The effects of Lactobacillus buchneri and 1-propanol on the nutritive value of corn silage for dairy cows

Abstract

L. buchneri is a heterolactic microorganism capable of producing significant amounts of acetic acid that has antifungal action and usually increase the aerobic stability of silage. In addition, silages inoculated with L. buchneri typically exhibit higher levels of 1-propanol. There is a clame that 1-propanol is associated with decreased dry matter intake (DMI). Thus, the objective of this work was to evaluate the effects of inoculating L. buchneri at corn ensiling and supplementing total mixed rations (TMR) with 1-propanol on the performance of lactating dairy cows. The experiment was conducted in the Department of Animal Science, College of Agriculture "Luiz de Queiroz" (ESALQ / USP). Corn crop was harvested at 35% DM and ensiled in farm scale bags (40 t/bag). At ensiling, treatments were: control (C) and L. buchneri 1 × 105 cfu/g (LB). After 247 d of storage, silos were opened and the lactation trial was carried out. Twenty Holstein cows housed in a Tie-stall barn were assigned to a replicated 3 × 3 Latin square design, with 21 d periods (14 d adaptation). Diets contained (DM basis): 8% whole cottonseed, 9.5% citrus pulp, 18% soybean meal, 9% dry ground corn, 2.5% premix mineral + vitamins, and 53% corn silage C or LB or corn silage C + 1% of 1-propanol (PROP). The 1-propanol was diluted in water (1:1) and sprayed onto the TMR during mixing, immediately before each feeding. Silage fermentation and chemical composition were evaluatedin each period, as well as the aerobic stability. Fractional disappearance rates of ethanol, acetic acid and 1-propanol were determined in TMR during feedbunk exposure. The DMI, milk yield and composition, total tract digestibility, ingestive behavior and particle sorting index were recorded from d-15 to d-21 in each period.. In addition, rumen fluid and blood were sampled to determine the concentrations of VFA and 1-propanool, and glucose and non-esterified fatty acids (NEFA), respectively. Analysis of variance was performed using the Mixed procedure of SAS and treatment means were compared by Tukey-Kramer test (± = 0.05).