Good planning for lambing means that you are attending to the health, physical and nutritional needs of both ewe and lamb.
Properly addressing these needs in the last few weeks of pregnancy can involve several different management practices (e.g. scanning, & supplementary feeding), but at the very least it should include the following:
Treating your animals for parasites, disease and mineral deficiency is treating for productivity.
Prior to lambing and during lactation ewes are under increased stress because of the demands placed on them by the foetus and milk production respectively.
The increased protein and energy demands placed on the late pregnant and lactating ewe will result in a lowered immune response from the ewe and therefore increases the ability of worms in her gut to lay eggs. Consequently, the pastures become more contaminated with larvae. This in turn results in a higher challenge by parasite larvae to the ewe and her level of contamination increases as her poor immunity prevents her from dispelling the new infections. This scenario is referred to as the peri-parturient rise in worm egg counts and is well demonstrated in a study by (Beasley, Khan and Windon, 2006) see chart below. This study showed that dry ewes run alongside pregnant and lactating ewes had worm egg counts (WEC) that remained at 200 eggs per gram (epg) while the pregnant and lactating ewes WEC started to climb two weeks prior to lambing and increased to over 2000 epg by day 42 post lambing.
Figure 1: Worm egg count by ewe lactation status
Ultimately, this contamination increases the exposure of young grazing lambs to worms at a vulnerable age which can impact upon their growth and long-term productivity.