In vitro gas and methane production and dry matter degradation of pumpkin (Cucurbita argyrosperma) silages with pangola grass (Digitaria decumbens) hay

Abstract

Objective: To determine the production of gas, methane and degradation of dry matter in vitro of silage made with pumpkin pulp shell (PPS; Cucurbita argyrosperma), pangola grass hay (Digitaria decumbens) and urea as additives and two inclusion percentages of molasses fermented for 14 and 21 days.

Methodology: The silages (2 kg) were: E1= 72.5% PPS, 22.5% pangola grass, 3% molasses and 2% urea; and E2= 72.5 % PPS, 19.5% pangola grass, 6% molasses and 2 % urea. Both silages were fermented for 14 and 21 days. Gas production was evaluated, methane (CH₄), total bacteria count and dry matter degradation (DMDEG). The experimental design was a completely randomized 2 × 2 arrangement with types of silage and fermentation time as factors.

Results: The E1 at 21 d showed the lowest gas production at 72 h (46.96 mL g-1 MS) and the lowest DMDEG (35.78%; p ? 0.05). CH₄ production and total bacteria count did not show differences (p> 0.05) between types of silage, nor fermentation times.

Limitations on study: The inclusion of 3% molasses with a fermentation time of 21 days showed the lowest gas production and degradation of dry matter in silage with pumpkin pulp shell and pangola grass hay.

Conclusions: Silage made with pumpkin pulp shell is a viable alternative to preserve and produce feed for ruminants in the dry season; likewise, properly use potentially contaminating materials such as pumpkin pulp shell.

Keywords: Digitaria decumbens, Cucurbita argyrosperma, gas production, ensilage, in vitro.