Yolk Colour Development, Plateau Stability and Post-Withdrawal Depletion with Marigold, Paprika and Annatto Pigments in Laying Hens
B. Sagar *
Department of Poultry Science, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600007, India.
B. Vasanthi
Poultry Research Station, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai – 600051, India.
R. Richard Churchil
Poultry Research Station, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai – 600051, India.
D. Gandhimathi
Livestock Farm Complex, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai – 600051, India.
K. Sangilimadan
Poultry Research Station, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai – 600051, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Natural botanical pigments can enhance egg yolk colour, but their temporal responses during supplementation and after withdrawal may differ.
Aims: This study evaluated the comparative pigmentation kinetics, plateau stability, and post-withdrawal depletion of three natural plant pigment sources in laying hens.
Place and Duration of Study: This study was conducted at the Poultry Research Station, Madhavaram Milk Colony, Chennai-51, Tamil Nadu, India, over a total experimental period of 90 days.
Methodology: Thirty Rhode Island Red laying hens (42 weeks old) were allocated to three dietary treatments: dried African marigold petal powder (MPP; 1.0%), annatto seed powder (ASP; 1.0%), or paprika pepper powder (PPP; 0.1%). Following a 6-day baseline period (Periods 1–3; 3 periods × 2 days), the respective supplemented diets were provided for 28 days (Periods 4–17; 14 periods × 2 days), followed by an unsupplemented withdrawal phase. Yolk colour was evaluated using a DSM Yolk Fan. Dietary supplementation significantly influenced yolk colour, with significant main effects of treatment (P < .001) and time (P < .001), as well as a significant treatment × time interaction (P = .0077).
Results: Marigold induced the fastest colour development and the highest colour intensity, reaching a DSM yolk colour score of ≥8 by Period 7 (Days 13–14; 6 days after the start of supplementation) and peaking at 10.07 in Period 16, representing a 101.07% increase from baseline. Paprika reached a DSM score of ≥8 by Period 9 (10 days after the start of supplementation) and peaked at 8.50 in Period 13, an 88.35% increase from baseline, whereas annatto reached a score of ≥8 by Period 8 (8 days after the start of supplementation), peaked at 8.50 in Period 9, and subsequently declined despite continued supplementation. Near-maximum colour (≥95% of the treatment-specific peak) was maintained for 16 days by paprika, 14 days by marigold, and 12 days by annatto. Following withdrawal, paprika exhibited the greatest colour retention, maintaining a DSM score of ≥8 for 8 days, compared with 2 days for marigold and 0 days for annatto.
Conclusion: Overall, the three pigment sources exhibited distinct combinations of response characteristics: marigold provided the fastest colour development and highest colour intensity, whereas paprika showed greater plateau stability and post-withdrawal persistence. These findings indicate that evaluation of dietary pigment sources should consider depletion dynamics alongside peak colour response when selecting pigments for consistent yolk colour in specialty egg production.
Keywords: African marigold, annatto, botanical pigments, carotenoids, DSM yolk fan, egg yolk colour, laying hens, paprika, pigment withdrawal, plateau stability, pigmentation kinetics