The yield of animal by-products ranges between 50-60% of the live weight. It accounts for more than 10 million MT of edible and inedible by-products. Though no reliable data is available on the economic losses caused to the nation, yet some estimates put it as   Rs. 1000 crore/annum from slaughter houses (Thota, 1999). The animal by-products fetch 10-15% of the value of the live animal in advanced countries and proper utilization contributes significantly to the profitability of the meat business thus benefiting the farmers, processors and consumers (Chatli et al., 2005).

In India the value of unprocessed by-products from buffalo and sheep alone was reported to be 30% and 35% respectively (Chaterjee et al., 1991) which is quite high which might be due to the fact that these animals are not raised for meat purpose specifically. If these by-products are processed, then the returns will be almost equal to the value of the meat derived from an animal. Therefore, the potential and scope of by-product utilization is really great in the country from various aspects like industrial development, generation of employment, environmental management and better returns to the farmers.

Glandular by-products: Glands and organs are an important by-product of animals primarily slaughtered for meat. Since time immemorial glands have been consumed and used in medicine for their medicinal properties. There are number of ductless gland (endocrine glands) that secretes hormones, whose underproduction or overproduction causes drastic changes in the body. These glands accounts for only approx. 0.28% of the animal’s live weight.

Guidelines for collecting glands

The glands and organs should be collected only from healthy animals. The location of the glands requires experience as some of the glands are often small and are encased in other tissues. Glands and organs are usually more perishable than meat cuts and therefore must be handled quickly to retain their ‘active principle’ which is necessary for their ultimate pharmaceutical use.

• Should be excised immediately (within 15-20 min.) from slaughtered animals to reduce their exposure to high temperature.
• Should be immediately chilled in metal container using dry ice without allowing any direct contact with ice.
• Fat, facia, and connective tissues should be immediately trimmed off before chilling/freezing.
• At each step of processing, glands should not be allowed to come in contact with water.
• Cleaned glands are quick frozen at -18 to -20?C in covered container to stop tissue breakdown from bacterial activity.
• Packing should be done individually without leaving any air space.
• Best way to preserve glands for longer time while retaining its active principle is by preparing acetone dried powder.
• Properly handled and frozen glands should be bright pink in colour except suprarenal gland, which have a light brown colour.

Processing of gland: The hard frozen glands (-18?C) should be removed from trays and placed in covered containers to minimize contact with air. It should remain frozen until processed by the pharmaceutical manufacturer. Under no circumstances glands should be permitted for thawing, because freezing breaks some of the cell wall and on thawing destruction of the active compound often occurs. Glands on arrival at the pharmaceutical plants are usually vacuum dried (most popular), spray dried or freeze dried. Vacuum drying allows drying at a low temperature to prevent coagulation of protein and it also does not destroy the heat sensitive pharmaceutically active ingredient.

Constraints in utilization of organs and glandular by-product:

Indian meat industry has numerous constraints which hampers the proper utilization of the animal by-products. The major constraints are:

1. Lack of modern abattoir with required facility for collection: Generally, in India, food animals (mostly sheep, goat, poultry or pig in some areas) are being slaughtered in some local or panchayat slaughter house. Slaughter of animals are also being done in various meat shop, road side stalls or family functions. Therefore, the collection from these small and scattered slaughter houses becomes difficult. However, the total volume of by-product generated in these unregulated slaughter houses will be huge in quantity if aggregated, but due to lack of facilities it is being ignored and not collected. Moreover, it is also not economically feasible to start by-products utilization plant attached to these small slaughter houses as the yield is low in nature.
2. Poor cold chain logistics: The glandular by-products are unable to reach the processing plants due to lack of transportation system and unorganised cold supply chain.
3. Unorganised meat industry: In India, there are about 8000 registered and more than 20,000 unregistered slaughter houses. Most of these unregistered slaughter houses are unorganised and is regulated by unscrupulous uneducated meat traders. These unorganised slaughter houses are devoid of basic amenities and they do not know the benefits of processing of animal by-products in turn of economic, pollution control as well as pharmaceuticals values.
4. Lack of processing facilities: There is a hardly limited processing plant in such a vast country with largest livestock population. The by-product processing plants are attached only to modern abattoirs. And the small-scale meat handlers are devoid of processing facility even if they are aware of its utilization.
5. Lack of human resource: There is also scarcity of technically trained and scientific personnel in this area. The veterinary education at present also lacks the curriculum to train man power in by-product processing.
6. Lack of R&D: There is lack of interface between academia, industry and laboratory. Even the modern abattoir does not have proper R&D unit. Development of economical processing equipment for by-products processing is the need of the hour.
7. Disease concern: There are several diseases in India like FMD, Rabies, and Salmonellosis etc. which severely disrupts the market of animal by-products.
8. Ethical issue and religious taboos: Some social ethical groups discourage the use of organ meat and glands. Many of the by-products are also not being utilized due to several religious taboos which also provides hindrance in the development of animal by-product processing plants in India.

Potential use of organs and glandular by-products with their active components:

Conclusion

            The utilization of animal by-products mainly organs and glands are often ignored in developing countries. Presently its utilization is limited only to some section of population who use some of the edible offal like heart, liver, skin (pig) and intestine (after processing) for direct consumption. The majority of the by-products goes as waste resulting into various pollution and health related issues. Therefore, development and implementation of technology is the need of the hour for efficient utilization of by-products emanating from slaughter houses in India. The efficient and planned utilization of by-products will result in the creation of nutrient rich secondary products which will help in attaining sufficient profit margins and will generate direct/indirect employment. In addition, it will help in reduction of cost of pharmaceutical products due to the availability of the raw materials or the active compounds.