A review of the nutritional value of lupins for dairy cows

Abstract

Australia is the world’s leading source of lupin grain, producing ~1 million tonnes annually, of which 30% is used by the domestic livestock industry and the rest is exported for use in animal diets, including dairy cows. The domestic dairy industry uses ~70 000 tonnes annually, mainly as a supplementary feed source in pasture-based systems. Although much published information exists on the nutritive value of lupins for dairy cows, it tends to be fragmented and, in some important instances, exists only in the form of reports or publications outside the mainstream scientific journals. This paper aims to present a critical assessment of the current knowledge regarding the nutritional value of lupins as a feed for dairy cows, and offers recommendations for future research. For cows grazing pasture or fed diets based on conserved pasture or cereal hay, the mean fractional response to lupin feeding was 0.53 kg milk/kg DM lupins, with a range of 0–0.97 kg/kg. The mean fractional forage substitution rate was 0.54 kg DM/kg lupins, and this appeared to be independent of the type of basal forage. In experiments using cows fed iso-nitrogenous and iso-energetic total mixed rations, substituting oilseed protein such as soybean meal with cracked lupin grain had no significant effects on yield of milk, fat, and protein, but it reduced milk protein concentration and had mixed effects on fat concentration. There were no significant differences in milk yield or in fat or protein concentration when lupins were substituted for other pulse grains such as faba beans or peas. Treatment of lupin grain with heat or formaldehyde reduced lupin protein degradability in the rumen, but was not shown to have consistent benefits over untreated lupins in terms of increased milk yield. Substitution of cereal grains with an equivalent weight of lupins in dairy concentrate rations generally resulted in increased yield of milk, fat, and protein, and a higher fat concentration. The higher yield responses in most cases could be explained on the basis of the higher metabolisable energy content of lupins compared with cereal grains, although the contribution from a potentially lower incidence of rumen lactic acidosis could not be discounted. Feeding Lupinus albus lupins to cows significantly increased the concentration of C18 : 1 in milk and reduced that of C12 : 0–C16 : 0, thus shifting the fatty acid profile of milk towards national dietary guidelines for improved cardiovascular health in human populations. Although the review lists some recommendations for improving the nutritive value of lupins, current commercially available cultivars possess characteristics that make them attractive as a feedstuff for dairy cows.

Dietary sources of unsaturated fatty acids for animals and their transfer into meat, milk and eggs: A review

“…The lupin diet had a tendency to reduce the proportion of short-medium chain fatty acids in milk fat, especially C16:0, and to increase the proportion of C18:0 and MUFA. White et al (2007) noted that in general, when cereal grains were substituted with an equivalent weight of lupins, there was an increase in milk yield, fat and protein in addition to milk having a higher concentration of fat. Offering Lupinus albus to dairy cows significantly increased C18:1 c-9 in milk and reduced SFA C12:0-C16:0 compared to a control diet.…”

Nitrogen metabolism in dairy cows fed restricted amounts of grass–clover silage supplemented with seeds from narrow-leafed lupin or pea

“…Narrow-leafed lupins are coated by a fiber-rich hull corresponding to 240 g NDF/kg DM, which is two-to threefold than in peas and faba beans (Daveby and Åman, 1993). Crude protein and fat contents of narrow-leafed lupin are 350 g/kg DM and 65 g/kg DM, respectively (White et al, 2007), which is higher than for peas and faba beans. Legume grains generally have the disadvantage of a high ruminal degradability of their protein fraction when fed without previous heat treatment (Lund et al, 2004).…”

Follicle development, endocrine profiles and ovulation rate in adult Merino ewes: effects of early nutrition (pre- and post-natal) and supplementation with lupin grain

“…Thus, ovulation rate can be increased by short-term supplementation with lupins, a legume grain with high contents of metabolisable energy (ME) and protein that can be safely fed as an acute supplement in large amounts because it contains low concentrations of fermentable starch (White et al 2007). However, responses to shortterm lupin supplementation are variable and largely dependent on the ovarian population of antral follicles (Gherardi & Lindsay 1982, Leury et al 1990, Nottle et al 1997, Viñ oles et al 2010b.…”