May 12, 2020
Farmer Testimonial: Developing a successful autumn calving system
May 12, 2020
As seen in British Dairying – March 2020
Four years ago, a Devon dairy farm made the decision to move to autumn block calving and continues to refine their system with an emphasis on quality silage.
Joseph Andrews farms at Silkland Farm, Buckland Brewer with his father Steve and brother Jack. They farm a total of 220 hectares which is mainly down to grass, but they also grow 40 hectares of maize and 12 hectares of spring barley for wholecrop.
The farm is home to a herd of 350 Holstein cows which until four years ago were all year-round calving, but now calve in an autumn block, starting at the beginning of August and all cows will calve by the end of December.
“We are in a good grass growing area and wanted to focus on maximising the contribution from forage to help reduce purchased feed use,” Joseph explains. “We felt autumn calving would be the best way to achieve this and are pleased with the move, but we are learning all the time. In particular, we initially thought cows would graze more and this would be the way we would see the biggest benefits. But we are moving away from this thought this year.”
The dairy herd is averaging 9000 litres at 4.3% fat and 3.4% protein. Milk quality is important as milk is sold to Saputo Dairy UK on a cheese contract.
They rear all their own heifers looking to calve them in at the start of the block. Heifers are served at 12 months and when they have sufficient stature. They have built a new calf shed to help improve health and growth rates and will look to have 100 heifers available to bring into the herd. At the latest PD session, 80 heifers were seen by the vet and 78 were in calf.
All cows and heifers will be served twice to sexed semen before being put to beef.
Cows are housed as soon as a group of 50 has calved in, justifying opening up the housing and giving a large enough group for feeding. As 100 cows and heifers will calve in August, fresh calved cows are effectively housed from mid-August.
All cows are housed in one group and fed a single TMR which comprises maize silage, grass silage, wholecrop cereals and a rape:soya blend supplied by Harpers Feeds. The TMR is formulated for M+20 litres and the aim is to feed a consistent diet throughout the winter, only tweaking it when clamps are changed. An 18% Harpers dairy compound is fed to yield throughout our parlour feeders.
At peak, cows were averaging 34 litres per day and now are producing 33 litres with an average of 180 days in milk.
How the farm has improved consistency of silage supply and quality – A key element to the profitable dairy system
The Andrews want enough maize to feed right through until turnout and for buffer feed. They will close the clamp up as cows dry off to ensure they have silage to feed as cows are housed in August and before the current year crop has been harvested. The drive for silage quality is being extended to grass silage too.
“In previous years we had turned cows out as soon as we could but this reduced the amount of first cut we can make. So this year they will be housed until after first cut, allowing us to make 90 hectares of first cut,” Joseph explains.
“To make the best use of silage we need the highest quality first and subsequent cuts to get cows milking and keep them performing. The cows are milking well on the winter diet and there is no reason this won’t continue, so we are happy to keep them in leaving more grass for first cut. If we have more first cut grass silage, we can get better performance in the first 150 days of lactation next winter. As the majority of grass is young leys on a five year rotation, making more first cut silage will mean we have a higher protein feed which should help keep costs down.”
The aim will be to definitely make four cuts and possibly five if the first cut comes off soon enough. Around 60 hectares will be taken for second and subsequent cuts.
Maize is grown on a 40-hectare block away from the farm so is grown continuously. The field received slurry and manure from the 28,000 broiler unit.
They grow an early variety as they want the crop off quickly, so it is in the clamp and ready to feed. They mainly grow the LG variety Ambition as it grows consistently well, although they have also used LG Pinnacle. They are looking to make 1800-2000 tonnes per year. In addition, they will buy in 500 tonnes from a neighbouring farmer.
This year Joseph is considering undersowing the maize to help prevent soil erosion as stubbles are left overwinter. If conditions allow it can then be taken as an early first cut or just ploughed in.
They grow spring barley for wholecrop silage. In total, they will grow 24 hectares with half grown on a local farm. They prefer spring barley because it is simpler and less expensive to grow than winter crops. Also, having been in the ground for a shorter time it will be harvested greener and with less lignin. They look to harvest at 40%DM. While starch will be 26-28% compared to winter wheat at over 30% starch, they believe the other benefits outweigh the lower starch, especially as they can feed plenty of maize silage.
Wholecrop plays a key role in dry cow feeding. Close up dry cows are housed a month before calving and go onto a diet based on wholecrop silage.
“We used to feed a straw-based DCAB diet but thought if we could feed straw, we could use wholecrop. We now feed 80% wholecrop and 20% of the milking cow buffer or TMR. We also feed dry cow rolls and have very few calving problems.”
The Andrews pay particular attention to clamping of crops as they do not have a series of silage pits but rely on some earth walled clamps with other cuts being built into clamps on a concrete pad.
“Having focussed on producing high yields and cutting crops at the optimum stage, we can not afford to waste silage,” Joseph points out. “Our system is geared towards utilising as much forage as we can, so we pay close attention to ensiling to reduce the risk of waste.”
Joseph takes responsibility for building all the clamps, buck raking and rolling to achieve a high standard of consolidation. All clamps are sealed with an oxygen barrier, a sheet of black plastic, two heavy woven sheets and as many tyres as possible. All crops are treated with Lallemand Animal Nutrition’s heterofermentative silage inoculants as aerobic stability is vital. They had tried homofermentative silage inoculants but were disappointed with the results so now use heterofermentative products.
“We have often had to open wholecrop and maize clamps sooner than we would like so want them to be as stable as possible to reduce spoilage and heating,” Joseph continues. “Then we don’t want the clamp face to spoil as we feed out while can be a practical challenge. For example, our current maize face is over 20 feet high and it is taking us 10 days to get across the face, so heating is a real concern.”
What are the benefits of heterofermentative bacteria in silage inoculants?
Steve Symons from Lallemand Animal Nutrition explains that the mode of action of heterofermentative bacteria specifically helps improve aerobic stability when opening silage clamps.
“To improve aerobic stability and reduce heating you need to restrict the action of yeast and moulds present on all silages. Homofermentative silage inoculants have no positive effect against yeasts and moulds. As they produce lactic acid which is a food source for yeasts and moulds, they can increase the populations. Heterofermentative strains will improve stability by killing yeast and moulds while also ensuring an effective initial fermentation.
“L buchneri NCIMB 40788 has long been the gold standard for aerobic stability but when paired with L hilgardii CNCM I-4785 in Magniva Platinum silage inoculants the two work in synergy. During the fermentation they quickly produce a number of antifungal compounds that significantly reduce the yeasts and moulds that cause heating, improving immediate aerobic stability, meaning clamps can be opened safely much sooner. In trials both maize and wholecrop silage can be opened and remain aerobically stable just 15 days after harvest, increasing feeding flexibility. They also improve longer term aerobic stability, protecting the silage while the clamp is open. Despite having to open wholecrop silage soon after harvest and work with a large maize face, Joseph has had virtually no waste allowing him to maximise the silage fed. We will be moving to Magniva Platinum silage inoculants on all grass cuts this year too.”
Joseph Andrews concedes they are still learning about how to get the best from an autumn block-calving herd but is confident they are heading in the right direction.
“We now have a system which works for dry cows, meaning cows are calving down well. We are on target to get heifers coming in at the start of the block which will help keep it tight. We have refined our forage production to ensure cows remain on a consistent diet throughout the winter and have learnt that early turnout is not necessarily a pre-requisite for autumn calving. Maximising production from forage is about year-round quality and maximising the amount available to feed. At the same time, using the right forage inoculant means we can open clamps early if we need to. We will continue to fine-tune the system to reduce cost of production and drive the use of quality forage,” he concludes.