Chemical composition and fermentative characteristics of old man saltbush silage supplemented with energy concentrates

Abstract

The objective of this study was to evaluate the fermentation profile and chemical composition of old man saltbush (Atriplex nummularia Lindl.) silage supplemented with cassava (Manihot esculenta Crantz) scraps or grain sorghum (Sorghum bicolor) in the proportion of 10% based on natural matter. The experimental design was completely randomized, in a 3 x 7 factorial arrangement (3 treatments and 7 opening days), with three replications. The treatments consisted of three silages: old man saltbush silage, old man saltbush silage + cassava scrap, and old man saltbush silage + grain sorghum. The experiment was conducted at the EMBRAPA Semiarid Animal Nutrition Laboratory, located in the city of Petrolina-PE. Twenty-one experimental silos were used for each treatment; these silos were opened after 1, 3, 5, 7, 14, 28, and 56 days in ensiling. The pH, ammoniacal nitrogen and total nitrogen ratio, dry matter, crude protein, ether extract, mineral matter, organic matter, neutral detergent fiber, acid detergent fiber, total carbohydrates, non-fibrous carbohydrate, and dry matter in vitro digestibility. The additives grain sorghum and cassava scrap increased the dry matter content and reduced pH values. N-NH3 NT-1 values increased as the fermentation processes progressed, and after 56 fermentation days were close to 11%. Silages were classified as excellent in the fermentation process. The addition of cassava scrap and grain sorghum favors the ensiling process of the old man saltbush, providing improvements in the silage nutritive value. During the storage period, the use of these additives promoted a reduction of total losses, inhibition of alcoholic fermentation, and greater carbohydrates recovery, resulting in silage with a nutritive value similar to that of fresh forage, representing an alternative source of additives.