INFLUENCE OF MOLASSES OR MOLASSES-FORMIC ACID-TREATED RED-CLOVER SILAGE ON FEED-INTAKE AND MILK-YIELD

Ensiling of red clover (Trifolium pratense L.) without additive potent ially results in excessively high fermentation products in the silage. Concentrations of fermentation products, such as lactic acid, acetic acid, butyric acid, and ammonia are regarded to be lower and residual sugars higher in silage treated with molasses and formic acid. The aim of this experiment was to examine the potential of molasses and formi c acid additives for red clover silage and to study the effects on sil age quality, feed intake, and milk production by dairy cows. Red clove r was ensiled by using three levels of sugarbeet molasses, i.e. 0, 40, or 100 litre ton(-1) fresh matter (FM) and two levels of formic acid, i.e. 0, or 5 litre ton(-1) FM in a 3 x 2 factorial combination. Two s uccessive silage feeding-trials were carried out by using three friesi an breed dairy cows in a 3 x 3 latin square design. In the first trial , silages without formic acid (0-0, 0-40, 0-100) were used and in the second trial, silages with formic acid (5-0, 5-40, 5-100) were used. S ilage was offered ad libitum and supplemented with 2 kg hay cow(-1) da y(-1), and 0.25 kg concentrate for each 1 kg of energy corrected milk (ECM). Fermentation of silage was satisfactory with or without silage additives. Molasses stimulated production of lactic acid when applied at 40 kg ton(-1) fresh matter (FM) and resulted in higher residual wat er soluble carbohydrates (WSC) in the silage compared with untreated c ontrol. Formic acid separately or in combination with molasses restric ted fermentation, resulting in lower lactic acid and more residual WSC in the silage. The daily dry matter intake (DMI) of silage increased with increasing level of molasses from 9.5 kg without molasses up to 1 4.6 kg when 100 1 of molasses was used (p < 0.02). Intake of digestibl e crude protein (DCP) and metabolisable energy increased by 26% and 22 %, respectively (p < 0.04, p < 0.01). Milk yield increased from 19.8 k g cow(-1) day(-1) to 20.4 kg (p < 0.05) as result of higher DMI. When molasses was used in combination with formic acid, DMI increased from 9.8 kg without molasses up to 16.5 kg at 100 1 molasses (p < 0.02). Mi lk yield also increased, but the results were not significant (p < 0.2 ). In both feeding trials the utilization of metabolisable energy decr eased with increasing level of molasses as result of higher feed consu mption. It is concluded that silage quality was satisfactory with or w ithout silage additives. Application of molasses to red clover increas ed DMI. Milk yield tended to increase with increased DMI while utiliza tion of metabolisable energy decreased.