Protein Requirement of Japanese quail (Coturnix coturnix japonica) During Rearing and Laying Periods

ABSTRACT

Two completely randomized trials were conducted to estimate protein requirements of Japanese quails during the rearing and laying periods. In each trial, 150 quails were distributed in five treatments with five repetitions. Crude protein levels in the rearing period were 18, 20, 22, 24 and 26% (Trial 1) and during the laying period were 16, 18, 20, 22 and 24% (Trial 2). A quadratic effect of protein level was observed on weight gain from seven to 35 days (Trial 1). There were no effects of protein levels on feed intake and feed conversion. Protein levels in experimental diets during rearing had no effect on egg production up to 63 days. However, laying was delayed and variation in body weight was greater in quails fed lower protein levels. In Trial 2, a quadratic effect of protein levels was seen on egg production and feed conversion; and a linear effect was seen on mean egg weight and feed intake. Crude protein levels of 23.08% and 21.95% were estimated by regression equations for rearing and laying, respectively.

INTRODUCTION

Quail production has shown increasing importance in Brazil because quails show early sexual maturity and have small body size, which results in lower necessity of housing space and feed. However, most of the data on nutritional requirements were obtained in other countries that have different climatic conditions, preventing that an adequate feeding program is established. It is important to determine more precisely the nutritional requirement of quails raised in recommended by NRC (1994) for quails in the rearingBrazil. Although data not produced in our country can be used in feed formulation for quails, this might result in lower productivity and poor economic performance due to the use of a possible excess of some nutrients in the diet. Protein of high quality with adequate amino acid balance is one of the most important nutrients for quails. It is also one of the most expensive nutrients. Excessive protein intake results in higher nitrogen excretion and lower feed efficiency for egg production. Four crude protein levels (20, 22, 24 and 26%) were evaluated for Japanese quails and it was concluded that after lysine and methionine + cystine requirements were met, 20% crude protein level resulted in best performance from 1 to 42 days of age (Murakami et al., 1993a). Hyankova et al. (1997) reported that Japanese quails fed 26 and 21.6% crude protein had good performance from 1 to 21 and from 22 to 35 days of age, respectively. Thus, requirements decrease with age, similar to other animal species. During the laying period, Murakami et al. (1993b) recommended 18% of crude protein, which is lower than the level of 22.42% recommended by Pinto et al. (1998). Levels of 24 and 20% of crude protein are and production periods, respectively. The objective of this research was to estimate crude protein requirements of Japanese quails in the growing and laying periods.


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