Silkworm pupae meal is a silk industry by-product that in some countries is available as a local product. It contain up to 30% crude fat and 50% crude protein. The chemical score of silkworm pupae protein is 60 and tryptophan is its limiting amino acid. The silk worm pupae meal fat contains 25.7% linoleic acid (Udayasekhara Rao, 1994). Reddy et al (1991) reported that use of diets contain 5% 8% SWP so that replaced 50% of fish meal, lowered weight gain. The aim of this study was to measure the effects of substituting different levels of silkworm pupae (SWP) for soybean meal (SBM) in Arian (an Iranian strain) broiler rations.

Many studies have been carried out to reduce dietary mineral premix level with no adverse effect on broiler performance. Controversial results have been reported in this respect. Deyhim et al (1994) showed that at normal temperature and also under heat stress at 28-49 days of age, removing mineral and vitamin supplements cause reduction in performance, but withdrawal of mineral premix alone, didn’t affect production. Christmas et al (1995) suggest that it is possible to removing vitamin and mineral supplements from finisher diets of broiler chickens at last week of raring period. The aim of this trail was study of effect of withdrawing or reduction mineral premix from diets with normal vitamin premix level on broilers performance.

Fat saturation degree and the age of bird are two important factors for broilers’ ability to digest fats. It has been shown that hepatic fatty acid synthetase activity is decreased by diets with added sunflower oil (rich in PUFA of n-6 series) compared with those fed lard and this can result in abdominal fat pad reduction. (Sanz et al., 2000). It is well known that dietary intake of n-6 and n-3 PUFAs is effective in lowering blood lipid level, but they differ in their effect on serum lipid concentrations. It has been observed that n-6 fatty acids lower serum cholesterol level, but not triacylglycerol; n-3 fatty acids lower both serum cholesterol and serum triacylglycerol level in experimental animals (Berr et al., 1993). The objective of this study was to survey the effects of different dietary unsaturated to saturated fatty acids ratio on performance, abdominal fat pad and serum lipids in broiler chickens.

Aflatoxins (AF), natural contaminants of food stuffs and are toxic metabolites produced by Aspergillus flavus and A. parasiticus. Aflatoxins damage the liver, kidney and thymus resulting in a variety of effects including decreased growth rate, poor productivity and immunosuppression. Recently we have reported that ammonia solution can directly inhibit aflatoxin production in Aspergillus parasiticus in culture growth (Namazi et al., 2001). A study was conducted to determine the efficacy ammoniation of contaminated-corn with aflatoxin in decreasing aflatoxin in diet of broiler chicks and its effects on production and biochemical parameters.

Phytic acid is the main storage form of P in grains and seeds. Cereals and grain legumes that are commonly used as poultry feed ingredients have similar phytate levels, approximating 0.25 percent of dry matter (Ravindran et al., 1995). There is not enough phytase activity in the digestive tract of chickens to digest phytate (Maenz and Classen, 1998). Phytate contributes to environmental pollution by reducing mineral and N bioavailability. The capacity of phytic acid to bind minerals reduces the utilization of P, Ca, Zn, Fe and N from plant ingredients by chickens (Sell et al., 2000). Phytate may form complexes with proteases, such as trypsin and pepsin in the gastrointestinal tract (Singh and Kricorian, 1982). These complexes may reduce the activity of digestive enzymes with a subsequent decrease in the digestibility of dietary proteins. It has been reported that microbial phytase improves the utilization of amino acids (Ravindran et al., 1999) and minerals in broiler chicks. The objective of the present study was to evaluate the effect of microbial phytase on the apparent digestibility of amino acids (AA) and some minerals in the diet of female broiler chickens.

Crude protein is an expensive nutrient in broiler diets and the supply of essential amino acids is more important than crude protein. Therefore it’s possible to reduce crude protein level by supplementing diets with methionine and lysine as limiting amino acids. The object of this study was assaying low protein diets supplemented with DL-methionine and L-lysine hydrochloride on male broiler chicks.

One prerequisite for efficient broiler production is suitable litter. In addition to desirable chemical and physical characteristics, poultry litter must also be low in microbial load to minimize risk of incidence or transmission of diseases. This study was conducted to assess the mycoflora of six kinds of litter materials and evaluate the effect of litter kind and preslaugther feed withdrawal (PSFW) on gut bactrioflora of broilers.

While vitamins naturally occurring in plant and animal based feed ingredients can supply a reasonable proportion of the birds daily needs, their contribution is rarely considered during formulation. This situation arises due to variability, especially in cereals and vegetable proteins, for example, the vitamin E content of corn can vary from 10 to 40 IU/kg. Because of this uncertainty in the natural supply of vitamins within a feed, the bird’s vitamin supply is therefore met by the addition of synthetic vitamins, usually in the form of a so called premix, that contains all vitamins and perhaps some other micronutrients and feed additives. This premixes use according to producer suggestions and in some cases their doses can be higher than real requirements. Skinner et al (1992) removed vitamin premixes from 21 day of age and did not report any adverse effects. Gwyther et al (1992) showed sever performance reduction by vitamin premix withdrawal from 21 to 49 day of age. This experiment was conducted to determine the effects of Vitamin supplement levels on broiler chickens from 28 to 49 days of age.

Using inorganic additives is one suggested approach for improvement of performance or for preventing some disorders and poisoning of farm animals. One of those which use in animal diets is zeolite. There are more than 40 types of natural zeolites, of which one of the commonest is Clinoptilolite. Clinoptilolite has a relatively constant crystalline structure and has good adsorption properties. One of the most important problems in the poultry industry is low eggshell quality, particularly at end of lay. This leads to problems such as the breaking of egg in transport. Research on this has indicated positive effects of zeolites. Adding 1.5% clinoptilolite causes a significant increase in the calcium CA concentration of serum (Hossein et al., 1994). Olver (1989) observed a significant increase in eggshell thickness when 5% clinoptilolite was added to the diet of laying hens. The purpose of present study was to investigate the effect of different dietary concentrations of clinoptilolite on some blood parameters and eggshell quality.

The stress of high environmental temperature may have a deleterious influence on the performance of broiler chickens by reducing feed intake, live weight gain and feed efficiency. Exposing chicks to 36-38°C for 24h at 5d of age reinforces the resistance of older (6 to 7 wk-old) broilers to heat stress (De Basillo et al., 2003). Several studies have revealed that antioxidant nutrient supplementation especially vitamin C and E can be used to alter the negative effect of environmental stress (NRC, 1984). Combination of antioxidant vitamins generally shows greater antioxidant activity than that of each component alone. The objective of this study was to investigate the effects of early age thermal conditioning and vitamin C, E supplementation on performance, carcass characteristic in broiler chickens reared under heat stress.

During growth period of 6 to 7 weeks, broiler chickens are exposed to different stressors, the effects of which are dependent on the type, duration and intensity of stress that affects the bird. Stress-induced changes in muscular metabolism alter the physico-chemical traits of meat, thus affecting its quality (Ali et al., 1999). The negative effect of ante-mortem thermal stress on the quality of broiler meat has been the object of many studies and is relatively well documented (Warriss et al., 1999). There is a scarcity of data on whether and to what degree hyperthermia in growing chickens affects the technological parameters of poultry meat. Therefore we carried out an experiment to determine the effect of 5-day heat stress in 4-week-old broiler chickens on their later meat quality.

Accessibility of enviable litter materials and litter treating aimed at reducing ammonia and dust levels in poultry houses and pathogen population in litter are the points of interest in poultry research. A study was conducted to evaluate leaves and ground corncobs as alternative litters for broilers and examine the effect of surface spraying of antimicrobial solutions, oil and apply of both on performance of broilers.

Red mite (Dermanyssus gallinae; De Geer, 1778) is currently the most economically deleterious ectoparasite of layer hens in several countries (Chauve, 1998). D. gallinae is an obligatory haematophagous ectoparasite of both domestic and wild birds (Bruneau et al., 2001), only found on the host during darkness when obtaining a blood meal. The remaining part of its lifecycle is spent concealed deep in the house substructure, in cracks and crevices, with control typically implemented via chemical spraying. Mite exposure in laying hens generally results in irritation, restlessness, anaemia, and occasionally death and may subsequently lead to decreased egg production, poor shell integrity, blood staining and egg size reductions (Chauve, 1998; Cosoroaba, 2001). Natural exposure to mite-antigens during feeding activates humoral immunity of the fowl, in the form of immunoglobulin production. However, the magnitude of this serological response over a prolonged infestation period and at different mite population levels is unclear. Therefore the aim of this study was to determine the levels of anti-mite immunoglobulin present in egg yolks of laying hens in flocks infested with differing population levels of red mite over a period of 16 weeks.

Feed is a major cost in beef production during the winter feeding period. One potential method of reducing cost is to purchase grain at harvest. However, grain must be processed either by rolling or milling prior to feeding and this is a labour intensive process. Currently labour is an expensive and scare resource on many beef units. Recently different techniques have been developed for storing and feeding grain to beef cattle, which involve the processing of the grain prior to storage. The objective of the current study was to evaluate the effects of grain storage and processing method, and grain feed level on the meat quality of beef cattle offered two contrasting grass silages.

Cost effective performance from birth to slaughter must be achieved in order for beef producers to maximise income and survive in a subsidy-free, market led environment. The aim of the present study was to evaluate the effects of gender, plane of nutrition during the growing and finishing indoor feeding periods, and stocking rate and concentrate supplementation from weaning to finishing on meat quality.

The commercial value of beef carcasses can be assessed by several methods including the yield of primal joints and meat quality characteristics. However, it is also important to determine the composition of the carcass in terms of lean, fat and bone concentrations, and to evaluate individual fat components of the carcass, to provide an overall assessment of the commercial value of the carcass. The objective of the present study was to evaluate the effect of slaughter weight on carcass composition of Holstein-Friesian bulls and steers offered cereal-based rations.

Meat from Holstein-Friesian bulls, which are bred for dairy traits, is generally regarded as low quality and is usually destined for the commodity (mince) market. However, given their ready availability as a by-product from the dairy herd, it is important to determine if meat from these animals would be suited to higher-priced markets. Furthermore, meat from bulls is generally considered to be lower quality than that from steers, though there is a paucity of data comparing meat from both sources. Hence, the objective of this study was to evaluate the effect of slaughter weight on meat quality characteristics of Holstein-Friesian bulls and steers offered a cereal-based ration.

A considerable proportion of beef produced in the UK is a byproduct of the dairy industry. Young animals from this source are generally regarded as low in quality and meat from animals of this type is usually destined for the commodity minced beef market. The objective of the present study was to evaluate the effect of slaughter weight on sensory characteristics of meat from Holstein-Friesian bulls and steers offered a cereal-based ration.

Both breed and feeding system can affect the composition of fat depots in cattle. Furthermore, carcass fat colour may be influenced by forage-based diets due to the deposition of pigments, but also by changes in texture and firmness because of differences in the fatty acid (FA) profile. The objective of this work was to study the relationship between colour and FA profile of subcutaneous (SC) fat depending on breed and feeding systems in yearling bulls.

Beef production is the most important farm enterprise on Northern Ireland farms, accounting for 32.5% of Gross Agricultural Output. In beef production the end saleable product is carcass rather than live weight. When undertaking nutrition studies with beef cattle, it is essential to evaluate effects on carcass characteristics, as improvement in live weight may not transfer to improvements in carcass weight and characteristics due to change in gut fill effects. Undertaking carcass assessments in beef production studies increases experimental costs. To determine carcass gains it is essential to slaughter a representative batch of cattle pre-experimentally in order to develop a relationship between initial live weight and initial carcass weight. Slaughtering store cattle further adds to the costs of beef experimentation. The present study was undertaken to develop a relationship between live weight and carcass weight of beef cattle offered grass silage-based diets to facilitate the determination of initial carcass weight of store beef cattle at the point of initiation of nutritional studies.