Kamil Küçükyılmaz

Effects of dietary mannan oligosaccharide and herbal essential oil blend supplementation on performance and oxidative stability of eggs and liver in laying hens

The role of dietary supplemental mannan oligosaccharide (MOS) and an essential oil blend (EOB) on performance of laying hens, and susceptibility of egg yolk and hen liver to lipid oxidation were examined. Four hundred and thirty-two 52-week old Lohmann laying hens were divided into three groups and fed a basal diet containing no antioxidant as control (CNT), basal diet plus 1 g/kg MOS and basal diet with 24 mg/kg EOB, for a 10-week experimental period. Supplementation of diet with MOS and EOB improved egg production rate and eggshell weight, but did not influence other performance or egg quality traits. MOS and EOB provided higher antioxidant activity in egg yolk than the control regimen at all storage time periods. EOB also retained the oxidative stability of liver by measuring malondialdehyde (MDA) levels. Liver antioxidant enzymes, including superoxide dismutase (SOD) and glutathion peroxidase (GSH-Px), were higher in birds fed the additives. MOS and EOB tended to increase serum glucose concentration (6.2% and 8.8%, respectively) while they slightly decreased triglycerides (11.0% and 4.8%, respectively) without affecting cholesterol level. Relative weight of pancreas and spleen were not affected by dietary treatments whereas diet supplemented with EOB significantly increased liver weight. The findings of this study suggest that EOB and MOS could act as free radical scavengers that enhance performance and also increase eggshell weight.

Long-term effects of dietary supplementation with an essential oil mixture on the growth and laying performance of two layer strains

One thousand two hundred 1-day-old Lohmann LSL white and Lohmann Brown layer chickens were fed diets supplemented with either an antibiotic growth promoter (AGP) or an herbal essential oil mixture (EOM) till 58 wk of age to reveal the long-term effects of those additives on growth, performance and wholesome egg quality parameters. The study was arranged in a 2×3 factorial design with two layer strains and three feed additive regimens. Thus, the layer birds of both strains were randomly assigned to the three dietary treatments, i.e., standard basal diet (control), control with AGP (specifically, avilamycin, 10 mg/kg diet) and control with EOM (24 mg/kg diet). The data regarding egg production were recorded between 22 to 58 weeks of age. Neither the dietary treatments nor the bird strain influenced the body weight and mortality of the birds in both the growing and laying period. AGP or EOM supplementation to the laying hen diet significantly increased the egg production rate and egg weight as compared to the control diet alone, but egg mass output, feed consumption, and feed conversion ratio were not affected by the dietary treatments. Neither dietary treatment created any statistically significantly differences in egg quality parameters. The research findings have confirmed the beneficial effects of supplementation with feed-grade EOM on the laying rate and egg weight of both white and brown layers. Indeed, EOM, being a novel feed additive natural origin, proved to be as efficacious as AGP in promoting egg yield.

Effects of boron supplementation to diets deficient in calcium and phosphorus on performance with some serum, bone and fecal characteristics of broiler chickens.

Three levels of boron (0, 30, 60 ppm) were supplemented in practical corn-soybean based starter and grower diets, containing either adequate or inadequate Ca or P. A total of 1,800, 1-day-old sexed broiler chicks were assigned to six dietary treatments and fed with the experimental diets for 42 days. Boron improved the overall feed conversion ratio, but increased body weight only at 21 days of age (p<0.01). Boron decreased feed intake in the case of feeding on a diet deficient in Ca and P, and tended to increase feed intake when birds received a diet adequate in Ca and P, signifying significant boron by Ca-P interaction (p<0.01). Mortality was not influenced by boron (p>0.05). Dietary Ca and P deprivation reduced body weight and feed consumption significantly, but did not influence the feed conversion ratio and mortality (p>0.05). Serum Ca level, ALP and ALT activities were not influenced either by dietary Ca and P deficiency or boron supplementation. Serum P content increased with respect to boron at 30 ppm. Bone breakage strength was not affected by dietary variables. Tibia ash, Ca and P were increased in response to the supplementation diet with 30 ppm boron, whereas 60 ppm showed no effect in most cases. Accordingly, the dietary boron supplementation of 30 ppm significantly decreased fecal Ca and P excretion, while there was a numerical decline in the 60 ppm boron as compared to the 0 ppm boron group. Data presented herein indicated that boron, either at the 30 ppm or 60 ppm supplementation level, was effective in conversion of feed to body weight, whereas only boron at 30 ppm contributed to the mineralization of bone thereby augmenting more Ca and P while excreting less through faeces.

Effects of vaccination against coccidiosis, with and without a specific herbal essential oil blend, on performance, oocyst excretion and serum IBD titers of broilers reared on litter

The aim of the present experiment was to investigate the effects of oral administration of a live attenuated vaccine (VAC) and an essential oil blend (EOB), either alone or in combination, as a novel anticoccidial strategy for broiler chickens with a mixed Eimeria spp. infection. A total of 624 broiler chicks were randomly assigned to one of six treatments. Two of the groups, only one of which was challenged with coccidiosis, were given a basal diet and served as controls. The other two groups, also infected, were given a basal diet supplemented with monensin sodium (MON, 100 mg/kg) or the EOB (75 mg/kg). Of the remaining two groups, which were infected with coccidiosis, one was vaccinated against coccidiosis (VAC) and the other was both vaccinated and fed a diet with an EOB (VAC+EOB). Birds treated with VAC and VAC+EOB had comparable live performance to MON-fed birds challenged with coccidiosis. Conversely, EOB diet supplementation had negative effects on growth, feed intake and feed conversion ratio throughout the growth period. None of the coccidial control strategies kept pace with the uninfected procedure in terms of performance during the course of the infection. There was no significant difference in mortality among treatments. All of the anticoccidial procedures kept serum infectious bursal disease titers at high levels after coccidial infection and reduced fecal oocyst excretion, with the exception of the MON-based procedure. The results indicate that vaccination against coccidiosis, with or without EOB, demonstrated the same efficacy in promoting recovery from coccidial infection and in reducing oocyst shedding as MON.

Influences of an essential oil mixture supplementation to corn versus wheat-based practical diets on growth, organ size, intestinal morphology and immune response of male and female broilers

The aim of this study was to investigate the effect of diet type, supplementation diet with an essential oil mixture (EOM), and bird gender on the growth performance, carcass yield, internal organ weight, immune response, and small intestine histology of broiler chickens. To do this, a 2×2×2 factorial arrangement was designed. The variables used were: two diet types (based on either wheat or corn), 2 feed additives (with or without EOM), and gender (male or female). EOM supplementation in the diet decreased body weight in corn-fed male birds at Days 21 and 42, but not in those fed the wheat-based diet, signifying a diet × EOM × gender interaction. Cumulative feed intake was not influenced by either the diet type or EOM. The feed conversion ratio was not affected by diet type, whereas EOM improved feed conversion ratio over the 42-day growth period. Feeding birds on wheat decreased the carcass yield while it increased relative small intestine and large intestine weight. Relative weights of liver, bursa fabricius and serum infectious bursal disease (IBD) and Newcastle disease (ND) titers were not affected by any of the variables studied. EOM supplementation and feeding birds on corn increased jejunal villus height at both 21 and 42 days of age, while bird gender showed no effect. In general, EOM positively influenced body weight gain and efficiency of feed conversion in broiler chickens. Birds receiving the corn-based diet were more efficient in converting feed to body mass as com-pared to those fed on the wheat-based diet.

Efficacy of Supplemental Natural Zeolite in Broiler Chickens Subjected to Dietary Calcium Deficiency

Natural zeolite, or sodium aluminosilicate, influences calcium (Ca) and phosphorus (P) utilisation in chicks. A 2×2 factorial arrangement of treatments was used to investigate the effect of dietary Ca (recommended and below recommended levels) and zeolite (0 and 0.8%) on growth, plasma, tibia and faeces in chickens from 1 to 42 days of age. Zeolite supplementation did not affect overall body weight (BW) gain, feed intake (FI) or feed conversion ratio (FCR) of broiler chickens (P>0.05). Overall mortality of zeolite-fed chickens was lower than in untreated ones (P<0.01). Reduction of dietary Ca of approximately 10 to 18% decreased (P<0.05) BW at 14 and 42 days of age in association with reduced FI, but overall FCR was unchanged. Serum protein and sodium constituents were reduced in birds fed zeolite (P<0.05). Decreasing dietary Ca level increased (P<0.01) serum, total protein and glucose concentrations, but decreased Ca level. Zeolite decreased bone ash in birds fed a Ca-deficient diet while increased faecal excretion of ash, Ca, P and aluminum. However, zeolite increased tibia weight (P<0.05) and thickness (P<0.01). No significant response (P>0.05) in relative weight and gross lesion scores of liver or footpad lesion scores was found related to changes in dietary regimens. The results of the present study do not corroborate the hypothesis that the effectiveness of zeolite may be improved in Ca-deficient diets in association with its ion exchange capability.

Performance of layer or broiler breeder hens varies in response to different probiotic preparations

The effect of three probiotic dietary supplements on the laying and reproductive performance of layer hens and broiler breeder hens was investigated. A total of four hundred and eighty, 22-week-old layer hens were given diets containing one of three probiotics (1 g/kg diet for each probiotics) from weeks 22 to 49. Seven hundred and twenty female and sixtyfour male broiler breeders were also subjected to the same additive feeding procedure between 21 and 50 weeks of age. The layer hen and breeder trials were initiated simultaneously and performed in pens located in the same area. Either egg production rate or egg weight was affected by the microbial cultures administered. Body weight and mortality were not affected. Egg production rate, egg weight and egg mass benefited from some of the probiotics, while, overall, the probiotics led to significant improvements in the feed conversion rate of layer hens. All of the probiotic preparations decreased the cracked-to-broken egg ratio, compared to the untreated control group. One of the three probiotic supplements significantly improved the egg production rate and increased the settable egg and chick yield per hen in broiler breeders, whereas, overall, probiotics tended to decrease settable egg weight. Probiotics enhanced hatchability, but no beneficial effects were observed on fertility. Based on these findings, it can be said that the microbial cultures in the probiotic preparations exhibited host-specific and strain-specific differences in their activities as performance-enhancer feed additives, with improvements in some selected performance parameters.

The Long Term Effects of Fairly Low-level of Supplemental Fat on the Productive Performance of Commercial Layers

Laying hens were fed commercial diets added with supplemented fat (SFAT) at 0.6, 1.2, and 1.8% in order to study the long term dietary effects - on - their productive performance from 22 to 75 wk of age. Five hundred and seventy six Single Comb White Leghorn hens were assigned to one of the four dietary treatments. The experimental phase consisted of three periods of 18 wk each. The final body weight and gain of hens fed on diets with SFAT at 1.2% and 1.8% were lower (p<0.05) than those hens given no SFAT. The SFAT at the 1.2% and 1.8% levels improved egg production rate, egg weight and mass, as well as FCR. Mortality and feed consumption were not affected by dietary SFAT. Administration of a diet with SFAT significantly decreased the cracked-broken egg ratio (p<0.01). The beneficial effects of SFAT on egg production performance were particularly more pronounced at intermediate and later ages. Hence, SFAT by period interactions were significant for all traits studied except feed intake. Hens fed SFAT deposited significantly higher abdominal fat than those on the no-SFAT diet. As a result, SFAT at 1.2% and 1.8% inclusion levels provided benefits in terms of efficient table egg production.