Abstract:
Proc. Aust. Soc. Anim. Prod. Vol. 16 GRAIN LEGUMES IN ANIMAL PRODUCTION SYSTEMS IN SOUTH AUSTRALIA INTRODUCTION P.I., HYND* Grain legume crops such as field beans (Vicia faba), field peas (Pisum sativum), and lupins (Lupinus angustifolius) have attained an important position in the cereal-growing/livestock regions of southern Australia, In South Australia alone, the area sown to grain legumes has increased from approximately 17,000 ha in 1977/78 to 70,000 ha in 1983/84, the main reason being that the grain legume crops are valuable in rotation with cereals, they fix atmospheric nitrogen and are high-yielding. To date the use of grain legumes has been largely confined to livestock feeding and the aim of this contract is to examine how the various grain legumes available in South Australia influence reproduction in the ewe, growth of young sheep, the yield and composition of milk in the dairy cow, and growth of pigs. THE INFLUENCE OF GRAIN LEGUME S UPPLEMENTS ON REPRODUCTI ON IN AUTUMN MATED BORDER LEI CESTER X MERINO EWES P-E- GEYTENBEEK* and W-G..ALLDEN* Autumn mating of the Border Leicester x Merino ewe results in high levels of both fertility and fecundity (Allden 1956) There is evidence to show that feeding lupins to crossbred ewes in the autumn is associated with higher ovulation rates (Davis et al- 1981) Little has been done to extend this work to other species of grain legumes which do not have the toxicity problems of grazed lupin crops, In commercial practice the principal deterrent to an autumn mating in southern Australia is the problem of 'finishing' lambs to market weight before the onset of the dry summer months and the associated factors of low quality feed and grass seeds, Satisfactory growth rates of weaned lambs when grazing standing crops of grain legumes (Allden and Geytenbeek 1980b, 1984) suggest that such crops can serve the dual purpose of 'finishing* the late lamb crop and maximizing ovulation rate in the autumn-mated crossbred ewe. In two successive seasons at the Mortlock Experiment Station, Mintaro, we studied the influence of field beans and lupins, when provided before and during mating to 'ewes grazing stubbleMATERIALS AND METHODS Experiment 1. Three groups each of 72 five-year old Border Leicester x Merino ewes grazing three barley stubble plots in a daily rotation were joined with vasectomized rams on 11 February 1983 for 14 days and entire Suffolk rams on 8 March for 42 daysThe ewes were individually fed daily for 14 days premating and the first 21 days of mating with 700 g/day of lupins or faba beans, The control group were unsupplementedLiveweight was recorded at intervals during 'teasing' and mating (Fig. 1) From mating to lambing the three groups grazed together but were separated again during lambingExperiment 2, In 1984 the original ewes were randomly allocated to three groups of 69 on the basis of live weight, body condition score and previous seasons production and rearing record- Ewes grazed oaten stubble, ran with vasectomized rams for 14 days and were fed 500 g daily of lupins, beans or no supplement. *Department of Animal Sciences, University of Adelaide, Glen Osmond, S-A-, 5064 26 Proc. Aust. Soc. Anim. Prod. Vol. I6 were performed on all ewes before vasectomized rams were Laparoscopies introduced on 21 February (Hl), just prior to mating on 6 March (H2), and thereafter at weekly intervals on those ewes mated in the preceding week (H3-H7). In all other details the design was similar to that for Experiment 1. Reproductive data has been analysed by the use of the Chi-square test- RESULTS AND DISCUSSION The ewes were approximately 10 kg heavier in Experiment 1 than a year later but liveweight changes were similar in the two seasons (Figure 1) Groups receiving supplements maintained weight in both seasons while the control group lost 2.3 kg in Experiment 1 and 3-l kg in Experiment 2 during the experiment. Lambing results for both seasons are shown in Table 1. In the first year the greater number of lambs born to the supplemented groups did not differ significantly from the controls though there were triplets in both the lupins The very high (9 sets) and beans (3 sets) groups and none in the controlslambing percentage in all groups (166% to 190%) confirms the findings of Allden (1956). In Experiment 2 ewes had lower live weights at joining and reproduction rates were lower than in the previous season (Table 1) There was no difference between the supplemented groups in the number of lambs born/ewe joined with the level in both being significantly (P < 0,05) higher than in the control flock. 27 Proc. Aust. Soc. Anim. Prod. Vol. 16 The major effect of the supplements was to reduce the proportion of non-pregnant ewes- This was associated with a higher proportion of ewes lambing to both first and subsequent services (Table 2). Table 1 The effect of grain legume supplements on reproduction in Border Leicester x Merino ewes in two seasons fwithin years, in rows, values with different letters do not differ significantly, P < O-05, Ovulation rates (0-R) of all groups prior to and throughout mating are shown in Table 2- At Harvest 1 on 21 February before association with Veasertt rams only 54 of the 206 six-year old ewes showed evidence of prior ovarian activityAfter twelve days with 'teasers' a high proportion of ewes in all groups had ovulated (H2). These figures suggest that even in February the onset of the breeding season for many first cross ewes is initiated by the introduction of the ramsOestrus activity in the pre-mating period was virtually restricted to the supplemented groups but this early oestrus promotion was not reflected in an earlier lambing. Table 2 The effect of grain legume supplement on oestrus, ovulation rate, lambing rate and ova loss in autumn mated Border Leicester x Merino ewes - 1984 $ Corpora lutea observed per ewe ovulating. Figures in parenthesis represent number of ewes with corpora lutea at that harvest, TtProportion of ova lost between ovulation and parturition5 Within rows values with different letters differ significantly, (P < O-05). 28 Proc. Aust. Soc. Anim. Prod. Vol. 16 Feeding supplement for fourteen days pre-mating had little effect on O-RHowever for the first ovulation in the mating period the supplemented groups had The major effect of the supplements was to a higher O-R- than did the controlsreduce the proportion of non-pregnant ewes. This was associated with a higher proportion of ewes lambing to both first and second services, The estimates of proportion of ova lost between ovulation and parturition range from 18-6s for the bean group to 30.8% for the controls, and are of the order reported by Edey (1969). Knight et al. (1975) noted that the number of ewes lambing increased in all cases where lupins were fed during joining. Those findings and our data support the hypothesis that the feeding of grain legume supplements may improve the uterine environment at the time of implantation and in early pregnancy, and so reduce early loss of embryos. Triple ovulations were recorded in only eighteen ewes, were evenly spread through treatments and resulted in only three triplet births, Ova wastage from the triple ovulators was, however, significantly reduced (P < 0.05) by the supplements. In two seasons the feeding of grain legume supplements at mating have resulted in small increases in the number of lambs born, When liveweight was high at mating the final benefit was small as a consequence of high mortalities in triplets (41.8% compared with 12-3s for twins and 6.5% for singles). Similar observations were reported by Donnelly (1984), When ewes were lighter at mating the major effect of grain legume supplements was to reduce the proportion of dry ewes. In both instances an estimated increase of 15% in the number of lambs weaned was required to cover the feed costThe similarity between the effect of beans and lupins on ovulation rates and the number of lambs born suggest the faba bean is a suitable alternative to the sweet lupin as a supplement. The crop will be grown in higher rainfall regions where the lack of harmful effects following summer rains is in its favour when the whole crop is grazed in situ. Other workers (Denney 1983, Croker et al- 1985) have reported variable responses in the reproduction rate of Merino ewes fed lupins. When we fed beans or lupins to the autumn mated crossbred ewe the biological gains have not been economically justified. The data of Hynd and Allden (this contract) will suggest that the grain legumes may be more profitably fed to finish the spring born lamb to a suitable market weight. LAMB GROWTH ON GRAIN LEGUME CROPS AND GRAINS P-I- HYND and W-G- ALLDEN Annual pastures in southern Australia at best provide only a maintenance diet for grazing sheep and cattle during the dry summer and are inadequate for finishing spring lambs to market weight. The major nutritional requirements of these lambs are for an adequate supply of metabolisable energy and for protein, some of which should be available for digestion in the intestines (Kempton et al- 1978)w Cereal grains can supply the former, but are deficient in protein for rapid growth, and in addition, can cause perturbations in rumen function (Bartsch and Valentine - this contract), The grain legumes,. on the other hand, are a rich source of protein as well as energy and should therefore be a useful supplement for growing lambs, but little was known of the relative value of the This has been various legume stubbles and grains for growth of young sheepexamined in a series of trials conducted in S.A, since 1978- 29 Proc. Aust. Soc. Anim. Prod. Vol. 16 Lamb growth on whole grain legume crops The liveweight gain of young sheep grazing mature legume crops has always exceeded that of sheep on either mature summer pastures or cereal crops (Table 1) Of the legumes, field beans and lupins have generally produced the highest growth rates, a reflection of agronomic superiority as well as the higher nutritive value of their herbage and grain. Field beans, for instance, have frequently out-yielded the other legumes on heavy soils in S-A,, thereby providing more metabolisable energy and protein per hectare, *Expt.l: **Expt.Z: ***Expt.3: Allden 6~ Allden & days. Allden, stubbles Geytenbeek (1980a) - young Merinos for 12 wk at 40/ha Geytenbeek (1984) - Suffolk x Merino store lambs for 100 unpubl. - pen study, Suffolk x Merino store lambs; of each crop plus 1000 g/d of each grain, Lamb qrowth on qrain legume stubbles The legume stubbles are more digestible and induce greater weight gains than cereal stubbles (Allden and Geytenbeek 1980b), but rapid growth is wholly dependent on the presence of unharvested seed in the stubble. Allden (unpubl,) has shown that even young lambs can effectively utilise legume stubbles- Dorset Horn x Merino lambs ranging from 5.8 to 23-O kg (3 to 8 weeks of age) were turned onto field bean and lupin stubble containing c-1000 kg/ha fallen grain. The rate of growth of weaned lambs was 181 and 172 g/d respectively (n-s.) for the 42 day experiment. When the lambs were suckled a further benefit of 128 g/d Growth rate of the weaners was not gain was observed (total gain 305 g/d)related to initial live weight indicating that young lambs could effectively utilise the legume residuesLegume qrains as supplements for young sheep. Two experiments were conducted to investigate the growth rates of young sheep fed legume or cereal grains as supplements to poor quality summer roughages- In the first experiment store lambs were ,group-fed on cereal chaff plus one of the following grains : Cyprus vetch, lupins, beans, peas or barley (30~70 chaff:grain) to simulate lot-feeding conditions. Dry matter intakes on the legumes ranged from 1040 to 1130 g/d while barley-fed sheep consumed only the legumes daily (P < 0,05). Liveweight gains of sheep on 810 g (216-283 g/day) were significantly greater (P < 0.001) than those on barley (14 g/day), there being no statistical differences among the legumes. 30 Proc. Aust. Soc. Anim. Prod. Vol. 16 The second experiment compared the hay intake and growth performance of young crossbred sheep (store condition), individually penned and fed 500 g/day of cracked grains (barley, lupins or beans)The meadow hay (2.0% N) was available ad libitum, Each grain was offered with or without prior treatment with Flavomycin (Hoechst, A-G-), an antibiotic which has%een predominantly used for growth promotion in non-ruminants, but which has recently been found to increase growth rate and feed efficiency in beef cattle (R. James pers- comm-). The effect of formaldehyde treatment of lupin grain was also examined to determine whether the utilisation of lupin protein could be improved. All grains depressed hay intake but the effect was greatest with barley (Table 2) The highest weight gains were achieved with the lupin supplement. Formaldehyde treatment did not significantly improve growth, possibly indicating a deficiency in the amino acid composition of lupin protein for growth, or that protein supply to the intestines was already adequate with this grainBeans produced significantly greater gains than barley which depressed growth relative to controls, Flavomycin increased gains on all grains but only barley utilisation was significantly improved. Table 2 Growth of penned lambs fed hay plus grains Values in parentheses are for Flavomycin (Hoechst AX.) treated grains (Flavomycin levels 15 ppm barley, 13 ppm beans, 7 ppm lupins)In the majority of our experiments lupin grain has produced the highest roughage intakes and growth rates, a result which may relate to a greater supply of intestinally digested protein (Kempton et al-, 1978) or to the effect of non-starchy carbohydrate on rumen functionThe grain legumes then are a valuable source of nutrients for growing sheep- The stubbles and unharvested grain can be utilised effectively by young lambs, the whole, mature standing crops can be grazed, or the grains can be used to supplement low quality roughages. In all cases growth rates are superior to those obtained on any other feedstuffs which are available over the ,dry summer period in South Australia, ACKNOWLEDGEMENT Financial support for the work in this and the previous paper was provided The technical assistance of by the Australian Meat Research committeeJ- Warwick, G- Ware and S. Salter is gratefully acknowledged- 31 Proc. Aust. Soc. Anim. Prod. Vol. I6 GRAIN LEGUMES IN DAIRY COW NUTRITION B.D. BARTSCH* and S.C, VALENTINE* In some parts of southern Australia particularly in South Australia, many cows are calved during the autumn period to take advantage of the higher seasonal milk fat price. This is particularly the case in non-irrigated areas where the growing season is not long enough to maintain the lactation curve on pasture alone, Hay and cereal grains have traditionally been the major feeds used during autumn prior to pasture being available, but in recent years grain legumes have been used to raise the protein content of rations and improve milk production (Bartsch and Wickes 1984). The feeding of cereal grains to dairy cows as the'major portion of the diet changes the fermentation pattern in the rumen and is generally associated with a decrease in fat content and an increase in protein content of the milk- In an experiment on the effect of proportion of lupin grain to hay in the rations of cows during early lactation, we found that even when more than 13 kg of lupin grain was fed per cow per day, cows continued to produce approximately 1 kg of milk fat per day with milk fat content being 4-O% and protein content 3.0% (Bartsch et al. 1985) The compositional differences between cereal grains and grain legumes (especially lupins) other than in protein content are therefore also of economic significance to the dairy industry. Compositional differences other than in protein content between grain legumes may also influence milk production- Cows fed lupin Pea or bean grains of similar protein content as supplements hay-based ration have produced 12% more milk and 18% more milk fat al- 1986) Table 1 the various compared to to a cereal (Bartsch et Composition (% dry matter) of barley grain and grain legumes When major changes occur in rumen fermentation due to the feeding of high levels of barley grain to dairy cows as supplements to hay, digestive disorders, reductions in hay intake and losses in production often result- This is due to the rapid fermentation of starch in the grain to volatile fatty acids and lactic acid resulting in a lowering of rumen pH below 5-8 and consequent reduction in the rate of fibre digestion- Grain legumes such as peas, beans and particularly lupins contain less starch and more fibre compared to barley grain (Table 1) Our work with cows fitted with rumen cannulae has shown that when legume grain is administered through the cannula twice daily as 70% of the total ration, the pH of the rumen does not fall below 5-8 in contrast to when barley (including 2% urea) is fed (Figure 1). Minimum rumen pH was reflected in rumen lactic acid concentration and may be related to starch content of the grains (Table 1) The diurnal variations in rumen pH were generally similar to those recorded by Watson et al- 1984 who found a lower minimum rumen pH by sheep offered whole *South Australia Department of Agriculture, Box 1671, G-P-O., Adelaide, 5001- 32 Proc. Aust. Soc. Anim. Prod. Vol. I6 wheat compared to those offered whole lupins. Ammonia-nitrogen concentration in the rumen of the cows offered hammermilled barley grain with 2% urea was below 5 mg/lOO mls for 7 hours of the 12 hour feeding interval (Figure 1). This suggests that ammonia-nitrogen concentration in the rumen may limit bacterial protein synthesis in the rumen of dairy cows offered cereal hay based diets supplemented with cereal grains (Pisulewski et al. 1981). Preliminary data (Hynd et al. 1985) on the rumen microbial population of cows fed hammermilled cereal and lupin grains indicate that the cows fed the lupins had a similar number of protozoa per ml of rumen fluid to those fed hay, but only one half to one quarter the number of protozoa compared to those fed barley, The possible beneficial effects of a reduced protozoa1 population, leading to an increased supply of bacterial protein to the small intestine, on production systems with high protein requirements has been discussed by Leng and Production responses and the rumen characteristics of cows fed grain legumes suggest that these grains are less likely to cause problems when introduced suddenly into a diet compared to cereal grain, We have studied the effect of the sudden introduction of hammermilled lupin grain into the diet of dry dairy cows by giving lupin grain twice daily (via a rumen cannula) up to 70% of previous voluntary hay dry matter intake, Minimum rumen pH occurred on day 3 following the sudden introduction of hammermilled lupins to the diet on day 1, but was above a pH of 6-O at all levels of lupins. When hammermilled barley grain was used, minimum rumen pH on day 3 was below 6-O at the higher levels of barley grain. The feeding of hay-based diets containing up to 80% hammermilled lupin grain over a 9 week period did result in some mild cases of bloat (Bartsch et al, 1985) We have recorded the ad libitum grain intakes of cows offered whole legume grains twice daily. Although cows ate more whole lupin grain than pea or bean grain, Valentine et al, (1983) found that it is necessary to hammermill lupin grain to maximize digestibility by dairy cows, When whole grains were fed to 33 Proc. Aust. Soc. Anim. Prod. Vol. 16 dairy cows as a supplement to roughage diets, 30% of the grains were excreted in the faeces- Since the dry weight of the whole lupin grains in the faeces was only 73% of that of the grains fed, the loss of whole lupin grain dry matter in the faeces was 22%. Dry matter digestibility of whole lupin grain was therefore 64.5% compared to 78,9% for hammermilled lupin grain. -The cost of whole lupin grain excreted in the faeces was more than adequate to off-set the cost of hammermilling. Rogers (1985) concluded that for cows at pasture, concentrate type is . likely to have little effect on production if less than 4 kg per cow per day is fed. However, with autumn calving cows where pasture is limited and supplementation is necessary, the type of grain supplement may well influence milk yield if larger quantities of grain are fed during early lactation to cows capable of relatively high levels of milk production. It also appears that the depression in the fat content of milk associated with the feeding of cereal grains with pasture may not occur as readily with grain legumes. However, high protein diets, particularly of readily degradable protein can result in induced ketosis, ammonia toxicity or reduced reproductive performance (Chalupa 1984). Whether in practice diets of legume grains and young pastures fit in this category needs to be established, The superiority of legume over cereal grains for feeding to cows on hay-based diets to increase milk production during early lactation has been demonstrated, Although the higher protein content of legume compared to cereal grain is likely to contribute to this response, other compositional differences between the grains are also implicatedThe feeding of large quantities of legume grains, especially lupins, with hay does not result in major disturbances in rumen metabolism and resultant changes in milk composition. These grains are relatively safe to feed but need to be processed to be effectively digested by dairy cows. There is a need to investigate the use of legume grains with pasture during early lactation to establish whether such a diet will improve milk production or have any detrimental effects on cow health or reproductive performance. ACKNOWLEDGEMENT We thank the Australian Dairy Research Committee for financial support. GRAIN LEGUMES IN PIG PRODUCTION R-L- DAVIES* INTRODUCTION Peas (Pisum sativum) have been grown as a food crop in South Australia since at least 1878 (Meinig 1962) Until 1979 only peas which had been rejected for human consumption and those which were surplus to that market's requirement had been available for stock feed, In 1978-79 pea production more than trebled to 31,000 t, and significant quantities were used. Pea production has continued to increase, to about 60,000 t in 1984085,and something like half the current pea crop is used in pig production. The nutritive value of peas for pigs has been studied in a number of countries (Henry and Bourdon 1977). Overseas and local work has shown that peas provide reasonably high levels of digestible energy (DE) and modest essential *South Australia Department of Agriculture, Box 1671, G-P-O., Adelaide, 500134 Proc. Aust. Soc. Anim. Prod. Vol. I6 amino acid levels, that the lysine in peas is highly available and that there is only limited evidence of inhibitory effects on growth at up to 40% of the dietLupin (Lupinus angustifolius) production has remained at about 18,000 tonnes per year since 1980-81. Lupins are a secondary but still significant grain legume in pig productionThere is continuing interest in other grain legumes, particularly faba beans (Vicia faba). Overseas work has shown varying responses when beans are substituted for other protein supplements in pig diets The most common recommendation is that they should not be used at more than 15-20s of the diet because of the risk of depressed performance (Simpson 1984) The reason for this problem is not understood though trypsin inhibitors, lectins, tannins and the glucosides vicine and convicine have been suggested as possible causes- A preliminary test on Fiord faba beans (Davies 1983) suggested they might have potential as a feed crop in some areas unsuited to peas and lupins. More recent work with 12 samples from commercial crops grown in 1982-83 has concentrated on three aspects of the evaluation of faba beans for growing pigs: nutrient analysis, lysine availability and evidence of inhibitory effects. MATERIALS AND METHQDS Twelve Fiord faba bean samples were collected from areas of the State where they may have potential. Crops were grown on soils ranging from grey mallee and sandy loam through red brown earth, terra rossa, rendzina and peat to heavy alluvium, Topsoil pH ranged from 5-8 to 8.8 and total soluble salts from 0.023 to 0.245%. January to December rainfall ranged from 386 to 770 mm, the number of sprays applied to control Botrytis fungus varied between nil and three and seed yield ranged from 0.4 to 3-2 t/ha, Nutrient levels other than DE were determined as described by Davies (1984) DE was measured on six of the 12 samples by total faecal collection from growing pigs and bomb calorimetry, Diets were based on wheat and contained 350 kg/t beans. In an experiment to estimate lysine availability sixty four pigs (mean weight 16 kg) were allocated to eight dietary treatments so that each treatment and sex was equally represented in four blocks of two adjacent pens, Four pairs of diets were fed, Two were based on wheat and soybean meal, formulated to 0.4 and O-48 g lysine/MJ DE (diets contained 87 and 130 kg/t soybean meal respectively) An additional 5-6 kg lysine HCl/t was added to one diet of each pair. The other two pairs were formulated to 0.48 g lysine/NJ DE, using wheat - and 311 kg/t peas or 314 kg/t faba beans (a mixture of six of the 12 samples). These diets also contained synthetic methionine, threonine and tryptophan to satisfy requirements of these amino acids (ARC 1981) One diet of each pair was supplemented with synthetic lysine as above, Pigs were fed individually at 3-l times their daily maintenance DE requirement until they reached 48 kg. Backfat thickness at the last rib was measured ultrasonically before slaughter and intrascopically on the carcasses. Results were interpreted using measured DE and lysine levels of the base dietsRESULTS AND DISCUSSION Table 1 shows the level and var iation of significant nutrients for the pig, with mean values for peas and lupins 35 Proc. Aust. Soc. Anim. Prod. Vol. 16 Results from the experiment on lysine availability are shown in Table 2The feed conversion ratio on all base diets improved with lysine supplementation (P < 0.0001). Daily gain on all base diets except the bean responded in the same way as feed conversion- When daily gain was corrected for differences in DE intake above maintenance, gain on all base diets responded significantly to lysine supplementation (P < O-0001). These responses provide the justification for estimating lysine availability of the base pea and bean diets. Lysine supplementation had no effect on dressing percentage or backfat thickness by either measure on any of the base diets (P > O_OI)Table 1 The nutrient composition of Fiord beans, peas and lupins (air dry basis) * Davies (1984) ** DE from Batterham (1979), amino acid data from Batterham et al- (1984). Table 2 Performance of pigs fed diets containing two levels of soybean meal, peas or faba beans; with or without synthetic lysine ** ADG corrected for differences in daily DE intake above maintenance Lysine availability was estimated by comparing adjusted conversion ratio versus lysine intake of pigs fed the pea with those of the two base diets containing soybean meal. lysine availability and a linear relationship between daily gain and feed and bean base diets One hundred percent growth performance 3 6 Proc. Aust. Soc. Anim. Prod. Vol. 16 and lysine intake on the soybean diets were assumed. Estimates differed slightly depending on the response criterion, with corrected ADG giving values of 98% and 97% availability for peas and beans respectively, and FCR giving values of 100% and 94% respectively. Both criteria indicate high lysine availability in pea and bean base diets, Given the agreement between this estimate and Batterham's for peas, it is unlikely that slope ratio assay on these beans would give substantially different results, This work suggests that Fiord faba beans have similar DE, calcium, phosphorus and selenium levels to those of peas. Lysine availability appears to be high but the level of essential amino acids is about 12% lowerWork on inhibitory effects is incomplete but has so far failed to demonstrate any deleterious effect of feeding diets containing 35% beans to growing pigsCONCLUSIONS Grain legumes are unusual in that they not only contain highly digestible energy substrates, but also are rich in protein, a feature which makes them an attractive feedstuff for protein-limited animal production systemsRapid growth and lactation in ruminants are two such systems and the grain legumes are superior to cereal grains for these purposes, However, much of the protein in the grain legumes is degraded in the rumen and ultimately excreted as urea- For this protein to be used efficiently for ruminant production in the future, it may be necessary to breed varieties which contain naturally protected proteins (e.g. tannin-containing cultivars)- Alternatively the legume protein could be used in non-ruminant rations, provided anti-nutritional components and poor essential amino acid availability do not depress feed utilisation efficiency. On present indications faba beans could be a valuable complement to peas and lupins in the diets of growing pigs, extending the areas where grain legumes can be grown economically, and providing a buffer against seasonal and marketing fluctuations. The feeding of legume grains, especially lupins, instead of cereal grains can improve milk production during early lactation when cows are fed a hay-based diet- The current over-production of milk and subsequent economic downturn in the dairy industry could well result in a decrease in the feeding of all grains. However, under these conditions the decision of which grain to feed becomes even more critical, and more work is required to evaluate these alternative grains for the supplementation of grazing dairy cows. There are two further areas of research into grain legumes for ruminant production which should be explored. The first is to elucidate the mechanisms Field beans achieved whereby grain legumes increase reproductive performancesimilar increases in ovulation rate to lupins, but the relative roles of protein More precise and energy in effecting these responses are still unclear. knowledge of the mechanism by which short term nutritional changes influence ovarian function is essential if efficient feeding regimes are to be promotedGrain legumes are valuable supplements for ewes grazing poor quality autumn residues but will be more economically used in the field or feedlot to promote growth in the early weaned and store lamb. The second research requirement is to determine the effects of the non-starch carbohydrates found in legume grains Evidence to date suggests that these on rumen function and nutrient supply. carbohydrates do not support large populations of protozoa nor do they depress rumen pH and cellulolysis to the same extent as the starches. 3 7 Proc. Aust. Soc. Anim. Prod. Vol. 16 REFERENCES 'The Nutrient Requirements of Ruminant AGRICULTURAL RESEARCH COUNCIL (1980) (Commonwealth Agricultural Bureaux: Slough, England). Livestock'AGRICULTURAL RESEARCH COUNCIL (1981) 'The Nutrient Requirements of Pigs-' (Commonwealth Agricultural Bureaux, Slough, England). ALLDEN, W-G- (1956) J- Agric. South Aust- 59: 337, Proc- Aust. Soc, Anim- Prod(1980a). and GEYTENBEEK, P-EALLDEN, W-G. 13: 249. Proc- Aust. Soc, Anim- Prod(1980b). ALLDEN, W-G. and GEYTENBEEK