Normal Eye Color in the Chicken

Nelson, Norman M.

doi:10.3382/ps.0260061

Cited by 4 publications

(5 citation statements)

References 12 publications

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“…Significant effect of the interaction between eye color and breed on ranging frequency was identified. In chicken, 5 main iris colors: gold, red, brown, black, and pink (albino) can be distinguished ( Nelson, 1947 ). In some colored breeds like Barred Plymouth Rock, green-gray irises are common, for simplicity called gray, and they were correlated with quantity of black feathers in this breed ( Slinger and McIlraith, 1944 ).…”

Section: Discussionmentioning

confidence: 99%

“…In this study, Sasso birds with gray eye color used the ranges significantly less frequently, as compared to Green-legged Partridges with either brown or gray eyes. In the past, it was a standard procedure to eliminate chickens with gray eyes from the production, to avoid potential risk of introducing pathological lymphomatosis ( Nelson, 1947 ). Nevertheless, chicken can have gray eyes unrelated to any pathology, as was the case for the birds in the current study ( Marchewka et al, 2020 ), while lymphomatosis cannot be accurately diagnosed on the basis of color alone ( Nelson and Thorp 1943 ).…”

Section: Discussionmentioning

confidence: 99%

“…One of variable phenotypic external features is iris color, often referred to in animals, including chicken, as eye color ( Nelson, 1947 ). The iris of the eye primarily controls the amount of light that enters the eye, by varying the size of the pupil opening.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, it has been proposed that eye coloration in various species may be related to social ranks, aggression, mate recognition, and sexual selection (e.g., Volpato et al, 2003 , Amat et al, 2013 ). Chicken eye color is largely determined by genetics, but age, diet, and disease can affect it as well ( Nelson, 1947 ). However, to our knowledge no studies have investigated the link of the eye color with the behavior of chickens in free-range systems.…”

Section: Introductionmentioning

confidence: 99%

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Associations between neck plumage and beak darkness, as well as comb size measurements and scores with ranging frequency of Sasso and Green-legged Partridge chickens

et al. 2021

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Despite the intensive genetic selection in modern poultry, variability of domestic fowl phenotypes has remained, especially in breeds adapted to local conditions. The relevance of this variability to the chicken outdoor ranging activities remains unknown. The aim of this study was to investigate if external features were associated with the ranging frequency of the 48 female chickens from each of the 2 breeds: Sasso and Green-legged Partridge. In each of 6 single-breed pens, 8 hens and 2 roosters were housed under conditions of EU requirements for organic meat chicken production, including free access to an outdoor range, from wk 5 to 10 of age. The birds were video-recorded during the experiment to obtain frequencies of individual birds' use of the ranges. Comb size (length and height) was measured using a digital ruler, while the sizes of the dark area of neck plumage and beak were processed and analyzed using ImageJ software. The same traits were scored using direct visual assessment by a trained observer on a scale of 1-3. In addition, the eye color of the bird was recorded. Statistical analysis was conducted independently for each breed using regression models, ANOVAs and Spearman correlations. Significant positive associations between neck plumage ( P < 0.01), beak darkness ( P = 0.03) measurements, comb length ( P < 0.01) and comb height ( P < 0.01) and frequency of range use were identified for Sasso. Sasso hens scored with darkest neck plumage ( P = 0.03) and biggest comb size ( P = 0.04) ranged the most, while their external features were significantly and positively correlated between each other, except beak darkness and comb length. No significant associations between ranging and external features were found in Green-legged Partridge birds, except that their comb height was significantly and positively correlated with neck plumage and beak darkness (r = 0.39 and 0.33, respectively). In some genetic strains, better understanding of the associations between chickens’ external features with ranging behavior could contribute to improve selection programs and bird welfare, assuring production of breeding stock suitable for outdoor conditions.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Associations between neck plumage and beak darkness, as well as comb size measurements and scores with ranging frequency of Sasso and Green-legged Partridge chickens

et al. 2021

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show abstract

“…Further, he reported that the vascular system of the iris contributes a great deal to the normal bay iris color. Nelson (1947) stated that the gross eye color of those chickens with a reddish-bay iris is a result of the blending of the red and yellow pigments.…”

mentioning

confidence: 98%