scholarly journals Adaptation Mechanisms of Small Ruminants to Environmental Heat Stress

Animals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 75 ◽  
Author(s):  
Haile Berihulay ◽  
Adam Abied ◽  
Xiaohong He ◽  
Lin Jiang ◽  
Yuehui Ma

Small ruminants are the critical source of livelihood for rural people to the development of sustainable and environmentally sound production systems. They provided a source of meat, milk, skin, and fiber. The several contributions of small ruminants to the economy of millions of rural people are however being challenged by extreme heat stress difficulties. Heat stress is one of the most detrimental factors contributing to reduced growth, production, reproduction performance, milk quantity and quality, as well as natural immunity, making animals more vulnerable to diseases and even death. However, small ruminants have successfully adapted to this extreme environment and possess some unique adaptive traits due to behavioral, morphological, physiological, and largely genetic bases. This review paper, therefore, aims to provide an integrative explanation of small ruminant adaptation to heat stress and address some responsible candidate genes in adapting to thermal-stressed environments.

2017 ◽  
Vol 17 (1) ◽  
pp. 59-88 ◽  
Author(s):  
Amani Al-Dawood

Abstract Small ruminants (sheep and goats) play a predominant role in the economy of million people, and have provided meat, milk, skin, wool and fiber for centuries. Animals undergo various kinds of stressors, i.e. physical, nutritional, chemical, psychological and heat stress (HS). Among all, HS is the most concerning at present in the ever-changing climatic scenario. Climate change is the most serious long-term challenge faced by small ruminants’ owners worldwide. HS results in decreased growth, reproduction, production, milk quantity and quality, as well as natural immunity, making animals more vulnerable to diseases, and even death. Thus, HS results in great economic losses, emphasizing the necessity to objectively assess animal welfare. The increasing demand for animal products paralleled by the frequent hot climate is a serious threat for the agriculture sector. The ability of sheep and goats to cope with HS without harming their welfare and productive performance has been often overrated. To date, little attention has been paid to comprehensive detailed data on the adverse effect of HS on sheep and goats. Therefore, this review discusses in detail the sheep and goats’ behavioral, physiological, molecular/cellular, hematological, biochemical and immunological responses under HS conditions. In addition, this review also presents the adverse effects of HS on reproduction and fertility, milk quantity and quality, feed intake, and water consumption of sheep and goats. Finally, this review suggests various methods for HS alleviation. In conclusion, HS impairs productivity and well-being in sheep and goats. The improved understanding of the impact of HS on small ruminants will help in developing management techniques to alleviate HS and highlighting the need for future researches on HS in sheep and goats.


2020 ◽  
Vol 50 (10) ◽  
Author(s):  
Luana Oliveira Leite ◽  
Fabiana de Orte Stamm ◽  
Marcelo Adriano Corrêa Maceno ◽  
Jomar Antonio Camarinha Filho ◽  
Rita de Cassia Maria Garcia

ABSTRACT: The aim of this study was to apply a protocol based on the Animal Welfare Indicators (AWIN) protocols for small ruminants in Brazilian Northeast farms to evaluate the welfare of meat goat, comparing animals kept on semi-intensive (S) and extensive (E) farms. Fifteen farms located in the Metropolitan Region of Quixadá and Quixeramobim, Ceará, Brazilian Northeast, were recruited. Assessments were performed at group and individual level. Significant differences between S and E farms was set at P<0.05 to all tests. At group level, there was a significant difference between groups, with more goats from E farms affected by heat stress and more animals from S farms presenting oblivion. Resource-based indicators, type of drinkers and access to shelter, differed significantly between S and E systems, with goats on S farms allocated in places with access to water more frequently during night period and protected from wind. Type of facility was more complex for animals on S farms (n=2) than on all E farms due to internal divisions, with S farms presenting feeders, drinking fountains, salt shakers, and slatted or cemented floor. At individual level, abscess and ocular discharge were more frequently observed on S farms and ears lesions were more frequent on E farms, probably due to distinct management of goats. Similarities between results showed that farmers in both production systems faced problems related to heat stress, lack of forage and health issues.


Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 948 ◽  
Author(s):  
Richard Osei-Amponsah ◽  
Surinder S. Chauhan ◽  
Brian J. Leury ◽  
Long Cheng ◽  
Brendan Cullen ◽  
...  

Variations in climatic variables (temperature, humidity and solar radiation) negatively impact livestock growth, reproduction, and production. Heat stress, for instance, is a source of huge financial loss to livestock production globally. There have been significant advances in physical modifications of animal environment and nutritional interventions as tools of heat stress mitigation. Unfortunately, these are short-term solutions and may be unsustainable, costly, and not applicable to all production systems. Accordingly, there is a need for innovative, practical, and sustainable approaches to overcome the challenges posed by global warming and climate change-induced heat stress. This review highlights attempts to genetically select and breed ruminants for thermotolerance and thereby sustain production in the face of changing climates. One effective way is to incorporate sustainable heat abatement strategies in ruminant production. Improved knowledge of the physiology of ruminant acclimation to harsh environments, the opportunities and tools available for selecting and breeding thermotolerant ruminants, and the matching of animals to appropriate environments should help to minimise the effect of heat stress on sustainable animal genetic resource growth, production, and reproduction to ensure protein food security.


2020 ◽  
Vol 13 (8) ◽  
pp. 104
Author(s):  
S. C. O. Domingues ◽  
I. C. O. Silva ◽  
J. S. Santos ◽  
O. M. Yamashita ◽  
M. A. C. Carvalho

Urban sprawl, agricultural and livestock sprawl, are the main activities involved in economic development in the Midwest and Northern regions of Brazil and are directly associated with the conversion of native vegetation areas to pasture formation and agricultural production. The objective of this work was to carry out a review research regarding the deforestation arc due to the pressure of the agricultural borders. Information about the production systems in the Arc of Deforestation was collected through bibliographic references and web graphics. From 1988 to 2018, 13.72% of forest cover occurred, which lost natural forest areas, mainly due to the implementation of agricultural and urban expansion activities in the Midwest and Northern regions of Brazil. Regarding production areas, observe all states that are part of the deforestation arc. It requires the adoption of measures aimed at environmentally sound production, trying to combine the conservation of the Amazon Forest's natural resources with agricultural production.


Author(s):  
Lily N Edwards-Callaway ◽  
M Caitlin Cramer ◽  
Caitlin N Cadaret ◽  
Elizabeth J Bigler ◽  
Terry E Engle ◽  
...  

ABSTRACT Shade is a mechanism to reduce heat load providing cattle with an environment supportive of their welfare needs. Although heat stress has been extensively reviewed, researched, and addressed in dairy production systems, it has not been investigated in the same manner in the beef cattle supply chain. Like all animals, beef cattle are susceptible to heat stress if they are unable to dissipate heat during times of elevated ambient temperatures. There are many factors that impact heat stress susceptibility in beef cattle throughout the different supply chain sectors, many of which relate to the production system, i.e. availability of shade, microclimate of environment, and nutrition management. The results from studies evaluating the effects of shade on production and welfare are difficult to compare due to variation in structural design, construction materials used, height, shape, and area of shade provided. Additionally, depending on operation location, shade may or may not be beneficial during all times of the year, which can influence the decision to make shade a permanent part of management systems. Shade has been shown to lessen the physiologic response of cattle to heat stress. Shaded cattle exhibit lower respiration rates, body temperatures, and panting scores compared to un-shaded cattle in weather that increases the risk of heat stress. Results from studies investigating the provision of shade indicate that cattle seek shade in hot weather. The impact of shade on behavioral patterns is inconsistent in the current body of research, some studies indicating shade provision impacts behavior and other studies reporting no difference between shaded and un-shaded groups. Analysis of performance and carcass characteristics across feedlot studies demonstrated that shaded cattle had increased ADG, improved feed efficiency, HCW, and dressing percentage when compared to cattle without shade. Despite the documented benefits of shade, current industry statistics, although severely limited in scope, indicate low shade implementation rates in feedlots and data in other supply chain sectors do not exist. Industry guidelines and third party on-farm certification programs articulate the critical need for protection from extreme weather but are not consistent in providing specific recommendations and requirements. Future efforts should include: updated economic analyses of cost versus benefit of shade implementation, exploration of producer perspectives and needs relative to shade, consideration of shade impacts in the cow-calf and slaughter plant segments of the supply chain, and integration of indicators of affective (mental) state and preference in research studies to enhance the holistic assessment of cattle welfare.


1967 ◽  
Vol 7 (26) ◽  
pp. 217 ◽  
Author(s):  
MJT Norman

The liveweight performance and carcase characteristics of Brahman x Hereford, Africander x Hereford and Africander x Shorthorn F, crossbred spayed heifers were compared with those of local Shorthorn spayed heifers on native pasture at Katherine, N.T., between 1962 and 1965. The breed groups were divided for planes of winter nutrition, viz., with and without 2 lb a day of peanut meal from early June until the start of the wet season. Without supplement, the average weight gains of B x H, A x H, A x S, and Shorthorn cattle between June 1962 and May 1965 were 0.49, 0.37, 0.36, and 0.23 lb a day respectively. With supplement, cattle reached slaughter weight a year earlier ; the average weight gains of B x H, A x H, and Shorthorn cattle between June 1962 and May 1964 were 0.61, 0.63, and 0.50 lb a day respectively. (There was no A x S supplemented group). Without supplement, the dressing percentage and estimated proportion of fat of B x H cattle was higher and the estimated proportion of muscle and bone lower than those of other breeds. With supplement, there were no significant differences in dressing percentage or carcase composition between breeds. Measurements made of thermoregulatory attributes indicated that the local Shorthorn cattle, through body temperature control, showed adaptation to heat stress.


2008 ◽  
Vol 37 (spe) ◽  
pp. 143-160 ◽  
Author(s):  
Carlos Sañudo Astiz

Small ruminants have been one of the first domesticated species and from their origins have produced multiple benefits to humans. In the last two centuries, world sheep production has become more and more specialised upon geographical areas. But, recent changes in consumer attitudes, together with the increment in artificial fibre industries and human world population, some crisis related with the international wool market and some increments in lamb prices, have provoked that lamb meat has increased its relative importance inside the global sheep income. Also, sheep production systems vary considerably across the world, and reflect the different local environmental conditions, which determine, to a large extent, breeds, housing, levels of intensification and, at the end, local market requirements and qualities. However, among all the meats, sheep meat remains the most internationally traded (16 % of total world production is exported), which explains the potential existence of different lamb products in the same market. Then, the new requirements have created a higher interest for meat production, including its quality and quality marks. This interest from producers and the industry should be reflected in a proportional higher interest from the researches towards sheep and goat, where it exists, in general, important lacks of knowledge and, in particular, in lamb and kid meat Science. In the present speech we will made a special incidence on the relationship between carcass quality and lamb acceptability and on some factors like breed and species, diet and production system, slaughter weight and ageing time and their importance on the variation of the carcass and meat quality, including consumer acceptability.


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