【作者】 桑军亮；

【导师】 田科雄；

【作者基本信息】 湖南农业大学 ， 动物营养与饲料科学， 2012， 硕士

【摘要】 本研究以后备母猪为试验动物,试验选取日龄和体重(44.98±4.27kg)相近的大白后备母猪72头,随机分到三个营养水平组(高、中、低水平)中,各营养水平组后备母猪的采食量控制分别为：高营养水平组采食量的设置为料槽基本不剩料为原则,中营养水平组的采食量为高营养水平组的90%,低营养水平组的采食量为高营养水平组的80%。每个营养水平组设4个重复,每个重复设6头猪。分别在后备母猪80kg、100kg和达到初情时进行称重和采集血样。在100kg之后用青年公猪对后备母猪进行诱导发情并试情。用生物素双抗体夹心酶联免疫吸附法(ELISA)测定后备母猪血清中leptin和生殖激素的浓度。旨在探讨不同的营养水平对后备母猪初情的影响及其内分泌机理,从而为确定合理的后备母猪饲养方案提供依据。试验结果表明：1)营养水平对后备母猪初情体重、初情日龄、发情率和产仔性能的影响差异性均不显著,但营养水平对后备母猪初情体重、初情日龄和发情率的影响表现为随着营养水平的提高,初情体重增加、初情日龄提前和发情率有提高的趋势。2)营养水平对产仔数、产活仔数和初生窝重的影响差异性均不显著,但均以中营养水平表现较好,中营养水平的初生窝重比高营养水平提高了37.33%。3)在达到初情前,中营养水平和低营养水平的血清leptin浓度显著高于高营养水平(P<0.05)；在达到初情时,低营养水平组血清E2、FSH浓度显著高于中营养水平组(P<0.05)。结论：1)高营养水平使后备母猪初情体重增加、初情日龄提前和发情率提高,低营养水平使后备母猪初情体重降低和发情率降低。2)血清中瘦素浓度随日粮营养水平的降低而升高。血清瘦素浓度的提高可以使雌二醇、促卵泡素、黄体激素和胰岛素分泌增加,使母猪达到初情期应有的体况并启动发情。3)血清中瘦素浓度可以作为判定后备母猪是否到达初情的一个重要标志。综合初情体重、初情日龄、发情率、产仔性能、血清激素指标和经济效益,生产中建议,45-80kg之间的后备母猪参照2.66倍维持需要采食量进行饲喂,80kg之后参照2.42倍维持需要采食量进行饲喂,既降低了饲料成本,也能使后备母猪适时启动初情期,并获得较理想的初情体况和产仔性能。更多还原

【Abstract】 Experimental animals of the study were gilts. A total of72Yorkshire breed gilts, every of which body weight was44.98+4.27kg, were randomly allocated to the three different feed intake level (high, middle, low).The feed intake among different nutritional levels respectively was:high trophic level group feed intake settings for trough basically not leftover material as principle, middle nutritional level group feed intake settings for90%of high trophic levels, low nutrient levels group feed intake settings for80%of high trophic level group. There were four replicates in every feed intake level and each replicate includes six gilts. The gilts were weighted, collected blood samples when the weights of gilts respectively was80kg,100kg and puberty. When gilts were100kg, young boars were used for estrus induction and teasing in gilts.Then, ELISA was applied to determine the hormone concentration in serum. This research was conducted to study the effect of feed intake level on the puberty and secretion mechanism of hormone in gilts. Thus this can determine the reasonable feeding programs of gilts.The results showed that:1) Effects of nutritional level on puberty weight, puberty age, estrus rate, reproductive performance in gilts are not significantly difference. But along with raising the level of nutrition, puberty weight gain, puberty age advanced and estrus tends to be improved.2) Nutritional level on litter size, number of live births and litter weight at birth are not significantly difference. But middle nutrient levels was as better performance, newborn litter weight of middle levels increased by37.33%than the high nutrient levels.3) Before reaching puberty, serum leptin concentration of middle nutrition levels and low nutrient levels was significantly higher than that of high trophic levels(P<0.05); when reaching puberty, serum E?, FSH of low nutrient levels were significantly higher than that of middle nutritional level group(P<0.05)Conclusions:1) High nutrient level can make puberty weight increasing, puberty age advancing and estrus rate rising. Low nutrient level can make gilts puberty weight reducing and the rate of estrus reducing. 2) Serum leptin concentration increases as dietary nutrient levels decreased. Serum leptin concentration makes estradiol, luteinizing hormone and insulin secretion increasing, make gilts reaching puberty body condition and start the estrus.3) Serum leptin concentration can be used as an important mark to determine whether the gilts can reach puberty.Integrated estrus weight, puberty, rate of estrus, serum hormone index, reproductive performance and economic benefit, the suggestion of production is that, between45kg and80kg, the gilts may obtain2.66times maintenance intake, after80kg the gilts may obtain2.42times maintenance intake for feeding, so this feeding program can reduce feed cost, but also can make the gilts starting puberty timely, obtaining the ideal puberty body condition and reproductive performance.更多还原