From previous reports indicate that broiler chickens fed diets enriched with polyunsaturated fatty acids have less abdominal fat or total body fat (Sanz et al., 1999) deposition than do broiler chickens fed diets containing saturated fatty acids. In general, body fat accumulation may be considered the net result of the balance among dietary absorbed fat, endogenous fat synthesis (lipogenesis) and fat catabolism via β-oxidation (lypolysis). Thus, if the amount of absorbed fat is the same, lower body fat deposition may be attributed to increased fat catabolism or diminished endogenous fatty acid synthesis or to both process. Differences in lipid oxidation rates seem to be the main mechanism involved in this effect. Supplementation of unsaturated fatty acids in diets can be enhanced fat catabolism and reduced fatty acid synthesis were reported to occur in rats fed polyunsaturated fatty acid rich in diets compared with rats fed diets enriched with saturated fatty acids (Crespo and Esteve-Garcia, 2002). Polyunsaturated fatty acids rich in diet effect on fat absorption were increased. In, contrast amount of abdominal fat deposition was decreased. It may be that the polyunsaturated fatty acid was higher rate fat oxidation or lower rate of fatty acid synthesis or both. The present study was undertaken to determine the effect of amount of beef tallow versus soybean oil absorbed is the same on energy intake, energy excretion, energy retention and energy expenditure of broiler chickens.

Egg yolk colour has always been regarded as an important egg quality characteristic and recently has had an even more important role in the marketing of eggs. One of the dietary factors influencing egg yolk colour is dietary fat. Dietary fat has been reported to have a positive or negative effect. Mackay et al (1963) reported that the addition of 4% animal fat improve egg yolk pigmentation. Hamilton and Parkhurst (1990) found that fats with lowering melting point resulted in higher oxycarotenoid level in yolk. An investigation of the role for dietary fat in yolk pigmentation appeared worthwhile because the sources of fat are different in the formulation of diets and because yolk pigmentation is an economically important quality factor. The objective of the present study was to investigate the influence of three sources of fat and levels of pigment on yolk colour and performance of laying hens.

Trimethylglycine has two primary metabolic roles: it is a methyl group donor and an osmolyte that assists in cellular water homeostasis. Tissues that rely on zwitterionic betaine as an osmolyte include the intestines, kidney, liver, brain and leukocytes. Osmolytes are particularly important in situations in which cellular dehydration is present because these compounds help minimize water loss despite a prevailing osmotic gradient. Thus, water balance homeostasis is an important factor for cells exposed to a variety of osmotic conditions (Klasing et al., 2002). For example, the osmotic pressure of the intestinal contents varies during the process of digestion. The osmotic difference between the intestinal epithelium and the luminal fluid is likely to necessitate means to control the osmotic pressure inside the intestinal epithelial cells. Betaine, as an organic compatible osmolyte, is one of the most likely candidates for the task.

Low pH and high lactic acid concentration of fermented feed has been reported to be responsible for the antimicrobial activity of fermented feeds (Brooks et al., 2001). For example, to prevent the growth of Salmonella spp. in liquid feeds, a threshold lactic acid concentration of 75mM is required (Beal et al., 2002). Therefore, factors that are likely to affect the production of lactic acid during fermentation will have important implications for the ability of such feeds to withstand colonisation by pathogens. The objective of the present study was to investigate the effect of water quality on the fermentation pattern of sorghum and barley.

There is a growing interest in the use of lesser known plant seeds as sources of protein in monogastric feeding in the tropics. It is thought that the exploitation of novel seeds which are currently not utilized by man can contribute to the amelioration of the insufficient feed supply situation in tropical countries like Nigeria. The seeds of Manihot esculenta (Cassava) have the potential to complement the conventional plant protein in poultry diets. Lack of information on the nutritional quality and digestibility of the protein and amino acids in the seeds has caused a limitation in their use for poultry feeding. The objectives of this study were 1) to investigate the chemical and antinutritional constituents in the seeds of Manihot esculenta, and 2) to determine the precaecal digestibility of crude protein (CP) and amino acids (AAs) in the seeds with broilers and their effect on the performance of the birds.

Several researches was conducted to investigate the effect of Saccharomyces cerevisiae on poultry performance, but Saccharomyces cerevisiae has an especial quality that makes its more noticeable for continuing research about its. This quality is:a) improving fatty acid digestibility (Kautz and Arens,1998), Improving of ether extract, cellulose digestibility and retention of nitrogen 2) improving of Phosphors digestibility(3) b) Stimulation of immunity c)improving of bronchitis and gambro Elisa titer d) have a several strain. According to this, an exprement was conducted to investigated the effects of SC47 on broilers performance and immune organs.

In the productive chain of broiler chicken the sanitary problems are minimized with the use of alimentary additives. The official Brazilian Health Department has established criteria for the use of antibiotic in broilers chicken diet and the use of probiotics, prebiotics and simbiotics has increased (Miltenburg, 2000). This paper was developed to evaluate the effect of different growth-promoters in diet for broilers chickens from 1 to 21 days age on weight gain, feed intake and feed conversion and to study the economic viability of addition of those promoters.

Feed remains the most important cost in animal production. The need for feed ingredients, which will reduce the cost of production, is the basis for most livestock feed and production research. Man and his livestock are in competition for the basic ingredients. Availability of such feed ingredients thus becomes the key limiting factor in poultry production, hence the need for alternative and locally available feedstuffs. The presence of undegradable and complex carbohydrate, non-starch polysaccharides (NSPs) in some alternative and locally available feedstuffs exerts some anti-nutritional properties and thus can limit their use in livestock feeding (Yoruk et al., 2006). Worse still is the fact that chickens are not capable of hydrolyzing NSPs that mask protein carbohydrate (Petterson and Aman, 1989). Exogenous enzyme supplementation has been reported to be used in poultry diets to improve nutrient utilization, the health and welfare of the birds, product quality and to reduce pollution as well as to increase the choice and content of ingredients which are acceptable for inclusion in diets (Aderemi et al., 2006). Since most work with exogenous enzymes has been carried out to evaluate its effect on feed intake and growth characteristics of broilers, the aim of this study was to investigate the effect of graded level of feed enzyme Roxazyme-G® on the performance, carcass and meat qualities of broiler finishers.

The effect of glutamine on the structure of the intestinal mucosa, after suffering any damage is raising interest due to the fact that this amino acid is the main metabolite which nourishes the enterocytes. Yet, the mechanism that promotes proliferation of the intestinal cells is not well known. It might be related with two events: increase of Na+/H+¨ exchange at the plasmatic membrane and increase of ornithine descarboxylase specific activity. Glutamine is also able to raise gene transcription, by increasing the activity of kinase protein which activates mitogenesis (Blikslarge et al., 1997). Chick’s weight is determinated by eggs initial weight. Older breeders produce bigger eggs which become chicks with higher weight at eclosion moment. In other words, higher consumption levels of protein at the beginning of laying, provide better albumen quality which becomes thicker, delaying oxygen exchanges, the absorption of yolk sac and embryo uptake of vitamins through egg yolk (Brake, 1995). As the embryo produces 90% of its energy from fat acid oxidative process, oxygen deficit would slow lipid oxidation and embryo development. The purpose of this study was to evaluate the development of the intestinal mucosa of chicks at 7 days of age, proceeding from breeders of different ages and fed with and without glutamine supplement.

The objective of this research was to look for the evidence of segregating major genes in an Iranian pedigree chicken flock (Mazandaran station), using four statistical tests: Normality, Bartlett, Fain and Mixture tests for four economically important traits. These traits are age at first egg (AFE), body weight at the end of week eight (BW8), average egg weight (EW) and number of eggs laid during egg production period (EN).

High levels of TDS in drinking water, has negative effects on broiler performance. Consumption of saline water results in increases blood pressure. In order to expulsion salt, water consumption increases, total amount of blood K decreases and an increment occurs in litter moisture. Consequently performance decreases, anion-cation becomes imbalance and some diseases such as ascites and coccidiosis happen. Change in anion-cation balance affects a lot of physiologic and metabolic functions of body, so can reduces performance and also increases FCR. Nowadays poultry producers in regions with high levels of NaCl in water, try to solve the problem by reducing NaCl content diet, purifying water or etc. Current study examined betaine supplementation for searching another way to get rid of this problem. Betaine implicated in methionine sparing and osmotic stress protection. It can protect intracellular proteins against hyper tonicity induced denaturation. Betaine is a naturally-occurring product present in relatively large quantities in sugar beet and aquatic invertebrates, but is not present in most animal feedstuffs (Wang et al., 2004). As a by-product of sugar beet processing, betaine is commercially available as a feed additive (Eklund et al., 2005).To date, concerning to our knowledge no information has been published about the osmolytic effects of betaine on performance and carcass traits of broilers in response to saline water consumption.

The UK’s Farm Animal Genetic Resources (FAnGR) – its farm animal breeds, strains and varieties, and the variability within them-are of great economic, social and cultural importance. For these reasons alone it is important that we care for them, but we also have national and international obligations to do so.

Conservation is a long term activity, and the objectives of the activity must be clear and justified for it to be sustained in the long-term. Whilst the obligations for conservation-related activities are clearly set out in the Convention on Biological Diversity (“Rio” convention or CBD), the scale of activities will depend on the scope and quality of the case. A market-led justification for conservation of livestock is fraught with difficulty since if markets supported the full scope of existing genetic variation there would be no need for conservation. This does not imply that a long-term economic case cannot be made, but it does focus the arguments onto the future importance of the range of livestock breeds. Therefore beyond the benefits of visual diversity on the quality of life, there is a need for evaluating the scientific justification for conserving livestock breeds.

The concept of conserving genetic resources was first introduced in 1928 by Vavilov, a Russian botanist who founded a plant genetic resources bank at the All-Union Institute of Plant Breeding, Leningrad (Simon, 1984). The issue was first raised by the animal production world in 1959 where a need to conserve animal genetic resources was expressed at a Joint Symposium on Germplasm Resources for plant and animal breeders in Chicago (Simon, 1984). The emergence of these ideas can be associated with the recognition of advances in animal breeding and reproductive technology leading to a small number of highly productive breeds taking a dominant position in the production process. Three main forms of conservation can be considered; (i) cyopreservation (gene bank); (ii) maintaining control populations (no selection); (iii) managing live animal populations. This overview will focus on the role that cyopreservation plays in conservation of animal genetic resources.

Some of the many pig, sheep and cattle breeds in the British Isles are present in very small numbers and in only a few locations. The names of these rare/traditional breeds often reflect the place they originated from, e.g. Gloucesteshire Old Spots pigs. They are ‘unimproved’ in the sense that they have not been bred for greater production. The Rare Breeds Survival Trust (RBST) has an important role in the conservation of these breeds. The Traditional Breeds Meat Marketing Co Ltd (TBMM) developed out of RBST to market meat from them on the basis that one of the best ways to conserve breeds is to develop markets for their produce, making it financially feasible for farmers to maintain them. Consumers are often prepared to pay a higher price for the meat, which offsets higher production costs.

‘Conservation grazing’ is normally interpreted to mean livestock grazing for wildlife conservation purposes. Farm livestock grazing is essential for the management of many of the United Kingdom’s most important habitats. For example, permanent grassland, heathland, wood pasture, floodplain and coastal marshes all require some grazing to maintain the structure and composition upon which a wide variety of wild plants and animals depend for their survival. Farming activities have played a significant role in shaping these habitats over time and the continuation of certain livestock husbandry practices is often crucial for their sustained existence. The key livestock species utilised for conservation grazing are cattle, equines (mainly ponies), sheep, goats and occasionally pigs. Wild herbivores (e.g. deer and rabbits) may also play a significant part in conservation grazing outcomes.

The Post War era has seen UK agriculture experience mixed fortunes. Following the scarred memories of food shortages farming experienced one of its regular cyclical booms in the sixties and seventies with guaranteed prices that pushed forward production to improve the level of self sufficiency demanded by the politicians. In continental Europe this encouragement was provided by the emerging Common Agricultural Policy (CAP) which Britain joined in 1973. The CAP promoted greater food production by different methods based on intervention buying at guaranteed prices when there were surpluses only to release the products back on the market at times of shortage. This system worked effectively while the periods of excess were smaller than the periods of surplus. The eighties saw the reversal of this pattern and the establishment of unacceptably high levels of intervention stocks of all major commodities. The system became unworkable and although the French and Germans fought to retain the status quo, the old CAP had become not only indefensible but critically not in the best interests of either consumer or farmer.

Agricultural activity is determined by the simultaneous operation of four underlying exogenous forces, natural resources, markets, science and social values. All these forces have been changing and the UK agricultural industry, including not only farms but all the businesses involved in turning raw materials into food and other consumer products are compelled to adapt. An account of agriculture today is in practice a single frame of a moving picture.

Mixed farming systems, in which crops and livestock are integrated on the same farm, are the backbone of small-scale agriculture in most developing countries (Lenné and Thomas, 2006). Crops and livestock contribute in a diversity of ways to enhancing the livelihoods of the poor through provision of food, income, draught power and employment. Livestock are a major source of high-quality protein, minerals, vitamins and micro-nutrients for developing country populations and livestock-derived food items contribute significantly to agricultural GDP. Animals also play a major role in improving food security in such countries, because cash income obtained from the sale of animals is regularly used to buy non-livestock food items and inputs to farming. It is predicted that the demand for livestock products in developing countries will increase substantially over the next 25 years (Delgado et al., 1999). Failure to meet the challenge of further growth in the livestock sector in these regions is likely to result in the growing urban demand for livestock products being met by subsidized imports. This will be to the detriment of small-scale producers and national and regional economic growth.

Robustness can be defined as “the capacity to handle disturbances in common and sustainable, e.g. economically, systems”. To achieve a robust farming system, a broad perspective is needed (Napel 2005), but here we focus on genetic selection for robust cows and the origin of the need for such animals.