The effect of formaldehyde or glutaraldehyde application to lucerne before ensiling on silage fermentation and silage N digestion in sheep

Abstract

1. The primary growth of lucerne (Medicago sativa) was ensiled after treatment with either formic acid alone (4.1 litres/t; silage F) or with formic acid and either formaldehyde (30.5 g/kg crude protein (nitrogen x 6.25; CP); silage FF), glutaraldehyde (44.2 g/kg CP; silage FG) or a mixture of the two aldehydes at approximately half their individual application rates (silage FFG).2. Compared with formic acid alone, both formaldehyde and glutaraldehyde reduced protein breakdown and carbohydrate fermentation during ensiling. The extent of protein protection afforded within the silo was similar for the two aldehydes, whereas formaldehyde was more effective in restricting carbohydrate fermentation. The effect of treatment FFG on silage fermentation was confounded by the silo bag bursting and the development of a clostridial-type fermentation. All aldehyde treatments reduced silage soluble-N content but N disappearance when the silages were incubated in polyester bags in the rumen was high for all silages and reductions due to the aldehydes were small.3. Silage digestion was studied in four mature sheep each fitted with a rumen cannula and re-entrant cannulas in the proximal duodenum and distal ileum.4. The apparent digestibility of organic matter (OM) in the whole tract was reduced (P i 0.05) to a similar extent by both aldehydes, whereas rumen OM digestion was reduced (P 4 0.05) more by glutaraldehyde than by formaldehyde. The effects on digestion appeared to be due to the action of the aldehydes on the foods rather than to any adverse influences of the aldehydes on the metabolism of the rumen microbes because, although rumen ammonia levels were lower (P < 0.05) when the aldehyde-treated silages were given, rumen casein-degrading activity, the degradation of different feedstuffs when incubated in polyester bags in the rumen and microbial N flow at the duodenum did not differ (P > 0.05) between silages.5. All aldehyde treatments decreased (P < 0.05) the apparent digestibility of N in the whole tract. Silage N degradability in the rumen was also decreased (P i 0.05) from 0.82 for silage F to 0.67, 0.60 and 0.62 for silages FF, FG and FFG respectively, and consequently non-ammonia-N (NAN) flow at the duodenum increased (P < 0.05). The aldehydes did not adversely affect the apparent digestibility of NAN in the small intestine, and net NAN absorption from the small intestine increased from 8.8 g/d with silage F to 11.4, 15.3 and 14.2 g/d with silages FF, FG and FFG respectively. Both the decrease in N degradability in the rumen and the increase in net NAN absorption from the small intestine were greater (P < 0.05) with glutaraldehyde than with formaldehyde.

Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC)

“…in the present study was also within the ranges of values measured in vivo in which total VFA ranged from 6.5 to 8.8 mmol g -1 DM or OM digested in sheep (Leng and Brett 1966;Hogan 1968, 1971;Siddons et al 1984), and from 3.8 to 11 mmol g -1 DM or OM digested in cattle (Davis 1967;Esdale et al 1968;Rogers and Davis 1982a;SicilianoJones and Murphy 1989). Moreover, the molar ratios of acetate:propionate:butyrate on the grass hay diet (63:26:11) and the concentrate diet (47:28:25) were well within the ranges of values found in the rumen (Hungate 1988).…”

In vivo production and molar percentages of volatile fatty acids in the rumen: a quantitative review by an empirical approach

“…Nevertheless, the available data exhibit a wide diversity of experimental dietary treatments. While it is likely that total VFA-PR closely depends on the amount of RfOM, we know only two publications reporting simultaneous measurement of both in vivo total VFA-PR and actual RfOM (Mercer et al, 1980;Siddons et al, 1984). We assessed this relationship by fitting results of measured total VFA-PR (VFA-Prod database) to the amount of OM fermented in the rumen estimated by a homogeneous characterization of feed and diets according to INRA feed tables.…”

Effect of ensiled hop (Humulus lupulus L.) residues on plasma acetate turnover rate in sheep

“…The higher urinary N excretion for Hop‐diet in the present study compared to the previous findings (Al‐Mamun et al . 2008) might be partially due to the difference of diet as well as ensiling of hop residues, because ensiling without using any additives increases rumen ammonia production, much of which is excreted through the urine (Siddons et al . 1984).…”

“…The lower N digestibility of Hop‐diet compared to Hay‐diet also partially might be due to the ensiling of hop‐residues. In a previous study it has been stated that ensiling results in the herbage protein being degraded to non‐protein N (Siddons et al . 1984).…”