The effect of maternal care and infrared beak trimming on development, performance and behavior of Silver Nick hens

In the commercial poultry industry, feather pecking leads to damage to the chickens and an increased mortality rate. The effects of two (possible) feather pecking prevention methods, infrared trimming and maternal care, on production parameters, fear, sociality, learning, feeding behavior, and feeding motivation were examined in young Silver Nick hens. Thirty-nine Silver Nick hens were tested from the day of hatching until 21 weeks of age. Half of these chickens were beak trimmed using an infrared beam. Half of the trimmed and half of the intact chicks were placed with a foster mother for the first 6 weeks. Thus, four groups of nine or ten chicks each were formed: trimmed x reared by mother (nine), trimmed x reared without mother, intact x reared by mother, and intact x reared without mother. Starting at 5 days of age the chickens were weighed weekly and an egg productivity indicator based on physical characteristics of each hen was scored at 17 and 20 weeks of age. An open field test, a first voluntary human approach test, a Y-maze test for sociality, a food preference test, a food rewarded Y-maze test, and a second voluntary human approach test were preformed successively between 4 and 21 weeks of age. Trimmed birds had a lower body weight than those with an intact beak up to and including 8 weeks of age. Furthermore, trimmed birds had lower egg productivity indicator scores based on physical characteristics at 17 weeks of age, and to a lesser extent at 21 weeks of age. The trimmed birds were also less efficient at eating grains, mealworms, grapes, spaghetti and raisins and picked up 63% less food per peck than the intact chickens in the food preference test. Overall, the results show that infrared beak trimming has a slightly suppressive impact on production parameters and pecking efficiency, but not on fear, learning or sociality. Maternal care had very little effect on any of these parameters. (C) 2012 Elsevier B.V. All rights reserved.