Lathyrus (Lathyrus cicera cv. Chalus) : a potential new ingredient in pig grower diets.

Abstract

12A 12A Lathyrus (Lathyrus cicera cv.Chalus): a potential new ingredient in pig grower diets B.P. Mullan, C.D. Hanbury, J.A. Hooper, R.R. Nicholls, C.R. Hagan and K.H.M Siddique Agriculture Western Australia, Locked Bag No 4, Bentley Delivery Centre WA 6983 In low rainfall (<400 mm p.a.) regions of southern Australia field peas are one of the few well adapted pulse crops but, in recent years, problems with fungal diseases have caused a decline in the area sown to this crop. Recent research at the Centre for Legumes in Mediterranean Agriculture in WA suggests that some species of Lathyrus are adapted to low rainfall regions (250 500 mm p.a.), particularly on fine textured alkaline soils. Compared to the chemical composition of lupin seed ( Lupinus angustofolius) , Lathyrus cicera (cv. Chalus) is lower in crude protein (270 vs 320 g/kg) and fat (5 vs 58 g/kg) but has relatively more total lysine (16 vs 13 g/kg) (Hanbury, unpublished). The major concerns are the higher concentrations of trypsin inhibitor activity, chymotrypsin inhibitor activity, and the presence of a neurotoxin identified as bNoxalyl La, bdiaminopropionic acid. Castell et al. (1994) reported a significant linear reduction in voluntary food intake (VFI) and average daily gain (ADG) when grower pigs were fed diets containing up to 400 g/kg Lathyrus sativus, which was attributed to the presence of these antinutritional factors (ANF). In the current experiment, seed from new breeding lines was fed to Table 1 growing pigs as a replacement for soybean meal. Diets were formulated to be isonitrogenous and isoenergetic (14.0 MJ DE/kg, 0.70 g available lysine/MJ DE), and were fed ad libitum to a total of 24 female pigs housed in individual pens. Results indicate that increasing the inclusion level of Lathyrus cicera up to 300 g/kg of the diet had no significant effect on either VFI, ADG or feed conversion ratio (FCR), neither for the initial phase of the experiment nor over the total time of the experiment. There was also no significant effect of inclusion level on carcass weight, dressing percentage or depth of subcutaneous fat. A lack of difference in either weight of liver or kidney, unlike results from other studies (Castell et al. 1994), indicates that the concentrations of ANF in current lines of Lathyr us cicera are sufficiently low not to cause a problem when the seed is fed to pigs of 16110 kg. Castell, A.G., Cliplef, R.L., Briggs, C.J., Campbell, C.G. and Bruni, J.E. (1994). Evaluation of lathyrus (Lathyrus sativus L.) as an ingredient in pig starter and grower diets. Canadian Journal of Animal Science 74, 529539. Performance of growing pigs fed diets with increasing concentrations of Lathyrus. 0 16.0 109.3 899 100 16.0 110.0 896 200 16.1 109.0 895 300 16.0 110.7 912 P= 0.996 0.906 0.956 LSD 1.12 5.01 69.7 Lathyrus (g/kg) Liveweight (kg) _ start Liveweight (kg) _ end ADG (g) VFI (kg/d) Day 0 to 40 Day 0 to 97 FCR Day 0 to 40 Day 0 to 97 Liver wt (g) Kidney wt (g) 1.46 1.96 1.38 1.76 1.38 1.77 1.48 1.81 0.346 0.444 0.148 0.290 1.91 2.18 1794 381 1.87 1.97 1866 360 1.77 2.05 1779 401 2.01 1.99 1780 383 0.480 0.405 0.661 0.651 0.202 0.279 168.8 68.4 Recent Advances in Animal Nutrition in Australia, Volume 12 (1999)