Potency of copper as growth promoter in broiler chickens

An experiment was conducted to study the efficacy of certain copper sources and levels as growth promoter in broiler chickens. 175 days old Cobb broiler chicks were divided into seven equal groups. The experiment lasted six weeks, during which body weight development [BWD] and feed consumption of chicks were recorded weekly, then body gain [BG] and feed conversion efficiency were calculated. At the end of the experiment, liver copper concentration was determined as well as the cecal appearance and intestinal histological morphology were measured. Both levels of CuCO3 supplementation achieved significant increase in BWD and improved feed conversion. Low level of CuSO4 had no influence on BWD which was markedly improved with the high level. CuO failed to improve BWD significantly. Liver Cu concentration was significantly increased by CuSO4 supplementation which was insignificant in CuCO3, while the oxide form had no effect. Liver weight was not affected by any of the dietary treatments, meanwhile, cecum weight was increased markedly in all treated groups. Cecal appearance was affected markedly by CuSO4 supplementation and it was mildly affected in case of CuCO3, but oxide form did not exert such effect. Intestinal histological morphology indicated that copper has antimicrobial action within the gut

Effect of chemical treatment of poultry diets on the control of salmonella enteritidis in broilers

To evaluate the effect of acid treatment of broilers' diet to control S. enteritidis, propionic acid [PA], buffered propionic [BAP], lactic [LA] and formic [FA] acids were used at levels of 0.6% and 0.8% in experiment I. The inclusion of PA and FA at level of 0.6% in sterilized starter diet was capable to reduce S. enteritidis contamination from 1 X 10 3 to < 10 CFU/g feed at 2 h post- inoculation. BAP and LA seemed to be less effective in controlling S. enteritidis contamination in broilers diet. Experiment II planned to study the effect of feeding PA at two levels [0.6 and 0.8%] in broilers diet to control S. enteritidis infection in broiler chickens. The PA fed at level of 0.8% had given encouraging results as it was able to eliminate mortalities and to cease shedding of S. enteritidis at 3-day post-inoculation. However, S. enteritidis was recovered from the intestine and the cecum of the slaughtered chickens at the end of 6 weeks experimental period at rates of 3.3 and 6.7%, respectively. Continuous feeding of PA at 0.8% level had no adverse effect, but lowered abdominal fat%, and significantly improved dressing%. The foregoing results suggest that use of PA at level of 0.8% may be able to control broilers carcasses contamination with S. enteritidis by eliminating the main source of salmonella contamination which is feed

Impact of different dietary fat sources on performance and immune response of broiler chickens

Four groups of broiler chicks [n=40] were fed on concentrate soybean- corn-basal diet to which either beef tallow or linseed oil or mixture blend of linseed oil and beef tallow was included at level of 3 and 4% [starter and finisher, respectively]. The mixture blend of tallow and linseed oil achieved better performance and significantly higher body weight than when each fat source was fed solely. Regarding immune parameters, the linseed oil feeding had significantly improved several immuno-indices [hemagglutinin antibody titers against SRBC and delayed hypersensitivity reaction to phytohemagglutinin-P] in broiler chickens over the control and the other fat sources-fed groups. No significant changes were observed due to the inclusion of different fat sources in the relative weights of spleen and thymus, however, the relative weight of the bursa was significantly increased at age of 3 and 7 weeks in the linseed oil fed group. It is concluded that whereas linseed oil feeding improved several indices of immuno-status in broiler chickens which might be useful to fight infections, it was not able to compete with the tallow-linseed oil mixture in respect to performance. Further studied are needed to evaluate such effects and to underst and the mechanism underlying the modulation of the immune system by linseed oil feeding

Yeast as fered additive in tilapia fingerlings diets

An experiment was conducted to evaluate the possibility of usage of dried baker's yeast [DBY] as feed additive in tilapia fingerling diets. Four experimental diets were formulated to be isonitrogenous and isocaloric. Diet 1 served as a control one, while diets 2, 3 and 4 contained 1, 2 and 3% DBY, respectively. Diets were fed for an 8-week experimental period. Fish fed on diets contained 3% DBY showed very high mortality even with fish replacement. Fish fed on the control diet showed the best performance parameters [final body weight, weight gain, increase in total body length, FCR and PER]. Fish fed on diets contained 1% DBY showed a closely related performance as control group, while 2% DBY showed a negative effect. Apparent digestibility coefficient [ADC] was determined for all experimental diets using chromic oxide as indicator. The results revealed that DBY at level of 1 or 2% did not significantly affect the ADC of DM, GE, EE and CP of the diets

Practical approach to fat inclusion in broilers diets

This work was planned to throw a light on a practical approach currently used by poultry growers in Egypt to include different sources of fat in broilers diets to promote more gain and better finished carcass. One hundred and fifty day old commercial broiler chicks were equally allocated into six groups and fed on basal diet to which either animal fat [beef tallow] or vegetable oil [cottonseed oil + sunflower oil] was added at the level of 1 or 2% for 6 weeks experimental period. It is concluded that the inclusion of fat [animal and vegetable] at the level of 1 or 2% to broiler diets could improve broiler performance under high environmental temperature. In regard to fat source, CSO as a vegetable oil seemed to achieve better performance than did beef tallow, meanwhile, the higher level of CSO achieved better performance than its lower level. However, the usage of 2% CSO in growing period was not able to overcome the adverse effect of heat stress commonly occuring during our summer season. Concerning blood parameters, no significant difference could be detected for SGOT, SGPT and total serum protein which indicated that there are no detrmintal influence for such treatments. Serum cholesterol level was increased due to fat supplementation but beef tallow addition induced the highest values

Role of dietary zinc on immune response of broiler chickens

Tow hundred and twenty one-day old Hubbard broiler chicks were used to study the possible role of dietary zinc on chicks performance in relation to Newcastle disease vaccine challenge and relative weights of some immune lymphoid organs. Feeding different levels of supplemental zinc 50 and 150 mg/kg as zinc oxide had significantly improved 8-weeks body weight, feed efficiency, HI titres against ND virus as well as protection percentage and relative weights of spleen and bursa of Fabricius. On the other hand, increasing the level of calcium in the corn soybean meal diet without any zinc supplement was associated with zinc deficiency symptoms as well as lowered body weight, HI titres and protection percentage against ND virus. The present study supports that corn soybean meal diet cannot cover the zinc requirements for broiler, an interesting notice, which needs further investigation that zinc supplement to such diet play an important role as an immuno-stimulant