Taking animal breeding a step further
MEAT markets are dynamic and ever changing. Genetically modified meat was once in high demand as technological advances permitted scientists to create, ‘the perfect animal producing high quality meat’. Those in countries where genetically manipulated animal meat could be sold had the option of selecting a specific meat quality they wanted.
So much is the technological advancement in this field that some scientists are able to even produce meat with an added specific taste to it. Beef producing cattle can now be manipulated to produce meat with a garlic flavour. When the international community began to question the long term health effects of consuming meat from genetically manipulated animals and meat from animals fed with GMO feed, consumers also began to shy away from it. Thus, the traditional method of cross breeding animals with desired physiological characteristics still remains the common and healthier practice for breeders. The main purpose of breed improvement is to introduce a positive characteristic into a local breed. For example in goat breeding this can be achieved by crossbreeding an indigenous goat breed with an exotic one. The offspring is likely to inherit the body shape and good growth rate from its father and the tolerance to environmental stress from its mother and simultaneously produce a new breed with particular performance traits.
Other reasons for breeding include producing a new breed with high resistivity to diseases, parasites and viruses; coming up with a breed with high converting ability in terms of feed and meat mass; to create a breed that is able to mature early and to improve the meat quality of the animals. Also to increase milk yield and composition, raise egg production in layers and improve litter size in pigs. Breeding solves calving difficulty, survival, and length of the productive life of animals.
Breeding of animals beings first with selecting the breeding stock. This process requires breeders to search for specific characteristics in purebred or crossbred animals to produce a new stock with improved qualities. Types of breeding include pure-breeding, outbreeding and in-breeding. Pure breeding involves mating purebred individuals of the same breed. The progeny has the same genetic makeup. The major objective of pure-breeding is to identify and propagate superior genes for use in commercial production primarily in crossbreeding programmes as well as to propagate and identify superior females for maintaining valuable genetic material.
Out-breeding involves mating individuals of the same breed but who are less closely related than the average of the breed. For example in piggery there should not be a common ancestor for at least four generations back in the pedigree of the boar and the females with which he is mated. It is a useful mating system in purebred individuals.
Mating between individuals of the same breed but which are more closely related than the average of the breed is termed in-breeding. This could be between as close individuals as full sibs or sire – daughter, mother - son. Pure breeding is a special kind of in-breeding. The effect of inbreeding is the concentration of common genes in the offspring. Breeding also involves the utilisation of statistics. According to Professor Daniel Gianola at the American Statistical Association Journal, animals’ merits (characteristics) can be a linear or nonlinear combination of genetic values for several traits that are economically important. Genetic merit cannot be observed, so it must be inferred from data. Relevant statistical problems encountered are; assessing whether traits have a genetic basis; developing accurate methods for inferring merit (‘genetic evaluation’) and designing the mating plans.
There are three main apparatus involved in creating statistical models for animal breeding which are; formulating the mathematical function that will link observations to local parameters and random effects; the genetic and environmental dispersion parameter, which entails the application of variance and covariance and finally one has to make suppositions about the joint distribution of the observations and of the random effects.
Breeding can be beneficial for high productivity. However, it must be combined with good animal management. This management system necessitates: the proper feeding of animals through the use of locally available feed resources; the efficient prevention and control of infectious diseases; the alleviation of fertility constraints; the implementation of artificial insemination (AI) programmes; the creation and maintenance of updated field and animal records for each production system and also of importance are proper financial planning management systems (gross margin analysis, break even analysis, cash flow budgets etc.).
The writer is Engineer Tapuwa Justice Mashangwa, chief consultant at Emerald Agribusiness Consultancy based in Bulawayo. He can be contacted on +263739096418 and +263771641714 and email; tjmashangwa@gmail.com.