Nutrition VI

Experience and research demonstrated that the quality of the day-old chick has a big influence on the growth and final performance of the broiler. Describing and measuring chick quality is considered to be very difficult. Visual score, Tona or Pascar score, day-old chick weight and chick length are commonly used for measuring chick quality. Visual scoring include color of the chickens, navel quality, feather development, the firmness of legs, the size of beak and eyes etc. Although visual scoring gives a good estimates on the quality of the day old chicks, it is a subjective measuring. Usually chick weight is used as an indicator for chick quality. But measuring yolk free body mass is ratherly laborious and has limited practical for field evaluation. One of the practical way employed to measure chick development is to determine the length of the chicken. By the present study, we planned to compare different methods in order to determine the optimal one as chick quality indicator. For this reason; 480 day old male chicks were used. Chicks were classified into two groups on the basis of feather color: deep and light yellow. Then, chicks in each group was further divided into three groups as small, middle and large according to their body length. The lenght of the middle group birds was varied between 18.0-18.3 cm, while that of the largest group was greater than 18.3 cm and the small group was less than 18.0 cm. A positive correlation between chick lenght at day 0 and chick weight at subsequent days was observed. On the other hand there was no significant differences when the chicks were evaluated by taking into account their colors, except for first week. The measured body weight of chicks in deep yellow groups was greater compared to light yellow ones during the first week. Consequently; chick length was determined as an important criteria to evaluate chick quality since longer chicks exhibited better growth potential.