New technologies related to the identification of bacterial communities in fresh forage and silage may give valuable detailed information on the best practices to produce animal feeds. The objective was to evaluate how management conditions during silage making manipulate the profile of bacterial communities and fermentation quality of grass silages. Silages were prepared from mixed timothy and meadow fescue grass using two compaction levels. As an additional treatment the grass was contaminated with soil and feces prior to tight compaction. Four additive treatments with different modes of action were applied: control without additive, formic acid-based additive, homofermentative lactic acid bacteria and salt-based additive. After 93 days the silos were opened, samples were taken and routinely analyzed. DNA extraction was carried out and PCR amplification of the bacterial 16S rRNA gene V4 region was performed using universal primers. The silage pH was higher for loose than tight compaction and higher for non-contaminated than for contaminated silages. Great shift was observed in bacterial profiles from fresh material towards silage. Lactobacillus genus was barely found on the relative abundance of fresh grass but became predominant in the final silage along with Sphingomonas genus. Use of additives improved fermentation quality and modified the bacterial profiles of grass ensiled under different management conditions.
Mycotoxin incidence in forage may heavily affect the amount of toxins consumed by cattle. However, many studies have focused on mycotoxin occurrence in cereals and there are less studies of forages, particularly of grass silages. For determining the occurrence of mycotoxins in farm silages under Northern European conditions in Finland, 37 grass silage and 6 whole-crop cereal silage batches were analysed separately for surface, core and, if present, visibly mouldy spots. Mycotoxins were found in 92% of the samples. All mouldy samples contained mycotoxins. Beauvericin was the most common mycotoxin in grass silages and roquefortine C in whole-crop cereal silages. In mouldy samples, beauvericin, mycophenolic acid and roquefortine C were the most common mycotoxins in the grass silage and mycophenolic acid in the whole-crop cereal silage. Aflatoxins were not found in any of the samples. On average, all samples contained more than one type of mycotoxin. Concentrations of mycotoxins varied considerably from very low to very high values. The results of this survey indicate that silage-fed ruminants can be exposed to a broad range of mycotoxins. The absence of visible moulds does not always indicate mycotoxin-free feed. All moulded samples contained mycotoxins and some at very high concentrations, and they contained more different types of mycotoxins than samples without visible mould. Thus, feeding mouldy feeds to animals should be avoided.
The objective of this study was to determine the effects of silage plant species (faba bean and field pea based whole crop legume-cereals vs. grass) on performance and meat quality of growing Aberdeen Angus (AA) and Nordic Red (NR) bulls. A 2×3 factorial design was used. The experiment comprised 30 AA and 30 NR bulls. Both breeds were randomly allotted to the three feeding treatments. The compositions (g kg-1 dry matter) of diets were: 1) grass silage (650) plus rolled barley (350), 2) faba bean-wheat silage (650) plus rolled barley (350) and 3) pea-wheat silage (650) plus rolled barley (350). The experimental diets were offered as total mixed rations ad libitum. The AA bulls grew faster, had better feed conversion rates and superior dressing proportion and carcass conformation compared to the NR bulls. Replacing grass silage by whole crop legume-cereal silages in the diet did not have remarkable effects on animal performance, carcass characteristics or meat quality.
1 November 2020 in The Journal of Agricultural Science
The effects of different barley grain preservation techniques on intake, growth and carcase traits of dairy bulls were determined in a feeding trial using 52 Holstein and 48 Nordic Red bulls which were allotted to four feeding treatments (five pens and 25 bulls per treatment). Spring barley was harvested with a conventional combine harvester and four different preservation techniques formed the four experimental treatments. Dry grain (DG) was dried to the targeted dry matter (DM) concentration of 870–880 g/kg and rolled within 7 days prior to feeding. High moisture grain treated with a formic acid-based additive (FA) was harvested and crimped on the targeted DM content of 700 g/kg. Low moisture grain treated with a urea-based additive (UR) and low moisture grain treated with a propionic acid-based additive (PA) were harvested and crimped on the targeted DM content of 800 g/kg. The bulls were fed with total mixed ration ad libitum. On DM basis, the diets included grass silage (500 g/kg), barley grain (485 g/kg) and a mineral–vitamin mixture (15 g/kg). Daily DM intake (DMI) and live weight gain were 6% higher when crimped grains were used instead of DG (P < 0.05). There were no observed significant differences in DMI, gain or carcase traits between high moisture and low moisture crimped grain treatments or between UR and PA. The current results show that producers have the option to vary grain preservation system without major changes to growth performance or carcase traits.