In last decade, the uncontrolled use of antibiotics as growth promoter for livestock has led to the appearance of antibiotic-resistant pathogens and increased risk of infectious diseases. This situation has triggered intensive research efforts to find safe alternative strategies. Certainly, the plants and vegetables and their derivatives as natural safe substances could be good candidates in this respect. There is huge information on the immunostimulatory properties of herbal plans in human, and may contribute considerably to the improvement of the health and immune response and prevention of certain diseases in animals including poultry. Garlic (Allium sativum) is an herbal plant that has traditionally been used for the healing a number of human diseases and has in recent years been revealed to have immunostimulatory, anticardiovascular disease, antitumour, antioxidant and antimicrobial properties. The scientific evidences suggest that allicin and other active components of garlic have also some positive effects for livestock, including hypocholesterolemic, growth promoting, antimicrobial and antioxidant effects. تفاصيل المقالة

An experiment was conducted on broiler chickens to study the effects of conjugated linoleic acid (CLA), fish oil, both at 7% of the diet, or their mixtures at 3.5% of the diet, on the performance, carcass traits and intestinal morphology of broiler chickens. The chicks fed with 7% fish oil or 7% CLA diets, were found to have an inferior weight gain in grower and finisher phases, respectively. A significant reduction in feed intake was observed with the diets containing 7% fish oil. However, adding CLA to the diets, did not affect birds feed intake. The dietary fish oil and CLA supplementation adversely affected the feed conversion ratio as well as carcass yield. CLA at the 7% level increased liver weight. There were no differences in the carcass, thigh or abdominal fat pad percentages between the experimental treatments; however the birds fed the diet containing 7% fish oil had the lowest breast and the highest liver percentages. Histological examination of small intestine revealed that, the diet containing 3.5% fish oil + 3.5% CLA resulted in higher villus height than the diets with 7% fish oil or CLA. Such an increase was observed in the crypt depth of the duodenum and jejunum, but no difference was detected in the crypt depth of the ileum. The small intestinal wall thickness and goblet cell numbers in the chickens fed the diet containing the mixture of fish oil and CLA were lower than those of the other treatments. The results of this study showed that a high dose of fish oil or CLA can reduce broiler chickens performance, but their combination can moderate this adverse effect. تفاصيل المقالة

The aim of the current study was to evaluate the replacement effect of soybean meal (SBM) at different levels (0 as D1, 33 as D2, 67 as D3 and 100% as D4 based on crude protein (CP) content) by guar meal (GM) on ruminal gas production kinetics, ruminal digestibility and fermentation characteristics of a fattening diet for lambs. Three experiments were conducted. The first experiment of 144-h incubations was aimed to determine comparatively the gas production kinetics of SBM and GM. The gas production kinetics and the ruminal digestibility and fermentation of the fattening diet, containing different proportions of SBM and GM, were also studied by the incubations of 144-h and 24-h in the second and last experiments, respectively. The results of the first kinetic experiment indicated a higher asymptote of gas production (a), half time to asymptote of gas production (T1/2) and metabolizable energy (ME) and a lower fractional rate of gas production (µ) for SBM than GM (P <0.001). Replacing SBM with GM had no effect on gas production kinetics of the fattening diet at any substitution levels in the second kinetic experiment (P>0.05). However, the gas produced after 24-h of incubation (GP24), in vitro true dry mater degradability (IVTDMD), in vitro true organic matter degradability (IVTOMD), partitioning factor (PF), microbial biomass production (MBP) and total volatile fatty acids (TVFA) concentration increased with D2 compared to D1 and D3 in the last experiment. The ammonia concentration decreased with D2 and D3 compared to D4 (P<0.05), nevertheless, the ruminal volatile fatty acids (VFA) pattern was not affected by the treatments (P>0.05). These results demonstrated that the protein from SBM might been replaced by that from GM in fattening diets for lambs at the levels up to 67%, but the 33% substitution is recommended because of its beneficial effects on ruminal digestibility and fermentation. تفاصيل المقالة