Influence of exogenous corticosterone on testicular function and mating behavior of Nigerian indigenous cocks.

In bridging the knowledge gap on stress physiology of Nigerian indigenous chickens, this study investigated the effect of exogenous corticosterone (eCORT) as stress inducing agent on the testicular function and mating behavior of Nigerian indigenous cocks. Twenty-four (24) cocks and one hundred and forty four (144) hens (mating ratio of 1 cock: 6 hens) were grouped into four and assigned to each of the four eCORT treatments (0, 2, 4 and 6 mgeCORT/KgBW) daily for 14 days. Semen samples were collected on days 0, 7 and 14 and analyzed for semen volume (SV), progressive sperm motility (PSM), membrane integrity (MI) and sperm abnormality (SA). Mating behaviors were monitored on days 3, 5 and 8. Blood samples, for hormonal (Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH) Testosterone (TEST) and stress analysis (heterophil/lymphocyte ratio, H/L) were collected from brachial vein on days 7 and 14. On day 15, cocks were euthanized and testes harvested for histomorphometry. Data were analyzed using multivariate analysis, one-way ANOVA and Kruskal-Wallis tests all in SPSS 23. Administration of 4 mgeCORT/KgBW declined (P<0.05) PSM while 4 mgeCORT/KgBW and 6 mgeCORT/KgBW cocks had reduced (P<0.05) SV and MI with increased SA. Compared to baseline values, progressive sperm motility of cocks administered 6 mgeCORT for 7 and 14 days decreased (P<0.05) by 57.5% and 52.4%, respectively. Exogenous CORT had no significant (P>0.05) influence on the mating behaviors, H/L ratio, FSH and TEST. However, 2 mgeCORT/KgBW enhanced LH levels. Administration of eCORT did not affect the testicular epithelial height and seminiferous tubular diameter. In conclusion, optimal stress induced by eCORT impaired semen quality but with less impact on reproductive hormones, H/L and mating behaviors of intensively raised Nigerian indigenous cocks.

Performance of weaner rabbits fed a concentrate diet supplemented with pawpaw leaves.

This experiment investigated the performance of weaner rabbits fed concentrate diets supplemented with pawpaw leaves (PPL). Twenty-four male weaner rabbits aged 5 weeks, weighing between 350 and 450 g were used. Concentrate diet was supplemented with PPL in ratios 100:0, 70:30, 50:50 and 30:70. Rabbits were randomly allotted to the four diets in a completely randomised design for 8 weeks, with six rabbits per diet. Results showed that rabbits supplemented with 30 and 50 % PPL had higher (P < 0.05) dry matter intake to sole concentrate. At 70 % PPL, dry matter intake did not vary with other treatments. Weight gain was higher (P < 0.05) in rabbits fed 30 and 50 % PPL than sole concentrate. Rabbits fed 70 % PPL had lower (P < 0.05) weight gain to animals fed 30 % PPL but gained similarly (P > 0.05) to those fed on 50 % PPL and sole concentrate. Feed conversion ratio improved (P < 0.05) in animals fed 30, 50 and 70 % PPL. Rabbits fed 30 % PPL had the highest (P < 0.05) protein efficiency ratio. Rabbits had higher dry matter digestibility (P < 0.05) with PPL supplementation than sole concentrate while crude protein and fibre digestibility was higher with 30 and 50 % PPL. Haematological and serum parameters in rabbits were unaltered with feeding PPL. It is concluded that weaner rabbits can utilise PPL as supplement to concentrate diet at 30 to 70 % dry matter with positive responses in performance and nutrient digestibility without deleterious effect on the physiological status of the rabbits.

Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance, hydrocyanide intake and haematological parameters of broiler chicks.

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2 × 2 + 1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P < 0.01) final liveweight and weight gain, least (P < 0.05) hydrocyanide (HCN) intake and best (P < 0.05) feed-to-gain ratio. Chicks fed with control and diet containing 100 g/kg peeled cassava root meal (PCRM) had the least (P < 0.05) feed cost per weight gain. Chicks fed with diet containing 100 g/kg cassava root meal had higher (P < 0.05) final liveweight and weight gain and reduced (P < 0.05) HCN intake than chicks fed with diet containing 200 g/kg cassava root meal. Dietary inclusion of peeled cassava root meal (PCRM) for broiler chicks resulted in increased final liveweight (P < 0.05), weight gain (P < 0.01) and feed intake (P < 0.01) when compared with birds fed with diet containing unpeeled cassava root meal (UCRM). The least (P < 0.01) final liveweight and weight gain and worst (P < 0.05) feed-to-gain ratio were obtained with chicks fed with diet containing 200 g/kg UCRM. Increased dietary inclusion levels of cassava root resulted in significant increase (P < 0.05) in white blood cell (WBC) count, heterophil count and serum thiocyanate concentration. In comparison with chicks fed with diet containing UCRM, dietary inclusion of PCRM resulted in increased (P < 0.05) red blood cell (RBC) count and haemoglobin (Hb) concentration and reduced (P < 0.05) white blood cell (WBC) count and serum thiocyanate concentration. Although inclusion of 100 g/kg PCRM showed some economic sense, dietary inclusion of either peeled or unpeeled cassava root poses a threat on growth and health status of broiler chicks.

Free range and deep litter poultry production systems: effect on performance, carcass yield and meat composition of cockerel chickens.

This study was carried out on 150 cockerel chickens each of Harco Black and Novogen strains to determine their performance, carcass yield and meat composition on free range and deep litter production systems. The birds were brooded for 4 weeks and thereafter allotted to the different production systems for a period of 12 weeks. Each production system was allotted 150 chicks (75 chicks per strain) with three replicates of 25 chicks. The birds on deep litter production system were fed ad libitum while each bird on free range was fed 50 % of its daily feed requirement. On the 84 th day, a total of 36 birds were randomly selected for analysis of the carcass yield and meat composition. The data generated were subjected to a two-way analysis of variance in a 2 × 2 factorial experimental arrangement. Novogen strain consumed less feed (P < 0.05) on free range and had the best feed/gain (2.72). A higher (P < 0.05) shear force value (3.74 N) was obtained in the thigh muscle for birds on free range. The tibia proximal length and breadth, and tibia distal length and breadth were significantly (P < 0.05) affected by the production systems and strains. On free range, Harco black had more meat (85.69 g) than bone (18.07 g) in the breast while Novogen had the lowest meat/bone (2.38). Conclusively, Novogen strain should be raised on free range for a better performance in terms of feed/gain, but for higher meat composition, Harco black is a better strain.