Abstract
Globally goat farming is being important in employment specially for the landless, labours and for unemployed forces. Among the farm animals, goats arguably are considered the best-suited animals to survive in tropical climates. Both cold and heat stress was found to negatively influence growth, milk and meat production and compromised the immune response, thereby significantly reducing goats’ welfare. Goat welfare could be assessed based on several indicators covering behavioral, physical, physiological and productive responses. The important indicators of goat welfare include agonistic behavior, vocalization, skin temperature, body condition score (BCS), hair coat conditions, rectal temperature, respiration rate, heart rate, sweating, reduced growth, reduced milk production and reduced reproductive efficiency.
Introduction
India has the second largest global goat population and has the potential to increase its role and profits in the lucrative global goat market. The initial investment in goat farming is very less compared to other livestock farming with no religious taboos on its commercial products. Chevon (goat meat) is the country’s most popular and extensively consumed meat. Goat milk has been used for therapeutic purposes since ancient times and has recently acquired popularity in human health due to its close proximity to human milk for simple digestion and all-around health benefits. To propose goat milk as therapeutic milk for human health, more research is needed to uncover and validate its medicinal characteristics. In the future years, demand for goat milk and milk products for domestic use and export is predicted to increase. Goat husbandry offers a ray of hope for future employment, nutritional security, and wealth for the country’s millions of small and marginal farmers.
Behavioral responses of goats under heat stress
Bunching in the shade, slobbering, panting, open-mouth breathing, decreasing feed intake and increasing water consumption. In severe cases of heat stress in goats, lack of coordination, trembling and down animals may be seen. Seeking shade is a conspicuous form of behavioral adaptation. If shade is not available, animals will change their posture to the vertical position in respect to the sun in order to reduce the effective area for heat exchange. Animals can change posture, i.e. stand or spread out to increase surface area for heat loss and reduce activity. Under severe heat stress, animals moisten their body surface with water, saliva or nose secretions.
Goats expressed decreased urination and defecation under heat stress conditions.The reason for reduced urination frequency could be due to increased respiratory and cutaneous cooling mechanisms which might lead to severe dehydration, thereby leading to a reduction in their urination frequency. Also, the reduction in defecating frequency could be an adaptive mechanism of these animals to conserve body water. In extreme heat, they tend to lie down to reduce their locomotion and spend more time in the shade. Standing and lying are behavioral adaptive mechanisms to prevent additional heat load from the ground and to facilitate effective heat dissemination.Heat-stressed animals decrease feed intake in an attempt to create less metabolic heat because the heat increment of feeding is an important source of heat production. Also, the maintenance requirements increased by 30% because of heat stress and the energy intake would not be enough to cover the daily requirements which results in an apparent body weight loss. Body weight, daily feed intake and gain decreased under heat stress conditions in goats. Body temperature, respiration rate and heart rate increases due to heat stress. Heat stress also leads to aberration of reproductive functions, oxidative stress, enzymatic dysfunction, electrolyte imbalances, promoting an unfavorable endocrine balance and reducing feed intake, and meat quality.
Strategies to alleviate heat stress
A variety of methods should be adopted by small ruminant producers/owners to overcome the negative effects of heat stress, including the use of shades, feeding and grazing strategies, providing water, handling time, the use of fans and evaporative cooling, and site selection of animals’ housing.
- Shade is the easiest method to reduce the impact of high solar radiation, and it is applicable under extensive conditions. The use of shades, fans or evaporative cooling is not possible in semi-intensive systems as goats are grazed in the open during most of the day, and this necessitates other strategies (i.e. portable shades) to counteract the adverse effects of heat stress. Accessibility of animals to shade during summer is simple, easy, cheap and an efficient tool to minimize heat stress. Providing goats access to shade allows a reduction in rectal temperature and respiration rate in goats. A well-designed shade structure reduces heat load by 30– 50%. Shelters do not need to be complicated or elaborate, trees and shrubs can serve as shelters for animals from solar radiation , and are usually the least-cost alternative. If natural shelter is not available, many goat producers use plastic calf hutches to provide shelters. In addition, hay or straw shades, solid shade provided by sheet metal painted with white on top and aluminum sheets are the most effective and cheap materials.
- Ration modifications can greatly help in reducing the negative effect of heat stress, and these adjustments may include changes in feeding schedules (feeding at cool hours, feeding intervals), browsing time, and ration composition such as dietary fiber adjustment, the use of high-quality fiber forage, increased energy density (supplemental protected fat) and use of feed additives [buffers (sodium bicarbonate), niacin, antioxidants and fungal culture (yeast culture)].
- During summer, the feeding behavior for most of the animals changes and they tend to consume more feed during the cooler periods of the day. Therefore, feeding animals during the cooler periods of the day encourages them to maintain their normal feed intake and prevents the co-occurrence of peak metabolic and climatic heat load. Also, feeding animals at more frequent intervals helps to minimize the diurnal fluctuation in ruminal metabolites and increase feed utilization efficiency in the rumen. Another point to be taken into account to alleviate heat stress is the grazing time. In extreme heat, animals decrease their grazing time and spend more time in the shade, especially during the heat of the day. They graze during the period of the milder weather during the day, i.e. before sunrise, at dawn and during the night.
- Careful ration modifications during heat stress are important in achieving the optimum animal performance. Decreasing the forage to concentrate ratio can result in more digestible rations that may be consumed in greater amounts. Feed containing low fiber rations during hot weather is logical since heat production is highly associated with metabolism of acetate compared with propionate. More nutrient-dense diets are usually preferred during the heat stress period. Dairy goats supplemented with 4% fat during summer had lower rectal temperature. Soybean oil fed to goats kept under heat stress increased milk fat content.
- Feed additives have been proposed to offset the consequence of heat stress. For example, antioxidants such as vitamin C and E protect the body defense system against excessive production of free radicals (antioxidants are free radical scavengers) during heat stress and stabilize the health status of the animal.
- One of the best practices to reduce heat stress is to provide adequate fresh and cool drinking water. The water requirements of goats increase under heat stress conditions, thus, it is essential that animals have a continuous access to adequate, clean, cool and fresh water. This is done by having adequate watering devices (making sure pressure is adequate to refill waterers), and providing more water sources in the pasture.
- In addition, handling animals should be kept at minimum. Goats can be handled (i.e. milking, transportation) in the early morning or late evening time, and the afternoon work should be avoided when body temperature is already high. One of the effective methods for prevention of heat stress is to delay afternoon milking for 1-2 hours.
- Also, it may be necessary to install fans or other cooling systems in barns and similar structures Cooling goats by spraying could reduce heat stress symptoms and improve animal welfare. Direct wetting of animals is often used as an emergency measure and can be an effective protective method.
- The site selection of animals’ housing is fundamental to decrease exposure and minimize the effect of heat stress. Proper selection of the housing site to emphasize factors for enhancing heat dissipation (minimal radiation, air temperature and humidity, and maximal air velocity) will have long-term protection benefits. Fully enclosed shelters are not recommended for hot climates because of the decreased natural air velocity, therefore, it is preferred to use partially enclosed shelters.
Winter management strategies
Goats cannot tolerate moist and cold climatic conditions so we need to take more care and give emphasis on making their microenvironment more comfortable like housing, bedding , feeding so that they remain in good welfare conditions and maintain their production which ultimately help farmers in getting profits from goat farming. These are some management practices we need to follow during winter season to reduce winter stress.
- Goats do not require elaborate housing during the winter months. The most important issues regarding housing is to block the harsh, cold north wind and to keep the animals dry. A three sided structure with the opening facing the south provides protection from the cold wind and yet allow plenty of ventilation to keep moisture down in the barn or shed.
- For each goat there is need to provide at least 3-6 meters of space and atleast 4-5 hours of sunlight during day time
- Sand bags or gunny bags can be used to cover the goats specially the young ones to prevent them from hypothermia, pneumonia or other respiratory diseases prevalent during winter season.
- Make sure there is plenty of clean, dry bedding available. For bedding straw or even thick clothing can be used.
- Goats kidding in the cold weather will require more shelter because young kids will not be able to maintain their body temperature outside. A heat lamp may be required in these situations but should only be used with extreme caution because of the risk of barn fires or animals chewing electric cords.
- During the winter, goats need more energy to help maintain body temperature. They will also need roughage which can be supplied in grass, alfalfa, or mixed hay. Salt and minerals should also be available. Grainy feed should not be given to kids as they are not able to digest grains while it can be fed to adult goats.
- Also there is a need to take proper veterinary care for preventing ecto-endoparasitic infections during this period.
- Trim the hooves every 3 months to take care of foot rot and other foot related conditions.
Conclusion
Goat farming no doubt requires very less initial investment and proves to be a major source of employment for poor farmers. Profit incurred by farmers from this farming can be increased by adopting simple management practices available at local level with little or no cost which can help in alleviating major stress affecting the performance of this farming. One of the major stress is due to heat and cold climatic conditions which affects the animal at behavioral, hormonal, physiological and production level. By practicing these simple and cost effective heat and cold management practices a farmer can reduce the stress and can increase its profit which also proves helpful at animal welfare level.