Sexing in guinea fowls (Numida meleagris)

Abstract

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.

Evaluation of Loss in Vigour of the Dual Purpose French Guinea Fowl and Their Mixed Genetic Grade in Katsina, Nigeria

“…The DPFG cocks had longer tail than the DMFG a cocks but strain had no effect on tail length among guinea hens. Mean tail lengths of the DPFG cocks and hens as well as those of the DMFG cocks and hens were higher than tail length of the pearl grey guinea fowl reported by [23]. This variation could be as a result of differences in the genetic make-up that promotes longer tail length expression of the investigated strains.…”

“…Helmet length and thickness of the DMFG were higher than 0.52 ± 0.03 and 0.47 ± 0.03cm (helmet length) and 0.52 ± 0.03 vs. 0.47 ± 0.03 cm (helmet thickness) reported by [23] but lower than 2.57 ± 0.40 cm by [24] and 2.8 ± 0.36 and 2.2 ± 0.24 cm [26]. Differences in helmet length and thickness due to sex effect among guinea fowl cocks and guinea hens agreed with [27] who informed that helmet length of guinea fowl cocks is higher than helmet length of counterpart guinea fowl hens.…”

“…The wattle length of the DPFG cocks and hens were higher than wattle length of the DMFG cocks and hens respectively. Wattle length of the DPFG cocks and hens were longer than the wattle length of helmeted guinea fowl reported by [24] and those of the pearl grey guinea fowl [23]. The longer wattles of the strain could be a pointer for variations due to strain effect and a strain developed with higher efficiency for body temperature dissipation since wattle are medium for body temperature regulation in birds.…”

“…The average wattle length of the DMFG cocks and hens were higher than the average of the pearl grey guinea fowls by [23]. Thus, it could be inferred that the strain could have better medium for heat dissipation due to crossbreeding of the local strain with the pure grade guinea fowls.…”

“…The DPFG and the DMFG cocks and hens had longer wing span than adult indigenous guinea fowls 19.34 ± 0.21 cm by [19] and those of indigenous ash, pearl and black guinea fowls [20] but shorter than wing span values (60.10 ± 1.70 and 56.70 ± 1.70 cm) for pearl grey guinea cocks and hens [23]. The differences may be due to strain effects.…”