒饲料含粉率, 这也是凹土作为饲料黏结剂根本所在。

3.2 凹土对樱桃谷肉鸭生长性能的影响

基础日粮中添加凹土可提高动物生产性能、改善动物健康。Zhang等[26]报道, 肉鸡日粮中添加凹土显著提高了肉鸡的平均日增重及平均日采食量, 其中添加10 g·kg-1凹土的试验组肉鸡日增重最高。曹发魁等[27]的研究表明, 凹土在增加蛋鸡产蛋率的基础上还可提高鸡蛋的品质。祝溢锴[28]报道, 日粮中添加凹土不仅提高了仔猪日增重, 而且降低仔猪腹泻率及腹泻指数。本试验结果表明, 基础日粮中添加凹土并没有改善樱桃谷肉鸭的终末体质量、平均日增体质量以及料重比, 但也没有影响肉鸭生产性能, 结果与前人研究并不一致。分析其原因这可能与动物种类、品种、饲养环境、日粮组成以及凹土添加量或纯度等因素有关。

3.3 凹土对樱桃谷肉鸭屠宰性能和肌肉品质的影响

屠宰性能是衡量肉禽产肉性能的重要指标, 反映了营养物质在动物体内不同组织以及同一组织不同部位内的沉积差异[29]。本试验研究表明, 日粮中添加凹土显著提高樱桃谷肉鸭的胸肌率、腿肌率与瘦肉率。这可能与凹土能提高消化酶活性[30]以及延长低黏度日粮在动物胃和小肠中停留时间[31]有关, 这有助于促进机体对营养物质的消化吸收, 从而增加产肉量, 提高动物的屠宰性能。

肉色是消费者评价动物肌肉质量的重要感官指标, 其中肉色亮度值及红色值在肉色测量结果中相对重要[32]。Cheng等[12]研究了基础日粮中添加10与20 g·kg-1凹土后发现肉鸡的胸肌红色值与黄色值均显著降低。在本试验中, 日粮中添加10 g·kg-1凹土显著降低了胸肌的红色度, 添加不同剂量凹土使胸肌黄色度也有所下降。肉色的变化主要受色素含量、肌红蛋白形态等的影响[33]。凹土造成动物产品色泽降低的原因与凹土的吸附性以及凹土与色素的亲和性有关[12]。因此, 日粮中添加凹土对肌肉的色素沉积有一定的负面作用。肌肉pH值反映了宰后机体糖原酵解的速度, pH值与肌肉系水力存在正相关关系[34]。肌肉的系水力不仅影响肉的风味、多汁性、嫩度、营养物质等食用品质, 而且还具有重要的经济价值。肌肉的系水力差会造成风味物质的流失, 影响肉的口感, 水分流失过多还会使肌肉柴而无味[35]。肌肉的滴水损失和蒸煮损失是反映肌肉系水力的重要指标。在本试验中添加凹土未对肌肉pH45 min以及pH24 h值造成显著影响, 但添加凹土均显著降低胸肌的滴水损失; 同时, 添加10与20 g·kg-1的凹土分别显著降低腿肌的滴水损失与胸肌的蒸煮损失, 这与Yang等[36]和Cheng等[12]的研究结果相一致。这可能与凹土提高饲料蛋白质利用率有关。蛋白质利用率提高后肌肉蛋白质与脂肪的比例增高, 使得肌肉亲水力提高, 从而改善胸肌、腿肌的系水力。另有研究证明凹土能提高动物机体金属Mg的含量[37], Mg含量的提高也可能提高肌肉系水力, 减少肌肉中水分流失[38]。但是, 杨雪等[38]发现生长猪日粮中添加凹土或改性凹土并不影响生长育肥猪肌肉的滴水损失及蒸煮损失。这种差异性出现可能与动物种类、饲养时期以及日粮组成等因素有关。

3.4 凹土对樱桃谷肉鸭肌肉抗氧化性能的影响

SOD、GSH-Px活性及MDA含量可以反映机体抗氧化性能的强弱。Cheng等[12]报道, 日粮中添加5或10 g·kg-1凹土可以在一定程度上降低胸肌与腿肌中MDA含量, 提高GSH-Px的活性。Chen等[11]发现, 日粮中添加10 g·kg-1的凹土显著提高空肠及回肠的总超氧化物歧化酶活性。在本试验中, 日粮中添加适量凹土可显著提高肉鸭胸肌和腿肌的SOD活性以及胸肌的GSH-Px活性; 同时, 添加凹土均显著降低了腿肌的MDA含量, 提高了肌肉的抗氧化能力, 该结果与前人研究结论一致。这可能与凹土的选择吸附性有关。Masimango等[9]发现凹土在Sprensen缓冲液(pH6.5)中对黄曲霉素B1有很强的吸附效果。Ramu等[10]在体外试验中发现凹土可以强烈吸附霍乱毒素及大肠杆菌毒素, 且吸附紧密, 解吸率小于1%。体内的有害菌会破坏动物机体的抗氧化系统, 真菌毒素如黄曲霉毒素B1、玉米赤霉烯酮等可引起脂质过氧化, 破坏细胞膜结构及功能完整。因此, 凹土则通过吸附有害细菌及霉菌毒素起到保护机体抗氧化系统的作用。此外, 凹土含有丰富的镁元素(MgO的含量约占13%), 镁与动物的抗氧化机能有密切的联系。有研究表明大鼠体内缺镁时, 会使组织和血浆内脂蛋白的过氧化程度增加[38]。这也可能是凹土增强机体抗氧化能力的另一个原因。

参考文献(References)
[1] Huang J H, Liu Y F, Jin Q Z, et al. Adsorption studies of a water soluble dye, Reactive Red MF-3B, using sonication-surfactant-modified attapulgite clay[J]. Journal of Hazardous Materials, 2007, 143(1): 541-548.
[2] Pappas A C, Zoidis E, Theophilou N, et al. Effects of palygorskite on broiler performance, feed technological characteristics and litter quality[J]. Applied Clay Science, 2010, 49(3): 276-280. DOI: 10.1016/j.clay.2010.06.003
[3] Galan E. Properties and applications of palygorskite-sepiolite clays[J]. Clay Minerals, 1996, 31(4): 443-453. DOI: 10.1180/claymin
[4] Murray H H. Traditional and new applications for kaolin, smectite, and palygorskite:a general overview[J]. Applied Clay Science, 2000, 17(5): 207-221.
[5] 周济元, 崔炳芳. 国外凹凸棒石粘土的若干情况[J]. 资源调查与环境, 2004, 25(4): 248-259.
Zhou J Y, Cui B F. Attapulgite clay in the oversea[J]. Resources Survey and Environment, 2004, 25(4): 248-259. (in Chinese with English abstract)
[6] Chalvatzi S, Arsenos G, Tserveni-Goussi A, et al. Tolerance and efficacy study of palygorskite incorporation in the diet of laying hens[J]. Applied Clay Science, 2014, 101: 643-647. DOI: 10.1016/j.clay.2014.09.035
[7] Zhang J M, Lü Y F, Tang C H, et al. Effects of dietary supplementation with palygorskite on intestinal integrity in weaned piglets[J]. Applied Clay Science, 2013, 86(8): 185-189.
[8] Almeida J A S, Ponnuraj N P, Lee J J, et al. Effects of dietary clays on performance and intestinal mucus barrier of broiler chicks challenged with Salmonella enterica serovar typhimurium and on goblet cell function in vitro[J]. Poultry Science, 2014, 93(4): 839-847. DOI: 10.3382/ps.2013-03587
[9] Masimango N, Remacle J, Ramaut J L. The role of adsorption in the elimination of aflatoxin B1 from contaminated media[J]. Applied Microbiology and Biotechnology, 1978, 6(1): 101-105. DOI: 10.1007/BF00500861
[10] Ramu J, Clark K, Woode G N, et al. Adsorption of cholera and heat-labile Escherichia coli enterotoxins by various adsorbents:an in vitro study[J]. Journal of Food Protection, 1997, 60(4): 358-362. DOI: 10.4315/0362-028X-60.4.358
[11] Chen Y P, Cheng Y F, Li X H, et al. Dietary palygorskite supplementation improves immunity, oxidative status, intestinal integrity, and barrier function of broilers at early age[J]. Animal Feed Science and Technology, 2016, 219: 200-209. DOI: 10.1016/j.anifeedsci.2016.06.013
[12] Cheng Y F, Chen Y P, Li X H, et al. Effects of palygorkite inclusion on the growth performance, meat quality, antioxidant ability, and mineral element content of broilers[J]. Biological Trace Element Research, 2016, 173(1): 194-201. DOI: 10.1007/s12011-016-0649-8
[13] 国家技术监督局. 颗粒饲料通用技术条件: GB/T 16765-1997[S]. 北京: 中国标准出版社, 1997.
State Bureau of Technical Supervision. Pellet feed general technical conditions: GB/T 16765-1997[S]. Beijing: Standards Press of China, 1997(in Chinese).
[14] 中华人民共和国农业部. 家禽生产性能名词术语和度量统计方法: NY/T 823-2004[S]. 北京: 中国标准出版社, 2004.
Ministry of Agriculture of the People's Republic of China. Performance ferms and measurement for poultry: NY/T 823-2004[S]. Beijing: Standards Press of China, 2004(in Chinese).
[15] Rezaian M, Yaghoobfar A, Barin A. Effects of pellet and mesh diets on the activity of the microflora, and morphology of the small intestine of broiler chicks[J]. Journal of Animal and Veterinary Advances, 2007, 6(5): 723-727.
[16] Ahmed M E, Abbas T E. The effect of feeding pellets versus mash on performance and carcass characteristics of broiler chicks[J]. Bulletin of Environment Pharmacology and Life Sciences, 2013, 2(2): 30-34.
[17] Sena S, Sena L, Hoda A, et al. Broiler performance fed on mash vs. pellets[J]. Albanian Journal of Agricultural Sciences, 2014, 13: 353-356.
[18] Choi J H, So B S, Ryu K S, et al. Effects of pelleted or crumbled diets on the performance and the development of the digestive organs of broilers[J]. Poultry Science, 1986, 65(3): 594-597. DOI: 10.3382/ps.0650594
[19] Abdollahi M R, Ravindran V, Svihus B. Pelleting of broiler diets:an overview with emphasis on pellet quality and nutritional value[J]. Animal Feed Science and Technology, 2013, 179(1/2/3/4): 1-23.
[20] Corzo A, Mejia L, Loar R E. Effect of pellet quality on various broiler production parameters[J]. Journal of Applied Poultry Research, 2011, 20(1): 68-74. DOI: 10.3382/japr.2010-00229
[21] Lilly K G S, Gehring C K, Beaman K R, et al. Examining the relationships between pellet quality, broiler performance, and bird sex[J]. Journal of Applied Poultry Research, 2011, 20(2): 231-239. DOI: 10.3382/japr.2009-00138
[22] Angulo E, Brufau J, Esteve-Garcia E. Effect of asepiolite product on pellet durability in pig diets differing in particle size and in broiler starter and finisher diets[J]. Animal Feed Science and Technology, 1996, 63(1/2/3/4): 25-34.
[23] Angulo E, Brufau J, Esteve-Garcia E. Effect of sepiolite on pellet durability in feeds differing in fat and fibre content[J]. Animal Feed Science and Technology, 1995, 53(4): 233-241.
[24] Zhou C H. An overview on strategies towards clay-based designer catalysts for green and sustainable catalysis[J]. Applied Clay Science, 2011, 53(2): 87-96. DOI: 10.1016/j.clay.2011.04.016
[25] Xu J X, Wang W B, Mu B, et al. Effects of inorganic sulfates on the microstructure and properties of ion-exchange treated palygorskite clay[J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects, 2012, 405(13): 59-64.
[26] Zhang L, Yan R, Zhang R Q, et al. Effect of different levels of palygorskite inclusion on pellet quality, growth performance and nutrient utilization in broilers[J]. Animal Feed Science and Technology, 2017, 223: 73-81. DOI: 10.1016/j.anifeedsci.2016.10.019
[27] 曹发魁, 崔伟林, 潘生功, 等. 饲喂凹土对鸡蛋品质的影响[J]. 甘肃农业大学学报, 2003, 38(2): 227-230.
Cao F K, Cui W L, Pan S G, et al. Effect of feeding attapulgite clay on quality of eggs[J]. Journal of Gansu Agricultural University, 2003, 38(2): 227-230. (in Chinese with English abstract)
[28] 祝溢锴. 凹凸棒石黏土对断奶仔猪生产性能和免疫功能的影响[D]. 南京: 南京农业大学, 2012.
Zhu Y K. Effects of palygorskite clay on production performance and immune function of weaned piglets[D]. Nanjing: Nanjing Agricultural University, 2012(in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=degree&id=Y2359966
[29] 陶勇, 杨晓志, 李小芬, 等. 玉米DDGS对苏邮2号肉鸭生长性能、肌肉品质及血清生化指标的影响[J]. 安徽农业大学学报, 2014, 41(5): 830-834.
Tao Y, Yang X Z, Li X F, et al. Effects of corn DDGS on growth, meat quality and serumbiochemical index of Suyou 2 meat ducks[J]. Journal of Anhui Agricultural University, 2014, 41(5): 830-834. (in Chinese with English abstract)
[30] Qiao L H, Chen Y P, Wen C, et al. Effects of natural and heat modified palygorskite supplementation on the laying performance, egg quality, intestinal morphology, digestive enzyme activity and pancreatic enzyme mRNA expression of laying hens[J]. Applied Clay Science, 2015, 104: 303-308. DOI: 10.1016/j.clay.2014.12.010
[31] Ouhida I, Perez J F, Piedrafita J, et al. The effects of sepiolite in broiler chicken diets of high, medium and low viscosity. Productive performance and nutritive value[J]. Animal Feed Science and Technology, 2000, 85(4): 183-194.
[32] Allen C D, Fletcher D L, Northcutt J K, et al. The relationship of broiler breast color to meat quality and shelf-life[J]. Poultry Science, 1998, 77(2): 361-366. DOI: 10.1093/ps/77.2.361
[33] Lindahl G, Lundström K, Tornberg E. Contribution of pigment content, myoglobin forms and internal reflectance to the colour of pork loin and ham from pure breed pigs[J]. Meat Science, 2001, 59(2): 141-151. DOI: 10.1016/S0309-1740(01)00064-X
[34] 寇涛, 胡志萍, 董丽, 等. 二甲基甘氨酸钠对肉鸡屠宰性能、肉品质及肌肉抗氧化能力的影响[J]. 食品科学, 2015, 36(5): 179-184.
Kou T, Hu Z P, Dong L, et al. Effect of N, N-dimethylglycine sodium on slaughter performance, meat quality indices and antioxidant performance of broilers[J]. Food Science, 2015, 36(5): 179-184. DOI: 10.7506/spkx1002-6630-201505034 (in Chinese with English abstract)
[35] 黄进. 大豆磷脂对AA肉鸡脂肪代谢及肉品质影响的研究[D]. 南京: 南京农业大学, 2008.
Huang J. Study on the effects of soy-lecithin on lipid metabolism and meat quality in AA broilers[D]. Nanjing: Nanjing Agricultural University, 2008(in Chinese with English abstract). http://cdmd.cnki.com.cn/Article/CDMD-10307-2009076480.htm
[36] Yang W L, Chen Y P, Cheng Y F, et al. An evaluation of zinc bearing palygorskite inclusion on the growth performance, mineral content, meat quality, and antioxidant status of broilers[J]. Poultry science, 2016, 95(4): 878-885. DOI: 10.3382/ps/pev445
[37] 王龙昌, 罗有文, 朱秋凤, 等. 凹凸棒石黏土对肉鸡生产性能、免疫指标和血液及肝脏镁含量的影响[J]. 粮食与饲料工业, 2007(5): 38-40.
Wang L C, Luo Y W, Zhu Q F, et al. Effects of attapulgite on production performance, immunity indexes and content of magnesium in plasma and liver of broilers[J]. Cereal and Feed Industry, 2007(5): 38-40. (in Chinese with English abstract)
[38] 杨雪, 冷智贤, 颜瑞, 等. 凹凸棒石黏土对生长育肥猪生产性能、金属含量及肉品质的影响[J]. 中国粮油学报, 2015, 30(4): 96-101.
Yang X, Leng Z X, Yan R, et al. Effects of attapulgite on growth performance, metal content in blood, muscle and meat quality of growing-finishing pigs[J]. Journal of the Chinese Cereals and Oils Association, 2015, 30(4): 96-101. (in Chinese with English abstract)