Investigation of chemical compositions, in vitro fermentation parameters and methane production of camelina seed and meal in different cultivated areas for sheep feeding

Background and Objectives: With the changing climate conditions of the world, the reduction of water resources and, as a result, the shortage of animal feed resources, especially soybean meal, and its price increase, the use of feed resources such as camelina in animal nutrition, which is low in water consumption, and has the potential to be planted in dry-land conditions seems necessary. This study investigated to investigate the chemical compositions, in vitro fermentation parameters and methane production of camelina seeds and meals in different cultivated areas for sheep feeding.
Materials and methods: Camelina plant (cultivar Soheil) was planted, grown, and harvested in three different regions of Fars province (Zarghan, Pasargad, and Fasa). Oil extraction was performed from the seeds and meals were used to determine chemical and fermentation parameters such as gas production in 24 hours of fermentation (GP24), in vitro organic matter digestibility (IVOMD), metabolizable energy (ME), microbial protein production (MP), NH3-N, volatile fatty acids (VFAs) profile and protozoa population (total protozoa, genus of Isotricha, Dasytricha, subfamilies of Entodiniinae, Diplodiniinae and Ophrioscolecinae).
Results: The highest DM and ash contents were observed in the Pasargad grain (961.30 and 42.60 g/kg DM), the highest CP and EE contents were observed in the Fasa grain (321.98 and 342.72 g/kg DM), and the highest NDF and ADF content was observed in the Zarqhan grain (281.32 and 142.93 g/kg DM) (P<0.0001). The highest DM and ash contents were observed in Pasargad meal (947.40 and 53.37 g/kg DM), the highest CP content was observed in Fasa meal (476.84 g/kg DM), and the highest EE content, NDF, ADF, total phenolic compounds, and total tannin content was observed in Zarqhan meal (69.53,225.84, 133.79, 1.35 and 0.34 g/kg DM) (P<0.0001). The GP24 (P=0.049), IVOMD (P=0.014) and ME (P=0.001) for the camelina grains of Zarghan and Pasargad were lower than those of the camelina grains of the Fasa region. The highest values of aspartic gas production, GP24, IVOMD and ME were observed for Pasargad meal (P<0.0001). The value of the PF24 and MP were higher in camelina meals compared to soybean meal (P<0.0001). The amount of NH3-N in camelina Zarghan and Pasargad grains was higher than Fasa grains (P=0.013). The amount of NH3-N was lower in camelina Pasargad meal than in soybean meal (P=0.0008). The total concentration of VFAs and the ratio of acetate to propionate in camelina meals were lower compared to soybean meal, but the concentration of propionate was higher (P<0.0001). The effect of camelina seeds from different regions was only effective on the population of Isotricha (P< 0.0001), Entodiniinae (P=0.066) and Diplodiniinae (P=0.056). Compared with soybean meal, the use of camelina meal reduced the total population of protozoa (P<0.0001), genera Isotricha (P=0.002) and Dasytricha (P=0.075) and subfamilies Entodiniinae (P<0.001), Diplodiniinae (P=0.017) and Ophrioscolecinae (P=0.015) and carbon dioxide (P=0.05) and methane production (P=0.024).
Conclusions: The effect of planting area on the chemical composition and nutritional value of camelina seeds were different. Some fermentation parameters of camelina meal were lower than soybean meal in all three regions. Camelina meals were superior to soybean meal in terms of improving fermentation parameters (increasing microbial protein and propionate production, reducing protozoa population, and carbon dioxide and methane gases). Considering the water crisis in the country and the ability to plant camelina in dry-land conditions and different climatic zones, the seeds and meal of this plant can be used in livestock diets, but research on live livestock is necessary.