عنوان مقاله [English]
Providing energy and protein in the diet comprises the greatest part of the diet consumption because the substructure materials are so expensive. So new internal and less expensive sources must be thought of to reduce the diet price. Lathyrus sativus as a source of protein has been used in ruminants’ diet and because of similar amino acids profile to soybean meal can be used instead of soybean meal in ruminants’ diet. There is limited information about in vitro effect of Lathyrus sativus.
Materials and methods
The first goal of this study was determining of chemical composition gas production and rumen, intestine and total tract dry matter and crude protein digestibility of Lathyrus sativus when processed by 1) Autoclave at 120 degrees centigrade, 2) Oven at 100 degrees centigrade, 3) Extruding at 110 degrees centigrade, 4) Roasting on direct heat, 5) Furnace at 120 degrees centigrade and 6) Furnace at 200 degrees centigrade methods. Data were analyzed using GLM procedure of SAS using a completely randomized design with 6 replications.
Results and Discussion
The amount of gas production during various hours and its rate were significantly affected by the different processing procedures. At the second and eight hours of incubation, the amount of gas produced in Lathyrus sativus and the one-hundred-degrees centigrade oven was higher than autoclave, furnace 120 degrees centigrade, and roasted Lathyrus sativus.
Also, the amount of gas produced in extruded Lathyrus sativus was lower than any other processed methods except those put in the furnace by 200 degrees centigrade. The Lathyrus sativus placed in 200-degree furnace severely diminished gas production of the incubation at primary hours. The extruded Lathyrus sativus showed higher gas at the 12th and 24th hours compared with primary hours. This trend continued up to the 96th hour of incubation. The results of gas production conformity with rumen and intestine digestibility. It seems that steam pressure in extrude and autoclave process can effect in Lathyrus sativus. This effect in extrude process was higher than autoclave.
Rumen and intestine digestibility were significantly affected by the different processing methods. The rumen and intestine digestibility in extrude process is higher than the others and in Lathyrus sativus with no process, oven at 100 degrees centigrade and furnace at 200 degrees centigrade was equal respectively.
The findings of the present research revealed that roasting and extruding heat processes lead to increase of dry matter through decreasing water content and that it had no significant effect on other chemical composition. The findings showed that the process of roasting and extruding caused the amount of actual protein of the Lathyrus sativus to increase and was not effective on the amount of insoluble nitrogen in neutral detergent of the Lathyrus sativus. The amount of acid detergent insoluble nitrogen Lathyrus sativus decreased which might be due to the removal of some of the shells in the processing Lathyrus sativus has taken place or influence of roasting and extruding decreased.
Consequently, it caused intestinal protein digestibility to increase and affected by thermal process, the amount of metabolic protein of the soybean increased significantly, too. The process of roasting and extruding reduced the rapid part degradation of dry matter of the Lathyrus sativus. Also, process of roasting and extruding caused the slow part of degradation to increase. In addition, the rate constants degradation of dry matter of the Lathyrus sativus in rumen decreased under the influence of roasting and extruding. The process of roasting and extruding reduced the rapid part degradation of crude protein and the slow part of degradation to increase the rate constants degradation of crude protein of the Lathyrus sativus decreased. Also, thermal processes reduced effective degradability of dry matter and crude protein of the Lathyrus sativus. Roasting and extruded with the reduction of the amount of ruminal disappearance and the increase of the post ruminal digestibility of dry matter and crude protein of soybean cased the degradability process of the Lathyrus sativus to be improved so that it transferred the place of the digestion of protein from the rumen to the small intestines and cased the amount of digestible of dry matter and crude protein in the intestine to increases. The increase of digestibility in the total digestive system shows that the reduction of ruminal digestion of Lathyrus sativus affected by the processes of roasting and extruding has been compensated by the increase of post ruminal digestibility.
Conclusion:In conclusion using of Lathyrus sativus grain may be replaced by soybean meal.