Comparison of Egg Production in Norwich Canaries Fed Moist and Dry Egg Food under Routine Husbandry Conditions

This study compared egg production in Norwich canaries fed moist or dry egg food, using routine production records kept by the breeder. Eighteen Norwich canary breeding pairs were evaluated; 9 pairs received only moist egg food and 9 pairs received only dry egg food. The two products were dry and moist canary bird egg food forms of the same imported commercial brand and were identified only by form, without using the brand name. Records were obtained retrospectively from the breeder's routine production database, without establishing a separate experimental or research group. The groups resulted from the practical use of existing egg food stocks in equal proportions and from the need to avoid feed waste. The production period started on 14 February and continued until mid-August; each pair was followed through four clutch cycles. Because eggs from Norwich canaries were transferred to foster canaries, hatchability and chick-rearing performance were not used as outcome variables. The primary outcome was the total number of eggs obtained per pair during the four clutch cycles. Due to the limited sample size and deviation from normal distribution in the dry egg food group, the Mann-Whitney U test was used for the primary comparison; repeated count data were evaluated with a Poisson GEE model. A total of 97 eggs were obtained in the moist egg food group and 91 eggs in the dry egg food group. Mean total egg number per pair was 10.78±1.56 and 10.11±3.22, respectively. No significant difference was found between groups for total egg number (Mann-Whitney U=38.5; P=0.893), and the result was unchanged with Welch's t-test (t=0.559; P=0.587). In the Poisson GEE analysis, the effect of clutch cycle was significant (Wald χ²(3)=28.34; P