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Öğe The effect of dietary calcium concentration and particle size on performance, eggshell quality, bone mechanical properties and tibia mineral contents in moulted laying hens(TAYLOR & FRANCIS LTD, 2011) Cufadar, Y.; Olgun, O.; Yildiz, A. O.1. A total of 72 H& N Brown Nick laying hens, 76 weeks of age (moulted at 60 weeks of age), were randomly assigned into a 3 x 3 factorial arrangement with three limestone particle sizes and three dietary Ca concentrations (30, 36 and 42 g/kg Ca); with 8 replicates per treatments, and one hen (individual) per experimental unit. 2. Particle sizes of the limestone were: distributions smaller than 2mm (Fine), between 2 to 5 mm (Medium), and larger than 5 mm (Large). The fine, medium and large limestone particles were all obtained from the same source, and sieve sizes used had screen sizes 2mm and 5 mm. 3. The different concentrations of dietary Ca, particle size or interactions had no significant effect on egg production, egg weight, egg mass, feed intake or feed conversion ratio. 4. The concentrations of dietary Ca and particle sizes had no significant effect on egg breaking strength, eggshell as % by weight of whole egg or eggshell thickness. The interactions between Ca concentrations and particle sizes had a significant effect on eggshell breaking strength, but not on other parameters. 5. Different dietary particle sizes had no significant effect on the Ca, P and Mg mineral contents of eggshell. While the different concentrations of Ca in diets had a significant effect on the P content of eggshell, they had no significant effect on Ca and Mg contents. 6. Different dietary concentrations of Ca had a significant effect on shear stress, and Ca and Mg contents of tibiae, but not other parameters. Also, dietary particle sizes had a significant effect on shear stress and Ca contents of tibiae. The interaction between Ca concentrations and particle sizes had a significant effect on tibia shear force and Ca content. 7. According to the results of this study, moulted brown laying hens should be fed 36 g/kg Ca and a medium limestone particle size (2-5 mm) in the diet to maintain performance, eggshell and bone quality.Öğe Effects of dietary organic and inorganic manganese supplementation on performance, egg quality and bone mineralisation in laying hens(ECOLE NATIONALE VETERINAIRE TOULOUSE, 2011) Yildiz, A. O.; Cufadar, Y.; Olgun, O.The aim of this study was to investigate the effects of different dosages of organic and inorganic manganese supplementation into diets on performance, egg quality and bone mineralization in laying hens. One hundred and fifty, 49 weeks old, H&N Brown Nick laying hens were assigned to 10 equal groups according to the diet regimen consisting in standard diet (based on corn and soybean meal) supplemented with Mn inorganic (Mn-sulphate) or organic (Mn-Bioplex) sources at 5 increasing doses (15, 30, 45, 60 and 75 mg/kg) for 12 weeks. Compared to the inorganic form, the Mn-Bioplex supplementation has significantly increased the body weight gains and the egg weight and reduced the percentage of damaged eggs. In parallel, the tibia cortex thickness and its cross area section were significantly enhanced, leading to a slight improvement in bone resistance. The bone proportions of mineral Ca and P elements have significantly increased according to the Mn doses but were not significantly affected by the Mn forms whereas the Mg percentage was significantly depressed with Mn-Bioplex. The tibial contents of Zn and Cu were maximal when low doses of Mn, mainly as Mn-sulphate, were used whereas the Mn accumulation in bone was mainly observed when Mn-Bioplex with doses above 30 mg/kg were used. These results sustained that organic Mn form supplementation positively affects the element distribution in the organism leading to improvement in the weight growth, the egg weight and in the bone solidity in laying hens.Öğe Effects of limestone particle size and dietary available Phosphorus (AP) contents on performance, eggshell quality and mineral excretion in laying hens(ECOLE NATIONALE VETERINAIRE TOULOUSE, 2013) Olgun, O.; Yildiz, A. O.; Cufadar, Y.The study was conducted in order to determine the influence of the limestone particle size and the available phosphorus (AP) contents in layer diets on performance, eggshell quality and mineral excretions. For that, 108 Hy-Line W36, 25 weeks old, were randomly allotted in 9 experimental groups according to the limestone particle size (fine (< 2 mm), medium (2-5 mm) and large (> 5 mm)) and to the AP contents (0.44, 0.55 and 0.66%) in diets distributed for 12 weeks. Performances (body weight, egg weight, egg production, egg mass, feed intake and food efficiency), eggshell qualities such as resistance, thickness, weight and mineral (Ca, P and Mg) accumulation) and mineral excretion were evaluated at the end of the experiment. The particle size and dietary AP content as main factors had no significant effect on food efficiency, egg weight, eggshell qualities and P and Mg eggshell accumulation. However, large particles have significantly decreased the egg production and mass, feed intake and the eggshell Ca amount but have significantly increased the Mg excretion. With 0.44% AP in diet, feed intake and Ca excretion were significantly depressed while eggshell Ca accumulation was enhanced and with 0.66% AP, the P excretion was markedly augmented. Considering interactions between the 2 factors, it was observed that maximal egg weight was obtained with fine particles associated with 0.44% AP and also with medium particles and 0.66% AP or large particles and 0.44% AP but with the 2 last regimens, feed intake, eggshell weight or resistance and Ca excretion were negatively affected in parallel, whereas Ca accumulation in eggshell was also amplified with fine particles and 0.44% AP. These results showed that fine limestone particles coupled to 0.44% AP in diets was the optimal combination for sustaining performance, egg production and qualities and limiting mineral excretion in laying hens.
