The Effect of Oscillating Dietary Protein Concentration on Growth Performance in Fattening Male Lambs

Crude protein is one of the most expensive components of feed and nutrients needed by animals. One of the ways to optimally use crude protein is to oscillating the level of crude protein in the diet and feeding it intermittently at intervals of one to several days. This study was conducted in order to investigate the effect of oscillating dietary protein concentration on growth performance and some rumen and blood parameters in fattening male lambs.

Three diets were adjusted with crude protein of 12, 14 and 16% and with the same metabolic energy. 36 male lambs with an average weight of 23.94±2.04 kg were used in four treatments in a completely randomized design. The first treatment received a diet with a crude protein level of 14%. The second to fourth treatments received diets with 12 and 16% crude protein at intervals of 24, 48 and 72 hours, respectively. Feed consumption, growth performance, feed conversion ratio, digestibility and some rumen and blood parameters were measured.

No significant difference was observed in terms of feed consumption and growth performance among the treatments, although the feed conversion ratio improved in the treatment with a 48-hour crude protein consumption interval and showed a tendency to be significant compared to the control treatment (p=0.063). The highest digestibility of organic matter was related to the treatment with 48-hour consumption interval, which shows a tendency to be significant compared to other treatments (p=0.091). No significant difference was observed between experimental treatments in terms of digestibility of dry matter, crude protein and neutral detergent fiber. The highest rumen ammonia nitrogen and blood urea nitrogen were in the treatment with 48-hour crude protein consumption interval (p<0.05).

The results of this research showed that the feed conversion ratio improves to some extent when using the method of creating oscillations the crude protein level of the ration and its intermittent feeding, but it had no effect on the growth performance of male lambs and feed digestibility, as well as rumen ammonia nitrogen and blood urea nitrogen increased. Therefore, it is recommended to use this strategy in feeding fattening male lambs.