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脂肪做为高能量饲料原料 ,经常被添加于肉用仔鸡日粮中以提高日粮能量浓度、提高增重速度和改善饲料效率。随着消费者对肉鸡胴体品质的要求不断提高 ,减少脂肪沉积 ,降低腹脂含量 ,提高胸肌产量 ,成为肉鸡营养研究中的重要课题。影响肉鸡腹脂沉积的因素很多 ,其中最主要的是营养和遗传因素。Ｃｏｌｅ等 ( 1 992 )认为 ,日粮中能量和粗蛋白质水平是影响腹脂的重要因素 ,并发现 6周龄肉用仔鸡腹脂含量受日粮能量的影响更大。用于饲料的脂肪一般可分为三大类 :动物脂肪、植物脂肪和混合脂肪。由于脂肪酸的组成、脂肪饱和程度、脂肪酸链的长短不… 相似文献
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AA肉仔鸡脂肪沉积规律研究与腹脂沉积模型的建立 总被引：1，自引：0，他引：1
《饲料工业》2015,(13)
试验旨在研究现代商品肉仔鸡脂肪沉积规律,建立腹脂重随日龄变化的生长模型,为营养因素调控腹脂沉积提供理论支持。试验选用144只1日龄AA公肉仔鸡,随机分为6个重复,每重复24只鸡。屠宰试验时记录活重,腹脂重以及皮下脂肪厚,计算腹脂率。根据所测数据计算累积生长系数、相对生长系数。用3种生长模型对腹脂重、活重随日龄的变化关系进行方程拟合,计算相关参数并比较其拟合度。结果表明,腹脂的沉积模型拟合度达到0.965,腹脂沉积的拐点在28日龄左右,快速沉积阶段为21~35日龄。腹脂拐点日龄早于活重的生长拐点日龄(35 d)。皮下脂肪厚随日龄增加线性增长,线性回归方程拟合度R20.99。通过饲粮调控腹脂沉积的最佳时间为21~35日龄,皮下脂肪厚可以作为观测脂肪沉积的活体指标,对生产具有指导意义。 相似文献
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饲粮能量、蛋白质水平对
肉鸡肉质的影响 总被引：3，自引：0，他引：3
近年来,随着肉鸡业对提高肉鸡生长速率和饲料效率的遗传选育,以及为充分发挥肉鸡遗传潜力在营养配方上的不断完善,使得肉用仔鸡生产水平得到提高,但同时肉质变得粗老、腹脂沉积增多,缺少风味,降低了消费者对肉质的满意度。肉鸡生长率不仅受遗传因素的影响,还受能量、蛋白质水平(以下简称能、蛋水平)的影响(Ｃｈｅｒｒｙ,1978;Ｍａｒｏｈ,1977)。1 能、蛋水平对肉鸡肉质的影响11 直接影响 饲粮能、蛋水平影响肉鸡腹脂沉积,直接影响肉质。许多研究表明,营养因素对肉鸡体成分(包括体脂)有显著影响,影响脂肪沉积的主要营养因素有能量、蛋白质… 相似文献
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《中国畜牧杂志》2021,(9)
本研究选取北京中农榜样蛋鸡育种有限公司531只2个矮小型纯系(记为A系和B系)为实验素材,其中A系254只、B系277只,在85周龄时屠宰母鸡测定体重、肝脏重、腹脂重、卵巢重、卵泡数、全净膛重等指标,并计算屠宰性状指标的遗传参数,分析腹脂率与其他性状的关联性,统计不同腹脂沉积组后期产蛋性能及其后代2～21周龄体重的差异。结果表明:体重、腹脂重、腹脂率属于中等偏下遗传力,全净膛率和发育卵泡数遗传力较低;腹脂率与发育卵泡数、卵巢重均呈遗传负相关,与体重、肝脏重、全净膛率呈遗传正相关。A系母鸡高腹脂组腹脂率与发育卵泡数呈表型负相关(P=0.855),B系母鸡高腹脂组腹脂率与卵巢重呈表型负相关(P=0.697);高腹脂沉积会导致产蛋后期产蛋数下降,腹脂沉积可影响其后代早期平均体重(P0.05)。综上,适当控制母鸡腹脂沉积有利于维持后期的产蛋性能,掌握矮小型纯系蛋鸡屠体性状遗传参数,为通过选育手段改善商品代蛋鸡腹脂沉积和后期产蛋性能奠定基础。 相似文献
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影响肉禽产品品质的营养因素 总被引：2，自引：0，他引：2
随着肉禽业对提高禽类生长速率和饲料效率的选育，以及为充分发挥肉禽遗传潜力在营养配方上的不断完善，使得肉禽生产水平得到提高。但同时肉质变得粗老、脂肪沉积增多、缺少风味，降低了消费者对肉质的满意度。影响肉禽产品品质的因素主要包括三个方面：遗传、营养、环境。目前，对营养因素的研究较多，本文对此做一综述。１能量、蛋白水平饲料能蛋水平影响肉禽腹脂沉积，直接影响肉质。肉禽脂肪沉积来源于饲料和由肝脏合成的脂肪。体脂沉积包括脂肪细胞素体脂增加和脂肪容积的扩大。当肉鸡的能量摄入超过其维持和生长需要时，便开始沉积脂… 相似文献
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DLM和MHA-FA是常用的2种蛋氨酸添加剂。试验旨在研究2种蛋氨酸添加剂对肉仔鸡胴体品质的影响。试验采用单因素完全随机设计。7日龄艾维茵肉仔鸡560只,随机分为7个处理,每处理5个重复,每重复16只,试验持续至42日龄,自由采食饮水。试验结果显示,添加MHA-FA对肉仔鸡的腹脂率无影响,添加DLM可显著降低肉仔鸡的腹脂率。添加DLM和MHA-FA均可提高肉仔鸡的胸肌率,降低腿肌率。MHA-FA相对于DLM的生物学效价是74%(胸肌率),72%(腿肌率)。添加DLM或MHA-FA影响肉鸡整体蛋白含量和蛋白沉积率,但影响规律不明显。同时还使肉鸡整体能量含量和能量沉积率升高。MHA-FA的相对生物学效价分别是52%(能量含量)、48%(能量沉积率)。 相似文献
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选取60只21日龄个体体重相近的溆浦鹅,随机分成3组,每组5个重复,每个重复4只鹅(公母各半),分别饲喂3种不同能量水平(13.38、12.13、10.87MJ/kg)的日粮,经49d后统一屠宰,研究不同日粮能量水平对溆浦鹅体脂沉积、血清参数及其相关激素水平的影响。结果表明:1)中能组公鹅屠体重、胸肌含脂率、腹脂率均显著高于高能组和低能组(P<0.05),中能组母鹅胸肌含脂率、腹脂率、皮下脂肪厚度、肌间脂肪宽均显著高于高能组和低能组(P<0.05)。2)日粮能量水平对70日龄溆浦鹅血清中甘油三酯、胆固醇无显著影响(P>0.05),但公鹅血清中高密度脂蛋白、低密度脂蛋白、极低密度脂蛋白随日粮能量水平提高而增加。3)无论公鹅还是母鹅,高能组血清中的生长激素含量均显著高于低能组(P<0.05),与中能组相比差异不显著(P>0.05),但日粮能量水平对溆浦鹅血清中类胰岛素生长因子的含量均无显著的影响(P>0.05)。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献