Peri-partum feeding of canola meal or lupins to Merino ewes does not improve wool production of their lambs

Abstract

Animal Production in Australia 1998 Vol. 22 PERI-PARTUM FEEDING OF CANOLA MEAL OR LUPINS TO MERINO EWES DOES NOT IMPROVE WOOL PRODUCTION OF THEIR LAMBS J.E. HOCKING EDWARDS, P.M. MURPHY, R.H. DAVIDSON, G.M. ALLEN and J.T.B. MILTON Faculty of Agriculture (Animal Science), The University of Western Australia, Nedlands, WA 6907 Hocking Edwards et al. (1996) found that the ratio of secondary to primary follicles (S:P) of twin lambs from ewes supplemented peri-partum with canola meal was higher than twins from ewes fed a maintenance diet and this supplement increased the S:P ratio in lambs from twin rather than single bearing ewes. The present study reports the clean fleece weight, fibre diameter and staple length of these lambs at eight and 17 months of age along with measurements on lambs from ewes supplemented with lupins to provide the same amount of CP and ME as ewes fed the diet with canola meal. Pregnant Merino ewes on dry standing pasture were supplemented with ad libitum oaten hay and either lupin seed at 380 g/head/day (maintenance diet) or 780 g/head/day (lupin diet) or 580 g/head/day of lupin seed plus 230 g/head/day of pellets containing canola meal (65%), lupin seed (24%), oat grain (10%) and calcium hydroxide (1%) (canola diet) from four weeks pre-partum to one week post-partum. The animals from all groups were run together except during the five week supplementary feeding period. Lambs were shorn at eight months and 17 months after birth and their fleeces were weighed and midside samples were collected. Mean and c.v. of fibre diameter of 2000 fibres was measured with an Optical Fibre Diameter Analyser and mean staple length of 10 staples was measured with an Agritest Staple Length machine. The results were analysed by repeated measures analysis of variance. For all measurements there was a significant effect of age on the wool production parameters (P<0.05) but there was no interaction between age and treatment. This implies that there is no long term effect of peripartum supplementation of the ewe on the wool that their lambs produce. Furthermore, supplementing the ewe had no effect on clean fleece weight, mean fibre diameter or c.v. of fibre diameter of their lambs nor was there any difference between twins and singles in mean (P>0.05; Table 1) or c.v. of fibre diameter. However, twins produced less wool than single born lambs (P = 0.001) but this difference was less at 17 months of age indicated by a significant interaction between age and litter size (P = 0.009). Lambs from ewes fed a maintenance diet had longer staples than lambs from ewes supplemented with lupins (P = 0.021; Table 1). Table 1. Least square means and their standard errors for clean fleece weight (CFW, kg), fibre diameter (FD, �m) and staple length (SL, mm) of lambs from ewes fed at maintenance or with additional lupins or canola meal four weeks pre-partum and one week post-partum. Results are combined for wool sampled at eight and 17 months after birth Mai nt enance CFW FD SL Single Tw i n Single Tw i n Single Twin 1.9�0.08 1.7�0.08 19.7�0.30 20.0�0.31 69.1�1.68 66.3�1.76 Lupin 2.0�.0.08 1.7�0.08 19.5�0.32 19.5�0.30 64.8�1.74 60.9�1.65 a b Canola 2.0�0.09 1.7�0.08 20.0�0.32 19.7�0.32 66.5�1.78 65.3�1.76 a b a b ab Values within columns with different small superscripts are different (P<0.05) Values within rows with different italic superscripts are different (P<0.05). The results indicate that additional supplementary feeding of ewes over the last four weeks of pregnancy and the first week of lactation is unlikely to affect the wool producing ability of their lambs, despite that feeding canola meal alters the S:P ratio of the follicles of the lambs. This work was partly funded by the Wool Research and Development Corporation. HOCKING EDWARDS, J.E., MURPHY, P.M., DAVIDSON, R.H. and MILTON, J.T.B. (1996). Proc. Aust. Soc. Anim. Prod. 21, 378. 422