运用计算机断层扫描技术活体评估种公猪瘦肉率、脂肪率和肌内脂肪含量     

任志强  王晨阳  寇忠云  蔡瑞  杨公社  庞卫军 《中国农业科学》2023,56(9):1787-1799

【目的】通过研究计算机断层扫描(computed tomography,CT)技术在活体评估种公猪胴体与肉质性状中的准确性,实现对表型组进行智能测定,为种猪的选育和精细化饲养管理提供技术参数。【方法】选择体重相近((42.02±1.05)kg)、健康状况良好的杜洛克公猪40头,饥饿处理24 h后,采取耳缘静脉注射麻醉剂,实行全身性麻醉。将猪只按照头前尾后俯卧姿势置于CT扫描床上,通过16排螺旋CT平扫获取原始图像序列。利用图像处理技术对获取的图像进行图像薄层重建与去噪、图像多平面重建和图像分割,进而对图像进行定量分析,并结合B超活体测定和屠宰测定评估了种公猪的胴体组成、背膘厚、眼肌深度、眼肌面积、胴体直长和胴体斜长等胴体性状;以屠宰测定瘦肉率为因变量,CT活体测定背膘厚、眼肌深度、眼肌面积、胴体直长和胴体斜长为自变量,运用偏最小二乘回归分析构建种猪胴体瘦肉率的预测模型;采用索氏提取法测定背最长肌、臀中肌和半膜肌样品中肌内脂肪(intramuscular fat,IMF)含量,并与CT活体评估对应部位肌内脂肪含量进行相关性分析。【结果】在对CT活体评估与屠宰测定瘦肉率、脂肪率、骨率、皮率...  相似文献   

鸡肉品质分析及关键风味物质和基因的筛选     

巨晓军  章明  单艳菊  姬改革  屠云洁  刘一帆  邹剑敏  束婧婷 《中国农业科学》2023,56(9):1813-1826

【目的】对不同品种鸡肉中的风味物质和基因进行筛选,为开展品种选育及鸡肉产品的开发利用等研究提供科学依据。【方法】首先对消费者购买肉鸡的主要选择因素进行市场调查。其次分别选取上市日龄的地方品种鸡（文昌鸡、鹿苑鸡）、培育品种鸡（817肉鸡、花山鸡）、引进白羽肉鸡（罗斯308）,每个品种选取接近平均体重的30只鸡（公母各15只）屠宰,屠宰后迅速取两侧胸肌,用于品尝评定、常规肉品质、肌纤维特性、肌苷酸、脂肪酸、氨基酸含量及相关基因表达的测定。最后通过偏最小二乘法（partial least squares,PLS）将品尝评定结果与理化测定结果进行关联分析,挖掘影响品尝评定的风味物质。【结果】（1）风味是消费者购买肉鸡的主要选择因素。文昌鸡肉的甜味、鲜味显著高于罗斯308(P≤0.05)。（2）文昌鸡、鹿苑鸡平均肌纤维面积显著低于其他品种（P≤0.05）,平均肌纤维直径显著低于花山鸡、罗斯308(P≤0.05)。文昌鸡肌苷酸含量显著高于其他品种（P≤0.05）。文昌鸡、鹿苑鸡饱和脂肪酸含量显著高于其他品种（P≤0.05）,罗斯308不饱和脂肪酸含量显著高于文昌鸡、鹿苑鸡、817肉鸡（P≤0.05...  相似文献   

射频解冻数值模拟过程中不同方法所获初始电压值对样品温度的影响     

李玉林  李锋  王易芬  焦阳 《中国农业科技导报》2019,21(4):114-122

针对射频解冻有限元模拟过程中所需极板电压难以由实验获取的问题,以冷冻牛肉为例,采用3种不同方式间接获取的输入电压(固定电压、实际阳极电压和公式推导电压),运用有限元模拟方法对3种尺寸(小:160 mm×102 mm×60 mm;中:220 mm×140 mm×60 mm;大:285 mm×190 mm×60 mm)的冷冻牛肉进行射频解冻,对比了模拟和实验获得加热速率和温度分布中电压选择的有效性。计算机模拟结果与实验结果对照表明,射频解冻能够均匀快速解冻冷冻牛肉样品,但存在少部分边角过热效应。对比三种输入电压模拟与实际试验验证得到的升温曲线和表面温度分布,结果表明阳极电压值数值与实际电压值较为接近,约为7.2～8kV,而推导电压值最高,约为9.2～10.7 kV。选用推导电压值的70%～80%作为模拟值时,所获得的样品升温速率和终温最为接近实验结果。该研究结果可为精确模拟射频解冻过程的输入参数的获取提供参考。  相似文献   

Effects of corn distillers dried grains with solubles on performance,oxidative status,intestinal immunity and meat quality of Chinese Yellow broilers          下载免费PDF全文

D. Ruan  S. Q. Jiang  Y. J. Hu  F. Y. Ding  Q. L. Fan  F. Chen  X. J. Lin  L. Li  Y. Wang 《Journal of animal physiology and animal nutrition》2017,101(6):1185-1193

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Influence of dietary rapeseed meal levels on growth performance,organ health and standardized ileal amino acid digestibility in meat ducks from 15 to 35 days of age          下载免费PDF全文

S. Qin  G. Tian  K. Zhang  X. Ding  S. Bai  J. Wang  G. Jia  Q. Zeng 《Journal of animal physiology and animal nutrition》2017,101(6):1297-1306

This study was conducted to investigate the effects of dietary rapeseed meal (RSM) inclusion levels on growth performance, organ health and standardized ileal amino acid digestibility (SIAAD) in meat ducks from 15 to 35 days of age. Six hundred and eighty 15‐days‐old ducks were randomly allotted to five treatments based on body weight. Five isonitrogenous and isoenergetic diets were formulated on a digestible amino acid basis by replacing 0% (the control), 25%, 50%, 75% and 100% (based on fresh) of protein from soya bean meal (SBM) with protein from RSM. The corresponding levels of RSM in experimental diets were 0%, 6.66%, 13.32%, 19.98% and 26.64% respectively. With increasing dietary RSM levels, body weight (BW) and average daily gain (ADG) linearly decreased (p < 0.001), whereas feed‐to‐gain ratio (F: G) linearly increased (p = 0.0078). Ducks fed the diets with 13.32% or more RSM had significantly lower (p < 0.05) BW, ADG and ADFI, or higher F: G than ducks fed the control diet. The maximum limit of dietary RSM supplementation was estimated to range from 4.27% to maximize ADG for 15 to 35 days to 11.69% to maintain feed intake for 15 to 35 days on the basis of a broken‐line model. At day35, the 4th primary wing feather length and SIAAD (except for Met, Thr and Val) linearly decreased (p < 0.001), and the thyroid glands weight (% of BW) linearly increased (p < 0.05) with increasing dietary RSM levels. Ducks fed the RSM inclusion diets had significantly lower (p < 0.0001) serum aspartate aminotransferase (AST) and alanine transaminase (ALT) activities than ducks fed the control diet. These results suggested that the maximum limit of dietary RSM containing 7.57 μmol/g glucosinolates was estimated to be 4.27% to avoid growth reduction.  相似文献   

猪IGFBP2基因遗传多态性及其与肉质性状的关联分析     

刘海霞  朱爱文 《中国畜牧兽医》2017,44(10):3016-3022

试验旨在探究胰岛素样生长因子结合蛋白2（insulin-like growth factor binding protein 2,IGFBP2）基因遗传变异对猪肉质性状的影响,为猪品种选育提供遗传学依据。参考GenBank中猪IGFBP2基因序列（登录号：BV727778）设计1对引物,采用PCR-RFLP技术检测IGFBP2基因在苏姜猪、姜曲海猪、长白猪中的遗传多态性,并分析基因座多态性与猪肉质性状的相关性。结果发现,3个猪种IGFBP2基因内含子3均具有Msp Ⅰ酶切多态性,分别检测到3种基因型：AA、AB和BB;χ²适合性检验显示,3个猪种IGFBP2基因基因型分布均处于Hardy-Weinberg平衡状态（P > 0.05）;多态信息含量（PIC）分析显示,3个猪种均为中度多态。IGFBP2基因不同基因型与肉质性状关联分析显示,3个猪种不同基因型肉色、肌内脂肪含量、大理石纹差异显著,AA基因型肉色（姜曲海猪除外）、肌内脂肪含量均显著高于AB、BB基因型（P < 0.05）;AA、AB基因型大理石纹显著高于BB基因型（P < 0.05）,其余指标间差异不显著（P > 0.05）。综上,苏姜猪、姜曲海猪、长白猪IGFBP2基因内含子3多态性对肉质性状影响显著,可作为潜在影响猪肉质性状的候选基因。  相似文献   

郏县红牛与不同品种肉牛杂交后代肉用性能比较研究     

张花菊  徐亚铂  王琳琳  孙斌斌  李志钢  丁亚军  孙红霞 《中国畜牧兽医》2017,44(12):3482-3490

为了研究郏县红牛与不同品种肉牛杂交后代的肉用性能和肉品质情况,试验选取红安格斯牛、西门塔尔牛、夏洛莱牛与郏县红牛的杂交1代公牛各5头,纯种郏县红牛5头,分为试验A组（郏县红牛公牛）、B组（红郏F1代公牛（红安格斯牛×郏县红牛））、C组（西郏F1代公牛（西门塔尔牛×郏县红牛））和D组（夏郏F1代公牛（夏洛莱牛×郏县红牛））4个试验组,在同样的饲养管理条件下,持续育肥3个月后屠宰,利用屠宰测定和检验分析的方法对郏县红牛及其不同杂交品种的体尺发育、肉用性能和肉品质进行分析测定。结果表明：采用红安格斯牛、夏洛莱牛改良郏县红牛,在体高、体斜长、胸围和管围方面与郏县红牛纯种牛相比均无显著性差异（P>0.05）;屠宰测定方面,杂交后代组的头重、皮厚、皮重、前二蹄重和尾重,屠体器官食道、气管、肝脏、脾脏、肺脏、肾脏的重量,以及胴体产肉率、眼肌面积、肉骨比与郏县红牛纯种牛相比均无显著性差异（P>0.05）,但其胴体后腿宽显著高于郏县红牛纯种牛（P<0.05）;红郏F1代公牛高档肉块重和优质肉块重最高,分别为70.22和105.22 kg,但高档牛肉率4组之间差异不显著（P>0.05）,红郏F1代公牛优质牛肉率达到34.43%,显著高于郏县红牛和西郏F1代公牛（P<0.05）,高于夏郏F1代公牛（P>0.05）。在肉品质方面,红郏F1代公牛与肉品风味有关的肌苷酸含量最高,而不饱和脂肪酸含量和与鲜味有关的氨基酸（天门冬氨酸、谷氨酸、甘氨酸和丙氨酸）含量均为夏郏F1代公牛含量最高,分别为53.85%和8.04%。结果提示,采用红安格斯牛、西门塔尔牛和夏洛莱牛改良郏县红牛,没有在体尺发育和肉用性能方面表现出显著优势,但采用红安格斯牛改良郏县红牛可提高郏县红牛肉用性能的潜力,可适度提高高档牛肉和优质牛肉肉块重量,而夏洛莱牛改良郏县红牛可适度提高牛肉品质。  相似文献   

Effects of enhancing vitamin D status by 25-hydroxycholecalciferol supplementation,alone or in combination with calcium and phosphorus,on sternum mineralisation and breast meat quality in broilers     

M. Bozkurt  S. Yalçin  B. Koçer  A. E. Tüzün  H. Akşit  S. Özkan 《British poultry science》2017,58(4):452-461

1. The aim of the present study was to examine the effects of improving vitamin D status in broiler diets by supplementary 25-hydroxycholecalciferol (25OHD₃), alone or in combination with calcium (Ca) and available phosphorus (aP), on live performance, sternum mineralisation and breast meat quality in broilers.

2. A total of 936 1-d-old Ross 308 broilers were used in the study. After gender determination at the hatchery, chicks from each sex were randomly distributed into three dietary treatments. The following dietary treatments were used in the experiment from hatch to 38 d: (1) A control diet formulated to meet all of the nutrient requirements of broiler chicks according to the management guide; (2) The control diet supplemented with 18.7–15.0 µg/kg of 25OHD₃; and (3) The control diet supplemented with 18.7–15.0 µg/kg of 25OHD₃ plus Ca + aP.

3. Improvement in vitamin D status by 25OHD₃ supplementation, alone or in combination with Ca and aP, had no effect on body weight and feed conversion ratio of broilers.

4. The serum 25OHD₃ concentration significantly increased with 25OHD₃ and 25OHD₃ plus Ca + aP supplementation (P < 0.05), whereas the ionised Ca and Mg concentrations remained unchanged.

5. Sternum absolute weight, ash content and the concentrations of Ca and P significantly increased (P < 0.01) with supplementation of 25OHD₃, alone or in combination with Ca + aP.

6. Supplemental 25OHD₃, alone or in combination with Ca + aP, slightly increased pH₂₄ (P = 0.05) and decreased (P < 0.01) squeezable water loss in breast meat, whereas it had no significant effect on lightness, yellowness and sarcoplasmic protein solubility.

7. In conclusion, the results suggested that enhancing vitamin D status by 25OHD₃ supplementation alone or in combination with Ca + aP may improve sternum structure and mineral accretion. Furthermore, supplemental 25OHD₃, even in a nutritionally complete diet, may offer an effective way to improve protein solubility in female broilers.  相似文献   

Influence of carbon dioxide stunning procedure on quality of turkey meat     

S. Mauri  A. Guijarro  C. Avilés  F. Peña 《British poultry science》2017,58(4):382-389

1. The objective of this study was to evaluate the effect of sex and gas stunning on quality attributes of turkey breast meat.

2. One hundred B.U.T. Premium turkeys (50 males and 50 females) were divided into four groups of 25 animals and subjected to one of two CO₂ stunning procedures: G1 stepwise (step 1: 30% CO₂, 15 s; step 2: 55% CO₂, 40 s; step 3: 70% CO₂, 45 s) or G2 fixed concentration (80% CO₂, 100 s). The pH and meat colour at 20 min post-mortem, and pH, colour (L*, a*, b*), water holding capacity (WHC), drip loss (DL), cooking loss (CL) and Warner–Bratzler shear force (WBSF) in breast samples at 24 h and 7 d post-mortem were assessed.

3. There were significant differences between stunning groups for pH, meat colour and CL, whereas no significant differences were found for DL and WBSF. Sex had a significant effect on pH and b* and ageing of meat affected pH, colour coordinates, DL and WBSF.

4. It was concluded that the G2 treatment affected negatively the pH value and colour coordinates. However, G2 stunning affected positively the WHC parameters. Female turkeys had better results than males for pH, and the colour of female turkey breast meat was less yellow than male breast meat.  相似文献   

Evaluation of sulphur amino acid requirement of male Korean native ducklings from hatch to 21 day of age     

J. Yoo  Y. J. Yi  S. S. Wickramasuriya  E. Kim  T. K. Shin  H. M. Cho 《British poultry science》2017,58(3):272-277

1. A dose-response experiment was conducted with male Korean native ducklings (KND) to evaluate the total sulphur amino acid (TSAA) requirement from hatch to 21 d of age.

2. A completely randomised design with 7 dietary TSAA concentrations (0.62%, 0.65%, 0.68%, 0.71%, 0.74%, 0.77% and 0.80%) were used with 6 replications per treatment.

3. Body weight (BW) and feed intake were measured weekly to calculate average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). One duckling per pen (n = 6) was killed by cervical dislocation to weigh empty body and drumsticks at the conclusion of experiment.

4. BW was improved significantly with increasing TSAA content, in a non-linear manner. A significant decrease of FCR was shown with increasing TSAA contents. TSAA requirement was determined by taking a mean value after fitting the data to both a linear-plateau and a quadratic-plateau model. Estimated TSAA requirements were 0.70%, 0.70%, 0.66% and 0.70% for the maximum BW, ADG and ADFI and for the minimum FCR, respectively. Increasing TSAA content improved quantity of full body weight (FBW), empty body weight (EBW) and drumstick weight (DSW), but there was no effect on proportion of DSW in relation to EBW and proportion of EBW to FBW.

5. In conclusion, the growth of male KND during 1 to 21 d of age was improved with increasing TSAA content, suggesting optimal TSAA requirements estimated by two analysis models.  相似文献