زهرا شیرنگار

Considering that soybean is mainly used in human nutrition and its meal is mostly used in poultry feed, and also due to the high price of soybean meal and its impact on the cost of each kilogram of feed, using of other protein sources such as camellia meal in the diet of fattening lambs can reduce the need of soybean meal for ruminant animals. Previous studies have shown that camelina meal with a suitable percentage of omega-3, crude protein, crude fat and poly unsaturated fatty acids (alpha-linolenic acid) makes it a suitable feedstuff for livestock, poultry and fish. However, due to the presence of anti-nutritional compounds such as trypsin inhibitor and glucosinolate, the limitations of camellia meal should be taken into consideration when used in the diet of animals. In many experiments, it has been determined that camelina is a plant resistant to harsh weather conditions compared to other oil plants, has a high yield potential, and it has been reported that it is possible to plant it in crop rotation with cereals.  In this study, the possibility of using camelina meal (CM) instead of soybean meal (SBM) in the diet of fattening lambs was investigated.

 Twenty-four male lambs aged four to six months with an average weight of 34.21±2.18 kg in a completely randomized design with four treatments and six replications were used. Animals were placed in the individual cages. Treatments included: 1) control (basal diet containing SBM), 2) basal diet with 33% replacement of SBM with CM, 3) basal diet with 67% replacement of SBM with CM, and 4) basal diet with 100% replacement of SBM with CM. Ruminal fluid was taken by esophageal tube and blood samples were taken from the jugular vein on days 0, 45 and the end of the experiment.

 The final weight and daily weight gain were not affected by the replacement of oil meals, but it caused a decrease in dry matter intake (P˂0.05). Ruminal ammonia nitrogen concentration increased in a way that was significant in 33 and 67% replacement (P<0.05). Volatile fatty acids concentration and pH were not affected by treatments. The total population of protozoa and genus Entodinium decreased with the increase in replacement percentage, and according to the interaction effect of time and treatment, the population increased with the increase in the duration of the experiment (P<0.05). The concentration of blood urea increased with the replacement of meals (P<0.05), although this process was influenced by the interaction of treatment and time. With the complete replacement of meals, the concentrations of blood cholesterol and triglycerides increased (P<0.05). Malondialdehyde in the blood of lambs was not affected by replacing SBM with CM. 

 According to the results, camelina meal can be used instead of soybean meal at a maximum level of 67% in diet of fattening lambs.