RESUMO
1. A trial was conducted to study the effects of additional dietary fibre (DF), resulting from partial replacement of soybean meal (SBM) with high-fibre sunflower meal (SFM), on egg production and gastrointestinal tract (GIT) traits in laying hens. 2. A total of 480 Nick Chick white laying hens (21 weeks of age) were randomly assigned to three dietary treatments and fed for 24 weeks. The hens were fed either the control diet based on corn and SBM, which contained 30 g/kg crude fibre (CF) without SFM, or test diets containing 40 g more CF/kg from adding 47 g/kg SFM or 50 g more CF/kg from adding 97 g SFM/kg. Each dietary treatment was replicated eight times (20 hens per replicate). 3. Body weight (P < 0.05), egg production rate (P < 0.05), egg weight (P < 0.01) and egg mass (P < 0.01) linearly increased but feed conversion ratio linearly decreased (P < 0.01) with increasing SFM supplementation. Feed intake, cracked/broken egg ratios and shell less egg ratios were comparable amongst the groups. 4. The egg quality indices were not influenced by dietary treatments, except for the Haugh units, which decreased (linear, P < 0.01; quadratic P < 0.05) when SFM was added. 5. Digestive organ size was not affected by the dietary treatments, but caecum length increased in hens fed SFM (P < 0.05). Digesta pH in the ileum and caecum was reduced linearly (P < 0.01) with SFM supplementation. 6. Small intestine morphology traits improved with 47 g SFM/kg supplementation, whereas negative effects were observed with 97 g SFM/kg. 7. Productive performance of laying hens improved with 40 or 50 g/kg more CF in feed, mostly from SFM supplementation. It was concluded that this performance increase was attributed mostly to the increase in fat content, rather than DF level, when high-fibre SFM was included in layer diets.
Assuntos
Ração Animal , Galinhas , Helianthus , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Suplementos Nutricionais , Feminino , Trato GastrointestinalRESUMO
1. The aim of the present study was to examine the effects of improving vitamin D status in broiler diets by supplementary 25-hydroxycholecalciferol (25OHD3), alone or in combination with calcium (Ca) and available phosphorus (aP), on live performance, sternum mineralisation and breast meat quality in broilers. 2. A total of 936 1-d-old Ross 308 broilers were used in the study. After gender determination at the hatchery, chicks from each sex were randomly distributed into three dietary treatments. The following dietary treatments were used in the experiment from hatch to 38 d: (1) A control diet formulated to meet all of the nutrient requirements of broiler chicks according to the management guide; (2) The control diet supplemented with 18.7-15.0 µg/kg of 25OHD3; and (3) The control diet supplemented with 18.7-15.0 µg/kg of 25OHD3 plus Ca + aP. 3. Improvement in vitamin D status by 25OHD3 supplementation, alone or in combination with Ca and aP, had no effect on body weight and feed conversion ratio of broilers. 4. The serum 25OHD3 concentration significantly increased with 25OHD3 and 25OHD3 plus Ca + aP supplementation (P < 0.05), whereas the ionised Ca and Mg concentrations remained unchanged. 5. Sternum absolute weight, ash content and the concentrations of Ca and P significantly increased (P < 0.01) with supplementation of 25OHD3, alone or in combination with Ca + aP. 6. Supplemental 25OHD3, alone or in combination with Ca + aP, slightly increased pH24 (P = 0.05) and decreased (P < 0.01) squeezable water loss in breast meat, whereas it had no significant effect on lightness, yellowness and sarcoplasmic protein solubility. 7. In conclusion, the results suggested that enhancing vitamin D status by 25OHD3 supplementation alone or in combination with Ca + aP may improve sternum structure and mineral accretion. Furthermore, supplemental 25OHD3, even in a nutritionally complete diet, may offer an effective way to improve protein solubility in female broilers.
Assuntos
Calcifediol/metabolismo , Cálcio da Dieta/metabolismo , Galinhas/fisiologia , Carne/análise , Fósforo na Dieta/metabolismo , Esterno/fisiologia , Ração Animal/análise , Animais , Desenvolvimento Ósseo/efeitos dos fármacos , Calcifediol/administração & dosagem , Cálcio da Dieta/administração & dosagem , Galinhas/sangue , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Masculino , Músculos Peitorais/fisiologia , Fósforo na Dieta/administração & dosagem , Distribuição Aleatória , Esterno/efeitos dos fármacos , Esterno/crescimento & desenvolvimentoRESUMO
The aim of this study was to investigate the efficacy of feed-grade preparations of mannan oligosaccharides ( MOS: ) and oregano essential oil ( OEO: ) in forced molted or fully fed 82-week-old, laying hens. A 2 × 3 factorial experiment investigated the influence of molting vs. full feeding and dietary supplements [i.e., unsupplemented control, MOS (1 g/kg) diet, and OEO (24 mg/kg) diet] on production parameters, egg quality, serum stress indicators, blood constituents, tibial characteristics, liver antioxidant status, and cecal microflora composition. A total of 864 Single Comb White Leghorn hens were randomly assigned to 6 treatments, each with 6 replicates of 24 hens each, and studied for 25 wk. Hens were fed a molt diet containing of 50% alfalfa and 50% wheat bran ( AA+WB: ) for 12 d, then returned to the laying ration. Results indicate that molt vs. full feed impacted more on most variables measured than supplementation or supplement type. Significant (P < 0.01) interactions between molting and diet were observed for the egg production, egg weight, egg mass, and feed conversion ratio ( FCR: ). In fully fed hens, MOS supplementation improved (P < 0.01) the egg production, egg weight, and FCR, and an OEO addition significantly improved the egg production and FCR in forced molted hens. Molting improved egg quality despite the significant regression in ovary and oviduct weight (P < 0.01), though supplements showed no influence. The bone ash (P < 0.01) and mineral content (P < 0.05) of molted hens were significantly lower than those of fully fed counterparts; however, poor mineralization was not reflected in the bones' mechanical properties. No significant differences were observed among treatments for hematological characteristics. Both the MOS and particularly the OEO supplementation improved (P < 0.01) liver antioxidant status and mitigated the significant increase in cecal pathogenic bacteria after molt. Our results indicate that full feeding with an aa+wb diet is an effective non-feed-removal method for molted hens, the benefit of which can be improved with MOS and OEO supplementation.
Assuntos
Galinhas/fisiologia , Dieta/veterinária , Mananas/metabolismo , Óleos Voláteis/metabolismo , Oligossacarídeos/metabolismo , Origanum/química , Prebióticos , Ração Animal/análise , Animais , Feminino , Muda/fisiologia , Distribuição AleatóriaRESUMO
Essential oil of oregano ( OEO: ) has proven to be a potential candidate for controlling chicken coccidiosis. The aim of the current study is to determine whether OEO and an approved anticoccidial, monensin sodium ( MON: ), as in-feed supplements could create a synergism when combined at low dosages. Day-old broiler chickens were separated into six equal groups with six replicate pens of 36 birds. One of the groups was given a basal diet and served as the control ( CNT: ). The remaining groups received the basal diet supplemented with 100 mg/kg MON, 50 mg/kg MON, 24 mg/kg OEO, 12 mg/kg OEO, or 50 mg/kg MON + 12 mg/kg OEO. All of the chickens were challenged with field-type mixed Eimeria species at 12 d of age. Following the infection (i.e., d 13 to 42), the greatest growth gains and lowest feed conversion ratio values were recorded for the group of birds fed 100 mg/kg MON (P < 0.05), whereas results for the CNT treatment were inferior. Dietary OEO supplementations could not support growth to a level comparable with the MON (100 mg/kg). The MON programs were more efficacious in reducing fecal oocyst numbers compared to CNT and OEO treatments (P < 0.05). Serum malondialdehyde and nitric oxide concentrations were decreased (P < 0.01), whereas superoxide dismutase (P < 0.05) and total antioxidant status (P < 0.01) were increased in response to dietary medication with MON and OEO. All MON and OEO treatments conferred intestinal health benefits to chickens by improving their morphological development and enzymatic activities. The results suggest that OEO supported the intestinal absorptive capacity and antioxidant defense system during Eimeria infection; however, it displayed little direct activity on the reproductive capacity of Eimeria This might be the reason for inferior compensatory growth potential of OEO compared to that MON following the challenge. Combination MON with OEO was not considered to show promise for controlling chicken coccidiosis because of the lack of a synergistic or additive effect.