When available, wheat bran is often a component of the concentrate in ruminant diets, due to its content of important nutrients: protein, minerals, fibre and starch. Maximum recommended inclusion rates are 10% in calves, 20% in dairy cows, 25% in beef cattle, 5% in lambs and 20% in ewes (Ewing, 1997). It has a slightly laxative effect, partly because the bran fibre is only moderately digested (Göhl, 1982).
Like maize grain and soybean meal, wheat bran is such an important staple of ruminant diets that most trials involving wheat bran are about replacing it with local ingredients, as described in the following paragraphs.
In Bangladesh, in a comparison of fishmeal and wheat bran diets for local lactating cows, it was concluded that the use of wheat bran resulted in slightly higher net returns over feed costs from selling milk due to the lower cost of the wheat bran diet (Khan et al., 1992). In Pakistan, a comparison of maize bran, wheat bran and rice bran for milk production of Holstein Friesian cattle showed that the wheat bran diet reduced milk yield compared to maize bran, but was better than rice bran (Tahir et al., 2002). In India, crossbreed dry cows on a straw diet supplemented with wheat bran gave superior results (feed intake and nutrient utilization) than those supplemented with deoiled rice bran (Singh et al., 2000).
In the USA, supplementation of beef cows and steers consuming low-quality, tallgrass prairie forage with wheat offals, bran or second clear (a high-starch product), and soybean meal showed that the nature of the milling by-product did not affect performance, intake and digestion of low-quality forage. The degradable protein intake was sufficient to mask any negative effects exerted by increasing levels of starch (Farmer et al., 2001). Supplementation of steers grazing endophyte-free fescue pasture with wheat bran at 0.48% of live weight increased live weight gain, but less than supplementation with cracked maize (Hess et al., 1996). In India, the supplementation of crossbreed bulls fed chopped green sugarcane tops with a concentrate mixture of wheat bran (50%) and lentil chuni, a by-product of lentil processing (50%), resulted in better intake, nutrient digestibility and growth than when the supplement contained only wheat bran or only lentil chuni. This was explained by better rumen fermentation with the wheat bran + lentil chuni supplement (Gendley et al., 2002; Gendley et al., 2009).
In India, in growing lambs fed wheat straw as the sole forage, replacement of maize grain with the cheaper wheat bran reduced the cost of the concentrate mixture, as well as feed cost per unit of live weight gain. Feed conversion efficiency was not affected and it was concluded that half of the maize grain could be safely and economically replaced with wheat bran in the concentrate mixture of growing lambs without reducing lamb growth rate (85-90 g/d) (Dhakad et al., 2002). In adult sheep, barley grain supplementation could be replaced with wheat bran at up to 50% of the diet (Singh et al., 1999). In Ethiopia, body weight was unchanged in Farta sheep fed hay alone or supplemented with either wheat bran or niger seed meal (Guizotia abyssinica), or with mixtures of the two feeds (Fentie et al., 2008).
In India, wheat bran supplementation improved the utilization of various nutrients in goats fed mixed straw as the roughage source (Maity et al., 1999). In Brazil, weight gain and food conversion were not affected by the inclusion of rough wheat bran instead of maize in the diets of growing goats. It was concluded that up to 14% wheat bran could be included, as the diet contained less than 50% NDF (Dias et al., 2010).