The effects of the quantity of formaldehyde applied at ensiling and of urea supplementation at feeding on the utilization of red clover silages by young growing cattle

Abstract

Six silages were prepared from a primary growth of red clover using additives of 2 1 formic acid/t fresh crop together with formaldehyde at 0, 16, 34, 52, 77 or 117 g/kg crude protein (CP) in the crop. These silages were offered to appetite, either alone or with a urea supplement at 19-4 g/kg total dietary dry matter (D.M.), to 60 British Friesian steer calves with an initial mean live weight of 106 kg.Formaldehyde treatment restricted silage fermentation, the effect increasing with level of application. However, butyric acid and 2,3-butanediol content increased at intermediate levels of application. Protein degradation in the silages was reduced by formaldehyde treatment, as evidenced by a decline in ammonia-N and an increase in insoluble-N content with increasing level of formaldehyde application. The recovery of applied formaldehyde in the silages was low (less than 13 %) but increased with level of application.Intake, live-weight gain and feed conversion ratio followed quadratic trends, with formaldehyde having a deleterious effect at high levels of application. The decline in these production measurements was associated with declines in the apparent digestibility of D.M., organic matter (OM), N and energy with increasing level of formaldehyde application, although there was no effect of formaldehyde on cellulose digestibility. Urea supplementation tended to increase intake and live-weight gain at formaldehyde levels greater than 34 g/kg CP, and apart from the expected increase in N digestibility, did not affect the digestibility of other dietary components. As urea supplementation did not overcome the adverse effects of high levels of formaldehyde application on intake, live-weight gain and digestibility, it appears that the supply of rumen-degradable N was not the major limiting factor on these diets. N retention followed a quadratic trend with level of formaldehyde application, increasing at intermediate levels (30-50 g/kg CP) and then declining markedly at the highest level of application. A similar trend was evident when N retention was expressed as a proportion of live-weight gain, suggesting possible formaldehyde effects on carcass composition. However, carcass composition data did not confirm any formaldehyde effect. Urea supplementation did not affect N retention, and N balance data indicated poor utilization of the supplementary urea N.When considering the use of formaldehyde, relative to a formic acid control, in additives applied to red olover at ensiling, these data demonstrate little advantage in favour of formaldehyde and serious disadvantages when large quantities of formaldehyde are applied.

The effect of paraformaldehyde on the fermentation quality and feeding value of ryegrass and lucerne silages

“…Cellulose digestibility was significantly depressed by paraformaldehyde addition in ryegrass, but not in lucerne. The reduction in cellulose digestibility probably arose from a reduced rate of cellulose digestion in the rumen, as reported for formalin-treated silages by Wilkins, Wilson & Cook (1974) and Kaiser (1979). This difference in response between crop species may, as suggested by Kaiser (1979), be due to differences in the composition of the cell-wall constituents between grasses and legumes, resulting in less binding of HCHO with cell-wall constituents in lucerne.…”

“…The failure of paraformaldehyde to increase silage intake was associated with relatively high intakes of the untreated silages, which were reasonably well preserved. The intakes of well fermented silages made from untreated crops, as characterized by a low pH and with <10% of total-N as ammonia, have frequently not been increased when formic acid (Wilkins & McLeod, 1970) or formalin (Wilkins, Wilson & Cook, 1974;Kaiser, 1979) have been employed as additives. Although the untreated lucerne had a pH of 5-0 and acid content of 7% of D.M., ammonia-N content remained relatively low at 12 % of total N.…”

Legume silages as supplements to a maize silage plus urea diet for young calves

“…This suggestion is supported by the findings of Osbourn et al (1978), that substituting fish meal for urea in a diet of maize silage increased the flow of undegraded dietary protein and total protein into the small intestine of calves; and those of Kaiser et al (1978), that ensiling red clover with a formic-acid/formaldehyde mixture containing 30 to 40 g formaldehyde/kg crude protein increased N retention in calves, relative to the same red clover ensiled with formic acid alone. Amongst the legumesupplemented diets, the highest daily LWG (0-93 kg/head) was sustained by the diet containing red clover silage with formic acid and formaldehyde, on a relatively low intake of DOM but a high food conversion efficiency (FCE).…”

“…However, the solubility of the N in ensiled red clover may be reduced by the addition of formaldehyde during ensiling (Kaiser, England and Gibbs, 1978). Red clover silage conserved with formic acid will usually have a high total N content but this N is highly degradable in the rumen.…”

Beef production from silage 1. The voluntary intake and live-weight gain of beef cattle given red clover silage

“…In the present trial the depression in intake may in part be linked with a depression in digestibility. Lonsdale et al (1977) suggested that the low intake of silage preserved with high levels of formaldehyde could be associated with a lack of rumen-degradable N, although recent evidence from Kaiser (1979) indicates that the effect is complicated by the direct action of formaldehyde on digestion. In the present trial the reduced performance of calves given formaldehydepreserved silage as the sole feed was not present when the silages were supplemented with barley/fish meal but was again apparent when the silages were supplemented with dried grass.…”