الفهرس Only 14 pages are availabe for public view
 |  | from | 163 |  |  |
| | | from | 163 | | |
Abstract
High ambient temperature is a problem in many parts of the world. Conditions of heat stress caused an increasing concern in poultry industry in hot-climate countries due to reduce the performance of poultry during summer months (Bonnet et al., 1997). Heat stress during summer season has a highly detrimental effect on broiler, which affects all physiological processes and productive performance such as feed intake and weight gain (Sahin and Kucuk, 2003). On the other hand, Egypt consider one of those countries which hot climate in summer season. Tollba et al. (2004a) and Abd-Elsamee (2005) indicated that as environmental temperature exceed to 35° C, the mortality % increased and the broiler performance decreased. High ambient temperature considered to have detrimental effects on metabolism and performance of poultry (Sahin et al., 2005).
Using feed restriction in feeding broiler depend on compensatory growth, which defined as the rate of the growth exceeding that normally observed in the breed of chicken at the same age (Yu et al., 1990). Most of broilers chicks fed ad libitum and the problems associated with fast growth are particularly evident under this feeding system (Jones and Farrell, 1992; and Yu and Robinson, 1992). Abdel-Fattah et al. (2003) indicated that feeding restriction regimens during the early growing period (1-4 weeks) is the most beneficial regimen for growth performance and immunity. Since the feeding restriction programs decrease the level of feed intake, therefore it would be plausible to use feed additives to alivate the heat stress.
Herbs and the logically active substances content stimulate body metabolism, improve digestion, have bactericidal, immunostimulant action and improved productivity of poultry (Sabra and Metha, 1990). QingJun et al. (1997) observed that, adding extracts of Eleutherococcus (herbs extract) confer beneficial anti-heat stress effects on breeding layers. In this respect, studies of Nakatani (2000) on spices and herbage observed that, over a hundred compounds, known and new, having high antioxidant activity. HyungKeun et al. (2002) reported the anti-microbial effect of Liquorice. Also, the anti-oxidant effect of Liquorice was investigated by Oganesyan (2002). In addition, Nagub (2003) observed that, Thyme (Thymus vulgaris) was used in folk medicine as stomachic, carminative, vermifuge and antiseptic. Furthermore, it had anti-microbial properties. Ninfali et al. (2005) recorded that, Ginger (Zingiber officinale) is the most significant contribution to the antioxidant capacity. Ginger’s effectiveness as a digestive aid is due largely to its active ingredients: gingerols and shogaols. These substances help to neutralize stomach acids, enhance the secretion of digestive juices (stimulating the appetite), limit flatulence which is supportive to the spleen, stomach and kidneys moreover it is carminative and a good laxative (Perez, 2005). Maheshwari et al. (2006) summarizes the multiple biological effects of Turmeric such as, anti-inflammatory, anti-microbial, anti-angiongenic, anti-oxidant, wound healing and anti-cancer effect.