Effects of rearing systems on performance, egg characteristics and immune response in two layer hen genotype

White (Lohmann LSL) and Brown (ATAK-S) laying hens, were reared under organic and conventional cage rearing systems, and the effects of the rearing system on performance parameters, egg production, egg characteristics, and immune response were investigated. For this purpose, a total of 832 laying hens of two commercial hybrids, i.e., 416 white (Lohmann LSL) and 416 Brown (ATAK-S) layers, were used. The experiment lasted between 23 and 70 wk of age. In this study, the white layers yielded more eggs as compared to the brown layers in both organic and conventional production systems. Egg weight exhibited a similar pattern to that of laying performance. However, the total hen-housed egg number for the white birds in the organic system was fewer than that of white birds in the conventional cage facility; conversely, a contradictory tendency was observed for the brown birds. Livability of the white layers in the organic system was remarkably lower (14%) than that of the brown line, whereas the white line survived better (3.42%) than their brown counterparts in conventional cages. The feed conversion ratio of the white hens was markedly inferior in the organic system as compared to that of the white hens in the conventional system, whereas relatively lower deterioration was reported in brown layers when reared in an organic system. The organic production system increased egg albumen height and the Haugh unit in eggs of the brown layers. The yolk color score of organic eggs was lower than that of conventional eggs for both brown and white hens. The egg yolk ratio of eggs from white layers was found to be higher in organic eggs as compared to those obtained in the conventional system. All organic eggs had heavier shells than those produced in the conventional system. Eggs from brown layers had more protein content than eggs from white layers. Neither housing systems nor genotype influenced egg yolk cholesterol concentration. When compared to conventional eggs, n-3 fatty acid content was lower in organic eggs, and the n-6:n-3 ratio was higher in organic eggs. In conclusion, two hen genotypes showed different responses in terms of performance and egg quality to two different rearing systems. A commercial white strain produced more eggs with higher egg quality as compared to a native brown strain. The brown strain was found to have adapted well to organic production conditions when survival and total egg number was taken into consideration

Evaluation of the Boron and Phytase, Alone or in Combination, in Broiler Diets

A total of 800 day-old broiler chicks were assigned to four test diets to assess the efficacy of phytase, fermented from Aspergillus niger, and boron, as boric acid, on the growth performance and mineral profile in chickens. The dietary treatments included the basal diet and the basal diet supplemented with boron (20 mg/kg), phytase (500 phytase units/kg diet), or a combination of boron and phytase. The following parameters were measured: growth performance indices, serum biochemicals, ash and the mineral profile of the tibia, breast muscle, liver and excreta. Boron decreased the overall feed conversion ratio by 1.9% (P<0.05) but did not affect the body weight and feed consumption of chickens grown for 42 days (P>0.05). The performance indices were not significantly influenced by dietary regimens for the first 21 days of the experiment (P>0.05). The addition of boron alone and boron+phytase resulted in significant increases in the boron concentrations of serum, bone, breast muscle, liver and excreta (P<0.001). The serum alanine aminotransferase activity of chicks fed phytase was higher (P<0.05) than all other treatments. The ash content and mineral composition of the breast meat, liver and tibia did not respond to individual or combined dietary modifications (P>0.05). The chickens administered a diet with boron excreted less Cathrough excreta. However, the ash content and Fe and Cu concentrations in the excreta increased in response to phytase supplementation (P<0.05). In summary, supplementation with boron alone improved the feed conversion efficiency of broiler chickens fed diets containing adequate levels of nutrients. However, the combination of boron and phytase did not cause further improvements in broiler performance or the bioavailability of minerals

The effects of an organic rearing system and dietary supplementation of an essential oil mixture on performance and meat yield of slow-growing broilers in two seasons

In this study, performance and carcass characteristics of slow-growing broiler chicks, reared in organic or conventional systems, and fed a diet with an essential oil mixture (EOM, 48 mg/kg diet), were evaluated in the autumn and spring seasons. The rearing system affected several performance indices, including body weight, feed intake and feed conversion ratio (FCR), but not mortality, within a high statistical significance at 42 and 81 days of age. However, this was observed only from 1 to 42 days in the spring trial. Dietary administration with EOM worsened the FCR at 42 and at 81 days of age in the autumn trial, but not in spring. Organically reared slow-growing chickens consumed less feed mixture per unit of body weight gain, but attained a higher final weight compared with those kept indoors. However, the effect was more pronounced in autumn, which displayed cooler temperatures and robust plant cover availability (i.e. lucerne and trifolium). The carcass yield and cut-up carcass yield were not affected by the rearing system, but EOM diet supplementation increased breast yield only in the spring. The results suggest that autumn conditions promote efficient organic chicken production in the subtropical climatic zone. The amount of herbage consumed represented up to 10% and 3% of the birds’ daily protein and ether extract requirements, respectively. Supplementing the diet with a mixture of plant essential oils did not support the hypothesis that phytogenic compounds may favourably affect gut function and poultry performance.Keywords: Broiler, carcass characteristics, essential oil, organic, performanc

Chemical composition, fatty acid profile and colour of broiler meat as affected by organic and conventional rearing systems

The major quality characteristics of breast and thigh meat, including chemical composition, fatty acid composition, cholesterol content and colour of slow-growing broilers (Hubbard Red-JA), reared under either organic or conventional rearing systems, and fast-growing broilers (Ross-308) grown under the conventional procedure, were investigated in this comparative study. Slaughter age was 81 days and 42 days for slow- and fast-growing birds, respectively. A lower protein, but higher fat content was measured in the thigh meat of slow-growing broilers reared both in the organic and conventional systems, compared with conventionally reared fast growers. In both systems the breast meat of fast-growing birds had a higher moisture content than those of the slow-growing birds. The organic system promoted ash retention in breast meat compared with conventional rearing procedures. The fatty acid profile of thigh and breast meat showed different responses to broiler rearing systems. Both thigh and breast meat of conventionally reared slow-growing birds contained higher cholestorel levels. Breast and thigh meat yielded from conventionally reared fast-growing birds had a markedly higher red appearance, but a lower yellow colour, than those of slow growers. The organic system increased the yellowness of the meat. In conclusion, the organic rearing procedure provided no added benefit to chicken meat quality than current conventional applications, except in yellowness. Meat produced from birds in the organic system did not meet consumer expectations of presenting a lower n-3 but a higher n-6/n-3 ratio in thigh meat

Effects Of Different Rotary Files Combined With Different Irrigation Needles On Apically Extruded Debris

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