Last winter, Roger Lewis was encouraged to ration his cows using the new NutriOpt Dairy system from Trouw Nutrition and the results have been significant for the 300-cow autumn block-calving herd.
Roger farms with his wife Sarah and parents Philip and Sheila at Poyerston Farm, Cosheston, West Wales, where the 202-hectare (500-acre) farm is down to grass with 28.3ha (70 acres) of maize and 36.4ha (90 acres) of cereals for crimping.
Roger says: “Achieving a tight block is the foundation of our system. Get it right and everything else falls into place. “Transition and fresh calver nutrition are crucial and when our nutritionist Ken March suggested we used NutriOpt Dairy as it would improve diet precision I was happy to give it a go. I didn’t imagine it would make such a difference.”
NutriOpt Dairy is the product of an extensive research programme carried out by Trouw Nutrition and, as Dr Liz Homer explains, it offers considerable advantages over the systems commonly in use to ration cows.
She says: “If we are going to feed cows more accurately and cost-effectively to maximise forage utilisation, optimise milk production and improve overall health we have to describe what happens in the rumen more accurately. “The better we understand how feeds behave in the rumen the more precisely we can feed the rumen microbes.
“NutriOpt Dairy incorporated new information about how feeds are fermented in the rumen and how quickly this fermentation happens. This allows us to ensure good rumen health with a more constant pH which reduces the risk of acidosis and improves the efficiency of digestion.”
The system focuses on improving the accuracy of determining energy requirements of cows and how these are supplied by different feed sources.
The more accurately the energy value of feeds can be assessed, the more nutritionally accurate diets will be. NutriOpt Dairy system is able to improve not only the accuracy of energy supply to the cow, taking into account digestion in the whole gastrointestinal tract, but also differentiating between sources of energy.
It uses a new term, dynamic energy (DyNE) to describe energy supply and demand. NutriOpt Dairy also more accurately assesses protein supply and requirement in the form of digestible intestinal protein; microbial protein yield plus bypass protein. “Overall, NutriOpt Dairy means dairy cows can be fed with greater precision,” Liz says.
For nutritionist Ken, the challenge has always been devising a diet which can support the high forage intakes Roger sets out to achieve. He says the results achieved this year using NutriOpt Dairy have demonstrated the benefits of the new approach.
The fresh calver diet has to evolve as cows will initially be out at grazing after calving and buffer fed with grass silage until the maize is available to incorporate into the diet. Ken says it is important to get cows settled into lactation and ease the changes in the diet. Once maize is available the ration is kept as consistent as possible until turnout.
The basic TMR ration is 60% grass silage, 40% maize silage, 3kg crimped cereals and 5kg of a blend. A 16% HDF dairy compound is fed flat rate in the parlour when cows are housed, dropping to a 14% when at grass. The TMR is formulated for M+35 litres and the target forage intake is a minimum of 14.5kg DM/cow/day.
“To achieve these forage intakes, Roger focuses on making top quality silage,” Ken says. “This year’s first cut was 35% dry matter, 6.57 DyNE (11.6ME) and 16.2% protein while second cut was 30% dry matter, 6.13 DyNE (11.5ME) and 15% protein. The maize came in at 33% dry matter, 6.98 DyNE (11.8ME) and 32% starch.
“Rationing using NutriOpt Dairy and the Dynamic energy approach, has allowed us to complement forages more precisely and make sure the rumen is looked after. To do this we have refined the blend and particularly the balance and sources of starch and protein.
“By paying close attention to how quickly carbohydrates are fermented in the rumen and balancing this with protein sources which ferment at the same rates, we have been able to increase the levels of starch in the overall diet without upsetting rumen health.
This, in turn, has improved the use of the protein in the diet and increased the supply of microbial protein in the rumen, balancing rumen protein and energy, so energy was not wasted getting rid of excess nitrogen. We have maximised the supply of glucogenic energy in early lactation to support both milk production and fertility.”
|Table 1:||Winter 2015/16 blend (%)||Winter 2016/17 blend (%)|
The blends fed are shown in the table. To balance the forage better, Ken included more fermentable protein and less bypass protein. He decreased the proportion of slowly fermentable carbohydrates and bypass starch and used wheat to provide more rapidly fermentable starch.
Ken adds: “This year we have safely fed a blend with 36% starch and sugars while last year it was 21%, and this is despite the maize silage being much higher starch this year too. Looking at the dung it is clear the rumen is working well and there are no problems with acidosis.”
Roger says the improvements in performance have been considerable. “In 2015/16 we didn’t push the cows because prices were so poor and maize silage was pretty disastrous. This year we wanted to get performance up and the new diet has certainly worked. “We have seen improved lactation persistency and higher weights of fat and protein which have boosted milk price.
In March we were averaging 32.6 litres per day with 12 litres from forage. Rolling yield is back up at 9196 litres with 4139 litres from forage and margins are improving. “And fertility has been excellent. Feeding the correct sort of energy in early lactation has improved energy balance so cows were cycling sooner.
Conception rates have been running at 55%. You won’t get these sorts of results if the diet isn’t right and the rumen isn’t healthy. “Next year we will have 310 cows calving between August 26 and November 26 which is the first year we will have got everything calving in our target three months window.
“I was a bit dubious about feeding higher starch and lower protein, but the cows are the ultimate judge of the adequacy of the diet and they are telling us it is working extremely well,” says Roger.