The effect of supplementation of grass silage with rapeseed meal or Gasol-treated barley on the performance of growing cattle

Abstract

Grass silage was offered ad libitum to 16 Ayrshire cattle in a 2 x 2 factorial experiment lasting 196 days. The silage was supplemented with barley preserved with 0.85 % of propionic acid (PAB) or 1.28 % Gasol solution (GB) 45 g DM/kg W0.75. Four of the animals in PAB and GB groups received no protein supplement(NPS) and four of the animals in both groups received extracted rapeseed meal as protein supplement(RSM). RSM was fed according to UDP (undegradable feed protein) requirements. The average age of the animals at the beginning of the experiment was 86 days and the average liveweight 106 kg. The average daily gains were 1066 and 1070 g/d for PAB and GB groups and 1012 and 1124 g/d (P < 0.01) for NPS and RSM groups. In feed intake and feed conversion there were no significant differences between the groups. Supplementation of silage barley diet with RSM increased the digestibility of organic matter from 71.1 to 73.5 % (P < 0.05), of crude protein from 62.8 to 67.4 % (P < 0.05) and of crude fibre from 57.2 to 60.2 % (P < 0.05). Both barleys were well preserved and there was no deterioration during the storage. The degradation rates of DM, crude protein and starch determined by nylon bag method were lower in GB than in PAB. Crude protein disappearances in 9 hours were 46.6 % for GB and 76.4 % for PAB. The utilization of absorbed protein calculated by factorial method averaged 0.566 ± 0.01 in the four different groups. Plasma urea N level was higher (P < 0.05) in the RSM than in the NPS group. The proportion of acetic acid in the rumen VFA was lower (P < 0.05) and that of propionic acid higher (P < 0.01) in the RSM than in the NPS group. PAB resulted in a higher (P < 0.05) proportion of propionic acid in rumen VFA than did GB.

Need for protein supplementation in the diet of growing dairy bulls fed total mixed ration based on moderate digestible grass silage and barley

“…In agreement with Huuskonen et al (2007a), RSM supplementation had no effect on OMD in the present trial, which is in line with the lack of significant effect on DMI. Inversely, the CP digestibility was slightly higher with the RSM diet than with the C diet, which is in accordance with the results of Huhtanen et al (1985), Aronen and Vanhatalo (1992), Aronen et al (1992) and Huuskonen et al (2007a). Some of the increased apparent digestibility of CP on the protein-supplemented diets may have reflected the better digestibility of protein, while most of the increase is only apparent, being attributable to the decreased proportion of faecal metabolic nitrogen recovered in faeces with increasing CP content (Minson 1982).…”

“…In some earlier studies on growing dairy bulls with separate feeding the RSM supplementation increased the intake of hay (Aronen 1990) or grass silage (Aronen 1990, Aronen and Vanhatalo 1992a but, for example, Huhtanen et al (1985Huhtanen et al ( , 1989 Differences between the diets were compared using an a priori test (Dunnett's test) so that comparison of the diets was based on the C diet. Contrasts: (1 = C vs. RSM), (2 = C vs. WDS),…”

Beef production as influenced by stage of maturity of grass for silage and level and type of supplementary concentrates

“…However, in experiments with grass silage, results have been somewhat contradictory. Huhtanen et al (1985), Steen (1988), Aronen (1990) and Moloney (1991) did not find any change in voluntary grass silage intake when protein supplements were included in the diet, while Aronen (1991) and Aronen and Vanhatalo (1992) recorded an increased grass silage intake with a resultant enhancement in LWG of bulls.…”

“…Special attention was paid to possible interactions between the stage of maturity of grass for silage and the type of the supplementary concentrates (i.e., barley or barley together with RSM) to find out whether the effect of RSM depends on the protein and energy content of the grass silage. Similarly, the interaction between the protein supplementation and the level of concentrate in the diet was ofinterest, because earlier findings by Waterhouse et al (1983) suggested that lower responses to protein supplementation were to be expected for diets with a high concentrate level.In some experiments (Hakkola 1985, JokiTokola 1991, Aronen and Vanhatalo 1992), the positive effect of protein supplementation on LWG was sustained throughout the experiment, while in others (Huhtanen et al 1989, Aronen 1990) the positive effect of RSM on LWG was restricted to the early phase of the growth period (i.e., live weight below 300 kg). Therefore, the manner in which the treatment effects and their possible interactions change with the phase of the production experiment was examined in the present study.…”

“…In some experiments (Hakkola 1985, JokiTokola 1991, Aronen and Vanhatalo 1992), the positive effect of protein supplementation on LWG was sustained throughout the experiment, while in others (Huhtanen et al 1989, Aronen 1990) the positive effect of RSM on LWG was restricted to the early phase of the growth period (i.e., live weight below 300 kg). Therefore, the manner in which the treatment effects and their possible interactions change with the phase of the production experiment was examined in the present study.…”