1. Two experiments were conducted to determine the effects of level of inclusion of poultry by-product and enzyme-prebiotic supplementation on grower diet digestibility and the performance of broilers. 2. Six grower diets were formulated to provide a similar nutrient profile with the exception of using three graded levels of poultry by-product, namely 0, 25, 40 g/kg of the diet with and without supplementation of enzyme preparation at the rate of 1 kg per tonne of feed and prebiotic preparation at the rate of 2 kg per tonne of feed. The experimental diets were used from 3 to 6 weeks of age. 3. Body weights, feed intake and feed conversion efficiency were not affected by poultry by-product; however, enzyme-prebiotic had a significant positive effect on feed conversion efficiency at 0 to 6 weeks in experiment 1. 4. Crude protein digestibility was decreased by feeding the diet containing poultry by-product while ether extract digestibility was increased by poultry by-product at the rate of 25 g per kg of feed only. Dry matter retention, crude fibre digestibility and organic matter retention were not affected by poultry by-product. Dry matter and organic matter retentions, crude protein, ether extract and crude fibre digestibilities were not affected by enzyme-prebiotic. 5. Protein efficiency ratio (PER) values were increased by poultry by-product at the rate of 40 g per kg of feed and addition of enzyme-prebiotic.

In this study, we examined the effects of formic acid administration to the drinking water on performance, intestinal microflora and carcass contamination in male broilers. A total of 312 day-old male broiler chicks were allocated to two groups with three replicates. The first group (control) received normal drinking water (pH 7.4) during the experiment. The second group consumed acidified drinking water (pH 4.5) after 5 d of age. At 43 d of age, twelve birds were randomly selected from the control group to determine the effect of acidified drinking water on carcass contamination. These birds were only given normal or acidified (pH 3) drinking water for 8 h prior to slaughter. The reduction of water pH from 7.4 to 4.5 significantly decreased body weights of male broilers at 21 and 42 d of age. However, no differences were observed between male broilers given normal and acidified drinking water in terms of feed intake, feed conversion ratio and mortality. The pH value of the gizzard contents was not significantly affected by acid water treatment. There were no significant differences in the intestinal population of E. coli, total organism and Salmonella between the groups. The total organism and E. coli counts of the carcass slightly decreased in the acidified group. No Salmonella was identified in carcass samples of any of the treatment groups. The results showed that drinking water acidification did not provide beneficial effects on performance, intestinal microflora and carcass contamination in male broilers.

The results showed that a milder oxidative stress occurred by supplementation of moderately oxidised oil to the diet of broilers and vitamin E supplementation had been helpful in alleviating lipid peroxidation.

1. Heterozygous naked neck (Na/na+) birds and their normally feathered counterparts (na+/na+) were fed from 0 to 7 weeks on 3 diets differing in methionine concentrations. From 0 to 3 and 3 to 7 weeks, respectively, the concentrations were: low containing 4.3 and 3.3 g/kg; optimum containing 5.0 and 3.8 g/kg and; high with 5.7 and 4.4 g/kg under spring (optimum ambient temperature) and summer conditions (high ambient temperature). Performance, carcase characteristics and breast meat chemical composition were determined. 2. Summer rearing resulted in a decrease in body weight, body weight gain, food consumption, and yields of carcase and breast. The summer temperature effect was more pronounced in males. Under summer temperatures, the protein content of the breast decreased while the fat content increased compared to birds reared in spring. 3. By 7 weeks of age, both genotypes reached similar body weights in the spring experiment while, in summer Na/na+ birds were 3.3% heavier and gained more in the period from 3 to 7 weeks than na+/na+ birds. Carcase and breast yields of Na/na+ birds were greater than in na+/na+ birds. 3. Second order polynomial coefficients of the dietary methionine effect were found to be significant for body weight at 3 and 7 weeks. Daily body weight gain between 3 and 7 weeks was linearly affected by the dietary methionine concentration. There was no interaction between genotype and methionine. 4. Methionine had no significant effect on carcase yield. Second order polynomial coefficients of the dietary methionine effect were found to be significant for breast yield while the methionine effect on abdominal fat was linear. Na/na+ females fed on the low methionine diet had lower protein content than the Na/na+ males. 5. It is concluded that the methionine requirement of Na/na+ birds did not differ from that of their normally feathered counterparts under either spring or summer ambient temperature conditions.

Objective:The experiment was conducted to determine the individual and combined effects of probiotic, prebiotic and enzyme on performance, carcase, organs, intestinal pH and viscosity of broilers. Material and Methods: A total of seven hundred day-old male Ross-308 broiler chicks were individually weighted and distributed into 28 floor pens with 25 chicks per pen in from 0 to 42 d of age. Seven starter and grower diets were formulated to provide a similar nutrient profile with the exception of using experimental feed additives (1 g per kg) or a combined addition of these additives (0.5 g+0.5 g per kg). The diets were supplemented with: no feed additives (control), probiotic, prebiotic, enzyme, probiotic+prebiotic, probiotic+enzyme mixture, prebiotic+enzyme mixture. Results: Probiotic, probiotic+prebiotic and probiotic+enzyme supplementation significantly increased body weights at 42 days (P<0.05). There were no differences in feed intake, feed conversion ratio, relative weights of the proventriculus, gizzard, duodenum, jejunum, ileum, colon, cecum liver, pancreas, spleen, heart and bursa of broilers among the treatments during the experiment (P>0.05). Intestinal pH and viscosity were decreased by adding feed additives when compared with the control. Conclusion: The synergistic effects between probiotics, prebiotics and enzymes should be further investigated, and suitable combinations and levels should be determined in practice. ÖZAmaç: Deneme, probiyotik, prebiyotik ve enzimin etlik piliçlerde performans, karkas, organlar, bağırsak pH'ı ve viskozitesi üzerine tek başına ve kombine etkilerini belirlemek amacıyla yürütülmüştür. Materyal ve Metot: Bir günlük yaşta 700 adet erkek Ross-308 etlik civciv, bireysel olarak tartılmış ve her bölmede 25 civciv olacak şekilde 28 gruba dağıtılarak 0-42. günler arasında barındırılmıştır. Denemede kullanılan katkı maddeleri dışında benzer besin madde profiline sahip ve kullanılan yem katkı maddesinin tek başına (1 g/kg) veya kombine şekilde (0.5 g/kg+0.5 g/kg) ilave edildiği yedi adet başlatma ve büyütme yemi formülasyonu oluşturulmuştur. Yemler, katkı maddesi içermeyen (kontrol), prebiyotik, enzim, probiyotik+prebiyotik, probiyotik+enzim ve prebiyotik+enzim içerecek şekilde hazırlanmıştır. Bulgular: Probiyotik, probiyotik+prebiyotik ve probiyotik+enzim ilavesi 42. gün canlı ağırlığını önemli derecede artırmıştır (P<0.05). Deneme süresince, gruplar arasında yem tüketimleri, yemden yararlanma oranları ile bezel mide, taşlık, duedonum, jejunum, ileum, kalın bağırsak, kör bağırsak, karaciğer, pancreas, dalak, kalp ve bursanın oransal ağırlıkları bakımından bir farklılık saptanmamıştır (P>0.05). Yem katkısı ilavesinin bağırsak pH'ı ve viskozitesi üzerine önemli bir etkisi belirlenmiştir. Kontrol grubu ile karşılaştırıldığında deneme katkılarının ilavesi ile bağırsak pH'ı ve viskozitesi azalmıştır. Sonuç: Probiyotikler, prebiyotikler ve enzimler arasındaki sinerjik etkiler daha fazla araştırılmalı, pratikte uygun kombinasyonlar ve seviyeler belirlenmelidir.

1. Heterozygous naked neck birds were raised under natural spring (average 21.2 degrees C) and summer temperatures (average 27.1 degrees C) to investigate the influence of dietary energy on broiler performance, carcase yield and nutrient composition of breast meat. 2. Birds were fed on a low energy diet of 12.12 MJ ME/kg, a medium energy diet of 12.96 MJ ME/kg and a high energy diet of 13.79 MJ ME/kg with 2 protein concentrations per energy treatment, 230 and 200 g/kg, from 0 to 3 and 3 to 7 weeks of age, respectively. 3. Summer rearing resulted in a decrease in body weight, body weight gain, carcase weight and carcase part yields of birds. 4. Increasing dietary energy from 12.12 to 13.79 MJ ME/kg increased body weight at 3 and 7 weeks, body weight gains from 0 to 3 and 3 to 7 weeks, carcase weights and relative abdominal fat weights of birds in a linear manner. There was no effect of dietary energy on the nutrient composition of breast meat. 5. It was concluded that there was no differences in dietary energy requirements of heterozygous naked neck birds when grown under natural optimum (21.2 degrees C) and summer temperatures (27.1 degrees C).

1. An experiment was conducted to determine the possibility of stimulating sexual development at an early age in male and female broiler chickens by administration of apilarnil, a natural bee product, in the pre-pubertal period. 2. From 28 to 55 d of age, birds were given apilarnil orally. The effects of low (2.5 g/bird) and high (7.5 g/bird) doses of apilarnil on growth performance, testicular weight, secondary sexual characteristics, blood lipids, testosterone and fearful behaviour were evaluated. 3. Apilarnil administration did not cause a positive effect on growth performance of male and female broilers suggesting that apilarnil did not have an anabolic effect. 4. Apilarnil administration suppressed blood glucose and cholesterol. 5. Birds receiving apilarnil remained immobile for a shorter period in a tonic imobiliy test and showed less home-cage avoidance responses suggesting a lower level of fearfulness. 6. Increases in testicular weight, testosterone concentration and comb growth in males receiving apilarnil implied that it stimulates the sexual maturation at an early age. However, a similar stimulation of secondary sexual characteristics was not observed in females.

________________________________________________________________________________ AbstractThe present study was conducted so that the possible effects of thermally-oxidised dietary oil and vitamin E supplementation could be determined on the performance, lipid peroxidation, antioxidant defence system and some blood and meat quality traits of broilers. Broilers were fed grower diets containing fresh or oxidised oil, supplemented with and without vitamin E (200 mg/kg) from four to six weeks of age. Neither oxidised dietary oil nor vitamin E supplementation had any adverse effect on weight gain, feed consumption or feed conversion ratio. However, the broilers that received oxidised oil had lower levels of plasma cholesterol and triglyceride compared to the control. The glucose level was neither influenced by oxidised oil nor by vitamin E supplementation. The plasma malondialdehyde level increased slightly in broilers fed oxidised oil, indicating increased lipid peroxidation. Higher glutathione peroxidise (GSH-P x ) activity observed in the broilers fed oxidised oil suggests greater oxidative stress. Vitamin E supplementation partly depressed GSH-P x activity in broilers fed oxidised oil. This depression in enzyme activity might be the result of homeostatic compensation. The uric acid concentration was not affected by oxidised oil and vitamin E supplementation. Feeding oxidised oil did not cause a marked discolouration in breast meat. Vitamin E supplementation had some beneficial effects on colour measurements.