Publisher's Synopsis
The conference opened with a keynote address from Professor Phil Thomas of SAC, who gave a very thought-provoking paper on European developments in animal nutrition. He predicted that the demand for animal products would continue, but that consumers are becoming more conscious of the effects of diet on human health and will require more information on productions systems and the way that animals are reared. Several recent food scares have emphasised the need for careful control of feed formulation and the use of additives in animal diets if consumer confidence in the safety of animal products is to be maintained. At the same time, consumers are often badly informed about the science behind food production and are very sceptical about new technologies such as genetic engineering. All sectors of the EU livestock industries are facing the challenges of new regulations and restrictions designed to meet the demands of the domestic consumer. The regulations that particularly concern feed manufacturers were discussed in the second paper. Ascites is an important problem in broiler production and is estimated to cost the industry 1 billion US dollars per year. The third paper presented new information on the incidence of ascites and possible measures that can be taken to reduce it. The other paper on poultry looked at how the composition of eggs can be manipulated to meet the demands of the modern consumer for a ‘healthier' product. Mineral supplements are required in the diets of most farm animals to correct deficiencies in the natural feed ingredients. In recent years, various organically-bound mineral sources have been introduced. Chapter five presents information on the utilisation of these compounds in comparison with traditional inorganic sources of minerals. Antibiotics have been widely used as growth promoters in pigs for many years, but concerns over their possible effects on public health have led to reductions in their general use and bans on certain products. In order to maintain the health of pigs without using antibiotics it is necessary to consider alternative feeding strategies. Two such strategies were considered in chapters six and seven. Short-chain acids can be used as feed preservatives, through their antimicrobial actions; they also appear to have beneficial effects on the microflora of the gut and improve animal performance. Alternatively, fermented liquid feeds contain high numbers of lactic acid bacteria and yeasts. These act as natural probiotics and help to maintain a healthy gut environment. Genetic engineering has received widespread media attention recently and a whole session, consisting of three papers, was devoted to this topic. One of the main objectives of the session was to present a rational scientific explanation of the benefits of genetic engineering, something that is usually lacking from the media coverage. The first paper was concerned with raw materials used in animal feeds, specifically plants with novel traits. It was explained that the major use of genetic engineering is aimed at improving the husbandry of the crop, but that some crops have been engineered to directly improve quality. There appears to be no effect on the nutritional value of the plant products for animals or humans. The second paper looked at the practical application of genetic engineering in animals. The main technologies available are transgenics, cloning and gene targeting. None of these is likely to be used for commercial animals in the near future, due to the technicalities, costs and politics involved. Their use is more likely to remain within the specialised biotechnology industry, for the production of medicinal products. The third paper presented a summary of the latest advances in technologies that form alternatives to genetic engineering in animals. Significant progress has been made in the fields of genetics, nutrition, reproduction, health and performance monitoring. Most of these are based on existing technologies that have already proved acceptable to the consumer. There is considerable scope to exploit these areas and increase the performance, health and welfare of commercial livestock. The session on ruminant nutrition consisted of three papers. The first of these described a new system of rearing heifers to increase their lifetime productivity. By making strategic use of compensatory growth, through energy restriction in various phases of the growing period, mammary development can be optimised and lactation performance enhanced. The other two papers presented new data on the nutrition of the high genetic merit dairy cow. The first considered energy metabolism and concluded that the efficiency of energy utilisation for lactation is not greater in these cows, but that previous estimates of the energy requirement for maintenance may need to be adjusted. The second paper looked at the practical considerations of feeding cows of high genetic merit. Although the use of concentrate supplements is likely to increase with milk yield, the negative effects of concentrate intake on silage intake, and therefore total energy intake, need to be considered when calculating optimum levels of supplementation.
