Abstract

Thirty two twin - and thirty two single - bearing ewes (W = 50.6 ± 0.13 and 48.9 ± 0.11kg respectively) were individually penned indoors nine weeks before lambing. Four dietary groups, balanced for pregnancy status were established utilising a 2x2 design for energy (E) and protein (P) levels. These were E1P1; E1P2; E2P1; and E2P2 (groups 1 - 4 respectively) and were based on a lucerne hay and barley diet. E1 and E2 were designed to promote 0 and +50g/d gain in maternal bodyweight, respectively. P1 and P2 contained approximately 120 and 200gCP/kg DM, respectively, the difference achieved through the inclusion of fishmeal in P2 diets. From seven weeks prior to and until parturition all ewes were trickle infected with 10,000 Teladorsagia circumcincta and 7,000 Trichostrongylus colubriformis larvae per day. Faecal egg counts were determined weekly from five weeks prior to and until three weeks after parturition when worm burdens were determined. Geometric mean faecal egg counts (epg) and worm burdens were 1610 and 145 epg and 12020 and 1540 worms, respectively, on low and high protein diets (P<0.01 in both cases) and 310 and 750 epg (NS) and 2290 and 8090 worms, respectively (P<0.01) in single compared to twin-bearing ewes. There was no effect of energy level. The periparturient breakdown in resistance to parasitic infection thus appears to be counteracted by protein supplementation. Supplementation of the ewe may provide an alternative parasite control strategy by reducing pasture contamination and may have greatest effect in prolific flocks.

J, Donaldson, MFJ Van Houtert, and AR Sykes

Proceedings of the New Zealand Society of Animal Production, Volume 57, , 186-189, 1997