Beef production from additive-treated silages

Publisher Website
Google Scholar
Abstract
SUMMARY: 1. Wilted (32% dry matter) Italian ryegrass was conserved: (A) untreated; (B) with 16·3 g/kg dry matter (4·6 1/t of fresh material) of an 85% w/w formic acid additive; (C) 12·1 g/kg dry matter (2·3 1/t fresh material) each of 85% formic acid additive and formalin (40% w/v formaldehyde); (D) 5·8 g/kg dry matter (1·3 1/t fresh material) each of 85% formic acid additive, formalin and a 96% w/v solution of propionic acid. The silages were individually fed ad libitum to 40 15-mo-old British Friesian steers of about 350 kg initial live weight.2. Treatment with additives inhibited fermentation, resulting in silages with higher levels of water soluble carbohydrates and lower levels of organic acids than untreated material. Lower levels of ammonia N and higher levels of true protein indicated that some protein protection resulted from the formaldehyde treatment.3. Formic acid alone (B) had little effect on digestibility but significantly (Pin vivo of nitrogen, significant increases in nitrogen retention were recorde relative to the control (A). Dry matter intake was not affected significantly by treatment with formaldehyde, but at the higher level of application (Treatment C) daily gain was significantly reduced compared with the control (A). These effects are discussed in relation to possible changes in VFA patterns within the rumen and to the levels of formaldehyde used.