The influence of eroding Djallonke genotype on the incidence of diseases and mortalities in Sahelian x Djallonke cross-bred sheep.

Despite cross-breeding of Djallonke and Sahelian sheep due to the higher growth rate and final body weight of the Sahelian breeds over time, little scientific evidence exists on the ability of the crosses to withstand diseases compared to their Djallonke parents. A study involving 700 Djallonke and two crosses of the Djallonke and Sahelian breeds (50% Sahel × 50% Djallonke, 75% Sahel × 25% Djallonke) was conducted, and documented incidence of diseases, parasites and mortalities in these animals. Enteritis, Ehrlichia ruminantium and orf were more prevalent in 25% Djallonke than both 100% and 50% Djallonkes. Similarly, pneumonia was more prevalent in 50% Djallonkes, individuals of all age groups and females than all other genotypes, adults and males, respectively. Enteritis prevalence was also higher in lambs and males than animals of all age groups and females, respectively. Coccidiosis was more prevalent in individuals of all age groups and males, than lambs and females, respectively. More abscess and trauma cases were found in males than females. Higher levels of tapeworm and flea infestations were seen in lambs than weaners and adults. Conversely, more mange mite and tick infestations were seen in adults than weaners and lambs. Higher mortality rates were recorded in all other genotypes, lambs and females than in 100% Djallonke, all other age groups and males, respectively. Higher case fatality rate was recorded in haemoncosis than taeniasis cases. The Sahel x Djalloke crosses are more susceptible to infectious diseases and record higher mortality rates than the pure Djallonke genotypes.

Vigour in West African Dwarf kids within the first 24 h post-partum.

One hundred and fifty West African Dwarf (WAD) kids were tested at the National Goats Breeding Station to determine the effects of some neonatal factors on their vigour levels within the first 24 h post-partum. The kids were also tested to establish the relationship between maternal weight, rectal temperature, times of first standing and sucking, sucking period and vigour. The distance covered (in meters) by a kid towards its mother during a 5-min test period was considered as vigour trait. Vigour levels increased significantly (p < 0.05) with increasing age within the first 24 h post-partum. Kids born to second parity mothers had higher (p < 0.05) vigour than those born to first parity mothers. Similarly, high birth weight kids had higher (p < 0.05) vigour levels than low birth weight kids. Weak positive and negative correlations (p < 0.05), respectively, were found between vigour and rectal temperature, and vigour and the time of first successfully standing. However, there was moderate positive correlation (p < 0.01) between vigour and sucking period. The time it took for the newborn kid to stand up for the first time also correlated weakly and negatively (p < 0.01) with the duration of sucking by the newborn within the first 5 min of accessing the teat. Vigour within the first 24 h post-partum in WAD kids increased with increasing age, parity and birth weight and might be responsible for the earlier and longer sucking time and periods, respectively, in high birth weight kids and those dropped by multiparous does.

Effects of season on the reproductive organs and steroid hormone profiles in guinea hens (Numida meleagris).

The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17ß-oestradiol concentrations were also compared in breeding and non-breeding hens. In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females. No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline. Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.

Effects of season on the reproductive organ and plasma testosterone concentrations in guinea cocks (Numida meleagris).

The physiological basis of seasonal breeding in the guinea fowl (Numida meleagris) still remains unknown, despite the socioeconomic importance of these birds, particularly in Ghana. A study involving a total of 50 local guinea cocks was conducted, and documented gross anatomical and histological differences in the reproductive organs of breeding and non-breeding male guinea fowls. The study also compared peripheral testosterone concentrations in breeding and non-breeding cocks. Seasonal differences in variables measured were determined using two-tailed t-test/Mann-Whitney U-test. All comparisons were made at 5% level of significance. Breeding males had significantly (P = 0.000) higher anatomical biometric parameters than their non-breeding counterparts. Also, breeding birds had thicker (P = 0.000) phalli than their non-breeding counterparts. Histologically, regressing testis was characterized by the presence of sloughed off cells and increased debris in the tubular lumen and within the excurrent duct system, collapsed tubules and reduction in tubular lumen. Germ and Sertoli cell populations and nuclear diameters and actual seminiferous tubular diameter and length in regressing testes were significantly (P = 0.000) lower than in active testes. Leydig cell nuclear diameters and populations were also significantly (P = 0.000) reduced. Relative volume of seminiferous tubules in the testis, testicular sperm production/mg testis and per testis and peripheral testosterone concentrations were all higher (P < 0.05) in breeding than non-breeding testis. The ducts in the epididymal region also saw significant (P < 0.05) reductions in luminal diameters in non-breeding birds. Significant regression in anatomical and histological structures of the guinea cock reproductive tract occurred during the non-breeding season, and lower peripheral testosterone concentrations may be responsible for this phenomenon.