Effect of dietary available phosphorus and phytase on production performance of old laying hens and tibia bone quality

Old laying hens are more prone to dietary calcium [Ca] and phosphorus [P] deficiencies as they absorb Ca and P less efficiently than younger hens. In a 2><2 factorial design, the influence of diets with two levels of available phosphorus [AP] and phytase enzyme on the laying performance, egg quality and tibia bone characteristics of laying hens at their late 2[nd] production phase was studied. The experiment used four treatments of 20 Hy-Line W36 hens of 140 weeks old. Treatments 1 and 2 received a 3.5 g kg[-1] AP diet while Treatments 3 and 4 received a 2.5 g kg[-1] AP diet for 12 weeks. Treatments 2 and 4 received 250 FTU kg[-1] phytase in their diet. Laying performance, egg weight, shell weight and shell thickness were measured. On the last day of the experiment, all birds were weighed and blood samples were collected for serum Ca and P measurements. Ten birds from each treatment were sacrificed and both tibiae were excised, defatted, weighed and ashed for Ca and P contents, cortical thickness and bone breaking strength measurements. Hens fed with 2.5 g kg[-1] AP diet without enzyme had the lowest body weight gain, serum P, tibia cortical thickness and tibia breaking strength among the treatments [p<0.05]. Phytase enhanced body weight gain, egg shell thickness, serum P, tibia weight/ body weight and tibia ash/body weight ratios, tibia cortical thickness and breaking strength, particularly in birds receiving 2.5 g kg[-1] AP diet [p<0.05]. Phytase may improve bone quality and strength of hens in the late 2[nd] laying period

Evaluating the resistance of eimeria Spp. field isolates to anticoccidial drugs using three different indices

In this study, the presence of resistance to diclazuril, amprolium+ethopabate and salinomycin, representing some of the commonest anticoccidials in Iran's poultry industry, against three mixed Eimeria field isolates were investigated. Three Eimeria field isolates, collected from typical broiler farms in Iran, were propagated once, inoculated to 480 broilers, comprising 30 chicks in each treatment. The non-medicated or medicated diets containing one of the above mentioned anticoccidials were provided ad-lib. Drug efficacy was determined using the Global index [GI], Anticoccidial Sensitivity Test [AST] and Optimum Anticoccidial Activity [OAA]. None of the field isolates were fully sensitive to the selected anticoccidials. All isolates showed reduced sensitivity/partial resistance to salinomycin. Resistance to amprolium+ethopabate was evident and partial to complete resistance was recorded for diclazuril. Limited efficacy of the selected anticoccidials is obvious. Considering the cost of continuous use of anticoccidials in the field, altering the prevention strategy and rotation of the anticoccidials with better efficacy, would prevent further economic losses induced by coccidiosis.

Influence of phytase on tibia bone characteristics of broiler quail fed on corn-soybean meal diets

Exogenous phytase enhances the utilization of plant phytate phosphorus in poultry. In the present study the effects of exogenous phytase was investigated on tibia bone characteristics of white quail. In a 2x2 factorial arrangement, eighty, 11-day old unsexed chicks were randomly divided into 4 treatments of 20 replicates. All birds received one of four experimental diets with two levels of aP [5.2 or 3.9 g kg-1] and two levels of phytase [0 or 500 FTU kg-1]. On day 25, all birds were weighed, sacrificed, and blood samples were obtained for the determination of blood phosphorus. Both tibiae were excised for the determination of ash, calcium and phosphorus content, bone length and thickness, and breaking strength. Birds which had received lower aP diets showed lower levels of blood phosphorus as well as tibia bone weight, ash, calcium, phosphorus, bone thickness and strength when compared with the higher aP fed birds. Adding phytase to the lower aPdiet was able to restore the above-mentioned variables. Phytase increases rigidity and strength of tibia by enhancing the availability of phytate phosphorus to the quail. This is important, particularly when the bird is grown for flight and hunting

Biopathologic characterization of three mixed poultry eimeria spp. isolates

Coccidiosis of domestic fowl, caused by species of the Genus Eimeria, is responsible for important economic losses in poultry production. Because different species and/or strains can vary in pathogenicity and other biological parameters, their precise characterization is important for epizootiological studies. Fifty samples from litter, whole intestinal tract and feces were collected from poultry houses located in different provinces of Iran. One hundred twenty male day-old broiler chicks were challenged with three selected isolates. Data on weight gain, Food Conversion Ratio [FCR], food intake, lesion scoring and shedding of oocysts per gram of feces were recorded and analyzed by the Duncan's test. In all treatments, the challenged groups had statistically significant lower weight gain than that of unchallenged control group. Isolate three caused the lowest weight gain and food intake and the worst lesion score as well as FCR. Despite originating from close geographical regions for isolates 1 and 2, the difference in biopathologic factors may be either due to different proportion of identified species or the different pathogenicity of the species present in the isolates. The results highlight the importance of considering various species of Eimeria in designing the preventive, control and treatment strategies to prevent coccidiosis in different regions of Iran. Further characterization of each isolate would be the next step to provide a basis for coccidiosis research with well-characterized local isolates

Comparison of the effects of propolis and virginia mycine on performance and immune response of broiler chicks

Three hundred and sixty male day- old Ross 308 broiler chicks were randomly assigned to four dietary treatments in order to evaluate the effect of propolis as growth promoter on the performance and the immune response of the broiler chicks to the ND vaccine. Each treatment contained three replicates of 30 chicks. Dietary treatments were as follow: Acorn - soy meal diet [control diet].Control diet + 3000 ppm [starter] and 2000 ppm [grower and finisher] propolis.Control diet + 6000 ppm [starter] and 4000 ppm [grower and finisher] propolis. Control diet + 100 ppm virginiamycine.The chick performance was evaluated by recording the body weight gain, feed intake, feed conservation ratio, and productive efficiency index at 21 and 42 days of age. Prior to the administration of ND vaccine [day 17] and 10 days post-vaccination, the blood sample was taken for HI test. The chicks fed diet supplemented with virginiamycin showed higher BWG, FI, PEI when compared with other treatments. However, those chick provided with dietary treatment 2 [3000 and 2000 ppm] had lower FCR. Propolis had no effect on antibody titer against ND vaccine. In this experiment propolis don't act as an immunostimulant, but appeared to be promising a potential growth promoter

Influence of dried tomato pomace as an alternative to wheat bran in maize or wheat based diets, on the performance of laying hens and traits of produced eggs

In a 2 x 3 x 2 factorial arrangement, 144, fifty-four-week-old laying hens, in 12 treatments with 12 replicates for each treatment, received one of 12 diets based on maize or wheat containing three levels of dried tomato pomace [DTP: 0, 50 and 100 g/kg] as a substitute for wheat bran, and two levels of pigment [0 and 900 mg/kg], for 9 weeks. Weight gain [WG], egg production [EP], egg weight [EW], egg mass output [EM] and feed intake [FI] were determined. Shell weight [ShW], shell thickness [ShT], Haugh unit [HU] and yolk colour score [YCS] were also measured. Maize decreased body weight of the birds and increased HU, ShW/EW ratio, ShT, and YCS of the eggs when compared with wheat diets. DTP had no effect on these parameters, but increased YCS. Pigment reduced ShW/EW ratio and ShT, but increased YCS of the eggs. There were significant interactions between the source of energy [ES] and DTP on ShT and YCS of the eggs. There were also interactions significant between ES and pigment on ShT and YCS. As an alternative for wheat bran, 100 g/kg of DTP produced comparable egg quality and laying performance, and it contributed to a deeper yolk colour

Influence of calcium and non-phytate phosphorus deficient diets with phytase on the performance of broilers, serum concentrations of minerals and the activity of alanin transaminase, aspartate transaminase and lactate dehydrogenase

An experiment was conducted to study the effect of microbial phytase [phyzyme XP5000G] supplementation in broiler chicks' diets on the performance, serum total protein [TP], minerals [Ca, Mg and P] and the serum enzyme activities [AST, ALT, LDH]. A reference -1 -1 diet adequate in calcium and non-phytate phosphorus [10.0 gkg Ca and 5 gkg nPP] and two -1 -1 -1 -1 deficient diets in Ca and nPP [8.5 gkg Ca and 3.5 gkg nPP, and 7.5 gkg Ca and 2.5 gkg nPP] -1 with or without phytase [0 and 100mgkg] were offered to broiler chicks from 1 to 21 days of age. Although the low-nPP diets had no significant effect on body weight gain [BWG] of chicks [p > 0.05] They increased [p < 0.01] feed intake [FI] and feed conversion ratio [FCR] when compared to the low-nPP diet supplemented with enzyme. Phytase had a favorable effect, although non-significantly, on BWG of chicks fed very low level of nPP. Enzyme reduced the feed intake [p < 0.05] and improved the FCR of Ca-nPP deficient chicks [p < 0.01]. The decrease in Ca-nPP content in the diet caused a significant increase in serum concentration of Ca [p < 0.05] and decrease in P concentration [p < 0.05]. Low Ca-nPP diets had no influence on serum Mg concentration. Dietary phytase reduced the Ca level and increased the P level [p < 0.05] of serum in chicks fed with Ca-nPP deficient diets. The activity of LDH increased [p < 0.01] in response to low dietary Ca and nPP, deficient but there was no influence on serum ALT and AST activity and TP content [p > 0.05]. Phytase supplementation reduced serum ALT [p < 0.05] and had no effect on AST [p > 0.05]. Serum LDH activity further increased [p < 0.01] by phytase supplementation. These results demonstrated that the performance of the chicks received low