Dry conditions influence livestock health considerations for the months ahead
The extremely cold, dry winter of 2017, followed by a mediocre spring, has resulted in many enterprises being low in feed reserves (both pasture and stored feeds), with extremely low soil moisture profiles. Therefore, substantial rain with good follow up will be required for a sustained change in the season. The current seasonal conditions warrant the following considerations: • Ensure all non-productive stock have already been marketed. Livestock markets are holding up well despite the dry conditions and this is no time to be carrying passengers. Breeders should be pregnancy tested as early as possible and empties culled as soon as practical. This means preg testing 6 weeks after bull removal for heifers and at weaning for cows. Note that empties can only be reliably diagnosed with a manual confirmation of a negative scan, and to this end you should use an accredited cattle veterinarian. Ewes should also be scanned to cull empties and to allocate feed resources appropriately for those bearing twins and singles. • Wean earlier. Our data shows that calves can routinely be weaned down to 130kg at approximately 3 months old and lambs down to 15kg whilst maintaining high production. Weaners need unrestricted access to high protein feeds (approximately 16 to 18% crude protein) of at least moderate energy density (11 MJ metabolisable energy/kg dry matter +). If these criteria are met, in addition to maintaining rumen health and preventing diseases associated with intensification such as pneumonia, weaners can achieve high growth rates. Note that this growth has a low cost of gain because of the low feed conversion ratio of lighter weight young stock resulting in lower maintenance costs. The fundamental principle here is that it is more efficient to feed a weaner directly than to feed a cow to feed a calf. • Don’t stop supplementary feeding when the rain starts falling. As we have outlined previously, it is imperative to maintain full supplementary feeding until there is sufficient pasture dry matter available for stock to fully meet their energy requirements. If we stop feeding while the new season pasture is still very high in moisture and low in availability, stock will lose weight due to inadequate dry matter availability and the negative effects of lush feed on rumen fermentation efficiency. • Manage the rumen to make the most from the lush feed when it arrives. To this end we should provide sources of roughage as part of the supplementary feed during the transition period, and once there is plentiful pasture dry matter available we should move to the provision of buffers such as Calsomag. This buffer will also ensure calcium and magnesium requirements are met with stock on grazing cereals, thereby preventing deaths from hypocalcaemia (milk fever) and hypomagnesaemia (grass tetany) whilst improving production. • Be diligent on vaccination against clostridial diseases (5-in-1 or 7-in-1). Protection against pulpy kidney is short-lived (as short as 3 months) and it is essential to vaccinate young stock placed on grain or lush pasture/grazing cereals if they have not been vaccinated within this time-frame. • Provide a “safe” paddock for weaners. Young stock are most susceptible to rapid development of worm burdens which can have rapid and drastic effects on production. Use faecal worm egg testing to guide drench selection decisions (don’t forget Paraboss) in conjunction with cleaning paddocks using mature cattle or cropping. • Generate the highest possible dry matter production from your forage crops. Talk to your agronomist about weed control and fertilizers to maximise forage crop production. Further, if low winter temperatures limit production, investigate the use of gibberellic acid in conjunction with additional nitrogen fertilizer to grow the most forage from the available moisture.