No abstract

There has been an unprecedented increase in global animal production, especially in subtropical and tropical areas in the last two decades (Renaudeau et al., 2012). The increase in the demand for food is due to a rise in human population (Godfray et al., 2010). Due to its potential role to provide food and livelihood securities (Paswan et al., 2014), poultry production, especially broiler production, are expected to meet the critical shortage in animal protein needed by Africa (Hatab et al., 2019).There has been growing concerns on the impacts of climate change on livestock production. For example, in West Africa, the expected increase in average temperature by 2°C-6°C by the year 2100 (Sylla et al., 2016) portends a serious challenge to sustainable broiler production. Due to the climatic challenge, heat stress events are expected to become more frequent in livestock species (Rahimi et al., 2020). A study by Tawfeek et al. (2014) showed that high ambient temperature adversely affected the performance of broiler chickens under high ambient temperature. However, the authors indicated that supplementation of antioxidants ameliorated the effects of thermal stress on the birds. Therefore, the diets of the birds are required to be adjusted to the climatic conditions (Attia & Hassan, 2017;Nir, 1992;Suganya et al., 2015) and also to the prevailing economic status of the countries where they are produced.The fast rate of development of the poultry production in tropical countries has also engendered a situation of overdependence on

Growing broilers were offered either 0 (0H), 10 (10H), 20 mL (20H) honey, or 0.5 g vitamin C/litre water (AA) during hot-dry season. Honey had no significant (P > 0.05) effect on feed intake (FI), weight gain (WG), feed conversion ratio (FCR), water intake (WI), survival (SURV), dressed percentage (DRE), breas tmeat (BRE), gizzard (GIZ), drumstick (DRU), shank (SHA), thigh (THI), tibia volume (VOL), and magnesium (MAG). Effect of honey was significant (P < 0.05) on tibial weight (WEI), density (DEN), calcium (CAL), and phosphorus (PHO). WEI and DEN increased with increasing level of honey. 20H broilers had higher CAL than 0H and 10H groups. Broilers offered honey had significantly lower PHO than AA group but the difference between honey groups was not significant. Honey significantly affected PR (P < 0.001) and HR (P < 0.001) but not RT (P > 0.005). Higher dose of honey lowered PR and HR. Honey significantly (P < 0.05) increased THY but LIV, KID, LUN, SPL, BUR, and HEA were not significantly (P > 0.05) affected. 20H broilers had higher THY than 0H and 10H groups. In conclusion, honey did not affect growth but might improve broilers' welfare when offered up to 20H during hot periods.

No abstract

Dietary manipulation has been seen as one of the practical ways to ameliorate the adverse effects of thermal stress in the hot humid tropical climate. In order to investigate the influence of Curcuma longa (turmeric) rhizome powder on physiological responses and performance under hot humid tropical climate, 240 broiler chicks were randomly assigned to four dietary treatments having four replicates of 15 birds each in a complete randomized design. Broiler birds were fed basal diets and supplemented with 0 (CT), 4 (TG), 8 (FT), and 12 g (SG) of turmeric powder/kg of diet for 8 weeks. Data were collected weekly on feed intake and body weights. Blood samples were collected from eight birds per treatment at week 4 (starter phase) and week 8 (finisher phase) of the experiment for the determination of plasma 3,5,3'-triiodothyronine (T), superoxide dismutase (SOD), malondialdehyde (MDA). Rectal temperature of the birds was also taken. At 56 days of age, eight birds from each treatment were slaughtered for the determination of relative organ weights. Results showed that the final weights of the birds in FT were significantly higher than those of the birds in TG, SG, and CT. The weight gain of the birds in FT was higher than those of the birds in SG while those of SG were higher than those of TG whose values were higher than that of CT. The feed conversion ratio of the broiler chickens in CT was higher (P < 0.05) than those of other treatment groups while the birds in FT and SG had similar feed conversion ratios. SOD of birds fed turmeric rhizome powder was higher than the birds in the control group at both starter and finisher phases. Furthermore, MDA of the birds in FT was lower than those of the birds in the other treatment groups at the finisher phase. Plasma T was higher in the birds fed turmeric at the finisher phase than chickens in the control group. There was no difference in the rectal temperatures of the birds. To conclude, turmeric rhizome powder improved the physiological response and performance of broiler chicken under hot humid tropical climate in a dose-dependent characteristic and the optimum supplementation rate of 8 g/kg of diet was recorded.

The objective of this study was to investigate the effects in ovo injection of black cumin (BC) extract on chick's quality and response of thermally challenged broiler chickens. A total of 700 hatching eggs of broiler chickens (Marshall) were assigned to 7 treatments of 100 eggs each and incubated using the conventional protocol (37.8°C) for the first 10 d and then exposed to a high temperature (39.6°C) for 6 h daily from day 10 until day 18 of the incubation. At embryonic day 17.5, the eggs were randomly allotted to 7 treatment groups, viz.: eggs without in ovo injection (WA), eggs injected with 0.9% saline solution (SA), 3 mg ascorbic acid (AA), 2 mg BC (TB), 4 mg BC (FB), 6 mg BC (SB), and 8 mg BC (EB) extracts. Experiment was laid out in a Completely Randomized Design. After hatching, the chicks were reared separately according to in ovo treatments for 8 wk. Data were collected on hatchability, chick quality, internal organs, growth performance, plasma superoxide dismutase, malondialdehyde, and triiodothyronine (T 3 ). The results showed that the hatchability of the eggs in the AA group was similar to that of SB eggs and higher than that of the other treatment groups. The intestinal weights of SB and EB birds were significantly higher ( P < 0.05) than those of TB, SA, and WA. The final weights of the birds of SB and AA were higher ( P < 0.05) than those of other treatments. The feed conversion ratio of the birds of TB and FB was comparable to that of EB and WA but higher than that of SB and AA. At hatch, the creatinine of the birds in SA and WA was similar to that of EB, FB, and TB but higher ( P < 0.05) than that of AA and SB. Also, the plasma malondialdehyde, T 3 , and superoxide dismutase of SB and AA birds were better ( P < 0.05) than those of the control groups. Overall, it was concluded that 6 mg of BC extract improved the antioxidant status and posthatch performance of thermally challenged broiler chickens.

Despite several studies carried out to investigate the effects of access to pasture on poultry performance, there is a dearth of information on the comparative benefit of grass and legumes. This study investigated the effects of rearing systems [deep litter system (DL), deep litter with access to legumes (LP) or grass (GP) pastures] on the performance of ISA Brown layers. Two hundred and forty 12-week-old pullets were housed for this study. They were reared until 60 weeks of age. Eighty birds were assigned to each treatment; each treatment had four replicates of 20 birds each. Two birds per replicate were slaughtered at weeks 20, 35 and 58 for determination of the weights of liver, ovary, oviduct and the number of follicles. Daily egg production records were kept from the day of first egg to 42 weeks in lay. Body weights were recorded weekly. Results indicated that at 20 weeks of age, the hens kept in the LP had higher (p < 0.05) ovary weight (g) (34.98 ± 1.4), oviduct weight (52.55 ± 2.28) and oviduct length (cm) (49.73 ± 11.34), and higher number of large yellow follicles (3.75 ± 1.31) and small yellow follicles (12.75 ± 5.17) than those in the GP (0.83 ± 0.02, 1.68 ± 0.19, 16.38 ± 1.14, 0.00 and 0.00), and DL (1.03 ± 0.11, 1.48 ± 0.48, 14.43 ± 0.58, 0.00 and 0.00) respectively. The age (days) at first oviposition was earlier (p < 0.05) in the LP (139.25 ± 0.85) than that in the GP (146.75 ± 0.48) and DL (146.75 ± 0.48). The hen-day egg production was lower (p < 0.05) in GP (74.19 ± 1.25) than that in the DL (78.82 ± 0.78) and LP (79.93 ± 1.13) at mid-laying phase. Concentrate feed intake was lower (p < 0.05) in LP and GP than DL suggesting economic benefit. It was concluded that access to LP enhanced the performance of layers than DL and GP as indicated by the parameters measured.

No abstract