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奶牛热应激及其防治对策 总被引：10，自引：0，他引：10
热应激给奶牛业造成很大的经济损失，为能有效地解决奶牛热应激问题，笔者综述了奶牛的热应激发病表现、发病机理及对奶牛生产性能、繁殖性能和免疫功能的影响的研究进展。旨在为开发热应激剂、诊断和防治奶牛热应激提供理论依据。 相似文献
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《畜牧兽医科技信息》2021,(10)
正奶牛耐寒怕热。热应激对奶牛的采食量、消化率、繁殖性能和泌乳性能等均有显著影响。本文从三个方面分析了热应激对奶牛生产性能的影响,即产前热应激、围产期热应激和产后热应激。应对奶牛热应激的方法有多种,如搭建可移动的遮阳建筑、使用弥雾器、联合使用喷淋系统和风扇、使用人工降温池等。1热应激对奶牛生产性能的影响1.1产前热应激在妊娠的最后3个月,环境温度升高可以改变流向子宫的血流和母体-胎儿激素的聚集, 相似文献
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热应激是限制奶牛生产最重要的因素之一,它对奶牛的生产力、健康、繁殖和整体福利都会产生重大影响,并且随着热应激程度的加深对奶牛造成致命性影响。全球变暖加剧了热应激的负面影响。动物会通过改变其表型和生理特征来应对不断变化的环境,动物的生存能力通常取决于其应对或适应现有条件的能力。奶牛是恒温动物,通过减少代谢热量产生与体温调节等来应对并适应热应激,但这会以牺牲掉部分生产性能为代价。本文综述了热应激对奶牛泌乳性能的影响、热应激下泌乳性能降低的原因、奶牛对热应激的适应机制以及牧场应对热应激的策略,为奶牛热应激的研究及生产中改善奶牛热应激等提供参考。 相似文献
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应激,即个体对自身平衡造成威胁的事件所引起的生物反应,与脑下垂体-肾上腺(HPA)轴的增强运动和交感肾上腺-髓(SA)系统的启动有关。应激分为慢性和急性应激,慢性应激通常会抑制繁殖性能,而急性应激有时会引起乏情,多数情况下会引起繁殖系统的损伤。母猪最重要的繁殖活动即发情、排卵、性行为表现和胚胎着床、泌乳和断奶,这些活动直接受神经内分泌系统控制。本文综述了包括环境、运输和管理等应激源对母猪繁殖性能的影响。应激对母猪繁殖性能的影响主要取决于应激的强度、个体对应激的遗传敏感度和应激的类型,同时也取决于不同应激源对个体影响的时间长短。 相似文献
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热应激是导致奶牛夏季产奶性能、繁殖性能和免疫能力下降的最主要原因之一。热应激作用会造成奶牛业巨大的经济损失。奶牛热应激机制及其对策的研究受到国内外广泛重视。为缓解奶牛热应激采取的主要措施包括营养调控、环境改善和育种途径。本文综述了奶牛热应激与营养调控的研究进展。 相似文献
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运输应激对肉牛不仅仅在屠宰性能有较大影响,处理不当对于后期的生长性能也有较大影响。本文重点分析了运输应激的发生机制及对肉牛生长与屠宰性能的影响,并结合以往经验提出了部分抗应激方案,旨在为今后肉牛生产中避免、降低运输应急对肉牛生产性能影响提供参考。 相似文献
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Maria Kalemkeridou Ioannis Nanas Katerina Moutou Georgios S. Amiridis Andreas Tsipourlianos Eleni Dovolou Zissis Mamuris Themistoklis Giannoulis 《Reproduction in domestic animals》2023,58(1):146-157
Heat stress causes extensive losses in the dairy sector, due to negative effects on milk production and reproduction. Cows have evolved a series of protective mechanisms, (physiological, biochemical, behavioural) to cope with the thermostressing environments, which have allowed the preservation of productive and reproductive potential of specific animals during summer; these animals are considered thermotolerant and could be used to design programs of selective breeding. These programs, targeting the generations of a population of heat-resistant animals, would increase the frequency of the desired phenotypes, tackling the financial losses on one hand and reducing the carbon footprints of the dairy sector on the other. The development of genomics techniques has enabled genome wide variant calling, to detect SNPs associated with the desired phenotypes. In this study, we used a comparative genomics approach to detect genetic variation associated with thermotolerance and to design molecular markers for characterizing the animals as tolerant/sensitive. A total of 40 cows from each group were split in four sequencing pools and a whole-genome sequencing approach was used. Results and conclusion: Genome-wide genetic variation between groups was characterized and enrichment analysis revealed specific pathways which participate in the adaptive mechanisms of thermotolerance, implicated into systemic and cellular responses, including the immune system functionality, Heat Stress and Unfolded Protein Response. The markers made a promising set of results, as specific SNPs in five genes encoding for Heat Shock Proteins were significantly associated with thermotolerance. 相似文献
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Ferdinando Nielsen Almeida John Kyaw Htoo John Thomson Hans Henrik Stein 《畜牧与生物技术杂志(英文版)》2014,(1):88-97
The primary objective of this experiment was to determine the effects of heat treatment on the standardized ileal digestibility(SID) of amino acids(AA) in corn distillers dried grains with solubles(DDGS) fed to growing pigs. The second objective was to develop regression equations that may be used to predict the concentration of SID AA in corn DDGS. A source of corn DDGS was divided into 4 batches that were either not autoclaved or autoclaved at130°C for 10, 20, or 30 min. Four diets containing DDGS from each of the 4 batches were formulated with DDGS being the only source of AA and CP in the diets. A N-free diet also was formulated and used to determine the basal endogenous losses of CP and AA. Ten growing pigs(initial BW: 53.5 ± 3.9 kg) were surgically equipped with a T-cannula in the distal ileum and allotted to a replicated 5 × 4 Youden square design with 5 diets and 4 periods in each square. The SID of CP decreased linearly(P 0.05) from 77.9% in non-autoclaved DDGS to 72.1, 66.1, and 68.5% in the DDGS samples that were autoclaved for 10, 20, or 30 min, respectively. The SID of lysine was quadratically reduced(P 0.05) from 66.8% in the non-autoclaved DDGS to 54.9, 55.3, and 51.9% in the DDGS autoclaved for 10, 20, or30 min, respectively. The concentrations of SID Arginine, Histidine, Leucine, Lysine, Methionine, Phenylalanine, or Threonine may be best predicted by equations that include the concentration of acid detergent insoluble N in the model(r2= 0.76, 0.68, 0.67, 0.84, 0.76, 0.73, or 0.54, respectively). The concentrations of SID Isoleucine and Valine were predicted(r2= 0.58 and 0.54, respectively) by the Lysine:CP ratio, whereas the concentration of SID Tryptophan was predicted(r2= 0.70) by the analyzed concentration of Tryptophan in DDGS. In conclusion, the SID of AA is decreased as a result of heat damage and the concentration of SID AA in heat-damaged DDGS may be predicted by regression equations developed in this experiment. 相似文献
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Anjali Aggarwal Ashutosh Gulab Chandra Anil Kumar Singh 《Tropical animal health and production》2012,45(1):239-245
The study was conducted to investigating the effect of α-tocopherol acetate on heat shock protein 70 (Hsp70), oxidative stress, and antioxidant status during periparturient period in medium body condition score crossbred cows. Twenty crossbred Karan Fries cows with confirmed pregnancy were selected 2 months before expected date of calving. The cows were randomly distributed in to two groups: 10 cows were kept as control and 10 were supplemented with α-tocopherol acetate during dry period for 2 months. Blood samples were collected at ?20, ?10, ?5, 0, 5, 10, and 20 days in relation to the expected date of calving. Superoxide dismutase, catalase, and total immunoglobulin were significantly higher (P?<?0.01) in treatment as compared to control cows. Heat shock protein 70 and thiobarbituric acid reactive substance levels were significantly lower (P?<?0.01) in the treatment cows than their counterpart. Treatment with α-tocopherol acetate during dry period resulted in reduced oxidative stress, heat shock protein Hsp70 levels, improved antioxidant, and improved immunity status indicating beneficial effect of α-tocopherol acetate treatment. 相似文献
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猪应激综合征是在受到外界不良环境或有害因子的作用下出现的非特异性反应,主要有猪恶性高温综合征、猪急性背肌坏死、猪宰后腿肌坏死、猪自然应激综合征、水猪肉、突毙综合征等几种表现形式。通过对猪应激综合征的症状、发病原因、发病机制、病变特征以及控制措施等方面进行综述,并结合临床所见,以亟为生产实践提供参考。 相似文献
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Estimation of genetic parameters for heat stress,including dominance gene effects,on milk yield in Thai Holstein dairy cattle 
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下载免费PDF全文 Heat stress in tropical regions is a major cause that strongly negatively affects to milk production in dairy cattle. Genetic selection for dairy heat tolerance is powerful technique to improve genetic performance. Therefore, the current study aimed to estimate genetic parameters and investigate the threshold point of heat stress for milk yield. Data included 52 701 test‐day milk yield records for the first parity from 6247 Thai Holstein dairy cattle, covering the period 1990 to 2007. The random regression test day model with EM‐REML was used to estimate variance components, genetic parameters and milk production loss. A decline in milk production was found when temperature and humidity index (THI) exceeded a threshold of 74, also it was associated with the high percentage of Holstein genetics. All variance component estimates increased with THI. The estimate of heritability of test‐day milk yield was 0.231. Dominance variance as a proportion to additive variance (0.035) indicated that non‐additive effects might not be of concern for milk genetics studies in Thai Holstein cattle. Correlations between genetic and permanent environmental effects, for regular conditions and due to heat stress, were ? 0.223 and ? 0.521, respectively. The heritability and genetic correlations from this study show that simultaneous selection for milk production and heat tolerance is possible. 相似文献
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Effect of steroid hormones on the innate immune response induced by Staphylococcus aureus in the goat mammary gland 下载免费PDF全文
下载免费PDF全文 The objective of this study was to compare the dynamics of innate immune components after intramammary infusion of Staphylococcus aureus (SA) under conditions of high oestrogen and high progesterone in goats. In one group (“E‐group”), controlled internal drug release (CIDR) devices were inserted intravaginally from days ?11 to ?4. Prostaglandin F2α was administered immediately after removal of the CIDR device at day ?3, and then oestradiol benzoate (E) was injected intramuscularly once a day from days ?2 to 3. Heat‐inactivated SA was then administered via intramammary infusion to the left udder at day 0, whilst only saline was infused to the right udder as a control. In a second group (“P‐group”), CIDR devices were inserted intravaginally from days ?3 to 7 and SA was infused at day 0 in the same way as in the E‐group. The milk yield and the concentration of innate immune components (somatic cell count (SCC), lactoferrin (LF), S100A7 and goat ß‐defensin 1 (GBD‐1)) in the milk were measured. Milk yield decreased drastically in both SA and control udders in the E‐group, whereas the P‐group exhibited increased milk yield in both SA and control udders. SCC increased after SA infusion in both E‐ and P‐groups, although it was higher in the E‐group than in the P‐group. There was no significant change in LF concentration in the E‐group, but a decrease was observed in the P‐group. Concentrations of S100A and GBD‐1 were significantly increased after SA infusion in the E‐group but not in the P‐group. These results suggest that E enhances the innate immune response induced by SA in the goat mammary gland. This effect may be due to the reduction in milk yield and upregulation of innate immune components. 相似文献
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Heat production of cattle acclimated to cold, thermoneutrality and heat when exposed to thermoneutrality and heat stress 总被引：1，自引：0，他引：1
Four Hereford X Red Angus yearling steers were acclimated to each of the following environments; cold (3 C), thermoneutrality (TNZ; 20 C) and heat (35 C). Intake was equalized for all treatments at 4.9 X kg X head-1 X d-1 (2.9 Mcal metabolizable energy/kg). Heat production, respiration rate and rectal temperature were determined after 3- and (21-h later) 24-h exposures to thermoneutral and heat stress test-temperatures: 25, 30, 32.5, 35, 37.5 and 40 C. Thermoneutral heat production (kcal X kg-.75 X d-1), after 3- and 24-h exposures, was greater (P less than .05) for the cold-acclimated cattle (139.6 +/- 5.0 and 153.0 +/- 5.8) as compared with the TNZ-acclimated cattle (117.7 +/- 5.0 and 121.6 +/- 5.8). Heat production of the heat-acclimated cattle after 3- and 24-h exposures to thermoneutrality was 121.0 +/- 5.1 and 123.5 +/- 3.2 and was not different from the TNZ-acclimated cattle. Heat production of steers acclimated to different temperatures was variable during the 3- and 24-h exposures to test-temperatures ranging from 25 to 40 C. Heat production increased linearly in the TNZ-acclimated cattle (24-h exposure) and in the heat-acclimated cattle (3-h exposure) at the rate of 1.3 and 2.3 kcal X kg-75 X d-1 X C-1 increase in test-temperature, respectively. In the other four comparisons, analysis by regression indicated no significant change in heat production. Rectal temperature and respiration rate increased significantly in either a linear or quadratic manner in all treatment groups exposed to test-temperatures from 25 to 40 C.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献