Comparison of Conventional and Semi-Conventional Management Systems on the Performance and Carcass Yield of Broiler Chickens

Animal welfare and products quality have become issues of great concern in animal agriculture. Industrialized commercial and highly production system has been criticized for failure to provide adequate welfare. Therefore, there is need to document commercial productivity research gap between conventional and semi conventional rearing systems on the performance and carcass yield of broiler chickens in Nigeria ecosystem. One hundred and fifty (150) 3 weeks old Marshal Strain of broiler chickens were randomly allocated into two treatments of three replicates per treatment to determine performance and carcass yield under conventional and semi conventional management systems. Birds under conventional system were fed ad libitum while those under semi conventional system were given seventy percent feed quantity of broilers under the conventional system. Data were collected on final body weight (FBW), total weight gain (TWG), feed intake (FI), Mortality and feed conversion ratio (FCR) for performance indicators while dressing percentage, major cuts, organs and offals were determined for carcass yield. Broiler chickens reared using conventional system recorded highest (p<0.05) final body weight (2238.7g/bird), total weight gain (1857.7g/bird) and relative breast weight (18.51%). Broiler chickens reared under semi conventional recorded superior (p<0.05) FCR (1.97) and abdominal fat content (0.89%) compared with those on conventional system that recorded 2.11 and 1.32%, respectively. The study revealed that semi conventional system could be employed in broiler chicken production where superior FCR and low fat (leaner meat) is preferred.Keywords: conventional system, semi conventional system, broiler, management, carcass yiel

Common genetic variants in the PSCA gene influence gene expression and bladder cancer risk

Genome-wide association studies have identified a SNP, rs2294008, on 8q24.3 within the prostate stem cell antigen (PSCA) gene, as a risk factor for bladder cancer. To fine-map this region, we imputed 642 SNPs within 100 Kb of rs2294008 in addition to 33 markers genotyped in one of the reported genome-wide association study in 8,652 subjects. A multivariable logistic regression model adjusted for rs2294008 revealed a unique signal, rs2978974 (r2 = 0.02, D′ = 0.19 with rs2294008). In the combined analysis of 5,393 cases and 7,324 controls, we detected a per-allele odds ratio (OR) = 1.11 [95% confidence interval (CI) = 1.06–1.17, P = 5.8 × 10−5] for rs2294008 and OR = 1.07 (95% CI = 1.02–1.13, P = 9.7 × 10−3) for rs2978974. The effect was stronger in carriers of both risk variants (OR = 1.24, 95% CI = 1.08–1.41, P = 1.8 × 10−3) and there was a significant multiplicative interaction (P = 0.035) between these two SNPs, which requires replication in future studies. The T risk allele of rs2294008 was associated with increased PSCA mRNA expression in two sets of bladder tumor samples (n = 36, P = 0.0007 and n = 34, P = 0.0054) and in normal bladder samples (n = 35, P = 0.0155), but rs2978974 was not associated with PSCA expression. SNP rs2978974 is located 10 Kb upstream of rs2294008, within an alternative untranslated first exon of PSCA. The non-risk allele G of rs2978974 showed strong interaction with nuclear proteins from five cell lines tested, implying a regulatory function. In conclusion, a joint effect of two PSCA SNPs, rs2294008 and rs2978974, suggests that both variants may be important for bladder cancer susceptibility, possibly through different mechanisms that influence the control of mRNA expression and interaction with regulatory factors