बेहतर उत्त्पादन हेतु बकरी-प्रजनन के तरीके
Goat farming is one of the major occupations of rural people in India and plays an important role in the livelihood of small and marginal farmers and landless laborers. In Bihar, goat farming was a traditional occupation of only economically backward classes in the past, but nowadays educated and economically advanced people have come forward in the profession considering it a profitable one.
Rearing one or two goats in the backyard generally fetch the farmers significant income more often than not. When rearing goats in few numbers, even the loss, if incurred, will not downsize the farmer’s economic status much.
However, vast challenges have been accrued in rearing large sized herds of goats in a business model. The business model may fetch very high return to the investors but the profession requires vast scientific acumen in order to succeed in the race unless other ventures.
In order to succeed in goat business, one has to define the breeding objectives initially. Once the objectives are defined, then strategies have to be made to go for selection of goats on the lines of objectives of breeding.
In India, the goats are, in general, reared for meat purpose to the maximum extent. In such cases, breeding for higher body weight should be the goal of a farmer or a goat breeder. Then the breeder has to select the breeding stock accordingly after giving top priority to the breed confirmation traits.
India is the country bestowed with vast genetic resources in terms of different livestock species. There are 43 cattle, 16 buffalo, 34 goat, 43 sheep and 8 pig breeds are registered in the country that play unmatched roles in rural economy in their respective breeding tracts.
Besides, there are also few more livestock varieties in certain regions of the country which confines to particular characteristics and are inhabited in a particular area. They are well recognized as distinct entities by farmers, cattle rearers and the localities in the area. These populations belonging to different species of livestock are being evolved by inter-se mating within the population over thousands of years.
These populations possess unique characteristics with certain gene sequences in their genotype which are inherited over many generations. In these ways, different breeds are evolved under different geographical environments.
The unique characteristics possessed by these breeds may be rewarding under certain economic points of view or may not be carrying much economic benefits for time being.
However, the characteristics which are least essential today may become vital tomorrow. Hence, it is essential to preserve those characteristics and the breeds possessing unique characteristics.
Eastern region of India possesses wide variety of populations with varying unique characteristics with respect to qualitative and quantitative traits. Many of different breeds of livestock from this region are known for high fecundity rate. Among different goat breeds of India, Black Bengal, native to Eastern region of India, is known for high fecundity rate.
Similarly, fecundity trait in sheep found across the world, had originated in Garole sheep, a micro sheep of West Bengal. On the similar lines, the prolific Gunguru pigs which are recently registered, also belong to Eastern region of India.
Unfortunately, the mettle of Garole and Gunguru came to lime-light after many decades and very scanty studies had been undertaken till few years ago. These incidences clearly explain why evaluation of indigenous germplasm is required on continuous basis.
With respect to goat breeding, the vast geographical region of Eastern India is covered by the breeding tract of Black Bengal goats. It is a preeminent breed with high fecundity rate. But, being in small size, the farmers look for crossing opportunity from large sized bucks from other breed, just ignoring the speciality of Black Bengal.
In fact, the research findings in ICAR-RCER indicates that the Bengal goats with 3 or more than 3 kiddings just overtakes even Jamunapari goats on bio-mass yield if we calculate productivity for 2 years.
Further, a farmer or a breeder who possesses typical true to type breed is an advantage for their side as purity in any population fetch quick and additional income to them.
Need for regular monitoring, registration and development
Black Bengal goat genetic resources has been evolved over natural selection and breeding happened for hundreds of years in their breeding tract. There are three varieties in the breed, viz. Black, Brown and White, which could be distinguished from each other by their coat colour characteristics.
Besides, there are more animals with mixed coat colour characteristics in the breeding tract. The other characteristics of the breed have been given under the topic Breeds of Goat, which may be referred.
After understanding the importance of breed characteristics, the farmers should adopt the strategy to preserve the breeding characteristics in goat. Every birth should be keenly monitored. Those newborn animals which possess the characteristics deviating from the characteristics of breed should be prevented from parenting.
There are many breeding methodologies in animal breeding overview of which could be seen before we discuss the breeding strategies in goats for improving their productivity.
Types of breeding
There are different types of breeding which can be employed in different species of livestock according to the situation and demand. The types of breeding can be grouped into two categories:
1. Inbreeding
Mating of closely related animals for 4 to 6 generations is called inbreeding. Inbreeding preserves germplasm and also help in formation of purelines. However, the continued inbreeding leads to inbreeding depression and finally the production performances of animals are getting affected.
The traits which are linked with reproduction fitness are affected by inbreeding in the first instance. One generation of outcrossing by crossing with unrelated animals would revert back the loss incurred due to inbreeding.
Line breeding is a kind of inbreeding in which a paternal or maternal line is constantly maintained while taking up inbreeding program. Line breeding and other forms of inbreeding have helped to evolve many different varieties and lines in different species of livestock.
2. Outbreeding
Mating unrelated animals which do not possess common ancestors for 4 to 6 generations is called outbreeding. Outbreeding generally increases the heterozygosity and decrease the homozygosity. There are variant forms of outbreeding and they are:
1. Outcrossing
Mating of unrelated animals for 4 to 6 generations within a breed is called outcrossing. Outcrossing is required in case if a population suffers from inbreeding depression. As this method brings in gene from distant sources, there are always chance to improve the variability within the population.
2. Crossbreeding
Crossbreeding is a method of breeding in which two individuals unrelated for 4 to 6 generations and belonging to two different breeds are mated. Crossbreeding brings in hybrid vigour in the offspring generation as the offspring generations tend to perform better than their parents. Many research experiments have been done across the world to develop new breeds with Boer buck crossed with does of different breeds.
3. Grading up
This is the technique in which genetically superior male germplasm is used to artificially inseminate and upgrade the non-descript population. For example, Artificial insemination using semen collected from Boer bucks on non-descript animals. This method is used to help improve productivity of the genotype of non-descript animals.
4. Species Hybridization
Species Hybridization is a technique in which two different and related species are crossed to produce a progeny. As this method mostly results in infertile progenies, the breeders do not show adequate interest to take up this method of breeding programme. Experiments were conducted to cross between sheep and goats and the resultant progenies, ‘Geep’ were found to infertile.
In order to improve the productivity of Black Bengal goats in particular, the following breeding strategies could be adopted under field conditions.
Advances in breeding methods
Artificial Insemination
Artificial insemination is the method in which semen is collected from genetically superior bucks and the collected semen is used to inseminate the rural herds to improve their genetic potential. The technique experienced a moderate success in India and also faces lots of challenges.
Important challenges include selection of bucks, semen collection, preservation and establishment of AI network system for goats. This exercise requires adequate manpower, training and funding which are the limiting factors.
Multiple Ovulation & Embryo Transfer Technology
Genetic potential of males are exploited through artificial insemination whereas the genetic worth of females are exploited through embryo transfer technology. As this technique poses biggest challenges in embryo collection and conception rate, the methodology is still in primitive stage as far as goats are concerned.
Genetically superior females are superovulated, inseminated and the embryos at 8 to 16 cell stages are collected and transferred into surrogate goats.
Open Nucleus Breeding System (ONBS)
Open Nucleus Breeding System is a method of breeding system aimed at improving the genetic potential of rural herds. This system comprises of three tier system in which there will be a
1) Nucleus farm (This is an organised farm managed by Government or a private Company where superior males and females are kept.
2) Multiplier farm (These farms need to be established with the progressive farmers for the purpose of buck production programme)
3) Farmers’ herds (From here, genetically superior males are collected regularly and transferred to nucleus farm.
Regular supply of superior bucks to multiplier herds and farmers herds ensure two way gene flow in open nucleus breeding system.
Methodologies adopted in open nucleus breeding system are enlisted as below:
- A nucleus farm need to be established with 200 superior does and 20 bucks
- Mating can be carried out in the nucleus farm by apportioning the entire herd into 20 different families. Mode of mating could be natural breeding or by artificial insemination.
- At the end of one year, 5 poor performing bucks could be replaced from multiplier flocks or from farmers’ field. Discarding the bucks shall be taken place based on own body weight, sex libido and the performance of progenies.
- Discarded bucks could be given either to multiplier farm or the farmers’ field.
- Similarly 10% of females could be replaced in the nucleus flock partly from multiplier flock or farmers field or partly from own progenies.
- The process continued and the stock number in the nucleus flock could be increased slowly to the maximum capacity of nucleus farm.
Group Breeding Scheme
The selection and breeding methods applicable for large animals cannot be applied directly to the small ruminants. Small ruminants are in generally raised in herds with adequate number of males which are genetically proven or unproven. In order to make the system more productive on the basis of scientific concepts, group breeding scheme or nucleus breeding scheme could be followed by the farmers.
Under this scheme, a number of herds with a minimum number of herd size will be registered to form a group. From each herd, small number of genetically superior animals would be selected and pooled. The pooled animal herd will always possess genetically superior animals.
Here, the average genetic merit of animals in the pooled animal herd will be greater than the genetic merit of each contributing herds. Pooled animals herd can also be called as ‘Nucleus Herd’.
The important point in this scheme is that the recording of selection, breeding and the production and reproduction performances of animals is not so difficult. Close monitoring of animals is possible in nucleus herd.
The best males are kept for breeding in the nucleus while other selected males are given to the base herds for breeding. Nucleus will be open for transmission of genetic materials both ways, i.e. from nucleus to base herds and from base herds to nucleus. From the base herds, top performing females are taken to the nucleus and they are compared with the animals in the nucleus.
Only females and not males are transferred from base herds to nucleus herds, as male selection in not possible in the farmers’ management systems. Hence, the nucleus scheme holds the advantage in the sense that it takes genetic advantage from base herds by the way of sire replacement and thus genetic superiority in the nucleus is always far greater than what it is present in the base herds.
It is particularly attractive in situations where within-herd selection programme are ineffective due to small population size or inadequate technical skill. Since the nucleus breeding scheme shifts the onus of operating the breeding programme from the farmer to the nucleus herd, it seems an attractive method for the tropics because of the limitations already discussed.
The core concept between ONBS and group breeding system is almost similar except that the nucleus herd under ONBS is managed by Government or Cooperative whereas the same is managed by group of farmers in cooperative mode in group breeding system.
To conclude, the options available with the breeders are very limited in case of goat breeding. Hence, the breeder or the farmer should spend more time on planning the breeding design before executing the plans.
Authors:
P.C.Chandran, Reena Kamal, Rajni Kumari, P.K. Ray, Pankaj Kumar, Shanker Dayal and A Dey
Division of Livestock and Fishery Management
ICAR Research Complex for Eastern Region, Patna – 800 014, Bihar (India)
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