Evaluation of the Effects of the Addition of Salt, Type of Additive and the Shelf Life, on Chemical Composition of Pennisetum purpureum (Schumach) (Maralfalfa) Silages in Niger

Abstract

Seasonal variations in the quantity and quality of fodder constitute an obstacle to the development of ruminant breeding in Niger. This is why this study was carried out to evaluate the effects of salt addition, shelf life, and type of additive on the chemical composition of Pennisetum purpureum Schumach (Maralfalfa) silages. These aspects were retained because salt, in addition to its preservative power, improves the palatability of the fodder. The duration of storage makes it possible to determine the optimum period for obtaining quality fodder. Additives, for their part, are retained, because, in this area, they are most commonly used as concentrates in ruminant feed. To do this, a completely randomized experimental design was used according to a 2×3×4 arrangement (2 levels of salt addition, 3 storage times, and 4 types of additive) giving 24 treatments repeated 4 times each, i.e. 96 repetitions in total. A comparison of means was carried out using the GLM (General Linear Model) procedure of the Statistical Package for Social Science (SPSS) software. DM, MM, OM, PB, CB, MG, and ENA were considered as dependent variables, while salt addition, shelf life, and additive type were used as fixed variables. Correlation tests were carried out to determine the different types of relationships between the variables and highlight the effects of the factors. The tests were carried out at the 5% threshold. The results obtained show that certain parameters of the chemical composition statistically (p˂0.05) varied depending on the treatment, the addition of salt, the shelf life, and the type of additive. The results also show that there are different types of relationships between chemical composition parameters and that their connections are influenced by one or the combination of several factors. In summary, this study made it possible to draw the following conclusions: i) Considering the BP and CB couple and to a lesser extent MS and MG, the T5 and T6 treatments stood out. ii) 30-day silages seem to be the most successful; iii) the addition of salt improved most of the parameters of the chemical composition, but statistically reduced the level of Crude Protein (CP); iv) finally, the addition of rice bran made it possible to obtain the best results compared to other additives. However, despite these disparities between the different types of silage, their chemical composition is satisfactory overall. This study lays the foundations for the characterization of Maralfalfa silage in Niger.