This study was carried out to investigate the effects of reduced dietary calcium (Ca) and non-phytate-phosphorus (NPP) levels on performance, carcase yield and bone mineralisation of modern broilers. 11,200 one-day-old chicks (Ross-308) were divided into 7 treatments and 8 replicates with standard recommended level and six different levels of Ca and NPP reduction with completely randomised block design. Treatments were divided into following diets; T1: ross recommended control, T2: 94%, 95% and 91% as percentage of T1, T3: 94%, 95% and 83% as percentage of T1, T4: 94%, 91% and 83% as percentage of T1, T5: 94%, 91% and 77% as percentage of T1, T6: 94%, 86% and 83% as percentage of T1 and T7: 94%, 86% and 77% as percentage of T1 for starter, grower and finisher periods, respectively. Results showed that, the Ca and NPP reduction (T2-T7) through starter period did not significantly (p>.05) affect performance but when considered whole period, quadratically (p<.05) improved body weight gain (BWG), feed conversion ratio (FCR) and European Production Efficiency (EPEF). In line with, Ca and NPP intakes were decrease linearly and quadratically with Ca and NPP reducing in diet and higher intakes at T1 resulted in impaired BWG and FCR. On the other hand, carcase parameters and tibia mineralisation were not significantly affected by the reductions. In conclusion, Ca and NPP requirements of Ross 308 broilers seem to be lower than the Aviagen 2014 and 2019 recommendations and reducing almost 20% Ca and NPP intake of broilers is possible, especially after starter period, to maintain performance without any negative effect on bone development. HIGHLIGHTS Excessive dietary Ca and P feeding have potential deleterious effects on broilers. Dietary Ca and NPP reduction improved growth performance, without impairment bone characteristics. Especially after starter period, Ca and NPP reduction, by keeping the dietary levels as 0.90:0.45, 0.75;0.38 and 0.60;0.30% for starter, grower and finisher phase respectively, seems enough for Ross-308.

Besi sığırı rasyonlarında tamamlayıcı yem olarak farklı şekillerde işlenmiş arpa ve mısır kullanımının performans, bazı biyokimyasal parametreler ile serum laktat ve bikarbonat düzeyi üzerine etkileri. Harran Tarim ve Gida Bilimleri Dergisi, 22(2): 275-283

A trial was conducted to assess the effects of phytase supplementation and substitute Vitamin D3 resource with Panbonis -a herbal vitamin D3 source-(PAN) on performance, some carcass characteristics, tibia and serum parameters of broiler chickens. For this purpose, 11200 one-day-old, mixed sex (5600 male, 5600 female) Ross-308 chicks were administered 7 different diets based on corn, soybean and wheat throughout the 41-day trial. Dietary treatments; control group as T1 (5000 IU vitamin D3), T2 (T1 + 500 FTU g -1 phytase), T3 (3000 IU vitamin D3 + 500 FTU g -1 phytase + 100 mg kg -1 PAN) and T4 (3000 IU vitamin D3 + 500 FTU g -1 phytase + 200 mg kg -1 PAN) were prepared to contain recommended levels of Ca-P however T5, T6 and T7 were formulated from T2, T3 and T4, respectively, by reducing 18% of Ca and P concentrations.When overall results considered, there was no significant difference among treatments in terms of final live weight, mortality, weight gain, European Production Efficiency Factor (EPEF) and carcass parameters and mortality (P>0.05). While birds consuming diets containing phytase exhibited better FCR than control group without phytase (P<0.05), no additional improvement was obtained with PAN supplementation compared to other treatments without control group. Additionally partial replacement of PAN for synthetic form had no significant effect on tibia parameters and serum Ca, P levels even though serum Mg (in chicks fed sufficient Ca-P) and calcitriol were increased.These results indicate that PAN could replace some part of synthetic vitamin D3 without any adverse effect in broiler chickens. However, substitution rate of PAN in Ca and P deficient diets should be carefully studied more due to possible adverse effects on feed intake (12-41d) and weight gain (12-41d) as observed in the present study.

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In this study, we investigated the effect of dietary olive leaf (oleuropein) supplementation at different levels on breast meat color and pH 24 in along with TBA values of breast meats which were stored at +4 °C during the 11-day in broilers. For this purpose 320 one-day-old Ross-308 chicks randomly assigned to four groups (5 replicates per group, 16 chicks per replicates). In trial, dietary treatments consist of corn-soybean meal diet without or with 125, 250 and 500 mg kg -1 oleuropein supplementation respectively. At the end of trial, two chicks per replicate were slaughtered and meat samples were collected for lipid oxidation, color and pH 24 measurement. According to the obtained findings, 250 mg kg -1 oleuropein supplementation on broiler diets significantly (P<0.05) decreased TBA values (mg MDA kg -1 meat) of breast meats compared with other groups. TBA values of breast meats significantly (P<0.05) increased during storage time. While breast meat brightness (L*) and yellowness (b*) values and pH 24 were not significantly (P>0.05) affected by oleuropein supplementation at different levels, redness (a*) value significantly (P<0.05) increased compared with control group. As a result of the study, it is possible to say that oleuropein demonstrated antioxidant activity linked with supplementation level and it can be used at level of 250 mg kg -1 as phytobiotic antioxidant in broiler diets.