Relationship between Forage Particle Size and Rate of in vitro Digestion Parameters of Alfalfa-based Lamb in Complete Pelleted Diets

Background: Intensive feeding systems for lamb production are based on high concentrations of feed, depending on the type of forage, which can cause digestive disturbances; however, forage particle length (FPL) and size (FPS) can affect the fermentation process and the productive performance of lambs. Intensive feeding systems for lamb production are based on high concentrations of feed, depending on the type of forage, which can cause digestive disturbances; however, forage particle length (FPL) and size (FPS) can affect the fermentation process and the productive performance of lambs. Understanding how the lambs meet these challenges requires a conceptual integration of forage structure, mechanical particle size of forage and microbial fermentation. This synthesis will hopefully contribute to the development of a biomimetic co-treatment process for translating the unique characteristics of digestion into an effective component of biorefineries for the industrial conversion of cellulosic in forage biomass to useful products. Therefore, this study aimed to evaluate the relationship among FPL, degradability of feed in vitro and digestibility of organic materials. Methods: As a laboratory simulation of rumen functions, four alfalfa FPS lengths were studied within the components of integrated feed pellets 0.1 mm, common in the Saudi animal feed market, 5, 10 and 15 mm using the same feed composition, but with different lengths. Result: Cumulative gas production in PSL8 and PSL12 lambs was higher compared with the other two groups, indicating that lengths greater than 15 mm and less than 5 mm affected gas production rates. The effect of FPL on rumen parameters had no effect on the pH of the rumen fluid. There were no significant differences in all values of the main volatile fatty acids acetate, propionate and butyrate and digestibility increased when the FPL ranged from 5 to 10 mm as in the PSL5 and PSL10 groups. Hydrogen levels were significantly higher in the PSL1 and PSL10 groups than in the PSL5 and PSL15 groups. Based on forage size, groups PSL5 to PSL10 showed the possibility of using this type of feed for growing lambs and small ruminants.