Effects of ensiling totally mixed potato hash ration with or without a heterofermentative bacterial inoculant on silage fermentation, aerobic stability, growth performance and digestibility in lambs

Abstract

Totally mixed rations (TMRs) that contained 804 g/kg potato hash (PH) were ensiled in 1.5 L jars with or without a heterofermentative inoculant, Lalsil Fresh Lactobacillus buchneri (LB) for 3 months. Jars were opened on days, 0, 3, 7, 10, 21, 45, 60 and 90 of ensiling and sampled for fermentation and chemical composition determinations. Aerobic stability was determined on day 90 of ensiling. Treatments were LB treated TMR (LB-TMR) and untreated TMR (U-TMR). Furthermore, three TMRs that contained 801 g/kg of either maize (320 g DM/kg) or PH (as fed basis) were ensiled for 90 days in 210 L drums for lamb growth and digestibility studies. The ensiled TMRs were: Maize TMR (M-TMR), U-TMR and LB-TMR and were fed to 24 South African Dorper lambs (20± 0.152 kg live weight) that were randomly allocated to the three TMR treatments (8 lambs/pretreatment). Inoculation with LB decreased ( P < 0.05) pH, butyric acid, NH 3-N, fibre fractions, CO 2 production and yeast population while lactic acid, acetic acid and propionic acid concentrations were increased ( P < 0.05) compared to U-TMR silage. The ensiled LB-TMR was aerobically more stable than U-TMR silage as indicated by lower ( P < 0.05) CO 2 production and yeast population and higher concentrations of acetic acid. Higher ( P < 0.05) feed intake, average daily gain (ADG), nutrient digestibility and N retention occurred in LB-TMR silage compared to the other silages. It was concluded that LB was effective in producing a better quality PHS as indicated by improved fermentation, aerobic stability, lamb growth performance and digestibility of LB-TMR silage.