Whole-crop Wheat Research Articles

Influence of crop stage of growth on aerobic-stability and chemical profile of enzyme-treated whole-crop wheat silage

Doubts have been expressed about the aerobic stability of whole-crop cereal silages. Urea and ammonia additives have proved effective in controlling aerobic deterioration (Deschard et al., 1988). The aim was to evaluate the effects of two commercially-produced (Finnish Sugar Co. Ltd., Helsinki) cellulase and hemicellulase mixtures (Clampzyme [CLZ] and Deezyme [DEZ]) on fermentation and aerobic stability of winter-sown wheat (cv Brock), harvested at four stages of growth.The experiment was of 4 x 2 x 4 x 2 factorial design. The crop was direct-cut harvested (precision chopped) and ensiled for 150 days in mini-silos (polypropylene sack enclosed in polyethene sack; 5.0 kg dry matter (DM) of crop; plastic-strip seals). Harvesting was at 4 moisture-content (g DM/kg) stages of growth: cut 1, 300 (heading); cut 2, 400 (mealy); cut 3, 500 (soft/medium dough); cut 4, 650 (hard dough). Enzymes were applied at 4 levels: 0, 0.3, 0.7 and 1.0 1/tonne (t) DM for CLZ and 0, 1.0, 1.3 and 1.7 1/t DM for DEZ. Silos were either evacuated and sealed immediately (IMM) or sealed after 24 h (DEL).

Ensiling characteristics of whole-crop small grains harvested at milk and dough stages.

Dynamics of the ensiling process and final quality of whole-crop wheat, oats, and barley harvested at the milk and the dough stage of maturity were studied using 2.2-liter laboratory silos. An ensiling period of 64 d was used. Silage DM was higher (P less than .05) at the dough than at the milk stage on d 0 and 64. Silage total N content was not different (P greater than .05) among small grain species or stages of maturity either at harvest or 64 d after ensiling. Overall, buffering capacity (BC) on d 0 was greater (P less than .05) in oats and barley than in wheat silages. Small grains had a greater (P less than .05) BC when harvested in the milk stage than when harvested in the dough stage. In all silages, pH had declined (P less than .01) by d 64, when it ranged from 3.8 to 4.1. During the ensiling period, lactic acid concentrations increased (P less than .01) and ranged from 6 to 11% of DM by 64 d of ensiling. Water-soluble carbohydrate (WSC) content was greater (P less than .01) in milk- than in dough-stage silages for each small grain species and declined (P less than .05) during the ensiling period. The WSC decline during ensiling was greater (P less than .01) for milk-stage than for dough-stage harvested forage. Water-soluble N increased during ensiling (P less than .01) and increased 100 to 200% by d 64 for all silages. Ammonia N increased during the 64-d ensiling period but never exceeded .2% of DM.(ABSTRACT TRUNCATED AT 250 WORDS)

Urea treated whole crop wheat for dairy cattle

Urea treated Whole Crop Wheat (WCW) provides a stable, alkaline high DM forage, which is a potential replacement for, or complement to grass silage. Harvesting at about 600 g DM/kg facilitates both optimum crop DM production and energy concentration within the crop. Urea treatment (40 kg/t DM) at harvest prevents fermentation during storage, and may increase the crop digestibility. The nitrogen status of the forage as ammonia is also increased. The aim of these experiments was to investigate the feeding value of WCW for dairy cattle, when offered as the sole basal feed.A spring wheat crop (var. Axona) was cut at about 600 .g DM/kg (hard dough stage), chopped using a conventional forage harvester and stored in an outdoor clamp silo. Urea was added at 40 kg/t DM during harvesting. After rolling, the clamp was sheeted with polythene for 125 days until feed out.

Intake and digestibility of urea-treated whole-crop wheat by growing heifers

The use of whole-crop wheat harvested at the hard dough (55-65% DM) stage has advantages of high yields of DM, and no effluent production. Treatment with urea prior to storage prevents fermentation or moulding, increases the nitrogen (N) content and may increase digestibility (Deschard et al, 1987; MacDearmid et al, 1988).The objective of this experiment was to investigate the intake and digestibility of urea-treated whole-crop wheat when fed alone, or when supplemented with an energy supplement (molassed sugar beet pulp) and a protein supplement (fish meal).

The effect of calcium and sodium hydroxides and of sodium acrylate on the fermentation and digestibility in vitro of ensiled whole-crop wheat and barley harvested at different stages of maturity

Whole-crop wheat and barley were each harvested at the soft-, medium- and hard-dough stages of grain development. Material from each harvest was ensiled in polythene bag silos without additive or after the addition of calcium hydroxide, sodium hydroxide or sodium acrylate at 50, 50 and 12.5 g kg −1 of the crop dry matter (DM), respectively. All silages were opened after 60 days. With advancing maturity there was an increase in the content of DM, starch and insoluble-nitrogen, but a reduction in water-soluble carbohydrates (WSC) and ash. When crops were ensiled without additives, only medium-dough barley fermented to give butyric acid. However, the addition of calcium hydroxide to crops of low DM (soft-dough) and medium DM (medium-dough) promoted the activity of clostridial bacteria giving rise to the production of butyric acid, but this did not occur with crops of high DM (hard-dough). Sodium hydroxide gave rise to butyric acid only at low DM, and to restricted fermentation at high DM content. Sodium acrylate restricted fermentation and prevented butyric acid production in all silages. Ensiling led to an average reduction of 5 percentage units in the digestible organic matter (DOM) of the control silages compared to that of the crops. Addition of calcium hydroxide and sodium acrylate gave values similar to the control silages. Only sodium hydroxide consistently increased DOM, the effect becoming more marked as the crops matured. The increases over the control silages were 10, 18 and 26 units for wheat and 15, 21 and 20 units for barley at low, medium and high DM, respectively.

Changes in the amino acid compounds of the whole-crop wheat during ensiling and after fermentation.

AbstractChanges in amino acid fractions of chopped low‐to‐medium protein whole‐crop wheat were studied at four stages of maturation and at two stages after a 24 h wilting period. Tests were carried out after an ensiling period of 90 days, and after a further 7‐day post‐fermentation aerobic exposure. Total amino acids contents in the dry matter during the fermentation period remained stable. Quantities of essential amino acids decreased during maturation and fermentation and remained stable during post fermentation aerobic exposure. The highest amino acid concentrations recorded in the fresh material were those of arginine, lysine, glutamic acid, alanine, leucine, glycine and aspartic acid. Free amino acids varied from a low level in the fresh material < 10% of the total amino acids to ca 65% after the aerobic process. Ammonia‐N content increased in the silage and remained relatively stable on post fermentation aerobic exposure. The concentration of all free amino acids increased except arginine and glutamine during the ensiling period and post fermentation aerobic exposure. After wilting, an increase in free amino acids and a decrease in insoluble amino acids was recorded. The changes in concentration of 18 amino acids during ensilage and following post fermentation aerobic exposure are given.

Studies on the aerobic deterioration of whole-crop cereal silages

SUMMARYAs a result of the treatment of made whole-crop barley silage with antimicrobial agents which are specifically inhibitory to fungi or bacteria, it was shown that the subsequent aerobic deterioration was essentially caused by yeasts. These microorganisms were instrumental in the rise in pH, the increase in temperature and the loss of dry matter observed. The filamentous fungi, like one group of bacteria (the streptomycetes), apparently had no part in the process. Bacteria, such as the lactobacilli and particularly proteolytic bacteria, may have had a role in the terminal stages of deterioration, although it was considered more likely that the yeasts again were involved.The whole-crop wheat silage employed in this work was stable in air, a factor attributed to the combined antimicrobial effects of butyric acid present and the relatively high dry-matter content.