FecB基因对杜×寒杂交肉羊产羔数及羔羊生长发育的影响

利用绵羊多胎基因FecB分子检测技术,检测分析杜×寒杂交肉羊基因型及对产羔数和羔羊生长发育的影响。结果表明：在杜×寒杂交F1、F2和F3代类群中,存在BB、B＋和＋＋三种基因型,并以B＋基因型为主。杜×寒F1代母羊B＋基因型频率极显著高于杜×寒F2、F3代母羊（P〈0.01）,F2代母羊B＋基因型频率显著高于F3代母羊（P〈0.05）。杜×寒F1、F2、F3代B＋基因型繁殖母羊产羔数比同代＋＋基因型母羊分别增加0.54、0.65和0.66只（P〈0.01）。杜×寒F1代繁殖母羊平均产羔数（1.67只）显著高于杜×寒F3代（P〈0.05）,比F2代平均产羔数增加0.28只（P〉0.05）。B＋基因型母羔初生体重、体尺和3月龄断奶体重极显著小于＋＋基因型母羔（P〈0.01）,B＋基因型公羔初生及3月龄断奶体重、体尺都小于＋＋基因型公羔（P〉0.05）,表明FecB基因不仅是影响杜×寒杂交肉羊产羔数的主效基因,而且在一定时期内也影响羔羊的生长发育。     

三元杂交肉用犊牛育肥效果试验报告

皮西本F1、利西本F1三元杂种犊牛在育肥场集中舍饲育肥180 d,头均增重158.25 kg和152.25 kg,日增重879.15 g和845.78 g,在农户一般饲养条件下育肥头均增重114.25kg和103.5kg,日增重634.68 g和574.95 g,在不同的饲养管理条件下育肥效果差异极显著(P<0.01),但在相同的饲养管理条件下,皮西本F1和利西本F1不同三元杂交组合间育肥效果差异不显著(P>0.05)。通过该试验说明三元杂种犊牛适于集中舍饲育肥,农户作为我市重要的育肥牛源基地,只有加强饲养管理采用综合配套技术措施,才能得到理想的育肥效果。     

An Evaluation of Brewery Waste as a Replacement for Concentrates in Diets for Growing Crossbred Common Ducks

An experiment was carried out to determine the effect of feeding brewery waste that replaced different levels of concentrate in diets for growing crossbred common ducks. A total of 300 ducks at 3 weeks of age were allocated in a 2 x 5 factorial experiment. Two feeding systems were compared, with the brewery waste provided separately (S) or mixed (M) with a concentrate. For the first feeding system the concentrate was fed alone (C100M), or replaced successively by brewery waste at ratios of concentrate to brewery waste: 75:25 (C75M), 50:50 (C50M) and 25:75 (C25M) on a dry matter basis, and fed ad libitum. For the second system concentrate and brewery waste were fed separately, with the same levels as in the first system. Total feed intakes for both feeding systems and intakes of brewery waste, total dry matter, crude protein, calcium and phosphorus increased significantly as concentrate was reduced (p <0.05). Daily weight gains were not significantly different between the two feeding systems, but were significantly lower for the C25 and C0 diets (p <0.05). Replacement of 50% of the concentrate by brewery waste resulted in the best growth performance. The highest net profits were from the separate feeding system, and for ducks fed brewery waste only (C0). It is concluded that brewery waste can replace traditional diets for crossbred common ducks based on concentrate.     

通城、瑞典长白、英国大白及其三元杂种猪部分免疫性状研究

通城猪是华中两头乌猪中的一个优良类群，具有肉质细嫩鲜美、耐粗饲、适应性广、抗病力强、遗传性稳定、杂交配合力好等特性，2000年被列入全国第一批国家级畜禽品种资源保护名录。地方猪普遍具有抗病力强的突出优点，这种抗病力多为一般抗病力。一般抗病力是机体对疾病的整体防御功能的体现，如何度量尚无统一规定，对其研究目前还欠深入。机体的免疫力可分为先天性免疫和获得性免疫(对疾病的抵抗力也分为先天性抗性和获得性抗性)，而获得性免疫又分为体液免疫和细胞免疫，     

品种及杂交组合效应对育肥猪猪肉羟脯氨酸和pH值的影响

通过对不同品种及杂交组合氟烷基因显性纯合子育肥猪肌肉中羟脯氨酸和pH值2个指标的测定,来分析品种及杂交组合效应对猪肉质的影响。试验结果表明,品种及杂交组合效应对猪肉的嫩度有影响。在屠宰后的前4 d大长猪(大白猪×长白猪)猪肉中羟脯氨酸含量低于长大猪(长白猪×大白猪),说明其嫩度要好于长大猪;猪肉离体后pH值先下降后上升。随着冷藏时间的延长,长白猪和大白猪猪肉pH值的升高速度要比杜洛克猪、长杜猪(长白猪×杜洛克猪)、长大猪、大长猪的速度要慢,说明长白猪和大白猪肉的货架期较长。长白猪与大白猪正反交,对肌肉pH值影响差异不显著(P>0.05)。     

Effects of long-term administration of recombinant bovine somatotropin on the plasminogen–plasmin system and milk composition of crossbred Holstein cattle

Experiments were performed to examine the effects of long‐term treatment with recombinant bovine somatotropin (rbST) on milk plasmin–plasminogen and milk composition by one injection of 500 mg of rbST in every 14 days throughout lactation in crossbred Holstein cattle. The animals receiving rbST gave a greater milk yield and rate of blood flow to the udder during early lactation than the control group. The milk lactose concentration remained constant while the milk protein concentration increased as lactation advanced in both groups. The level of milk fat in rbST‐treated animals was significantly greater than in controls in the early lactation period (P < 0.05). The milk sodium and chloride concentrations of the rbST‐treated animals significantly decreased in early lactation as compared with the control animals. The sodium : potassium ratio of the rbST‐treated animals was significantly lower than those of control animals in the early lactation (P < 0.05) and it markedly increased in late lactation. As lactation advanced, the concentration of plasmin in the milk gradually increased, while the milk plasminogen concentration significantly increased in both groups. The plasminogen : plasmin ratio decreased in the control animals while it increased in the rbST‐treated animals as lactation advanced. These findings demonstrate that rbST is involved the activity of the plasmin–plasminogen system but is not involved in maintaining tissue integrity in the mammary gland during late lactation in crossbred dairy cattle.     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis)

This study was conducted to determine and compare the live traits, carcass yield and the physical, chemical, processing and sensory properties of meat from 20 Brahman grade cattle (crossbred cattle) and crossbred water buffalo (Philippine carabao × Murrah, Bulgarian or Indian) with an average age and weight of 29 months and 434 kg, respectively. The animals were fed a similar diet for 180 days before slaughter. A survey was performed to establish consumer meat preference between the two species. Live weights before slaughter of the two species were found to be different (P < 0.05) with the crossbred water buffalo showing higher bodyweight. However, the crossbred water buffalo had a lower (P < 0.05) dressing yield based on hot carcass weight and chilled carcass weight. The lower dressing yield of crossbred water buffalo can be attributed to its higher (P < 0.05) weights of edible and non‐edible slaughter by‐products. The chilled carcass yield of the forequarters and hindquarters from crossbred cattle and crossbred water buffalo were comparable when expressed as percent of live weight and chilled carcass weight. The estimated lean yield was higher in crossbred cattle than crossbred water buffalo. Crude protein, ash, fat, cholesterol, myofibrillar, sarcoplasmic and insoluble protein contents of the beef and carabao meat were all similar. Water holding capacity, pH, muscle fiber diameter, tenderness, firmness and marbling score in carabeef were all comparable to the beef. Redness was found to be higher (P < 0.05) in carabeef than the beef as measured with a color meter. The consumer meat preference survey showed that 55.9% selected the beef while 44.1% preferred carabeef. The color and amount of fat on the outside of the beef sample were primary in buyer selection.     

Immunoprotective Efficacy of a Purified 39 kDa Nymphal Antigen of Hyalomma anatolicum anatolicum

Soluble nymphal antigens (HNAg) were purified by immunoaffinity chromatography using CNBr-activated Sepharose 4B coupled with immunoglobulin ligands from animals immunized with HNAg and 69–71% protected against challenge infestations, and 8% recovery of the purified protein (Aff-HNAg) was obtained. Following immunization of crossbred calves (Bos indicus×Bos taurus) with 1600 g of Aff-HNAg in three divided doses, significant rejections of larvae (p<0.001, 84.2%), nymphs (p<0.05, 61.4%) and adults (p<0.05, 58.7%) were recorded. No significant changes were recorded in the engorgement weights of the larvae and nymphs, but there was a significant (p<0.05) reduction in the weight of the engorged adults. Immunization conferred a significant decrease in the numbers of resultant nymphs (p<0.001) and adults (p<0.001) that had fed on the immunized animals. SDS-PAGE analysis identified a 39 kDa protein, previously isolated from larvae of Hyalomma anatolicum anatolicum, as the antigen responsible for the induction of resistance against all the stages of the tick.     

杂交猪繁殖性能的相关与回归分析

为合理调整猪群生产结构,最大限度地利用杂种母猪的生产力,利用SPSS 10.0软件中的相关模块,对510头杂交母猪繁殖性状间的相关关系及繁殖性状对胎次的回归关系进行了分析。结果表明:产活仔数(Y2)与总产仔数(Y1)、断奶仔数(Y3)、窝重(Y4)表现强相关,相关系数分别为0.883、0.893和0.845,并且都达到极显著水平(P<0.01),而总产仔数与断奶仔数和窝重也表现较强相关,相关系数分别为0.783和0.796,并且达到极显著水平(P<0.01)。繁殖性状对胎次(X)的回归方程如下:Y1=9.416+1.473 X-0.306 X2,Y2=9.416+1.636 X-0.333 X2,Y3=9.416+1.811 X-0.355 X2,Y4=9.416+4.865 X-0.834 X2。研究为合理利用二元或三元杂交母猪,提高商品猪生产效益提供了科学依据。     

非洲猪瘟背景下的三元商品母猪养殖策略

非洲猪瘟病毒(African swine fever virus,ASFV)是一种病毒分子巨大且复杂的DNA病毒,在无有效疫苗的情况下,会引起高度传染性且通常致命的猪瘟。目前非洲猪瘟(African swine fever,ASF)导致我国母猪存栏大幅度下降,猪场引种面临了巨大的生物安全风险,采用三元商品母猪留种成为了一种较好的选择。文章结合生产实践,旨在为三元商品母猪的饲养管理和营养调控提供指导意见。