Effect of Genotype, Sex and Age on Plumage Maturity, and Body Weight of Guinea Fowl (Numida Meleagris)

Abstract

Abstract The objective of this study was to investigate the effect of genotype and sex on the degree of maturity of the plumage of guinea fowl. The experimental materials comprised 300 slow-growing (Label group) and 300 fast-growing (Standard group) gray guinea fowl. At 12, 14 and 16 weeks of age, 12 birds from each group (six ♂ and six ♀) were slaughtered. Dry feathers were collected from the dorsal area on both sides of the spine, in the interscapular and thoracic region, and from the outer side of the left thigh. The percentages of feathers at five stages of development were determined for each bird: I - pinfeathers covered in sheaths, II - beginning of vane development, III - feathers unsheathed by half of rachis length, IV - feathers unsheathed by more than half of rachis length, V - fully developed vanes and afterfeathers. Feather weight was determined and expressed as a percentage of a bird’s total body weight. At 12 weeks of age, guinea fowl were characterized by the lowest (68.23%) percentage of mature feathers. The percentage of mature feathers increased to 79.36% in week 14 and to 83.20% in week 16. In weeks 14 and 16, the proportion of feather weight in total body weight was significantly lower (9.95 and 10.20%, respectively) than in week 12 (11.88%). Genotype had no effect on feather development, but it influenced feather weight and percentage. Significant (P<0.05) genotype × sex × age interactions were observed in percentage of stage I feathers. Label group guinea fowl were characterized by higher feather weight and a higher proportion of feathers in total body weight than Standard group guinea fowl (267.0 g and 11.01%, 248.9 g and 10.34%, respectively). The percentage of feather weight was lower in females than in males.