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

[Analysis of humoral immunity in broilers challenged with Eimeria prior to and following anticoccidial vaccination, by means of ELISA]

Background: Despite the use of prophylactic chemotherapy and vaccination, coccidiosis is still one of the most devastating diseases in poultry industry. Understanding the immune mechanism helps researchers to prevent this parasitic infection more effectively

Objectives: The purpose of this study was to evaluate the antibody response in chickens, induced by a live attenuated vaccine [Livacox Q], before and after challenge, by means of ELISA

Methods: One hundred and twenty one-day-old male Ross 308 broiler chicks were randomly divided into 4 groups of 30 birds. In 4th day of age, half the birds were orally vaccinated. The challenged groups received the infective dose at 14th day of age via oral administration. Besides recording weight gain, lesion score and oocyst count in 21[st] day old birds, humoral immunity was assessed by means of ELISA on serum samples taken from 7 and 21day-old birds

Results: Three days post vaccination, the average of optical density [OD] showed significant difference between vaccinated [0.553] and unvaccinated [0.686] birds [p

Conclusions:The results indicated that ELISA can be used for evaluating immunity uniformity of a flock after vaccination. Besides inducing antibody responses comparable to challenge with wild oocysts, vaccination with live attenuated coccidiosis vaccines may have inhibitory effects in intestinal lesion scores which are responsible for pathogenesis and economic loss during coccidial infections

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

[Differences in intestinal absorptive capacity of chickens for d-xylose]

BACKGROUND:According to literature, there are differences among different species of animals in respect to absorption of Dxylose

OBJECTIVES: In two experiments, the differences that might exist in absorptive capacity of small intestine for D-xylose, in different types of chicken were tested

METHODS:In experiment one, 2 groups of nine adult layer type males [48 weeks] and females [58 weeks], and in experiment two, 4 groups of ten young [4 week] broiler type or layer type male or female chickens were dosed Dxylose solution [50 mg/mL, 500 mg/kg BW], orally

One blood sample before, and 5 others immediately after the administration of D-xylose solution, were taken from wing vein of the birds at 30 minute intervals for 150 minutes, and the concentration of D-xylose in plasma was measured

RESULTS: In experiment one, D-xylose concentration reached its peak at 60 to 90 min in both adult males and females, and followed a quadratic trend with time [r2 for adult males = 0.735 and adult females = 0.801]. In experiment two, Dxylose concentration reached its peak at 60 min for all experimental groups and followed a quadratic trend with time [r2 for broiler type male = 0.681, broiler type female = 0.850, layer type male = 0.695 and layer type female = 0.748]

CONCLUSIONS:D-xylose test was shown to be a sensitive tool for the evaluation of intestinal absorption capacity of chicken

This test revealed that there were some differences in absorption function of intestine among the birds with different breeds, sexes, ages, and nutritional demands

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

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 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

[Comparative studies of the electrocardiographic parameters, mean electrical axes [MEA] and cardiac index[RV/TV]in two groups of normal and experimentally ascitic broilers [using cold stress as a model]]

To evaluate the electrocardigraphic changes in the experimentally induced ascitis in broiler chickens using cold stress as a model. Experimental study.A total of 300 day-old male Ross 308 broiler chickes.Chickenswere randomly divided into two equal groups, [control and test], chicks were reared for six weeks. Gradually Temperature was gradually decreased in the test group to 30% of the standard program from 2 nd week of the rearing period. At the end of each week, 5 chicks from each group were selected and electrocardiographic recordings were performed. Also after autopsy right ventricle / total ventricular weight was measured and recorded. t- student Test and Bivariate correlation. There were significant elevation of the S wave amplitudes in 4th week [leads II, III, aVR]and 6th week [lead III] .S wave had a significant correlation with RV/TV in 4th week[lead II] and 5th week [leadsII, aVF] in the test group, too. There were also significant increase in the T wave amplitudes in 4[th] and 5[th] weeks [leadsII, aVF]and 6[th] week[leads aVF, aVR] in the test group.In this study, R waves did not show a significant variation with the exception of 4[th] week[lead II]. There were an elevation of MEA in test groups [with a right-cranial direction] but it just was significant in 4th week compared with control group. Electrocardiograms can be used effectively to evaluate the development of ascites syndrome in broiler chickens. The increase in the amplitude of S and T waves could be considered as the sign of ventricular hypertrophy in ascites syndrome resulted from cold condition

[Effect of betaine on the efficacy of salinomycin in broiler chicks in experimental coccidiosis]

To study the interactive effect of betaine [BET]and salinomycin [SAL] in coccidian-infected broiler chicks.Randomized complete block with 2*2 factorialarrangement.Four hundred and eighty male Ross 308 broilerchicks.The chicks were randomly assigned to fourdietary treatments including: 1] basal diet, 2] basal dietplus .15% BET, 3] basal diet plus 66ppm SAL, and 4] basaldiet plus .15% BET plus 66ppm SAL. Each treatmentcontained 4 replicates of 30 chicks and fed ad-libitum. Allof the chicks were inoculated with a suspension of themixed culture of Eimeria oocysts on 15 days of age. Fecessamples were taken to determine the number of oocysts pergram of feces [OPG]. Plasma carotenoid concentrations[PCC] were evaluated on 14 and 28 days of age. Bodyweight gain [BWG], feed intake [FI], feed conversion ratio[FCR], and Europeanefficiencyfactor [EEF] weredetermined to evaluate broiler's performance.General linear model [GLM] andDuncan's multiple range test.Supplementation of diets with 66 ppmSALsignificantly on improved the performance, increased thePCC [P<0.05], and decreased the OPG. Adding 0.15% BETalone did not affect production performance, PCC andOPG significantly [P> 0.05]. Diet containing 66 ppm SALsupplemented with 0.15% BET significantly increased theBWG, EEF, and PCC while it decreased the FCR and OPG[P< 0.05].The results of this experimental studyindicated that BET at the level of 0.15% could increase theefficacy of SAL for preventing deleterious effects ofcoccidiosis in broiler chicks

[Effect of administration of anti-coccidial drugs and vaccines on broiler chicks performance in experimental coccidiosis]

To compare the effect of coccidiostate drugs and coccidial vaccines on the perfrormance of coccidia - infected broiler chicks. Completely randomized design.Nine hundred and sixty day-old Ross 208 broiler chicks. Chicks were randomly assigned to eight treatments. Each treatment contained 3 replicates of 40 chicks. Treatment 1 and 2 [as negeative and positive control] did not receive any coccidiostates or coccidial vaccines. Treatments 3 and 4 fed diets supplemented with Salinomycine and Diclazoril respectively, but did not immunize. Treeatments 5 to 8 immunized with coccidial vaccines [including Livacox Q, Paracox 5, Livacox T, and Iracoc, respectively] by drinking water on 5 days of age. Chicks in treatments 2 to 8 were inoculated with a suspension containing four Eimeria species on 26 days of age. Surveillances for coccidian oocysts of feces samples were carried out from 7 to 13 days of post-challanged. Body weight [BW], body weight gain [BWG], and feed conversion ratio [FCR] were determined weekly. Data for all response variables were subjected to ANOVA. Variable means for treatments showing significant differences in the ANOVA, were compared using the scheffe's test. The results indicated that using coccidial vaccines and coccidiostate drugs decreased oocysts per gram [OPG] of feces significantly [P<0.05]. The highest mean of BW was related to the chicks treated with salinomycine with significant differences in BW among treatments. The lowest FCR was related to non-challanged chicks [negative control].According to the results of this experimental trial, it could be concluded that coccidial vaccines and coccidiostate drugs could decrease the OPG significantly and improve production performance partially, in coccidia-infected broiler chicks