饲粮短期高剂量添加天冬氨酸镁对猪肉品质的影响

本试验研究了在基础日粮中短期添加不同水平的天冬氨酸镁对猪肉品质的影响。试验共分4个处理,每个处理6头猪。处理组镁(天冬氨酸镁)的添加水平分别为0、1 500、2 500和3 500 mg/kg。结果表明:屠宰前7 d饲粮添加天冬氨酸镁提高了猪肉品质,背最长肌肉中镁的含量分别比对照组提高了10.35%(P<0.05)、16.83%和18.61%(P<0.01),血清中镁的浓度分别比对照组增加了14.29%、27.14%和34.29%(P<0.01);显著提高了猪肉的初始pH(6.16~6.50)和最终pH(5.61~5.75)(P<0.05);对肉色评分改善显著(P<0.05);显著降低了滴水损失(P<0.05);但对猪的屠宰率、瘦肉率、背膘厚、眼肌厚度和肌肉中胶原蛋白含量等无显著影响(P>0.05)。回归分析结果表明:当镁的添加量在2 500~3 200 mg/kg时,对pH、滴水损失和肉色的改善作用达到最大,此时血清和肌肉中镁的含量约为0.90 mmol/L和241 mg/kg。     

近红外光谱技术在家禽养殖领域应用现状

近红外光谱是一种快速光谱分析的新方法,伴随着光谱技术与化学计量法的发展,近红外光谱已广泛应用于农业、食品、医药、石油化工等行业,极大地提高了各行业信息化水平。基于近红外光谱在家禽养殖领域的应用现状,本文总结了近红外光谱技术的发展及其在饲料成分检测和禽肉检测中的应用。在饲料检测和家禽肉类检测方面,通过将禽肉样品的光谱信息与质量指标的参考值相关联,建立了预测饲料和待测肉类高精度、高稳定性的数学模型。与传统方法相比,近红外光谱技术具有信息量大、数据计算速度快等优点。本文还归纳了近红外光谱技术在饲料品质检测和肉类品质检测的应用现状,指出了近红外光谱在家禽养殖领域的大规模应用推广的可能性。同时指出近红外光谱技术存在的问题和未来发展方向,结果表明近红外光谱技术在饲料和畜产品检测领域具有良好的发展前景和应用价值。     

新型生猪标识及肉产品可追溯系统的设计和实现

本文介绍一种新型生猪标识的研制,在利用新型生猪标识的基础上,采用信息网络技术、数据库技术、构件化软件设计技术、条形码和电子标识技术,进行生猪可追溯系统的设计,并在生猪养殖场、屠宰场、超市实现并成功示范。同时也介绍了国内外生猪标识的研究以及发达国家可追溯系统的试点及实施情况,为我国生猪和猪内产品可追溯系统建设提供参考,最终实现生猪的安全生产和肉产品的安全消费。     

Replacement of fish meal by meat and bone meal in diets for large yellow croaker, Pseudosciaena crocea

A growth experiment was conducted to investigate the effects of replacement of fish meal (FM) by meat and bone meal (MBM) in diets on the growth and body composition of large yellow croaker (Pseudosciaena crocea). Six isonitrogenous (43% crude protein) and isoenergetic (20 kJ g^− 1) diets replacing 0, 15, 30, 45, 60 and 75% FM protein by MBM protein were formulated. Each diet was randomly allocated to triplicate groups of fish in sea floating cages (1.0 × 1.0 × 1.5 m), and each cage was stocked with 180 fish (initial average weight of 1.88 ± 0.02 g). Fish were fed twice daily (05:00 and 17:30) to apparent satiation for 8 weeks. The water temperature ranged from 26.5 to 32.5 °C, salinity from 32 to 36‰, and dissolved oxygen content was approximately 7 mg l^− 1 during the experimental period. Survival decreased with increasing dietary MBM and the survival in the fish fed the diet with 75% protein from MBM was significantly lower than other groups (P < 0.05). There were no significant differences in specific growth rate (SGR) among the fish fed the diets with 0 (the control group), 15, 30 and 45% protein from MBM. However, SGR in the fish fed the diets with 60 and 75% protein from MBM were significantly lower than other groups (P < 0.05). No significant differences in feeding rate were observed among dietary treatments. The digestibility experiment showed that the apparent digestibility coefficients (ADC) of dry matter, protein, lipid and energy of MBM were significantly lower compared with those of FM (P < 0.05). Essential amino acid index was found to be correlated positively with SGR in the present study, suggesting that essential amino acid balance was important. Body composition analysis showed that the carcass protein and essential amino acids were not significantly affected by dietary MBM. The lipid and n-3 highly unsaturated fatty acid (n-3 HUFA) in fish muscle, however, significantly decreased with increasing dietary MBM. These results showed that 45% of FM protein could be replaced by MBM protein in diets of large yellow croaker without significantly reducing growth. It was suggested that the reduced growth with higher MBM was due to lower digestibility and imbalance of essential amino acids.     

Quality aspect of fish sauce prepared from underutilized fatty Japanese anchovy and rabbit fish

ABSTRACT:   To explore the potential utility of underutilized fish in the fish sauce industry, fish sauces were prepared from both raw and heat-induced meat of Japanese anchovy Engraulis japonica and rabbit fish Siganus fuscescens using wheat malt, and their quality aspects and sensory properties were assessed. Proximate composition of the fish meat represents protein as the major component (16.0–17.8%), other than moisture. Analyses of free amino acids, peptides including oligopeptides, and organic acids contents in fish sauces revealed suitability of both raw and heat-induced meat of the selected species in commercial fish sauce production. The variations in taste of raw meat fish sauces were species-specific, but the taste of fish sauces from heat-induced meat were similar.     

基于实例分割和光流计算的死兔识别模型研究

为实现自动化识别死兔,提高养殖管理效率,以笼养生长兔为研究对象,以基于优化Mask RCNN的实例分割网络和基于LiteFlowNet的光流计算网络为研究方法,构建了一种多目标背景下基于视频关键帧的死兔识别模型.该模型的实例分割网络以ResNet 50残差网络为主干,结合PointRend算法实现目标轮廓边缘的精确提取...     

转兔角蛋白基因改良棉纤维品质研究

通过花粉管通道转基因技术,将E6启动子驱动的兔角蛋白基因导入高产棉花品种苏棉16号。所用转基因表达载体还含有选择标记基因NPTⅡ(卡那霉素抗性基因)及Gus报告基因。对转化体后代的检测结果表明,T1代有2.1%呈现Gus阳性,在Gus阳性株中84.6%具有卡那霉素抗性。用依据E6启动子序列和兔角蛋白基因序列设计的两对引物,对经过上述筛选的植株进行PCR检测,多次重复,最终确定3株结果稳定的转兔角蛋白基因棉株。从品质分析结果看,这3个株系成熟棉纤维的品质部分得到改良,尤其比强度有较大幅度提高,与转基因受体相比平均提高6.3cN·tex 1。     

绵羊PRKAG3基因SNPs与肉质性状的相关性分析

为从分子水平研究甘肃境内典型养殖模式下甘肃高山细毛羊、小尾寒羊、藏羊、蒙古羊和滩羊5个绵羊品种的PRKAG3基因多态性与屠宰性能和肉品质的相关性,探讨以PRKAG3为候选基因,提高绵羊屠宰性能和肉品质的可能性。采用PCR-SSCP技术对5个绵羊品种的PRKAG3基因外显子4,5和内含子4多态性进行检测,并就PRKAG3基因多态性与9月龄屠宰性能和肉品质进行相关性分析。结果表明,在PRKAG3基因2 689 bp处发生了AG的突变,位于第4内含子第23 bp处,表现出3种基因型,AA、AB和BB。纯合度(Ho)分别为0.67,0.69,0.76,0.69,0.59,杂合度(He)分别为0.333 3,0.306 1,0.244 9,0.307 7,0.408 2,有效等位基因(Ne)分别为1.62,1.66,1.69,1.48,1.79,多态信息含量(PIC)分别为0.31,0.32,0.33,0.27,0.34。除藏羊外其他4个绵羊品种均处于Hardy-Weinberg平衡状态。关联分析表明,5个绵羊品种PRKAG3基因此变异位点的3个基因型间失水率性状差异显著(P0.05);BB基因型个体的胴体重显著高于AA型(P0.05),滩羊为极显著(P0.01),BB基因型个体的眼肌面积显著大于AA型(P0.05)(藏羊除外)。因此说明PRKAG3基因可作为候选基因用于绵羊产肉性能和肉品质的分子标记辅助选择。     

中药添加剂防治兔球虫病及其增重效果试验

40只家兔随机均分为4组，Ⅰ组为空白对照组，Ⅱ组为感染对照组、Ⅲ组为地克珠利组、Ⅳ组为中药添加剂组，用药组家兔饲喂含药饲料3 d后，人工感染兔混合球虫卵囊1×105。试验结束时，Ⅲ、Ⅳ组家兔平均OPG值均为0，并且两组家兔均无死亡；Ⅳ组家兔平均日增重为30.9±6 g，经q检验，与Ⅰ组、Ⅲ组比较差异显著（p<0.05），与Ⅱ组比较差异极显著（p<0.01）。结果表明：此中药添加剂具有与地克珠利相当的对家兔球虫病防治作用，并有促进家兔生长的作用。     

家兔在不同状态下实验性兔瘟病的疾病经过

观察了清醒(对照)、实验性发热、麻醉或人工冬眠状态的家兔对Y8504株强毒兔瘟病毒攻毒的敏感性。结果表明,和在清醒兔的所见相比,麻醉兔对病毒感染的发热应答明显地受抑制,在人工冬眠兔也有某种程度受抑制,但在实验性发热兔出现发热反应的重叠。实验性发热和人工冬眠使感染兔的存活时间延长,而麻醉则使死亡时间明显推迟。并且,所有状态下的感染都是致死性的,从而表明兔瘟病毒所致损害在兔瘟疾病经过中起决定性作用。