In some areas of Scotland, we have seen unusually high levels of rainfall for the time of year and flooding as a result. With this flooding has come some damage to conserved forage stocks. If you have flood damaged forage it will need to be assessed to see if it is still suitable for feeding and what the level of risk may be to animal health.
Flood damaged forage has a high risk of bacterial contamination, especially if it was flooded by slurry or sewage waste (avoid feeding forage that has been contaminated with slurry or sewage). There are several bacteria that can cause problems and there is particular risk from listeria, clostridia, bacilli and enterobacteria which can lead to poor intakes and growth rates, abortion and in serious cases, death. If you have contaminated forage, it’s important to consider if feeding it is too great a risk to animal health. In some cases, there will be no other option than to feed some affected forage and it is about minimising the risk.
What are you looking for in flood damaged forage?
- Texture – soil and silt contamination: Forages that have had water run through them have a high risk of soil and silt remains in the bale/pit will have a gritty texture. These are high risk of listeria bacteria, and the soil contamination will also act as an antagonist to minerals in the rumen. If it feels slimy this would indicate a clostridial secondary fermentation.
- Changes in smell: changes in smell of affected and unaffected forage will also indicate changes to fermentation and bacterial growth.
- pH change: check for a difference in the pH of the affected forage compared to unaffected forage (which would indicate changes in the stability of the fermentation). The pH can be tested easily using pH strips or send affected and unaffected silage samples away for testing at a laboratory to compare. This will give an indication of any secondary fermentation which is when the silage fermentation has been interrupted and it tries to ferment again. Poor fermentation makes it a better breeding ground for bacteria.
Practical advice for feeding contaminated forage
- Discard as much visibly mouldy material as you can and if using a mixer wagon do not put mouldy material in as it will spread the contaminated material and bacteria, the stock cannot pick it out!
- Avoid feeding contaminated forage to sensitive stock such as pregnant cows or ewes, or lactating animals, if it must be fed dilute it as much as possible with better forage.
- Use damaged bales quickly to avoid build up of bacteria.
- Patch and reseal what you can to avoid further damage from air getting in.
- Dry forages, such as hay and straw, that have been flood damaged may also go mouldy and heat if they have taken on water. Avoid feeding flood damaged straw, keep it for bedding. Use hay quickly and avoid using hay that has been sitting wet for a long periods.
RSABI are there to help if you have been unfortunate enough to have had severe forage losses, please do not feel stuck there is help on offer to get you through the winter.