No abstract

The addition of glycerol or free fatty acids either alone or in combination to concentrate was studied for the effects on feed intake, milk production, rumen fermentation, blood metabolites and diet digestibility in dairy cows given grass silage ad libitum. The study was conducted on 12 mid-lactating cows, four of them ruminally cannulated. Barley-based concentrate (control diet, C) was given 7 kg/d as fed. In the other three diets, 36 g/kg of barley was replaced by glycerol (G) or a mixture of free fatty acids (FA) or by a combination of the two, making a total of 72 g/kg (GFA). The experimental design consisted of balanced 4 x 4 Latin squares with a 2 x 2 factorial arrangement of diets: the effects of G, FA and G*FA interaction. The FA diets significantly decreased silage intake, increased milk yield, decreased milk protein content, increased the concentrations of C18:0, C18:1, and C20:1 and decreased those of C8-16, and C18:3 fatty acids in milk fat. The FA diets also increased the concentration of nonesterified fatty acids in plasma, and decreased the digestibility of organic matter and neutral detergent fibre but increased that of fat. Glycerol decreased the molar proportion of acetate and increased the molar proportions of propionate and butyrate in the rumen, but the addition of glycerol did not have any effect on silage intake, milk yield or milk composition. Milk yield was highest when glycerol and free fatty acids were given together, showing a positive interaction.

A first cut of timothy, treated with water (untreated), formic acid (FA), cellulase + lactic acid bacteria (CB), cellulase + hemicellulase (CH) or cellulase + hemicellulase + a ligninmodifying enzyme (CHL), was ensiled in pilotscale silos. Silages, except CB, were fed to four male cattle, each equipped with a rumen and duodenal cannula, in a digestibility tricil designed as a 4 x 4 Latin square. The animals were fed a diet of 400 g of concentrate and 600 g of silage at a level of 70 g DM kg " ' live weight (LW").All enzyme-treated silages were well-preserved with a more extensive fermentation than in FA silage. The quality of untreated silage was poorer as indicated by higher pH and ammonia-N content. The amount of effluent from enzyme-treated silages ranged from 116 to 127 g kg ~ '; for FA and untreated silages values were 101 g kg"' and 80 g kg"', respectively. Total DM losses from enzyme-treated silages were higher than from FA silage (P<0-Q5). No significant differences were noticed between silages in the apparent digestibility of organic matter (OM), neutral-detergent fibre (NDF), acid-detergent fibre (ADF) or nitrogen (N). The apparent digestibility of cellulose was higher with enzyme-treated silages than with FA silage (P

The effects of different types of energy or protein supplementation on performance of cows given grass silage-based diets were studied. The possibility of maintaining high energy intakes by using different grain sources, barley or maize, or by the use of the physical processing of the barley was investigated. In addition, the relative quality of rapeseed meal as a protein supplement compared with alternative protein supplements was examined. In experiment 1 16 Finnish Holstein-Friesian cows were used in a cyclic change-over design experiment with eight diets and four 21- day periods. The concentrate supplements comprised a 2 ✕ 2 ✕ 2 factorial arrangement of two grain sources (barley (B) and maize (M)) given either ground (T–) or steam-rolled (T+), each supplemented with either rapeseed expeller (R) or a mixture of maize gluten and soya-bean meal (GS). Grass silage was given ad libitum and concentrates at a rate of 11·2 kg DM per day. M supplements increased milk, milk protein and lactose output (P < 0·05) and decreased milk urea concentration (P < 0·01) compared with B supplements. Blood β-hydroxy-butyrate (BHB) and plasma urea concentrations were higher (P < 0·01) for B than M diets. R supplements increased silage intake, energy-corrected milk yield and milk protein output and concentration (P < 0·05) compared with GS supplements. Steam-rolled grain decreased food intake, blood BHB (P < 0·05) and plasma and milk urea concentrations (P < 0·001). Steam rolling improved organic matter digestibility (grain ✕ processing interaction, P < 0·05) with M but not with B supplements.In experiment 2 four Finnish Holstein-Friesian cows fitted with rumen cannula were used in a balanced complete change-over design to evaluate ground or steam-rolled barley (T– v. T+) and two protein treatments (rapeseed expeller, R or a mixture of maize gluten/soya-bean meal/sugar beet solubles, GSS). Cows were given concentrates at 11·2 kg dry matter (DM) per day and offered grass silage ad libitum. There were no differences (P > 0·05) in food intake, digestibility or milk production and composition between treatments. Plasma urea concentrations (P < 0·01) and molar proportion of butyrate (P < 0·05) in rumen fluid were decreased with R compared with GSS supplements. The results showed that replacing B with M grain resulted in minor increases in milk production. Steam rolling of grain did not influence animal performance. Among the protein supplements R increased animal performance compared with GS supplement.

Fungal glucose oxidase and cellulase were used as silage additives in laboratory (25 l), pilot (3 m3) and farm scale (250 t) silos. In 3 m3 scale silos, pH and the concentration of acetic acid were lower and the concentrations of lactic acid and sugars were higher in the enzyme treated than in untreated silage. The concentration of butyric acid was equal to or lower than in formic acid treated silage in all experiments. Cell wall constituents were degraded in the silo by cellulase and thus more energy was available for lactic acid bacteria. With increasing levels of cellulase application, the disappearance of organic matter (OM) from nylon bags incubated for 1 to 12 h in the rumen of a dairy cow increased significantly (P

In order to examine the effect of two levels of concentrate and the effect of glucogenic feed (0 1/d (GO) or 1 1/d (Gl)) 16 multiparous and 16 primiparous Friesian cows were used in a factorial 2x2 design. The concentrate levels for multiparous cows were 11 kg/d (CI 1) and 15 kg/d (CI 5) and for primiparous cows 9 kg/d (C9) and 12 kg/d (CI2). The glucogenic feed consisted of propylene glycol, polyols, molasses and niacin. All the animals were offered wilted silage ad libitum. The experimental period started from calving and lasted for 12 weeks.Multiparous cows substituted concentrate for silage when glucogenic feed was not given whereas with glucogenic feed the effect of concentrate on silage dry matter intake (DMI) was minor. Glucogenic feed had a minor effect on milk production at the higher level of concentrate and a negative effect on milk production at the lower level of concentrate. Due to this interaction the milk yield response to the higher level of concentrate was higher with glucogenic feed. The low rumen degradable protein supply in C11G1 was probably the cause of these interactions.The milk production response of primiparous cows to the higher level of concentrate was low. After peak yield the plasma insulin concentrations were higher with the higher concentrate level. This was accompanied by higher liveweight gain.In conclusion, the response of multiparous cows to higher concentrate level depended on the supply of rumen degradable protein, whereas the comparable response of primiparous cows was * Financial support by the Agricultural Research Foundation of August Johannes and Aino Tiura 564 GLUCOGENIC FEED FOR COWS limited by milk yield potential and the needs of growth. The glucogenic feed showed an ability to increase plasma glucose and decrease the concentrations of ketones.

] in the concentrate mixture on feed intake, live weight gain and carcass characteristics of growing Ayrshire bulls were examined in a 3 x 2 factorial design. Twenty-eight animals with a mean initial hveweight (LW) of 268 kg were used. Molasses replaced a part of concentrate, which was based on a mixture (1:1) of barley and sugar beet pulp. Grass silage was offered ad libitum and the concentrate supplements at the rate of 100 g per LW°6 on air dry basis. YC (5 g day' 1 ) was top-dressed on the concentrate. Feed intake was not affected by the treatments but LW gain decreased linearly (P<0.05) with increasing rate of molasses (1.21, 1.16 and 1.09 kg day" 1 ; SEM 0.029). As the proportion of molasses increased from 0 to 200 g/kg concentrate the efficiency of feed conversion declined (linear effect P < 0.01) from 6.10 to 6.75 kg DM kg" 1 LW gain. YC had no significant effect either on feed intake (7.26 vs 7.49 kg day" 1 ) or LW gain (1.14 vs 1.17 kg day" 1 ). Yeast interacted with concentrate so that with M 0 LW gain was increased and with M 200 decreased by YC. The differences in carcass weight and carcass gain reflected a pattern similar to those in LW gain. Dressing proportion and fat grades were not affected by the treatments but carcass quality grade was better in animals receiving YC.