Ensiling characteristics of prickly pear (opuntia-ficus indica) rejects with and without molasses for animal feed

Authors

• L El Hajji * ¹
• H Azzouzi ²
• M Achchoub ¹
• K Elfazazi ²
• S Salmaoui ¹

1. Ecology and sustainable development Laboratory, Faculty of Science and Technology, Sultan Moulay Slimane University, Beni Mellal, Morocco
2. Laboratory of Food Science and Technology, Regional Center for Agricultural Research in Tadla (CRRAT), Beni Mellal, Morocco

Abstract

Purpose The aim of this work was to study the effect of adding sugar beet molasses on the biochemical properties, microbial flora, fermentation quality, and aerobic stability of prickly pear cactus (Opuntia ficus-indica) waste silage.
Method Molasses (0%, 2%, 4%, 6%, 8% and 10%, w/w) was mixed with the cactus fruit scraps, straw and wheat bran.
Results The dry matter content, pH, total and reducing sugars of the pre-ensiling material increased after adding different percentages of the beet molasses (P < 0.05). During fermentation, we observed substantial protein and sugar degradation. All silage treatments reached stable pH values (pH 4.3-4.6). Among all the concentrations, the 10% beet molasses treatment underwent the highest lactic acid fermentation. Accordingly, the pH drop was higher in the 10% concentration (1.13 units) compared to lower beet molasses concertation  (1.03 units). Also, the 10% concentration has the highest number of lactic acid bacteria. The number of yeast and total aerobic mesophiles decreased continuously during silage. Moreover, during post-fermentation testing, the yeast multiplied little for the 10% concentration of beet molasses.
Conclusion The results show that the addition of molasses has a significant effect on silage characteristics of prickly pear cactus.

Highlights

• The cactus rejects are an important fodder in the arid and semi-arid zones.
• The valorization of these residues in the form of silage (with or without additives) seems to have an economic and environmental interest.
• The silage process improved the products by reducing the growth of spoilage microorganisms.
• The additive molasses improves the fermentation, aiding the preservation process, and nutritional quality of silage.

Keywords

• Fermentation
• Cactus rejects
• Molasses
• Silage