The purpose of this blog is to summarise some key findings to date and discuss the findings from a farmer survey I conducted. The survey involved three case study farms that had positive results from fodder beet grazing. The purpose of this was to compare the management of these case study farms with published information. Based on the information available I have made the assumption that misleading information would be a major cause of cow deaths associated with grazing fodder beet so finding out how farmers are managing fodder beet successfully was a good starting point to help explain where some confusion has arisen.
DairyNZ recommends a 14-21 day transition period where animals start on 2 kg DM/cow/day alongside pasture, silage and/or straw whereas Gibbs recommends a transition period of 10-14 days. Interestingly, none of the case study farms used the transition periods recommended. All three case study farms began transitioning during late lactation and transition periods were between 24 – 30 days with starting intakes between 1-1.5 kg DM/cow/day with an increase in crop allocation of no more than 0.5 kg DM/cow/day. All farms were supplementing with straw and silage. None of the farms had suffered fatalities during the transition period. Based on farmer experience and financially speaking, if the transition period can be increased it is better to have a slightly slower transition than a faster one. It has been emphasised that the cows vary in the rate that they adapt to a new feed type and the amount they can eat. Therefore, moving too quickly can result in cow deaths. Assuming an average herd size of 419 cows where 2 kg DM/cow/day of maize silage at 25 c/kg DM is supplemented during an additional 7 days of transition. This would cost approx. $1500 and taking into consideration the cost of a mature aged cow, it is not difficult to see the advantage of transitioning for a slightly longer period of time if it reduces the incidence of acidosis. Based on this information I would recommend that cows should be transitioned for a minimum of 24 days with a maximum starting intake of 2 kg DM/cow/day and increasing at no more than 0.5 kg DM/cow/day. Transitioning cows during the late lactation period also seems to prevent the desire to transition cows too quickly and results in cows being already partially adapted to the crop at drying off.
All three farms analysed their crops before feeding and again halfway through the season to determine dry matter yields and nutritive values. They then used this information and calculated areas required for allocation of the crop. Farmers have reported issues with allocation of the crop due to inaccurate predictions of yields and nutritive values. This is due to a limited number of credible animal feedings studies and is therefore, an area that requires further investigation. One case study farmer also mentioned that higher yielding crops were more difficult to feed due to the large dry matter yield or a small area. He said that a long face is critical which is in agreement with recommendations from DairyNZ however, still struggled to manage the crop for this reason. I could only recommend that using some under the wire feeding might be a way to help combat the issue of over-allocation in a high yielding crop.
DairyNZ recommended offering additional supplementary feed prior to allocation of the crop during the transition period to ensure the gut is full to minimise health risks. Two of the case study farms continued this management practice throughout the wintering period. If it is not too impractical, it would be sensible to continue this management practice outside of the transition period to encourage cows to eat the supplementary feed and prevent cows from missing out.
All three case study farms reported mild cases of acidosis however, were able to manage this by taking the cows that didn’t adapt to the crop off the crop and wintering those animals on pasture. One farm suffered fatalities however; this was due to a staff member feeding more than recommended and was completely avoidable. No farms reported an increased incidence in milk fever however, all farms supplemented with mineral licks or dicalcium phosphate over silage to account for mineral imbalances in fodder beet. It is worth noting that these farms also fed silage which would provide some minerals in addition, and by feeding the silage prior to the crop this would also help ensure that the cows are accessing the dicalcium phosphate supplement. I would therefore, support the management practice of feeding silage before allocating the crop throughout the entire transition and wintering period.
So in conclusion, the recommendations in addition to those published in literature are:
- Begin transitioning cows during late lactation to prevent the desire to transition cows too quickly if possible. This can be achieved using a cut and carry method where cows are fed fodder beet in addition to pasture.
- Transition for a minimum of 24 days with a starting intake of a maximum of 2 kg DM/cow/day and increasing at no more than 0.5 kg DM/cow/day. A slightly longer transition will allow all cows to sufficiently adapt to the new feed and may save money long term.
- Feed supplements prior to allocating fodder beet throughout the entire transition and wintering period to minimise the possibility of animals overeating, lack of fibre in the diet and mineral imbalances.
- Use under the wire feeding where there are large crop yields to avoid over-allocation.
- Winter cows on pasture if they don’t adapt to the crop.
These recommendations are based on information in literature and from farmer experience that have been successful with the crop to date. I’m hoping to this follow up with experiences from farmers that have had large numbers of fatalities, to try and narrow down the reasons these fatalities have occurred. I’m interested to see whether the deaths were completely avoidable or the farmers have been received misleading information in regards to the management of the crop.
No comments:
Post a Comment