Microbial network and fermentation modulation of Napier grass and sugarcane top silage in southern Africa.

IMPORTANCE: Feed shortage in the tropics is a major constraint to the production of livestock products such as milk and meat. In order to effectively utilize of local feed resources, the selected lactic acid bacteria (LAB) strain was used to prepare Napier grass and sugarcane top silage. The results showed that the two silages inoculated with LAB formed a co-occurrence microbial network dominated by Lactiplantibacillus during the fermentation process, regulated the microbial community structure and metabolic pathways, and improved the silage fermentation quality. This is of great significance for alleviating feed shortage and promoting sustainable production of livestock.

Microbial Co-occurrence Network and Fermentation Information of Natural Woody-Plant Silage Prepared With Grass and Crop By-Product in Southern Africa.

To facilitate the use of woody plant (WP) as a natural biomass resource to address the shortage of feed for ruminants in the tropics, we use PacBio SMRT sequencing to explore the microbial co-occurrence network and silage fermentation of gliricidia and leucaena prepared with Napier grass (NG) and corn stover (CS) in Southern Africa. Based on dry matter, the crude protein contents of WP are as high as 25%. Compared with NG, the addition of CS speed up the dynamic succession of microorganisms in the silage fermentation process from Gram-negative bacteria to Gram-positive bacteria, and promoted Lactiplantibacillus plantarum to become the dominant community and enhanced the metabolic pathways of lactic acid and citric acid, thus improved the fermentation flavour and quality of WP silage. WP can be mixed with CS to make high-quality silage, which can alleviate the shortage of feed and promote local animal production.

Ensiling characteristics of total mixed ration prepared with local feed resources in Mozambique and their effects on nutrition value and milk production in Jersey dairy cattle.

To effectively utilize total mixed ration (TMR) prepared with locally available feed resources, we studied the nutritional value and milk production in Jersey dairy cattle fed a local general diet (LGD) and fermented TMR in Mozambique. Ten head of Jersey dairy cattle with 337 ± 19.8 kg body weight, aged 3-4 years in mid location were used in this study. The LGD diet was designed following the general feeding method of local smallholding farms; it contained native grass, Napier grass, wheat bran, and mineral-vitamin mix. Fermented TMR was prepared using Napier grass, corn bran, wheat bran, formula feed, and mineral-vitamin mix. Fermented TMR was preserved as good quality, with a relatively low pH and high lactic acid content. Compared to LGD, fermented TMR significantly improved the dry matter intake and digestibility in dairy cattle. Milk yield was significantly higher in dairy cattle fed with TMR than in those fed with LGD, by 3.75 L/d; milk quality was not significantly different between treatments. The results confirmed that LGD had a low dry matter intake and milk yield, and fermented TMR prepared with local feed resources can attain good quality and improve milk yield in dairy cattle in Mozambique.

Community of natural lactic acid bacteria and silage fermentation of corn stover and sugarcane tops in Africa.

OBJECTIVE: To effectively utilize crop by-product resources to address the shortage of animal feed during the dry season in Africa, the community of natural lactic acid bacteria (LAB) of corn stover and sugarcane tops and fermentation characteristics of silage were studied in Mozambique. METHODS: Corn stover and sugarcane tops were obtained from agricultural field in Mozambique. Silage was prepared with LAB inoculant and cellulase enzyme and their fermentation quality and microbial population were analyzed. RESULTS: Aerobic bacteria were the dominant population with 107 colony-forming unit/g of fresh matter in both crops prior to ensiling, while 104 to 107 LAB became the dominant bacteria during ensiling. Lactobacillus plantarum was more than 76.30% of total isolates which dominated silage fermentation in the LAB-treated sugarcane top silages or all corn stover silages. Fresh corn stover and sugarcane tops contain 65.05% to 76.10% neutral detergent fiber (NDF) and 6.52% to 6.77% crude protein (CP) on a dry matter basis, and these nutrients did not change greatly during ensiling. Corn stover exhibits higher LAB counts and watersoluble carbohydrates content than sugarcane top, which are naturally suited for ensiling. Meanwhile, sugarcane tops require LAB or cellulase additives for high quality of silage making. CONCLUSION: This study confirms that both crop by-products contain certain nutrients of CP and NDF that could be well-preserved in silage, and that they are potential roughage resources that could cover livestock feed shortages during the dry season in Africa.

Influence of microbial additive on microbial populations, ensiling characteristics, and spoilage loss of delayed sealing silage of Napier grass.

OBJECTIVE: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. METHODS: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. RESULTS: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. CONCLUSION: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.

Rendimiento productivo y características de la canal de corderos alimentados con dietas con diferentes niveles de torta de palma / Productive performance and carcass characteristics of lambs fed diets containing different levels of palm kernel cake

Objective. The objective of this study was to determine the effect on productive performance and carcass characteristics in lambs fed with different amounts of palm kernel cake. Material and methods. Thirty-two Santa Inês lambs, with an initial live body weight of 24.8 ± 3.59 kg were used. Treatments consisted of four levels (0; 6.5; 13.0 and 19.5%) of palm kernel cake added to the dry matter diet. Lambs were fed for 80 days, and then slaughtered to be evaluated for the quantitative characteristics of the carcass. Results. Intake of dry matter and non-structural carbohydrates decreased with increasing levels of palm kernel cake. The intake of neutral detergent fiber showed a linear increase. Crude protein and total digestive nutrient intake were not affected. Weight gain, and the feed:gain ratio of dry matter, organic matter, crude protein and total digestive nutrients were similar among the four treatments. There was an increase on the feed:gain ratio of neutral detergent fiber and a decrease of nonstructural carbohydrates. The weight gain at slaughter and biometric measures were not affected by treatment. The carcass compactness index showed a linear decrease. The indexes of leg muscularity, compactness of the leg and rib eye area were similar among treatments. There was a linear decrease in the cold carcass weight and commercial yield of the carcass. Conclusions. The diet made of up to 19.5% palm kernel cake reduced DM intake, the carcass compactness index and carcass commercial yield, but did not alter weight gain, or feed dry matter intake.