2012 – 2017
LESSER KNOWN INDIGENOUS VEGETABLES AS POTENTIAL NATURAL EGG YOLK COLOURANT IN LAYING CHICKENS
Authors: BOLU, Steven Abiodun, ADERIBIGBE, Simeon Adedeji and ELEGBELEYE, E. Abiodun
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A six-week study involving two hundred and fifty (250) Harco black layer birds at the point of lay was carried out to investigate the effects of potential natural colourant on performance and egg quality traits. The birds were assigned to five (5) dietary treatments, each containing supplements either of control, baobab leaf (BL), waterleaf
(WL), red pepper (RP), canthaxanthin (CTX) at 40g/kg feed and 50mg/kg feed of natural and commercial colourants, respectively. Performance records showed no significant
(p>0.05) difference in feed intake across supplements of red pepper, waterleaf, canthaxanthin and control diet, however, baobab leaf treatment had a significantly lower
(p<0.05) intake value (94.07g) when compared with other treatments. Bodyweight gain and hen day production were not significantly influenced (p>0.05) by the dietary treatments, though baobab leaf supplement had the lowest mean HDP of 48.80%, red pepper and waterleaf supplement averaging 52.79%. There was no significant effect (p>0.05) of colourants on egg external traits, compared with the control; canthaxanthin treatment had higher mean egg weight (51.79g), egg length (4.55g), egg breadth (3.29g); red pepper treatment had highest mean shell thickness (0.29g), however, these differences were not significant (p>0.05). Yolk height, albumen height, yolk index and Haugh unit were not significantly affected (p>0.05) across treatments. Yolk width was lowest (p<0.05) in baobab leaf treatment (2.54cm); red pepper, waterleaf and canthaxanthin had 2.89cm, 2.62cm and 2.89cm, respectively and were not significantly (p>0.05) different from the control (2.73cm). Yolk colour score was significantly highest (p<0.05) in red pepper treatment (7.50); waterleaf, baobab leaf and canthaxanthin ranged between 2.25 - 3.31 on the DSM yolk colour, while the control treatment had the lowest yolk colour score of 1.31. The study showed red pepper as a good alternative to commercial yolk colourant. Waterleaf and baobab leaf were not good substitutes for canthaxanthin as a yolk colourant.