Volume 51 (2018): Issue 3 (September 2018)

Carotenoids are present in ingredients of feed for poultry. Their content can be further increased by supplementation of feed mixtures with synthetic or natural carotenoids. The present paper recapitulates knowledge on the use of carotenoids in broiler chickens and laying hens, and deals with synthetic or natural carotenoids derived from plants. The review describes effects of carotenoids on productive performance, oxidative stability of poultry products, colouring of yolks and accumulation of carotenoids in yolks. There are several alternatives to synthetic carotenoids which are usable in poultry diets and satisfy the interest of consumers in poultry products free of undesirable side effects.

The need to complement the supply of animal products with other sources of poultry necessitates exploring the potentials of domestic duck production. Studies conducted on indigenous ducks in Nigeria have paid less attention to the resource requirements and its determinants to duck production. This study therefore estimated technical efficiencies of domestic duck producers in South-western Nigeria, and identified some socio-economic factors, which influence them. A combination of purposive and random sampling was employed. Stochastic frontier production function approach using a translog production function was used to estimate the technical efficiencies of indigenous duck producers, while inefficiency model was used to determine the socio-economic factors affecting the technical efficiencies. The results showed that the level of technical efficiency ranged from 48% to 96% with a mean of 83.3%, which suggests that average duck output was 16.7% short of the maximum possible level. This implies that productive efficiency could still be improved using the subsisting resource base. The study concluded that mounting capacity building programmes for duck farmers generally, and availability of credit could increase the productivity of duck enterprise if monitored.

The aim of this study was to obtain base-line morphometric data on the whole brain and brainstem in the adult male and female helmeted guinea fowl (Numida meleagris), and compare the result in the two sexes. Brain samples of seventy adult helmeted guinea fowls, comprising 35 males and 35 females, intended for slaughter, were extracted for the study. The body weights for both male and female helmeted guinea fowls were 1247 ± 5.51 g and 1230 ± 4.85 g, respectively. The mean brain weights were 3.39 ± 0.02 g and 3.47 ± 0.18 g for male and female, respectively, and the difference in the values was not significant (P > 0.05). The lengths of the brain and medulla oblongata, as well as the lengths of the midbrain and mesencephalic tectum, did not differ between the two sexes. Neither the mean weights nor lengths of the pons differed between the two sexes. In conclusion, the results of this study showed that there was no sex dimorphism observed in the morphometry of the midbrain, medulla oblongata and pons in the helmeted guinea fowl.

In vitro selection of drought-tolerant cassava varieties is essential for rapid breeding for drought tolerance. The objectives of this study were to determine the response of three contrasting cassava varieties to mannitol-induced drought stress to establish its suitability for in vitro screening and examine relationships among growth parameters. Plantlets were raised from nodal segments on Murashige and Skoog (MS) medium containing 0 (control), 5, 10, 15, 20, 25 and 30 g/l mannitol. Variety CH 140 had the highest survival of explants and frequency of root formation, while MV 99/0395 recorded the highest number of chlorotic leaves and the lowest survival of explants. The lowest numbers of leaves were produced at 25 and 30 g/l mannitol by the three varieties. In CH 140, the highest number of leaves was produced in medium free of mannitol, while the highest number of leaves was produced at 5 and 10 g/l mannitol in MV 99/0395 and TMS 01/1206, respectively. In TMS 01/1206, number of roots produced decreased as the concentration of mannitol in culture media increased, whereas in CH140, number of roots increased as the concentration of mannitol increased before decreasing; while in MV 99/0395, number of roots was not affected by an increase in mannitol concentration. As the concentration of mannitol in the culture media increased shoot height of plantlets decreased with a sharp decline at 20 mg/l mannitol. Concentration of mannitol and survival of explants had significant negative correlation with all parameters. However, frequency of root formation only had significant positive correlation with shoot length. The study concluded that differential responses were expressed by the three varieties to mannitol-induced drought stress and mannitol at 20 g/l concentration was a suitable in vitro drought inducing-agent for screening cassava varieties for drought tolerance.