奶牛产奶量、繁殖率及血液氧化应激水平的观察

发布时间：2018-02-26 07:25

本文关键词： 氧化应激奶牛繁殖性能能量负平衡卵泡发育 TOS TAS OSI　出处：《山东农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：在奶牛养殖中,高产奶牛与低产奶牛相比,胎间距要长、情期受胎率低、繁殖疾病多。奶牛产犊以后,泌乳期开始,随着产奶量的增加,奶牛对能量的需求大于能量的摄入,此时奶牛处于能量负平衡。为了满足能量负平衡下的代谢需求,机体触发了异化途径,在细胞水平,增加了活性氧的产生,打乱了抗氧和促氧的平衡,出现氧化应激。有研究推测,高产奶牛繁殖力差的情况,很可能是氧化应激引起的。在关于小鼠的研究中,发现氧化应激能够影响小鼠的卵泡发育和早期胚胎发育,最终影响卵泡的正常发育和排出,并且导致早期胚胎死亡,受胎率降低。奶牛卵泡发育阶段和早期胚胎发育阶段是否也受氧化应激影响,本试验旨在探究影响奶牛繁殖性能的影响因素,探究氧化应激是否对奶牛卵泡发育和早期胚胎发育有不利影响。本试验选取了2胎,3胎,4胎健康的经产牛,按照产奶量将奶牛分为大于7000kg的高产牛和小于5000kg的低产牛,本试验选取了胎间距,第一情期受胎率,胎次这三个繁殖指标,针对分组后的高产牛和低产牛的繁殖指标进行汇总分析,从而得到高产牛和低产牛之间的繁殖指标差异情况。其次,通过B超对奶牛进行直肠检测,判断卵泡发育情况,并在卵泡直径为0.8cm,1.2cm,排卵,排卵后1天,第7天,和第13天时采集高产奶牛与低产奶牛的血清,检测其总氧化指标(TOS)和总还原指标(TAS),来探究高低产奶牛之间的氧化还原状况,并根据OSI (TOS/TAS)来判断氧化应激的强烈程度,从而判断氧化应激是否与奶牛繁殖指标挂钩,是否影响奶牛产后卵泡发育和早期胚胎发育,为提高奶牛繁殖力奠定基础。结果表明：(1)随着胎次的增加,高产牛的胎间距也就越大,而低产牛的胎间距增加的并不明显。(2)随着胎次的增加,高产牛产后的第一情期受胎率越来越低,而低产牛产后的第一情期受胎率降低的不明显。(3)机体氧化还原平衡被打乱,氧化自由基产生过多时,机体抗氧能力也会相应提高来减弱氧化应激的损伤。(4)高产奶牛在卵泡发育到0.8 cm,排卵阶段和排卵后1天,排卵后第13天时,氧化自由基含量显著高于低产牛。(5)高产奶牛产后卵泡发育阶段和早期胚胎发育阶段,氧化应激强度高于低产牛。随着胎次的增加,高产奶牛的繁殖性能越来越低,而低产奶牛的繁殖性能则变化不显著。
[Abstract]:In dairy cattle breeding, high-yielding cows have longer spacing, lower conception rate and more reproductive diseases than low-yield cows. After calving, the lactation period begins, and with the increase of milk production, the energy demand of cows is greater than the energy intake. In order to meet the metabolic requirements of negative energy balance, the body triggers the dissimilation pathway, which increases the production of reactive oxygen at the cellular level and disrupts the balance between oxygen resistance and oxygen promotion. Oxidative stress. Some studies have speculated that the poor reproductive capacity of high-yielding cows may be caused by oxidative stress. In the study of mice, it was found that oxidative stress can affect follicular development and early embryonic development in mice. Ultimately, it affects the normal development and excretion of follicles, and results in the death of early embryos and the decrease of conception rate. Whether the follicular development and early embryonic development in cows are also affected by oxidative stress, The purpose of this study was to investigate the factors affecting the reproductive performance of dairy cows and whether oxidative stress had adverse effects on follicle development and early embryo development. According to the milk yield, the cows were divided into high yield cattle with more than 7 000 kg and low yield cattle with less than 5 000 kg. In this experiment, three reproductive indexes were selected, namely, the spacing of the fetus, the conception rate of the first estrous period, and the birth order. The reproductive indexes of high-yield cattle and low-yield cattle were collected and analyzed, and the difference of reproductive indexes between high-yield cattle and low-yield cattle was obtained. Secondly, the follicle development was judged by rectal examination of cows by B-ultrasound. The follicle diameter was 0.8cm ~ 1.2cm, ovulation, ovulation, and serum samples of high-yield and low-yield cows were collected on day 1, day 7 and day 13 after ovulation, and the total oxidation index (TOS) and total reduction index (TAS) were detected to investigate the redox status between high and low birth cows. The intensity of oxidative stress was judged according to OSI / TOS / TAS, so as to determine whether oxidative stress was related to the reproductive index of dairy cows, whether it affected postpartum follicle development and early embryo development of cows. The results showed that with the increase of birth order, the spacing of high yield cattle increased, while that of low yield cattle did not increase obviously with the increase of birth order. The conception rate of the first estrous period of the high-yielding cattle is lower and lower, while the conception rate of the low-yielding cattle in the first estrous period after delivery is not obviously reduced. 3) the redox balance of the body is disturbed, and when the oxidation free radical is too much, the redox balance of the body is disturbed. The ability of body to resist oxygen will also be increased accordingly to reduce oxidative stress damage.) High-yielding cows develop to 0.8 cm in follicle development, ovulation stage and 1 day after ovulation, and 13 days after ovulation. The content of oxidized free radical was significantly higher than that of low yield cattle.) the content of oxidized free radical was significantly higher than that of low yield cow during postpartum follicle development and early embryo development, and the intensity of oxidative stress was higher than that of low yield cow. However, the reproductive performance of low yield cows did not change significantly.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S823

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