Diet of the helmeted guineafowl (Numida meleagris galeata Pallas) in the Waza region of North Cameroon

Through laboratory and field experiments, we investigated the effect of food availability and food nutritive value on food selection by helmeted guineafowl ( Numida meleagris galeata Pallas) during the dry season in the Waza region of North Cameroon. Field study and crop analysis shows that a wide variety of food types are eaten by guineafowl during the dry season. Analysis of 101 crops from wild birds reveals a statistically significant positive correlation between the sodium and water content of food items and the quantity found in the crops. Rhizomes of Stylochiton lancifolius and termites form the bulk of the diet of this species during the dry season. It is concluded that the selection of water‐rich food may be an adaptation to dry environment.     

Main arteries to the female reproductive organs in the helmeted guineafowl (Numida meleagris)

The helmeted guineafowl, Numida meleagris , is a member of the Galliformes (King & McLelland, 1975). This order includes the domestic fowl, Callus domeslicus , which has undoubtedly dominated research studies in poultry production generally. Many of the anatomical studies in birds have been carried out using the domestic fowl, with comparatively little mention of other genera. Although the genera in the Galliformes have very many similarities, few anatomical differences have been shown to exist. For example, Crowe & Crowe (1979) have found some striking differences between the blood supply to the head and neck of the guineafowl and the domestic fowl.
The guineafowl has become a popular poultry bird in Nigeria, and has been said to rank second to the domestic fowl, despite its seasonal breeding pattern. The further improvement of this genus in our poultry production has necessitated increased studies into its nutritional requirements, management procedures and disease prevalence. In line with this improvement is the need for anatomical data on the female reproductive organs as a basis for the breeding and selection programme. The aim of this study is to describe the macroscopic arterial blood supply to the reproductive organs of the guineafowl.     

Home range size and dispersion in the helmeted guineafowl (Numida meleagris galeata Pallas) of the Waza National Park, Cameroon

Field investigations of the home range size and emigration pattern of wild helmeted guineafowl ( Numida meleagris galeata Pallas) from 1992 to 1995 showed that home range size (±95% confidence limits (CL) ) varied with season from 3·6±1·5 km² for the dry seasons to 3·1±1·5 km² for the rainy seasons. Home range size varied depending on whether it was estimated with data for adult males, adult females or young birds, with a higher home range size for young birds, closely followed by adult males. Group size (±95%CL) varied by month, and was highest between March and April (47·0±8·1 birds/group) and lowest in August 9·0±5·1 birds/group). More young birds (±95%CL) (36·8±19·6%) dispersed than adult males (21·1±1·9%) or adult females (13·5±1·8%). There was a highly significant positive correlation between group size and the number of birds emigrating from the group. There was also a significant negative correlation between the weights of birds at tagging and the percentage that emigrated during the first year of study but not later. This is suggested to be linked to the high number of young birds emigrating, since they weigh relatively less than adults. The lack of correlation between body weight and number of birds emigrating a year or later after birds were tagged was thought to be due to the fact that birds tagged while young attained adult weight within a year.     

Semen characteristics of the guinea fowl Numida meleagris meleagris

Eighteen adult exotic Golden Sovereign guinea fowl (Numida meleagris meleagris) males identified by leg bands and housed individually in cages were ejaculated two times a week at 4- and 3-d intervals (Mondays and Thursdays) for 6 wk. Semen was obtained manually by gently massaging the dorso-lateral lumbo-sacral region. Semen collection and evaluation were done between 1400 and 1800 h each day of test. Mean semen volume was 0.032 +/- 0.001 ml, sperm motility was 37.1 +/- 0.1% and sperm concentration/ml was 2.62 +/- 0.01 x 10(9). Percentage live sperm averaged 91.6 +/- 0.1, while the mean percentage morphologically normal spermatozoa was 76.9 +/- 0.5. Primary and secondary sperm abnormalities were 11.9 +/- 0.2% and 11.3 +/- 0.2%, respectively. Birds differed significantly in all ejaculate characteristics studied except percent secondary abnormalities, indicating that considerable variation exists for improvement of these semen traits. There were significant bird x collection interval (P<0.05) and bird x week (P<0.01) interactions for sperm concentration/ml and bird x week interaction for sperm motility (P<0.05). The results generally are within acceptable levels and show that the semen is suitable for use in artificial insemination.     

Embryonic development of the domestic guinea fowl (Numida meleagris)

Inside the viable range 36–39°C, the development of the domestic guinea fowl embryo was studied during artificial incubation of about 5000 eggs. Equations giving internal and external pipping and hatching time as a function of incubation temperature were developed. Whatever temperature was used, internal and external pipping occurred at 89% and 95% of hatching time, respectively. The chronological development in ovo of the guinea fowl is illustrated by growth curves. Guinea fowl grew in ovo at the same rate as the chicken embryo. The embryonic mortality is significantly affected by incubation temperature. The thermal tolerance of the embryo follows a parabolic curve: temperatures below or above 37.2°C increase the rate of mortality. During the course of the incubation, the mortality frequency was mainly distributed around two peaks (each one third of the total), which occurred during the first days of incubation, that is, within the first 12% of the incubation time, and during the last days, that is, after 85% of the incubation time. At the optimal 37.2°C temperature, these two peaks occurred on days 1–3 and 23–27, respectively.     

The seminiferous epithelium in the guinea fowl (Numida meleagris)

Summary Spermiogenesis and cellular associations in the seminiferous epithelium of the guinea fowl were studied and described in sexually active adult birds. PAS stain was found to be useful in the recognition of steps of spermatid differentiation only in the first early stages. Nuclear morphological changes were subsequently found to be more reliable in tracing steps of spermiogenesis. It was observed that haematoxylin-eosin stained tissue can be used in the study of spermiogenesis in the bird. Various stages of the seminiferous epithelium were observed in any cross-section of the seminiferous tubules. Distinct cellular associations were observed, but intermix of adjacent germ cells or heterogenous cellular associations were frequently encountered.     

Molecular cloning, expression profile and functional implications of clusterin in the pituitary gland of helmeted guinea fowl (Numida meleagris)

Clusterin is shown to contain putative amphipathic alpha-helices that mediate hydrophobic interactions with numerous types of molecules and may be involved in clearance of cellular debris caused by cell injury or death. To assess this function in vivo, we have cloned the full-length cDNA encoding guinea fowl (Numida meleagris) clusterin and studied its synthesis and expression pattern in specific cell types in pituitary. Quantity of clusterin mRNA expressed in pituitary and endocrine tissues was quantified by real-time PCR. Highest levels were detected in gonads. In situ hybridization showed clusterin mRNA in endocrine cells and folliculostellate cells. Clusterin protein detected by immunohistochemistry was observed in endocrine cells, folliculostellate cells and in colloid. The expression pattern suggests that clusterin is produced by endocrine cells for cytoprotection. Degenerating endocrine cells are phagocytosed by folliculostellate cells and digested by their lysosomal enzymes. In folliculostellate cells clusterin interacts and aggregates with by-products of digestion that subsequently become stored in colloid.     

Effect of age and sex on digestive tract morphometry of guinea fowl (Numida meleagris L.)

As guinea fowl age, their body weights and length of the esophagus and crop increased significantly, and relative length (cm x 100 g b.w(-1)) of the small intestine, caeca and total intestine decreased significantly (P < or = 0.05) in males and females. In addition, 52-week-old males had a significantly higher percentage length of rectum and heart weight, and females a significantly higher gizzard weight compared to 13-week-old birds. Compared to females, adult males differed significantly (P < or = 0.05) in the length of caeca and also in the proportion of the gizzard, proventriculus, heart and liver in total weight.     

Effects of load carrying on metabolic cost and hindlimb muscle dynamics in guinea fowl (Numida meleagris).

The goal of this study was to test whether the contractile patterns of two major hindlimb extensors of guinea fowl are altered by load-carrying exercise. We hypothesized that changes in contractile pattern, specifically a decrease in muscle shortening velocity or enhanced stretch activation, would result in a reduction in locomotor energy cost relative to the load carried. We also anticipated that changes in kinematics would reflect underlying changes in muscle strain. Oxygen consumption, muscle activation intensity, and fascicle strain rate were measured over a range of speeds while animals ran unloaded vs. when they carried a trunk load equal to 22% of their body mass. Our results showed that loading produced no significant (P > 0.05) changes in kinematic patterns at any speed. In vivo muscle contractile strain patterns in the iliotibialis lateralis pars postacetabularis and the medial head of the gastrocnemius showed a significant increase in active stretch early in stance (P < 0.01), but muscle fascicle shortening velocity was not significantly affected by load carrying. The rate of oxygen consumption increased by 17% (P < 0.01) during loaded conditions, equivalent to 77% of the relative increase in mass. Additionally, relative increases in EMG intensity (quantified as mean spike amplitude) indicated less than proportional recruitment, consistent with force enhancement via stretch activation, in the proximal iliotibialis lateralis pars postacetabularis; however, a greater than proportional increase in the medial gastrocnemius was observed. As a result, when averaged for the two muscles, EMG intensity increased in direct proportion to the fractional increase in load carried.     

Isolation of viable Toxoplasma gondii from feral guinea fowl (Numida meleagris) and domestic rabbits (Oryctolagus cuniculus) from Brazil

Toxoplasma gondii was isolated from a feral guinea fowl (Numida meleagris) and domestic rabbits (Oryctologus cuniculus) from Brazil for the first time. Serum and brains from 10 guinea fowl and 21 rabbits from Brazil were examined for T. gondii infection. Antibodies to T. gondii were found in 2 of 10 fowl and 2 of 21 rabbits by the modified agglutination test (titer 1∶25 or higher). Viable T. gondii (designated TgNmBr1) was isolated from 1 of the 2 seropositive fowl by bioassay in mice but not from the 8 seronegative fowl by bioassay in cat. Viable T. gondii was isolated from both seropositive rabbits (designated TgRabbitBr1, TgRabbitBr2) by bioassay in mice from 1 and by bioassay in cat from the other. The TgRabbitBr1 strain was highly virulent for out-bred mice; mice fed 1 infective oocyst died of acute toxoplasmosis. The remaining 2 isolates were relatively avirulent for mice; lethal dose for mice was 10,000 oocysts. All 3 isolates were grown in cell culture, and tachyzoite-derived DNA were genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The TgNmBr1 was found to be clonal Type II, a rare finding in Brazil in any host. The rabbit isolates were atypical, similar to isolates from cats from Brazil (TgRabbitBr1 was identical to TgCatBr5, and TgRabbitBr2 was identical to TgCatBr1, a common genotype in Brazil denoted type BrII). This is the first genetic characterization of T. gondii isolates from the rabbits and guinea fowl in Brazil and the first host record for T. gondii in the guinea fowl.     

Melanism in guinea fowl (Numida meleagris) is associated with a deletion of Phenylalanine‐256 in the MC1R gene

We have characterized a deletion in the MC1R gene causing the loss of one amino acid (p.Phe256del), which is perfectly associated with melanism in guinea fowl (Numida meleagris). Co‐segregation of the p.Phe256del with melanism was confirmed in 25 offspring born from a cross of two heterozygote birds; therefore we suggest that this mutation is responsible for the black phenotype. Interestingly, this is the first case of recessive melanism linked to MC1R.