By Ginny Dodunski (Totally Vets Taumarunui)
- Cow-reared beef weaners – the smaller they are at weaning the longer the period they’ll need regular parasite control. A combination product containing at least both a ‘mectin and levamisole is important for this age group, to manage Cooperia, which are invariably resistant to single active ‘mectins. An oral triple combination drench is ideal if you can manage it.
- Artificially reared calves – these may have been more impacted by the dry and low feed quality. ‘Gold standard’ worm treatment with an oral triple combination for as long as possible is good advice for these.
- Causes of poor performance in R1’s includes inadequate feed quality and allocation, parasitism, a late F.E challenge and occasionally diseases like yersiniosis.
- Low trace element levels on their own rarely cause problems. At this time of the year copper is the element most likely to be required for supplementation. However, if you have been feeding PKE to young cattle, get advice before giving extra copper; this feed can be very high in copper and giving extra could be detrimental.
R2 cattle (non-pregnant)
- Don’t let these take a production-limiting worm burden into winter. Ostertagia is the important worm in this class in autumn, it damages the stomach lining and therefore reduces feed conversion efficiency.
- Work by AgResearch has shown that injectable ‘mectin drench products give superior levels of drug at target sites in cattle and therefore do the best job of removing Ostertagia.
- Liver fluke can be an issue on some properties; fluke activity stops once ground temperatures drop below about 12 degrees (the snail that transmits the parasite becomes inactive). Treating cattle at this time of year works well as they shouldn’t become re-infected once snail activity stops.
- While you don’t want R2’s to be grossly deficient in trace elements (copper and perhaps selenium in this age group); they don’t have the same demand as do breeding cows which are growing a calf inside them, or R1’s which are still doing a lot of skeletal growth.
Cows and heifers
- Same rules apply as for R2’s, but pregnant cows, especially light young cows, are more susceptible to the effects of parasitism and can develop clinical Ostertagia in winters after droughts.
- Cows also really dislike sharing their liver with flukes as pregnancy advances – there is a blood test available to assess the level of fluke challenge if you are not sure whether to treat or not. Kill sheets also provide useful information here. In addition, you can specifically request for the livers of scanned dry cows to be checked for fluke at slaughter.
- Be aware of the risk of ‘lack of grass’ staggers this winter; its not unusual to see metabolic disease (grass staggers/milk fever) in thin underfed cows at odd times through the winter; giving them access to magnesium in some form can help with this.
- Trace elements – cows need to have adequate copper stores in their liver going into winter. Copper availability in the pasture declines over this time; at the same time when demand from foetal growth is increasing. Getting the livers of cull cows checked for copper after scanning is a good routine to ensure your supplementation programme is on track. Selenium increases in importance closer to calving, and B12 is rarely required in adult beef cows.
- Finally cow condition: Just like ewes there’s a magic number for pre-winter body condition in cows below which the risk of cow losses and reduced production goes up. The magic number for cows is BCS5 on the 1-10 scale. What does this look like?
- both hip bones and pin bone are smooth (but not fat) v. flat and angular
- backbone is smooth not bumpy
- general appearance is smooth but when viewed from behind there is still a decline either side of the spine; not totally flat across the back and no fat lumps allowed!
Part of the job of a beef cow in hill country systems is for her to lose some bodyweight over the winter while waiting for that spring grass surplus. The best performance from cows under this system comes when they start winter in BCS 5 or better. Starting the winter with light cows increases the risks mentioned above, so ensure you have a solid plan to manage these, including that feed budget. If you can prevent them from slipping below BCS 4, and feed them really well in the three weeks leading into calving, as well as through the calving period, they will have better cow and calf survival outcomes and better in-calf rates.
For more information about beef cattle management go to: