494
A. Soliman and A. M. Safwat
it was noted that increasing dietary lysine concentration is necessary to compensate
partly for the reduced feed intake [15] and improve feed efficiency. There is a positive
effect to increase the Arginine: Lysine ratio on feed conversion ratio and growth
performance at high temperatures.
The imbalanced amino acids in the diet results in higher excretion of nitrogenous substances in faeces, which produces and accumulates ammonia in the house
atmosphere causing harmful effects on the performance and welfare of birds. The
accumulation of ammonia may increase the ambient temperature in poultry houses;
therefore it makes difficult for birds to regulate their body temperature.
5.3 Vitamins
Supplementing vitamins to poultry diets is highly recommended during the hot
weather, such as Vitamin A, E, C, etc., which play an important role in improving the performance and immunity of birds and significantly reduce mortality rates,
especially when birds exposed to heat stress. It is suggested to increase the levels of
vitamins during hot weather by 10–15% than the normal requirement because of the
low feed intake and potential damage due to feed storage or exposure to oxidation
factors, such as high temperature and/or humidity and trace elements presented in the
diet, unsaturated fatty acids and oxidation of peroxides, which affects the stability
of these vitamins.
5.3.1 Vitamin A
The supplementation of vitamin A in the diet reduces the detrimental effect of heat
stress on egg production and has a positive effect on the immunity of laying hens.
Higher dietary vitamin A intake is required by birds suffering from heat stress after
Newcastle vaccination; in order to produce the maximal level of antibody [16]. Also,
supplementing vitamin A to broiler diets improves body weight gain, feed efficiency
and carcass traits.
5.3.2 Vitamin C
Ascorbic acid has an important role as an antioxidant in the biological system and
under the heat stress conditions, it is important in maintaining the oxidation and
reduction processes in birds body. Supplementing ascorbic acid to the diets improves
egg production and egg shell quality of broiler breeders; additionally it has beneficial
effects on the fertility and hatchability of broiler chicks as well as molting process
of laying hens.
Furthermore broiler chicks tend to consume more amount of the diet supplemented
with ascorbic acid in the hot weather. Ascorbic acid supplementation improves
A. Soliman and A. M. Safwat
it was noted that increasing dietary lysine concentration is necessary to compensate
partly for the reduced feed intake [15] and improve feed efficiency. There is a positive
effect to increase the Arginine: Lysine ratio on feed conversion ratio and growth
performance at high temperatures.
The imbalanced amino acids in the diet results in higher excretion of nitrogenous substances in faeces, which produces and accumulates ammonia in the house
atmosphere causing harmful effects on the performance and welfare of birds. The
accumulation of ammonia may increase the ambient temperature in poultry houses;
therefore it makes difficult for birds to regulate their body temperature.
5.3 Vitamins
Supplementing vitamins to poultry diets is highly recommended during the hot
weather, such as Vitamin A, E, C, etc., which play an important role in improving the performance and immunity of birds and significantly reduce mortality rates,
especially when birds exposed to heat stress. It is suggested to increase the levels of
vitamins during hot weather by 10–15% than the normal requirement because of the
low feed intake and potential damage due to feed storage or exposure to oxidation
factors, such as high temperature and/or humidity and trace elements presented in the
diet, unsaturated fatty acids and oxidation of peroxides, which affects the stability
of these vitamins.
5.3.1 Vitamin A
The supplementation of vitamin A in the diet reduces the detrimental effect of heat
stress on egg production and has a positive effect on the immunity of laying hens.
Higher dietary vitamin A intake is required by birds suffering from heat stress after
Newcastle vaccination; in order to produce the maximal level of antibody [16]. Also,
supplementing vitamin A to broiler diets improves body weight gain, feed efficiency
and carcass traits.
5.3.2 Vitamin C
Ascorbic acid has an important role as an antioxidant in the biological system and
under the heat stress conditions, it is important in maintaining the oxidation and
reduction processes in birds body. Supplementing ascorbic acid to the diets improves
egg production and egg shell quality of broiler breeders; additionally it has beneficial
effects on the fertility and hatchability of broiler chicks as well as molting process
of laying hens.
Furthermore broiler chicks tend to consume more amount of the diet supplemented
with ascorbic acid in the hot weather. Ascorbic acid supplementation improves