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.

Despite the potentials and contributions of guinea fowls to economic and social life in Ghana, accurate sex identification in these birds is still a major problem. Three hundred and sixty guinea fowls (180 birds per sex) were used in determining a more accurate and farmer friendly sexing technique. The sexing methods explored were vent, biometric, and molecular techniques. Vent sexing was accomplished by measuring phalli in 28 and 32-week-old birds, while biometric sexing involved the measurement of morphometric traits and data analyzed using discriminant function analysis. Molecular sexing was carried out by DNA extraction and subsequent PCR using the 2550F/2718R primer set. Females had a wider (P<0.05) pelvic inlet than male birds from first week of age until the end of the study, while the opposite was true for wattle length. However, wattle length differed (P<0.05) between both sexes after 4 weeks of age. Combining the biometric variables in a discriminant function, males could be distinguished from females with an accuracy of 94%. During molecular sexing, the P2/P8 primer set was not effective in sexing guinea fowls because it amplified a single band in both sexes and in the same manner. The sex of guinea fowls was properly determined using the primer set 2550F/2718R. Females produced 2 bands of 396 bp and 344 bp, while males only produced the larger band. Phallus size in the 2 sexes were distinguishable from 8 weeks of age, with males having longer and thicker (P<0.05) phalli than their female counterparts. Combining the 2 variables in a discriminate function, males and females could be distinguished with 98.3% accuracy. While the molecular method remains the most accurate sexing technique, the biometric method emerged as the most farmer friendly approach to sexing guinea fowls.

Despite the increasing production of guinea fowls in most African countries, consumer preference information and constraints remain largely undocumented. A study involving 200 consumers and 50 processors was done in the Tamale metropolis to assess their respective roles in the guinea fowl value chain. Consumers were categorised into households and institutions. Household consumers were further partitioned into lower-, middle-and upper-income classes. Most (99%) of the consumers interviewed ranked guinea fowl meat as their most preferred poultry product, and taste was ranked as the top most reason for their choice. A large proportion of household and institutional consumers ate guinea fowl meat once monthly (42%) or weekly (33.5%). All categories of consumers preferred farmers as the source of birds for consumption. Live birds were the most preferred form of guinea fowl by both consumers and processors. Most (93.7%) consumers indicated that there are seasonal fluctuations in the price of guinea fowl leading to the use of products that are substitutes for guinea fowl. Price instability was ranked as the top constraint to guinea fowl consumption in the metropolis. Beef was the cheapest fresh guaranteed halal meat product on the market, and the prices of beef, mutton and chevon were the most stable, while that of the guinea fowl was the least stable. Institutional consumers used guinea fowls more frequently (p<0.05) as compared to household consumers. Similarly, upper-and middle-income households, as well as male heads of households used guinea fowls more frequently (p<0.05) as compared to low-income and female heads of households. Most (60%) processors processed birds either once weekly or monthly. The level of education of the heads of households had no effect (p>0.05) on the frequency of use of guinea fowl meat. There was also no difference between male and female heads of households in preference for guinea fowl packaging. Similarly, household consumers of all income classes chose all packaging of guinea fowl equally, while households and processors ranked friends as the top source of food safety information and institutional consumers ranked television as the number one source of food safety information. Guinea fowls have huge market potential, but the seasonal price fluctuations still remain a challenge. Additionally, the preference for live birds among institutional and household consumers seem to be related to uncertainty about conforming to halal standards in slaughter of birds by processors and poor meat handling and hygiene standards among processors in the metropolis.

Light and the Light Perception of BirdsLight is the visible part of the electromagnetic radiation. It plays an important role for the life of many organisms on earth. Light is perceived by them in different ways.

The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17β-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.