Energy and protein value of lupin seed as a production ration or as a supplement for sheep fed chaffed wheaten hay

Abstract

Lupin seed was evaluated as a supplement to cereal hay and as the sole component of a production ration, by measuring energy, nitrogen (N), and carbon balances in 4-6 adult wether sheep. Seven diets of different combinations of lupin seed and chaffed wheaten hay were fed in sequence to 4 sheep. The hay was offered as a restricted ration of 800 g/day with and without 100 g lupin seed/day, and ad libitum with and without 2 levels of lupin seed (100, 400 g/day). In addition, lupin seed alone was offered at near maintenance and ad libitum to 6 sheep. The dry matter (DM) content of the wheaten hay contained 7.7 g N/kg DM and 572 g cell wall organic matter (CWOM), and its gross energy (GE) value was 18.1 MJ/kg DM. The GE was 49% digestible, and its metabolisable energy (ME) value was estimated at 6.4 MJ/kg DM at ad libitum intake levels. Corresponding values for the lupin seed fed alone were 49 g N, 199 g CWOM, 20.1 MJ GE, 86% digestible energy, and 15.7 MJ ME/kg. Ad libitum intakes of wheaten hay were below that required to sustain energy maintenance, but total DM intake was increased substantially with 100 g/day of lupin seed supplement. At higher levels of supplementation some substitution did occur, although the response was variable. Methane production was reduced by increasing the level of lupin seed in the ration, but ME and heat (both expressed in relation to DE) and energy balance (expressed in relation to ME) could each be effectively described by single rectilinear relationships, suggesting that the energy value of lupin seed was similar if used as a production ration or as a supplement. Energy values of lupin seed fed alone compared favourably with published values for other leguminous seeds and some cereal grains. Net availability of ME for gain was estimated to be 61%. Urinary N loss, in terms of apparently digested N or available energy, was very high when lupin seed was fed alone, indicating that protein retention was low compared with legume forages of similar N and cereal grain (e.g. oats). Therefore, although leguminous seeds have rely high levels of protein and obvious potential as energy and N supplements, it may not be valid to presume they are ipso facto important sources of amino acids for ruminants. High energy availability and a low potential for protein deposition would imply a significant diversion of energy into fat with such diets.

Biofuels agriculture: landscape‐scale trade‐offs between fuel, economics, carbon, energy, food, and fiber

“…Food i , s is a layer quantifying the amount of biofuels coproducts (t ha −1 , ‘Agricultural productivity’) and α i is the GHG emissions (t CO 2 −e t −1 ) from coproduct consumption and waste by sheep. We used a value of α i =0.357 t CO 2 −e t −1 of coproducts for i = Wheat ( B ) and Canola ( B ) assuming that 1 ton of coproducts feeds 2.5 sheep yr −1 (Margan, 1994) and sheep emit 0.1428 t CO 2 −e head −1 yr −1 (Department of Climate Change, 2009). Layers of the mean annual net life‐cycle GHG emissions (negative values represent net GHG abatement in t CO 2 −e ha −1 yr −1 ) from biofuels agriculture GHG Biofuels, s were calculated as the average of GHG Wheat(B) , s and GHG Canola(B) , s .…”

“…We used values of for i = Wheat ( F ) and for i = Lupins ( F ) derived from simapro 7.2 representing the energy required for transporting lupins to other farms as stock feed via a distributor. To represent the energy content of food products we used values of for i = Wheat ( F ) from Lin et al (1987) and for i = Lupins ( F ) from Margan (1994). We calculated net energy layers E i , s (MJ ha −1 yr −1 ) for i = Grazing ( F ) based on a uniform rate for pasture management per unit area ω i (MJ ha −1 yr −1 ), the energy use in post‐farm‐gate stages of the product life cycle (transport, processing) for meat (MJ head −1 ) and wool (MJ kg −1 ), and the energy content of meat products (MJ head −1 ) such that where Q 1 i , s is the grazing productivity, Q 2 i is the wool production rate, and TRN i is the proportion of the sheep herd sold for slaughter as described earlier.…”

Understanding the nutritional chemistry of lupin (Lupinus spp.) seed to improve livestock production efficiency

“…In single-stomached animals and ruminants, energy contained within monosaccharides absorbed from the small intestine is utilized differently from volatile fatty acids derived from fermentation taking place in the hindgut (or rumen in the case of ruminants). For ruminants, high levels of fermentable NSP and negligible levels of starch in lupins contribute to the high ME value (Margan, 1994). Typical ME contents of lupins for sheep are 12Á2 MJakg (on an air-DM basis) for L. angustifolius and 12Á5 for L. albus (Petterson et al 1997) with rumen degradable protein ranging from 420 to 950 gakg (érskov & Macdonald, 1992; Table 4).…”

“…Dixon & Hosking (1992) suggest that most studies of ruminant degradability of lupins under practical conditions report high degradation rates of 800 gakg or more. Although the method of seed preparation can in¯uence the proportion of lupin protein that`by-passes' rumen fermentation, in most instances the proportion of lupin protein and amino acids that reach the abomasum intact is quite low (Dixon & Hosking, 1992;Margan, 1994).…”

Opportunities for energy efficiency and biofuel production in Australian wheat farming systems

“…Alternatively, 1.0 hectare under wheat and pasture rotation is made up of the inputs into 0.5 hectares of wheat (with 1.1 tonnes of wheat produced) plus all of the inputs into 0.5 hectares of pasture (which has no grain output). Energy values of grain were taken from the literature: wheat grain 18 MJ/kg [17], canola seed 26 MJ/kg [29] and lupin grain 20 MJ/kg [30].…”