Livestock production is a function of:—
feed availability and quality
the incidence of diseases including intestinal parasites, blood and other parasites of living tissues (e.g. protozoa), viral and bacterial invasive agents
the climatic and environmental conditions that prevail in the particular area
the genotype which fits it to a particular production system.
In the context of this report, which examines the prospects and perspectives for the use of high technology or biotechnology in nutrition to increase animal production, the target animals must be the domestic ruminants that are managed by small farmers in third world countries.
The developing countries, in general, have severe constraints on food availability for humans and are often critically balanced in producing sufficient starch-based carbohydrates and high quality proteins to provide for their human population. Thus, the grains produced are generally required for the resident population, which is often increasing at a rate several times that of the populations of the industrialised countries. Short term food surpluses due to good seasonal growing conditions and/or application of plant/soil research results, will inevitably be converted to deficits by the growing population's demand for food.
The only exception to this will be if birth rate is reduced and death rate accelerated in these countries. The impact of the presently untreatable viral disease HIV (or AIDS) will be significant in this area but no predictions are yet available on its effects on future population densities in developing countries.
The likely small surpluses of grains over and above that needed by humans indicates that the production of monogastric animals which compete with humans for the basic feed resources (grain) must have good political and or trade advantages before it can be encouraged. However, production of monogastric animals on sugar based products and various by-products may be a future direction for considerable research effort.
There is, of course, a middle class in all developing countries which demands meat from poultry and pigs and can afford to pay the relatively high costs of production. This group of people is expanding in the countries that are rapidly industrialising, and this together with the influx of tourists in such countries will increase demand for these products.
There is a high correlation between meat consumed and cash income or standard of living (see Brumby, 1989 and Figure 1.1)
The husbandry of monogastric animals is already at a very high level and, in general, research on grain-fed domestic animals is probably best left to the industrialised countries where surplus grains are generally available and their production is subsidised (e.g. approximately 40% of the value of grain production throughout the EEC and USA is met by subsidies).
In most developing countries pig and poultry production is either based on a scavenger system, (which is restricted to village farmers), or a high cost technology system as used, and transferred from, temperate countries (which is used by the large farmer).
Figure 1.1: Food consumption/percentage of diet for meat, wheat and rice, and coarse grains as per capita income increases (Marks & Yetley, 1987-see Brumby 1989)
Monogastric nutrition cannot be omitted from consideration, however, as the appropriate integration of monogastric animals with ruminants in cropping areas is potentially the most efficient systems that might be (or are being) developed to increase animal production overall. Within these systems the production of pig and chicken meats from non-conventional feed sources (e.g. sugar cane, molasses, household swill, tubers, roots and by-products) integrated with such systems as protein production from aquatic plants should be the major consideration in the future.
The ruminant animal, because it has pre-gastric fermentative digestion of feed, generally does not compete with humans for vital quality-feed resources and must therefore have the focus of the discussions. Ruminant animals (biomass) in developing countries far outnumber all other domestic animal not only as a source of high quality human food (meat and milk, with blood in some areas), but of fuel (from dung) and draught power.
The continuing use of ruminants as domestic animals resides in their ability to:—
convert fibrous carbohydrates through fermentative digestion, into nutrients that can be used for growth, and milk synthesis
efficiently utilise low protein feeds and non-protein nitrogen in the rumen and synthesise proteins with a high biological value for human consumption
convert the carbohydrates of fibrous feeds into nutrients that can be used to carry out work-functions (e.g. ploughing)
more efficiently use dietary protein for tissue synthesis than monogastric animals provided it is in a form protected from microbial attack in the rumen but digestible by gastric and intestinal enzymes.
Any biotechnology developments will undoubtedly have to target the improvement of efficiency of these attributes under practical conditions pertaining particularly to the small farmer.
There are five major ways by which any technology may significantly improve livestock production:—
by altering the feed base to provide a better quantity and balance of nutrients to the animal
by altering the digestibility of the feed base by treatment so that more nutrients are extracted.
by manipulating the fermentative, gastric and post-gastric digestive processes to extract more and a better balance of nutrients for the animal from the basal feed.
by manipulating the efficiency of partitioning of absorbed nutrients into productive processes including those that are involved in life-time productivity
by removing or ameliorating constraints that are part of the environment (largely disease, but also the effects of temperature and humidity stress)
Strategies for the future use of animals for work and food production cannot ignore the growing environmental crisis and the need to reduce gaseous emissions from farming systems. Some comments will be made on this in later sections of this report.
Biotechnology is a much used “in word” in research submissions since it conjures up images of research at the cutting edge of science. It also has an overtone of application, potentially patentable products or processes and therefore returns on investment. The promises have been much overrated in recent times and in general the promises for application from, for instance, recombinant DNA technology have failed to materialise in terms of animal production. In general, the results of recombinant DNA technology have been disappointing. For example transgenic animals have been produced but failure to control expression of the introduced genes has resulted in adverse effects often of a nature that horrifies animal welfare groups. This has been given ‘bad press’ but it has highlighted the need to study the basic aspects of control of gene expression and cell physiology.
This does not mean however, that the future for and importance of such work is debatable. In fact, the contrary is true, but it has indicated a major requirement for basic research to understand gene expression and that more time and funds will be needed before many new concepts can be applied.
Biotechnology in the context of this report cannot be restricted to recombinant DNA technology. Biotechnology is in reality, a science of great antiquity having its origins in processes such as brewing and wine making.
The broad definition used here is the application of biological organisms, systems or processes to production of animal products
These include meat, milk, hides, wool or hair and draught power. In particular, biotechnology stresses the integration of microbiology, biochemistry and chemical and process engineering. It is always multi-disciplinary, and its strongest aspect is that it is directed to application. It usually requires disciplinary scientists working together and shepherded by person(s) with major integrative abilities. Young scientists (or disciplinarians) caught up in biotechnology and working in isolation often lose the direction for application or seek out compromise objectives to justify their approach which may or may not be rational.
On the tour of institutions prior to the writing of this report, it was an observation that a number of young, newly trained (overseas) scientists in the less well developed countries, were still working in the area of their overseas training without true recognition of the potential application of their work. They were, thus, in some ways competing with their previous supervisors and are therefore unlikely to produce novel innovations.
For the purposes of this report biotechnology research is regarded as a multi-level activity. In animal nutrition this includes research that aims to improve the efficiency of production through manipulation of:—
the feed base
the animal's digestive system
the animal's metabolism
It must also consider the potential for augmenting the feed base with critically deficient nutrients that may be produced locally, particularly from non-conventional sources (e.g. production of protein meals from aquatic plants (algae) grown on biodigestor effluent). It must also consider the possibility of decreasing protein fermentability of plants consumed by ruminants by genetic engineering of plants and other techniques applied to the plant, the microbial digestion system and the animal.
The narrower definition will be referred to here as the new biotechnology. This is defined as the application of recombinant DNA technology to the improvement of animal production through improving nutrition.
The beginning of recombinant DNA technology arose from the work of Crick and Watson (Watson, 1968) and their colleagues at Cambridge. Research in this area is often seen as being superior to other forms of biological research. However, like all research it is often the acquisition of technology and instrumentation which triggers development or progress in this field. Example of developments which allowed many groups to begin or progress in their work include the development of techniques to split the ovum, to introduce foreign DNA into chromosomal DNA or to force a plasmid into a cell where it will replicate along with other DNA. This is not meant to be a criticism of modern biotechnology research but it is stated to point out that the new biotechnology is supported by a large group of ‘normal scientists’ led largely by a few highly capable and creative persons in the same way as every other field of research endeavour.
The concept of the new biotechnology as a science for the gifted and the imaginative promises of biotechnology put forward in most reviews, have undermined many other fields of research which have then suffered from financial stringencies. These fields often regain prominence when, for example, innovative gene transfer methodology has failed to produce the expected applied technology (e.g. higher productivity in domestic animals expressing genes for growth hormone). In this case there has been little recognition of nutritional principles; an animal capable of growing say to twice the size and at twice the rate because of the acquisition of a gene for growth hormone may need a totally new nutritional approach. For example, in order to provide for growth and normal bone growth in such animals it will be perhaps necessary to provide more calcium and phosphorus in forms more easily absorbed and assimilated; protein to energy ratios in the nutrients absorbed may have to be increased substantially as may be the availability of vitamins and other minerals.
The need is for a suitable balance of research which must be maintained. The new biotechnology needs to advance along with the fundamental and applied research that is needed to ensure that the application of molecular genetic research reaches the end user, in this case the farmer. It is a major theme of this report that it is imperative that research on nutrition must not compete for limited funds with the new biotechnology.
It is also a major conclusion that concepts of nutrition transferred from temperate countries have been misleading. Recently developed understanding of nutrition, which has massive effects on productivity, is the area with most promise and with potential immediate application. The great need is for research to find ways of applying these concepts in production systems under differing environmental conditions within countries. With a likely doubling of food requirements of developing countries by the year 2000 the need for research which will result in strategies that can be quickly applied is paramount.
This dissertation must deal largely with the “economically” (in its broadest sense) important ruminants in developing countries. These are largely cattle, buffaloes, sheep and goats. Other animals that pre-ferment their feed, include camels, alpaca, llama, yak, thimin and certain monkeys as well as certain deer species, and post-gastric fermenters such as the horse, donkey, guinea pig and rabbit must be kept in mind as they are often of major importance in some areas. However, the latter group have not been targeted because of the predominance of ruminant herbivores. Research on the use of non-conventional feeds is given a brief mention but the major research requirements here are to develop the systems which depend on locally available resources and particular within an integrated farming systems concept.