Although roughages are the main components of diets for ruminants their endogenous enzymes cannot digest lingocellulosic feedstuffs but is carried out by the rumen microbial population which comprises of bacteria, protozoa and fungi. Their main function in the rumen is the fermentation of feeds which yields energy to the host animal in the form of short chain fatty acids. Recent interest in the efficient utilisation of roughage diets has led to an increase in the use of the gas production (GP) technique due to the advantage of studying fermentation kinetics. This technique provides useful data on digestion kinetics of both soluble and insoluble fractions of feedstuffs. Several GP approaches have been developed including the use of glass syringes (Menke et al., 1979; Blümmel et al., 1997) which appears to be the most suitable for use in developing countries. The objective of this experiment was to evaluate the effect of defaunating the rumen of sheep on the amount of GP from wheat straw, alfalfa hay, cottonseed meal and barley grain.

Palm date leaves is an agricultural by product with high levels of lignocellulosic materials that limite its bioavailability for microbial and gastrointestinal tract enzymes. It contains more than 40 percent cellulose and 20 percent hemicellulose. The nature of steam treatment was acid hydrolysis which effectively affected cell wall fractions (Castro et al, 1993). Production of palm date leaves in Iran is more than 500,000 ton annually. The aim of this study was to assess the effects of steam pressure and reaction time on chemical composition and bioavailability of palm date leaves to rumen microbes.

The bioavailability of palm date leaves is low because of high levels of lignocellulosic materials in the cell wall. The presence of lignin protects carbohydrates from attack by rumen microbes (De La Cruz,1990). Steam treatment increases feed intake, overall digestibility and live weight gain, because of the extensive destruction of the cell wall (Castro and Macchado,1990). Steam treatment effects have been ascribed to complete hydrolysis of hemicellulose (Grohmann et al., 1985), lignin depolymerization and redistribution within the cell wall (Toussaint et al., 1991). The aim of this study was to assess the effect of steam pressure and reaction time on bioutilisation of palm date leaves.

Maize silage is a major source of forage for lactating dairy cattle throughout Iran. Therefore, it is important to understand and evaluate the characteristics that affect its feeding value of maize silage. Maize hybrids for ensilage and epiphytic lactic acid bacteria are the factors that can alter the nutritive value of maize silage. Homolactic bacteria have been used to inoculate silage and improve their fermentation and several studies have demonstrated the effects of inoculation of maize silage on silage fermentation characteristics. Hybrid also influenced the chemical characteristics of the maize silage. This experiment was conducted to evaluate the effects of bacterial inoculation and hybrids on fermentation quality and nutritive value of two Iranian maize hybrids.

The effect of inclusion of soya hulls (SH) as grains or forages sources in rations of dairy cows have been studied in many experiments. However, when SH are used to substitute for forage sources they induced milk fat depression, lower rumination time and ruminal pH (Weidner and Grant. 1994a, b). There is no data on effectiveness of diet particle size when SH used as a forages source. The objective of this study was to investigate the effect of physical effectiveness factor (pef) of diet on utilisation of SH in dairy rations.

Microbial inoculants are generally used to provide a better fermentation condition in silage making. A decrease in yeast and mould numbers with improvement in aerobic stability of high moisture maize silages has also been reported due to a microbial inoculation (Filya et al., 2004). Changes were observed in milk yield and composition of cows consuming diets containing inoculated silage (Kurtoglu and Coskun, 2003). The objectives of this experiment were to investigate the effects of Lalsil inoculant on aerobic stability of maize silage, and on feed intake, milk yield and composition of Holstein dairy cows when fed inoculated silage.

Information on starch degradation is required to promote a more efficient use of energy and protein in dairy cow diets. Several in vitro and in situ methods have been proposed to estimate starch degradability. However, they are not suitable for application in routine analysis as they often require the use of cannulated animals. The objective of this study was to determine starch degradation of cereal grains using a method based on boiling extraction for 30 minutes with αamylase solution. The starch degradation after incubation in sacco for 6 and 24 h was used to evaluate the new method proposed.

Maize silage is the main forage used for dairy cattle in Iran and plays an important role in supplying digestible fibre and energy to these animals. Microbial inoculants are the most commonly used biological additives to accelerate the decline of pH during the initial stage of silage fermentation and to preserve plant carbohydrates through homofermentation which may resulted in an improvement in nutrient digestibility (Aksu et al., 2004). However, their use in silage production has been very limited in Iran. The objectives of this experiment were to study the effects of a bacterial inoculant on the fermentation characteristics and dry matter (DM) degradability of ensiled low DM maize forage.

There are many rationing models used commercially for evaluating diets fed to dairy cows. A new model – BioParaMilk – uses a unique protein degradation model to determine microbial protein synthesis, based upon the in vitro gas production technique (IVGPT). Optigen®, a slow release, blended, non-protein nitrogen source, can partially replace soyabean meal (SBM) in a dairy diet. The partial replacement of soyabean meal and rapeseed meal with Optigen® has been shown to increase fibre digestion and may improve volatile fatty acid (VFA) and microbial nitrogen (N) flow in the rumen (Sinclair et al., 2008). The purpose of this study was to evaluate the protein degradation curve from Optigen® compared to SBM for use in this new model, using IVGPT.

Eucalyptus (Eucalyptus citriodora) is a tall evergreen tree native with many species available in many parts of the world including Australia, China, India, Portugal, Spain, Egypt, Algeria, the southern United States, and South America. There are few experimental data on effects of the eucalyptus fresh and residual leaves material (RLM) from oil extraction on rumen microbial fermentation patterns, therefore the objective of this study was to investigate the effect of eucalyptus fresh and RLM on methane emission and rumen activity in vitro.

Sugarcane pith is a by-product of the final stage of the processing of sugar cane as it passes through rotary sieves to separate fine particle. A technique, which has shown considerable potential as a method for the cost-effective pre-treatment of lignocellulosic material, is steam explosion. At the end of this process, a substantial proportion of the hemicellulose fraction is made water soluble and the lignin fraction is modified. This results in a cellulosic substrate with improved enzymatic accessibility and digestibility. It has been shown that energy availability is increased by solubilisation of cellulose and hemicellulose and/or by freeing digestible materials from lignin or silica (Hart et al., 1981; Horton et al., 1991). By applying the steam explosion process to sugarcane bagasse, Kling et al. (1987) demonstrated that about 60% of the hemicellulose fraction was hydrolysed and the susceptibility of cellulose to enzymatic hydrolysis was increased. For treatments based on the use of steam-pressure alone high temperatures are needed (t>180°C) which may result in the formation of anti-nutritional factors such as 2-furaldehyde (furfural) by secondary dehydration reactions of hemicellulosic pentoses and soluble phenolic compounds. Both of these inhibit the activity of rumen microbes and cell-free enzymes. The objective of this experiment was to evaluate the effect of high-pressure steam treatment on cumulative gas production (GP) profile of sugarcane pith.

Iran is a largest pistachio producer in the world. Typically about 300,000 tonnes were exported to other countries per annum. Total pistachio by-product production in Iran has increased at an average rate of about 400,000 tonnes per year, and is becoming an environmental problem. Pistachio hulls are produced during de-hulling of pistachio nuts soon after harvest. Pistachio hulls contain about 12%crude protein (CP), 5% ether extract, 34% NDF, 21% ADF, 9.20% ash and 8% tannin (DM basis). Using pistachio by-products for ruminant feed could reduce the feed cost, environmental pollution and associated difficulties. This study was conducted to determine whether there is a variation in nutritive value of pistachio by-product during harvesting time.

Dietary protein is the main source of nitrous oxide and nitrates, harmful pollutants which are produced in pig units. So reducing the level of protein in the diet may be environmentally friendly. But will this compromise performance? This study compared three ‘nutritional strategies’ providing different protein and energy levels as pigs of two breeds grew from 40 to 120kg live weight.

The production of pigs with low subcutaneous but high intramuscular fat (IMF) is one of the main challenges of the pig industry, and it requires the understanding of the mechanisms controlling fat formation in these two depots. IMF can be increased by reducing the ratio of protein to energy in pig diets (Wood et al.,, 2004). This is accompanied by activation of expression of the enzyme stearoyl-CoA-desaturase (SCD), which catalyses the biosynthesis of monounsaturated fatty acids (MUFA) (Doran et al., 2006). It is well known that IMF content varies between breeds. However it remains unclear as to whether pigs with predominantly high IMF (e.g. Duroc) will respond to a low protein diet in the same way as those with predominantly low IMF (e.g. Large White). The objective of the present study was to investigate whether the effects of low protein: energy diets on IMF, MUFA and total fatty acid content are breed-specific.

Phosphorus is the second most plentiful mineral in the animal body. It is present as structural component and it is involved in a wide variety of biochemical reactions. Research has been conducted in Brazil to study phosphorus metabolism in pigs using the model of Fernandez modified by Lopes et al. (2001). However there is little published information related to phosphorus metabolism in pigs using the model of Vitti et al. (2000). In the present study, it was considered the hypothesis that P intake regulates P utilisation and flow on gut, blood, soft tissues and bone. The isotopic technique by using labelled P allows the formulation of model of the biological flow of phosphorus in the animal organism. The aim of this study is to evaluate the effects of phosphorus intake on phosphorus metabolism in pigs, by using isotope and balance techniques. A mathematical model for phosphorus metabolism is formulated.

Non-ruminant animals do not synthesize phytase enzyme, a substance capable to act on phytate molecule to liberate phosphorus. The non-available phosphorus pass through the digestive system of the non-ruminants practically without being digested and the inclusion of inorganic phosphorus sources in diets of those animals is necessary. The use of phytase enzyme in rations for pigs can contribute to the elimination or reduction of the use of inorganic phosphorus sources and reducing the environmental impact caused by the excretion of this mineral. The experiment was designed to evaluate the biological phosphorus flow in pigs fed with diet containing different phytase levels, using the isotope dilution technique.

The metabolism and kinetics model of Fernandez modified by Lopes et al. (2001) is a fundamental tool for the study of the digestive physiology of phosphorus (P) in pigs. In Brazil there is a great potential of use of rock phosphate and those represents approximately 2.9 billion metric tons. Brazilian researchers are interested to evaluate those phosphate as alternative sources in diets of pigs. All of the natural sources of phosphate in Brazil presented low level of fluor, when compared with international sources and levels of heavy metals are considered low too. The main concern resides in the fact that non-absorbed P is excreted and can cause contamination of water. The purpose of this research was to evaluate the digestive physiology of pigs fed diets supplemented with different P sources and the study the environmental pollution provoked by P excreted.

The palm grows well in wet, humid parts of tropical Asia (mainly South-east Asia), Africa, and Central and South America Palm oil is a greatest oils the entire world. The palm oil has a greatest saturated fatty acid. The main aim of this study was to determine the best level of palm olein oil on production performance (gain body weight, egg production, egg weight, egg mass, FCR and feed intake), egg quality (Haugh unit, yolk index, yolk colour index, shell thickness and specific gravity), egg cholesterol and blood factors of laying hens of Leghorn W36.

The egg shell quality is related with bird age and is an important factor to poultry industry due to reproduction and economic implications (Peebs and Brake, 1987). Probiotics are biostimulators and immunomodulators containing live or lyophilizing bacterial cultures, which regulate and optimize the rations among the different types of microorganisms in the digestive system, preventing upsets and experting a stimulating effect on the disintegration and absorption of the nutrient substances (Nickolova and Penkov., 2004). Its stimulating effect on nutrients absorption possibility can improves the mineral availability such calcium and also egg shell quality. In some cases positive effects of probiotic (on damaged egg ratio; Balevi., 2001) or lactobacillus (on haugh units; Nahashon et al.,1994b) supplementations have indicated in layer hens. So possibility they could have positive effects on egg quality. Therefore this research was undertaken to asses the effects of probiotic (protexin) on egg quality (thickness, egg shell percentage, strength egg shell, egg shell weight and haugh unit) of old broiler breeder hens.

In the last ten years, interest in early nutrition research has increased due to the high correlation between 7-dold weight and final weight. Sodium (Na), chlorine (Cl) and potassium (K), are essential elements in chickens in order to maintain the osmotic pressure and acid-base balance within normal values, protein synthesis in tissues, maintain extra and intracellular homeostasis and the electric potential of the cell membrane. Electrolyte balance is defined as (Na+K-Cl mEq/Kg). Many studies have indicated that sodium supplementation in the first week of life stimulated feed intake and modified weight gain and feed conversion ratio. The purpose of this trial was to evaluate the effects of different levels of sodium and electrolyte balance in pre-starter diets in three periods of 4, 7 and 10 days on performance and serum electrolytes levels in broiler chickens.