Factors to consider when feeding fodder beet in late lactation.
Recommended upper limits to feeding lactating cows
- Grazed fodder beet 5-6kg DM, or lifted bulb only 4-5kg DM - when offered above these levels, the low protein intake can reduce milk yield and animal health issues related to low fibre (poor rumen function) and phosphorus and calcium intakes (production losses, SCC issues, down cows) can occur. Seek veterinary advice if you are concerned about mineral intakes.
- Recent research results indicate potential amino acid deficiencies (arginine and citrulline) above 30% fodder beet in the diet. The long-term impact of these changes requires further examination to ensure it is not having a negative effect on other metabolic processes.
- Until there is a better understanding of the long-term impacts of high fodder beet diets, farmers should remain cautious with their fodder beet allocation to lactating cows.
Practicalities of feeding during lactation
- Grazing is always the most cost-effective method of offering crop but increased walking between the pasture and crop paddocks can increase the risk of lameness, at a time when the prevalence of lameness is often increasing in our pasture based systems (autumn).
- Mastitis can be an issue if cows are grazing fodder beet in wet conditions.
- Commercial harvesting where the leaf is flailed off and the bulb stored for later use offers the most flexibility. If stored correctly the bulbs will last up to six months.
- Daily or weekly harvesting with a “beet bucket” is possible if the beet is close to/on the milking platform. Leaves will rot within a week therefore harvesting needs to occur regularly, which can be a challenge if conditions get wet.
- Not all varieties are suitable for lifting – higher DM varieties are better.
- Both lifted options can be fed through a silage wagon onto pasture or fed on a feed pad with silage.
- Fodder beet is highly palatable and can affect grazing behaviour on pasture. If feeding immediately after milking only allow access to the crop once all cows are back in the paddock.
Transitioning onto fodder beet in the lactation period
The same principles as non-lactating cow transitioning apply during lactation to avoid rumen acidosis from cows consuming too much too soon. However, access to ample other feed during lactation, because beet is a smaller component of the diet compared with wintering, and the need to maintain milk production makes transitioning during lactation more challenging.
Recommended transition feeding levels:
- Start at 0.5-1kg DM/cow/day and increase no more than 1kg DM every second day. It generally takes at least 14 days to get to 5kg DM.
- It is important to ensure ALL cows transition so that no cows are left behind and without going too fast that others eat too much and acidosis results. Initially up to 30-40% of the mob may ignore the fodder beet so the remaining 60-70% can over eat.
- Provide sufficient space and time – a least a metre of face width if grazing and the same for beet spread out in the paddock through a wagon and at least 1 hour so that all cows have time to try it.
- Using the tractor wheel across the row to break the bulb may help encourage cows to try it.
- Watch the cows for more than just the first couple of minutes to determine whether they are all eating. Cows may walk across and sniff it and maybe try the leaves but not touch the bulbs.
