用脂肪细胞膜免疫技术提高猪胴体品质

为了在满足动物营养需要和有效控制疫病的基础上进一步提高动物生产体系的经济效益,满足市场不断变化的需求,一直在探索和发展新的促进动物生长和提高胴体品质的技术手段。在认识到激素类制剂的残留和危害后,一种更新的非激素途径——脂肪细胞膜免疫技术日益受到关注。它高效、安全和作用持久的特点成为具有广泛研究和应用前景的新技术。     

Polymorphisms in the promoter region of myostatin gene are associated with carcass traits in pigs

Higher average daily gain, more lean meat yield and less fat yield of porcine carcass increase selling profits for animal producers. Myostatin (MSTN), previously called GDF8, is a member of transforming growth factor‐β (TGF‐β) superfamily. It is a negative regulator for both embryonic development and adult homeostasis of skeletal muscle. In this study, the genotypes of the previously described SNPs MSTN g.435G>A and g.447A>G SNPs in 66 Duroc pigs, 33 Landrace pigs, 180 Duroc × Landrace (DL) pigs and 155 Duroc × Yorkshire × Landrace (DYL) pigs were determined by Taqman SNP Genotyping Assays. For Duroc and Landrace pigs, MSTN g.435GG/g.447AA individual had greater backfat thickness (p < 0.05) than g.435AA/g.447GG individual, whereas MSTN g.435AA/g.447GG had greater meat (p < 0.05) and meat percentage (p < 0.05) than g.435GA/g.447AG individual. For DL and DYL pigs, the MSTN g.435GG/g.447AA animals were greater in backfat at ultrasound 10th rib (p < 0.05) and carcass 10th rib (p < 0.01) than g.435AA/g.447GG individual. The MSTN g.435AA/g.447GG individual also had higher values than g.435GG/g.447AA for anterior‐end meat (p < 0.05), posterior‐end meat (p < 0.01), total meat weight (p < 0.01) and meat percentage (p < 0.01). This study confirmed evidence that MSTN g.435G>A and g.447A>G affected carcass traits in pigs. The effects of the mutated alleles were additive with the maximal effects resulting from two copies of the mutated allele. Selection for MSTN g.435A/g.447G allele is expected to increase muscle of limb and total meat production and decrease backfat thickness.     

Growth,carcass, fiber type,and meat quality characteristics in Large White pigs with different live weights

The aim of this study was to compare the growth, carcass, histochemical, and meat quality characteristics in Large White pig groups that were categorized by live weight (Heavy and Light) and type I fiber percentage (High and Low), a procedure which resulted in four groups (Heavy-High, Heavy-Low, Light-High, and Light-Low). As expected, the Heavy group showed heavier live weight (114 vs. 94.7 kg, P<0.001) and larger loin eye area (53.3 vs. 47.8 cm², P<0.001), as well as, higher total number (1,223,000 vs. 1,140,000, P<0.05) and greater mean value cross-sectional area (CSA; 4031 vs. 3798 μm²P<0.05) of muscle fibers than the Light group. However, there were no significant differences in start and finish days among the groups (P>0.05). Heavier pigs harboring a higher percentage of type I fibers (HH) exhibited a similar mean CSA (3894 vs. 4101 μm²) and total number (1,249,000 vs. 1,198,000) of muscle fibers, even though these pigs had a greater CSA of type I fibers (3181 vs. 2719 μm², P<0.05) and a smaller CSA of type IIB fibers (4048 vs. 4457 μm², P<0.05) compared to heavier pigs harboring a lower percentage of fiber type I (HL). Both the HL and Light-Low groups exhibited a rapid decline of muscle pH at the early postmortem period (5.90 and 5.85 vs. 6.08, P<0.05), paler surfaces (43.07 and 43.55 vs. 40.73_,P<0.05), and higher degrees of fluid loss by exudation (6.26 and 6.39 vs. 4.22%, P<0.05) compared to the HH group due to their muscle fiber type composition. Thus, the HH pigs showed better meat quality characteristics without significant differences in growth and carcass performance compared to the HL pigs. Therefore, selection for increased live weight at the same age and muscle fiber characteristics, especially the increased type I fiber CSA and proportion, is one of the relevant indicators to improve and control meat quality without reducing the growth and carcass performance.     

Effect of chicken egg yolk antibody against adipose tissue plasma membranes on carcass composition and lipogenic hormones and enzymes in pigs

Chicken egg yolk antibody against pig adipose tissue plasma membranes (AIgY) was raised and used in the present experiment to evaluate the effect of dietary AIgY supplementation on pig growth and carcass composition. 160 crossbred (Duroc–Jersey × Landrace·Meishan) pigs, with initial live body weight of 27.5 ± 2.4 kg, were treated with AIgY or non-immunized control egg yolk powder (NIgY) at the inclusion level of 75 mg/kg diet. Following a 104-day trial, the pigs were slaughtered for analyzing the carcass and meat quality traits. The perirenal, mesenteric and subcutaneous fat depots were weighed and the diameter of adipocytes from different fat depots was measured with histological methods. Serum concentrations of insulin and leptin as well as the activities of malic enzyme (ME) and lipoprotein lipase (LPL) in adipose tissue were measured. Dietary supplementation of AIgY enhanced average daily gain and feed efficiency by 13.03% (P < 0.01) and 7.49%, respectively, with no influence on feed consumption. AIgY increased the lean mass by 10.3% (P < 0.01) without affecting the dressing percentage. Backfat thickness at 6th–7th rib and the weights of perirenal, mesenteric and subcutaneous fat depots were reduced by 24.14% (P < 0.01), 27.27% (P < 0.05), 20.42% (P < 0.01) and 29.21% (P < 0.01), respectively. Dietary supplementation of AIgY reduced the size of adipocytes in all the three fat pads (P < 0.05). The meat color was improved whereas the marbling score, the intramuscular fat content, and pH₄₅ of the longissimus muscle remained unaffected. Serum concentration of non-esterified fatty acids (NEFA) was significantly increased (P < 0.01) while urea-N content was reduced (P < 0.05). No alterations were detected for the serum levels of triacylglycerides (TG) and glucose. Serum concentrations of insulin and leptin were decreased by 26.19% (P < 0.05) and 26.53% (P < 0.05), respectively. LPL activity in adipose tissue was depressed significantly (P < 0.05) without affecting ME activity. This study demonstrates that dietary supplementation of AIgY can effectively improve growth and carcass composition of pigs and the changes of serum insulin and leptin levels as well as the tissue LPL activity may be involved in the acting mechanism.     

饲喂沼渣源饲料对猪胴体品质、肉质性状及营养成分的影响

以杜长大三元杂交猪为对象, 研究了饲喂沼渣源配合饲料对猪胴体品质、肉质性状及营养成分的影响.结果表明, 饲料添加不同量的沼渣对猪屠宰率和胴体长无显著影响(P>0.05), 但显著降低了瘦肉率、后腿比例和眼肌面积(P<0.05), 显著提高了背膘厚.饲料添加沼渣显著降低了肌肉颜色和熟肉率, 显著提高了滴水损失和剪切力值, 且添加量越多效果越明显;同时, 添加沼渣对肌肉失水率、pH无显著影响, 但大理石纹评分对照组和沼渣组差异显著.对猪肉营养成分测定结果表明, 添加沼渣显著降低猪肉粗蛋白质、粗脂肪和水分含量, 而对粗灰分含量无显著影响.因此, 猪日粮中添加沼渣降低了胴体品质、肉质性状以及营养价值, 如果将其应用到生产中, 需要解决胴体品质、肉质和营养价值下降的问题.     

五龙鹅产肉性能与肉质特性的研究

本研究用 1 80日龄五龙鹅 2 4只 ,测定其产肉性能、胸腿肉样的理化特性和组织结构等指标。公母鹅的胸肌率分别为 1 6 6%和 1 3 3% ,腿肌率为 1 5 2 %和 1 2 2 % ;主要肉质指标 (公母平均值 ) :系水力胸肌为 73 4 % ,腿肌为 80 2 % ,嫩度 (剪切力值 )胸肌为 4 9kg,腿肌为 3 7kg ,蛋白质胸肌为 2 3% ,腿肌为2 2 6% ,肌间脂肪含量胸肌为 4 % ,腿肌为 3 4 % ,肌纤维直径胸肌为 31 9μm ,腿肌为 33μm。综合分析该鹅屠宰率中等 ,除嫩度较差外 ,肌肉蛋白质和脂肪含量较高 ,肌纤维细 ,是一个具有肉用开发利用价值的地方鹅种     

Bodyweight and carcass characteristics of somali goats fed hay supplemented with graded levels of peanut cake and wheat bran mixture

The experiment was conducted for ninety days of feeding trial at Haramaya University, Ethiopia using twenty four yearling male Somali goats weighing 20.4 +/- 2.02 (mean +/- SD) with the objectives to evaluate the effect of supplementation of peanut cake and wheat bran mixture (3:1) on body weight (BW) gain and carcass characteristics of Somali goats. The experiment was arranged with six blocks and four treatments in a randomized complete block design. The treatments were ad libitum feeding of hay (T1, control) and supplementation with 200 g (T2), 300 g (T3) and 400 g (T4) peanut cake and wheat bran mixture on dry matter (DM) basis. Supplementation reduced (P < 0.001) hay DM intake, but increased (P < 0.001) total DM intake at 300 g DM (T3) and 400 g DM (T4) level of supplementation compared to the control treatment. Daily BW gain, final BW, empty BW, hot carcass weight and dressing percent were higher (P < 0.001) in the supplemented treatments. Goats on the medium (T3) level of supplementation had significantly heavier (P < 0.001) liver and more muscle deposition, whereas those on hay alone (T1) exhibited heavier bone, head as well as gut contents (P < 0.05). It was concluded that supplementation of Somali goats with the different levels of peanut cake and wheat bran mixture promoted BW gain, dressing percentage and increased the proportion of edible offals. Similarity between the different levels of supplementation used in this study with regard to BW and carcass characteristics favours the use of the low (T2) or medium (T3) level than the high (T4) level of supplementation.     

塞北兔生长性状与屠宰性状典型相关分析

对塞北兔生长性状与屠宰性状的6个指标进行了典型相关分析,为塞北兔的选育提供依据。结果表明:生长性状与屠宰性状的第一对典型相关系数为0.990(P<0.01),解释了总相关信息的77.8%,起主要作用的性状是胸围和屠宰率,在生产中可通过选择胸围达到提高屠宰率的目的。     

甜菜碱对肥育猪胴体组成的影响及其作用机理的探讨

用不同甜菜碱添加量（０、１００、１２５０、１５００和１７５０ｍｇ／ｋｇ）的同种饲粮,分别饲喂５组（１５０头）杜长大肥育猪（６３ｋｇ）４０ｄ,进行屠宰试验,并对血液、肝脏、背最长肌和皮下脂肪有关生化指标进行分析。结果表明：添加甜菜碱明显改善了胴体组成,以１０００ｍｇ／ｋｇ组效果最显著;不同剂量甜菜碱均使肝脏甜菜碱－高半胱氨酸甲基转移酶和胱硫醚β－合成酶的活性发生了变化,前者以１０００ｍｇ／ｋｇ添加量     

Effect of sex and feeding system on feed intake, growth, and meat and carcass characteristics of fattening Assaf lambs

The effect of feeding system and sex on intake, growth and carcass and meat characteristics of Assaf fattening lambs was studied. Twenty four weaned Assaf lambs, half males and half females were used. After an adaptation period, lambs were randomly assigned to one of the two feeding systems studied. Control lambs received ad libitum commercial concentrate (70% barley, 22% soybean meal, 4.8% wheat, 0.5% bicarbonate, 2.7% mineral–vitamin premix) and barley straw. Free Choice lambs had ad libitum and separate access to whole barley grain and a protein supplement (73.3% soyabean meal, 16% wheat, 1.7% bicarbonate, 9% mineral–vitamin premix). Lambs were slaughtered at 25 kg LBW. Feed intake was not significantly affected by sex (P > 0.05) but Free Choice lambs showed higher dry mater intake than the Control lambs. Nevertheless, only males from the Free Choice group showed an improvement in feed efficiency rate (P < 0.05) and average daily gain (P < 0.01) relating to the Control lambs. Neither feeding system nor feeding system × sex interaction significantly affected non-carcass weight, fat depots, cold carcass weight, dressing percentage, main proportions of commercial cuts and meat characteristics (P < 0.05). As it was expected, female lambs showed a lower average daily gain and a higher feed conversion efficiency than male lambs (P < 0.001) which was related to a greater fat deposition. Meat characteristics were unaffected by sex, with the exception of longissimus lumborum fat content, which was higher in female lambs.The present results suggest that Free Choice feeding system might be suitable for intensively reared male lambs since improvements in daily weight gain and feed conversion rate were achieved, with no adverse effect on carcass and meat quality. Despite the selected diet of both, males and females, did not differ in the crude protein content, the use of Free Choice feeding system for female lambs did not improve performance compared to the Control group.