scholarly journals Influence of heat stress on reproductive performance in dairy cows and opportunities to reduce its effects – a review

Author(s):  
T. Penev ◽  
D. Dimov ◽  
N. Vasilev ◽  
J. Mitev ◽  
Tch. Miteva ◽  
...  

Abstract. The goal of this review is to consider and discuss the scientific literature related to the effect of heat stress (HS) on reproductive performance in dairy cows and opportunities to reduce its effects. The information in literature shows that the HS topic in dairy cows began to be discussed in the 1970s. As genetic progress related to productivity increases, the requirements for cows also increase, including for their reproduction performance. In the present review, a significant array of scientific papers is examined, as a result of which it is established that HS has a multifaceted effect on reproduction in dairy cows. The main role for the negative impact of HS is the effect of high ambient temperature on the hypothalamic-pituitary-ovarian axis. As a result, hormonal changes occur in the body of cows, which affect the behavior of cows in estrus, the development of follicles in the ovaries and the survival of the embryo in the uterus. These changes affect the main elements of cattle breeding such as length of days open interval, conception rate, number of inseminations required for conception. To mitigate the negative impact of HS on cows, methods have been developed for better estrus detection, for microclimate control, as well as for hormonal treatment of cows in order to increase reproductive performance. Although some progress has been made in each of the measures, HS still poses a serious reproductive problem for dairy cows, especially in the countries with warmer climates. This provokes the interest of many scientists around the world who seek to offer a solution/mitigation to this problem.

2016 ◽  
Vol 187 ◽  
pp. 146-150 ◽  
Author(s):  
Simin Khorsandi ◽  
Ahmad Riasi ◽  
Mohammad Khorvash ◽  
Saeid Ansari Mahyari ◽  
Farhad Mohammadpanah ◽  
...  

Author(s):  
L. Roman ◽  
S. Sidashova ◽  
I. Popova ◽  
N. Stepanova ◽  
V. Chornyi ◽  
...  

The results of the influence of the conditions of keeping Ukrainian red dairy cows on the manifestation of clinical symptoms of damage to the lateral surface of the tibia and the level of reproduction are presented. The study was conducted on the basis of an industrial dairy complex (600 dairy cows with an average productivity of 6050 kg of milk per lactation) as part of agricultural associations in Odessa region. The objects of the study were cows during lactation, which were kept loose in sections with rest boxes (where the floor was a special rubber mat with a thickness of 30 mm). Evaluation (in points) was performed on the clinical manifestation of symptoms of damage to the skin epithelium of the lateral surface of the leg, which was injured by the rubber coating of the stall compared to the level of reproduction (service period, days/%) and the severity of skin pigmentation of the body surface (selection melanism). Clinical, zootechnical, biometric methods were comprehensively applied to realize the purpose of research. Comparison of data (n = 462) visual-clinical assessment of the condition of the skin of the lateral surface of the leg, as an indicator of the adaptability of lactating cows to keep in sections with rubber flooring and the area of pigmented hair of animals of different phenotypes by coat color, showed that cows typical pigmentation, characteristic of red dairy breed (red hair occupied more than 80 % of the body surface), wound lesions of the lower leg are much less common, namely: in comparison with red-spotted animals by 28.41–15.98 %, with mostly white – by 39.03–20.23 %, respectively. Due to the negative impact of open wounds of the skin of the leg on the immunity of lactating cows, it was found that increasing the number of animals with damaged epithelium as a gateway to infection, provokes an increase in the service period in cows with predominantly white or mottled color to 140.97 and 141.07 days, which is higher by 6.74 and 6.84 days, respectively, compared with red animals (P < 0.05).


2015 ◽  
Vol 13 (4) ◽  
pp. e05SC02 ◽  
Author(s):  
Mónica Barrio ◽  
Marcos Vigo ◽  
Luis A. Quintela ◽  
Juan J. Becerra ◽  
Pedro J. García-Herradón ◽  
...  

<p>The aim of this study was to evaluate the influence of subclinical endometritis (SE) on the reproductive performance of dairy cows. Ninety-four dairy cows of parity 1 to 8, distributed in 25 herds, were examined once between 30 and 45 days in milk using transrectal palpation, vaginoscopy and ultrasonography. A cytological sample of the endometrium was taken only from cows with an apparent healthy uterus (n=65). Serum glucose, total cholesterol, triglycerides, non-esterified fatty acids, β-hydroxybutyrate, total proteins, albumin, urea and hepatic enzymes were analyzed. Reproductive indexes were recorded during the next 11 months. Endometrial cytology was considered indicative of SE if percentage of polymorphonuclear neutrophils was superior to 5% of all cells present in the smear, except erythrocytes. Results indicated that 14.9% of the cows sampled for uterine cytology had SE, and that healthy cows become pregnant significantly before than those with SE (hazard ratio=2.35; 95% confidece interval: 1.05-5.3). From all the metabolic and productive variables analyzed, only triglycerides affected negatively to reproduction; serum albumin concentration, body condition score and milk production had positive effects on the reproductive performance. In conclusion, our results indicate that SE has a negative impact on reproductive performance and uterine cytology is necessary to diagnose it since almost 15% of the affected animals were not detected by other diagnosis methods.</p>


2020 ◽  
Vol 21 (11) ◽  
pp. 4162
Author(s):  
Dongyang Wang ◽  
Zujing Chen ◽  
Xiaona Zhuang ◽  
Junyi Luo ◽  
Ting Chen ◽  
...  

Summer temperatures are generally high in Southern China, and cows are likely to suffer a heat stress reaction. Heat stress will have a negative impact on the performance of dairy cows; however, the mechanism by which high temperature affects lactation is not clear. CircRNA is a type of non-coding RNA discovered in recent years, which performs a crucial function in many biological activities. However, the effects of circRNA on lactation function of dairy cows under heat stress is unknown. The present study aimed to explore the expression levels of circRNA in the mammary gland tissue of cows under heat stress. Firstly, we collected blood and milk samples of summer and winter cows and evaluated lactation performance using serum indicators, milk production, and milk composition. Incorporating the calculation of the temperature and humidity index, we conformed the heat stress status of cows in summer. Heat stress increased the concentration of HSP70 and decreased the concentration of SOD and PRL. Heat stress not only reduced milk yield but also affected milk quality, with milk lactose and milk protein decreasing with increased temperature. The analysis of the fatty acid composition in summer milk found significantly reduced concentrations of unsaturated fatty acids, especially long-chain unsaturated fatty acids. Sequencing of the cow’s mammary gland transcriptome revealed that compared to the appropriate temperature (ST) group, the heat stress (HS) group had a total of 2204 upregulated and 3501 downregulated transcripts. GO enrichment and KEGG pathway analysis showed that these genes were mainly related to milk fat metabolism. In addition, 19 upregulated and 19 downregulated circRNA candidates were found in response to heat stress. We used Pearson’s test to establish the correlation of circRNA-mRNA and identified four pairs of circRNA-miRNA networks between four circRNAs, six miRNAs, and the CD36 gene. In this study, we revealed the possible role of circRNAs in lactation of dairy cows and identified that circRNA-miRNA-mRNA networks might exist in the cow’s mammary glands, providing valuable experience for dairy lactation and milk quality.


2020 ◽  
Vol 51 (4) ◽  
pp. 511-520 ◽  
Author(s):  
A. Sigdel ◽  
L. Liu ◽  
R. Abdollahi‐Arpanahi ◽  
I. Aguilar ◽  
F. Peñagaricano

2020 ◽  
pp. 10-11
Author(s):  
Ekaterina N. Rud ◽  
◽  
Elena V. Kuzminova ◽  
Marina P. Semenenko ◽  
Andrey A. Abramov ◽  
...  

In the context of the industrial survival of animal husbandry, taking into account the climatic characteristics of Krasnodar region, climate is considered as a heat stress, the result of an imbalance between the intake of heat from the environment and its release by the body. To assess the risks of occurrence and severity of heat stress in cattle, it is necessary to take into account not only the ambient temperature, but also humidity indicators. The temperature and humidity index provides for these two variables and allows us to assess the need for cooling of animals. The article provides information on the possibilities of occurrence and impact of heat stress due to the temperature-humidity state of the environment. Analysis of the reporting data of the Veterinary Department of Krasnodar region and the number of industries in Krasnodar region and cattle sampling rates from 2017 to 2019 demonstrates an increase in the number of abortions and youth losses during the third quarter when the temperature of the environment reaches its maximum. With this in mind, to increase the adaptability of animals under prolonged heat stress, it is necessary to regularly monitor the environmental parameters (use of thermometers and hygrometers to assess the temperature and humidity index), as well as plan protective measures (adapted feeding technology, specialized additives, good bulky feed), which will help to minimize the negative impact of hyperthermia on the economy of livestock production.


animal ◽  
2012 ◽  
Vol 6 (9) ◽  
pp. 1398-1406 ◽  
Author(s):  
S. Khalajzadeh ◽  
A. Nejati-Javaremi ◽  
H. Mehrbani Yeganeh

2020 ◽  
Vol 12 (24) ◽  
pp. 10693
Author(s):  
Hammad Ullah ◽  
Rifat Ullah Khan ◽  
Vincenzo Tufarelli ◽  
Vito Laudadio

This review article discusses the importance and effects of Selenium (Se) in sustainable dairy cows’ production. The Se is an important micronutrient in dairy cows. It is one of the important feed derived antioxidants. It participates in important enzymes and enzyme reactions to improve metabolism, growth, and the defense system of the body, which results in the improved health of animals, particularly that of the mammary gland and reproductive system, thereby improving productive and reproductive performance. The Se is usually deficient in soil due to current extensive farming strategies, so its supplementation is generally advised. Supplementation of Se in organic form is generally preferred over inorganic form due to its better incorporation and uptake, resulting in improved performance. Kidneys, liver, testis, and lungs are important sites for Se storage. The Se is excreted in urine, feces, exhaled breath, loss of skin, and hair cells. Although Se supplementation plays an important role in the profitability of dairy cows, its excess intake is toxic and should be avoided.


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