Effect of substituting different levels of Camellina sativa meal instead of soybean meal on performance, rumen fermentation parameters, blood metabolites, and feeding behavior of fattening lambs

In the animal husbandry industry, more than 70% of the production costs are related to nutrition. Among the nutrients consumed by livestock, protein is one of the most important and expensive nutrients. Due to Iran's limitations in the production of oilseeds and consequently the production of protein meals, providing the protein needs of livestock has been associated with many problems. The use of new and especially local protein sources in ruminant feeding is one of the main solutions to cover the lack of protein sources and reduce the import of these sources, and it also reduces production costs in the livestock and poultry industry. Camelina sativa medicinal-oil plant has attracted a lot of attention, especially in recent years, and its most important advantage is extreme resistance to drought and cold conditions. The presence of high amounts of crude protein (CP), energy, and essential amino acids in camelina meal makes it a useful and potential option for use in the livestock and poultry feed industry. It was shown that the CP content of camelina meal was 41.9% of dry matter. Also, camelina meal has higher CP content and similar rumen undegradable protein compared to canola meal. In terms of lysine and methionine amino acids, which are important in muscle growth, camelina meal is considered a rich source. Camelina is a plant with a short growth period of 85-100 days and recently in Iran at the beginning of the camelina development project, the DH1025 line was produced, which is cultivated under the name of Soheil variety on a wide scale. Various studies have been conducted on the use of camelina meal for different purposes in ruminant nutrition. This is while there is little information about the nutrition of camelina meal and especially Soheil variety in the nutrition of ruminants in Iran. Therefore, this research aimed to investigate the effects of different levels of camelina meal on growth performance, rumen fermentation parameters, blood metabolites, and nutritional behavior of Lori-Bakhtiari lambs.
Thirteen Lori-Bakhtiari male lambs of four to five months of age with a mean live weight of 34.5±5 kg were used for 70 days of the experimental fattening period. Lambs were assigned to three experimental treatments (10 lambs per treatment) in a completely randomized design. Three experimental diets contained camelina meal at levels of zero (control), five, and 10% of dry matter (DM). Experimental diets were formulated according to nutritional requirement tables for small ruminants and were similar in terms of energy and protein. Also, the ratio of forage to concentrate in the diets was considered to be 30 to 70. From the first day, the animals were kept and reared in individual stalls. Two weeks before the start of the experiment (adaptation period), the lambs were vaccinated against enterotoxemia and the amount of 20 mL of anti-parasitic syrup (5% Clozantel) per 10 kg of body weight and niclosamide anti-parasitic syrup (seven to 10 mL per lamb) was fed to the lambs. Camelina meal used in this project was a genetically modified and localized variety. Experimental rations were provided in a completely mixed form (TMR) to the lambs daily at 8:00 am and 4:00 pm.
Results showed that increasing the level of camelina meal in the diet increased linearly the concentration of ruminal ammonia, propionate, and blood urea nitrogen (P<0.05), while ruminal pH and other individual volatile fatty acids, and blood parameters were not affected by the experimental diets (P>0.05). The activity of carboxymethyl cellulase enzymes decreased linearly with increasing the level of camelina meal in the diet (P<0.05). However, the activity of other rumen microbial enzymes was not affected by the experimental diets (P>0.05). In terms of behavioral traits, diets had no effect on DM and NDF intake, and also final body weight and average daily gain (P>0.05). Except for the amount of rumination and the ratio of rumination to DM intake, which increased linearly with increasing the level of camelina meal in the diet (P<0.05), other nutritional behaviors were not affected by the experimental diets (P>0.05).
In general, the results of the present study showed that the use of camelina meal, as a new source of protein, instead of soybean meal up to 10% of dietary DM of fattening lambs is recommended.