Digestible energy of wheat and oat grains when fed to sheep

Abstract

In pen feeding trials with eight Merino wethers, digestion coefficients were estimated for rations of cereal chaff-wheat grain-oat grain mixture, and wheat grain and oat grain fed separately at two levels of intake. Digestion coefficients for wheat and oat grain fed at 675 g/day in a double crossover experiment were dry matter 89.4, 80.8 per cent, organic matter 90.1, 82.6 per cent, protein 82.3, 77.6 per cent, ether extract 84.1, 90.9 per cent, crude fibre 33.2, 59.9 per cent, nitrogen free extractives 93.2, 85.8 per cent, energy 88.1, 81.0 per cent, total digestible nutrients 91.6, 87.1 per cent, and starch equivalents 90.7, 85.7. When these grains were fed at 785 g/day there was about 10 per cent improvement in crude fibre digestibility for both grains and 1-2 per cent improvement for other estimations with oats but not with wheat. The gross energy content of the wheat and oat grains when fed at 675 g/day was 4407 and 4700 calories/g dry matter. The digestible energy of the wheat in calories/g dry matter and organic matter was 3869 � 30, 3933 � 30 and for oats 3791 � 59, 3910 � 61. When fed at 785 g/day these values for wheat were 3850 � 50,3911 � 51 and for oats 3796 � 34, 3913 � 51. A highly significant relationship was found between energy and dry matter digestibility which for wheat diets was Y = 1.074x 7.840. r = 0.993 (P<0.001), and for oats and the mixed diet of cereal chaff-oat grain-wheat grain, Y = 0.983x + 1.550. r = 0.996 (P<0.001) where Y = energy and X = dry matter digestibility and r = the coefficient of correlation. Because of the similar digestible energy content of, and the body weight gains of sheep on, these two grains it was concluded that under the present conditions these grains were equivalent weight for weight.

Nutrient Requirements of Domesticated Ruminants

“…Mean values in the report of the MAFF Standing Committee on Tables of Feed Composition (MAFF 1990) are in the range of 18.2 to 19.0 MJ/kg for various conserved forages (grasses and legumes as hays or artifi cially dried, grass silages and maize silages with DM contents determined by toluene distillation), and 18.4 to 18.9 MJ/kg for barley, wheat, maize and sorghum grains. Compared with those grains, oats tend to have higher EE (ether extract; crude fat) content (50 g/kg DM, or more) and GE often exceeds 19 MJ/kg DM (Nottle 1971;Margan et al 1987); values for lupin are around 20 MJ/kg DM and whole cottonseed around 23 MJ/kg DM. Brassica (e.g.…”

“…In drought feeding, the recommendation of the NSW Department of Agriculture (Freer et al 1977;Clark 1980) that the ME of all cereal grains is to be taken as 12 MJ/kg as fed (10% moisture assumed) is supported by the work of Nottle (1971). However, when animals are given oats in circumstances other than drought feeding, account should be taken of the variability in its M/D.…”

The Influence of Climate, Soil and Pasture Type on Productivity and Greenhouse Gas Emissions Intensity of Modeled Beef Cow-Calf Grazing Systems in Southern Australia

“…The ME content (MJ/kg DM) of the pasture was estimated by [ 13 ] as δ dm × 16. The GE content of pasture was assumed to be 18.4 MJ/kg DM [ 45 ] and grass silage (based on the findings of [ 46 , 47 ] a 3% higher GE content compared to pasture was assumed) and grain [ 48 ] were both 19 MJ/kg DM. The following assumptions were fixed in the prediction of manure CH 4 emissions from dung and urine deposited on the pasture based on Australian GHG Inventory values which are: ash content of manure of 0.08 of DM; urinary energy content of manure of 0.04 of GE intake; CH 4 producing capacity of manure of 0.19 m 3 kg −1 volatile solids; CH 4 conversion factor of 0.015 [ 3 , 49 ].…”

“…The ME content (MJ/kg DM) of the pasture was estimated by [ 13 ] as δ dm × 16. The GE content of pasture was assumed to be 18.4 MJ/kg DM [ 45 ] and grass silage (based on the findings of [ 46 , 47 ] a 3% higher GE content compared to pasture was assumed) and grain [ 48 ] were both 19 MJ/kg DM.…”