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Breeding key to improving sustainability (Feb 23)

Challenging traditional approaches, to find ways to improve efficiency, profitability and sustainability, was the theme of this year’s British Cattle Breeders Club Conference.


TEXT CLEMMIE GLEESON



Efficiency, fertility, emissions, and profit are all linked, University of Nottingham’s Phil Garnsworthy told delegates at this year’s British Cattle Breeders Club conference, held in Shropshire in January.


“Milk yield drives production efficiency, and milk yield per hectare is key to whole-farm efficiency. But any efficiency gains are partly offset by lower fertility,” he said. “During the past 30 years, yields have increased, but dairy cow fertility has fallen. “Reduced fertility and poorer oestrus detection meant that more cows were being culled because they were not in calf,” added Professor Garnsworthy. “This meant that more dairy replacements were required, resulting in reduced herd efficiency.”


Calving interval also plays a key role. “Fertile cows with 365-day calving intervals will complete four lactations in four year, whereas the average cow, with a longer 410-day interval, will only complete three.


“A cow completing four lactations will produce 27% more milk during her lifetime, she will eat 12% more energy, and efficiency and net energy increases from 0.32 to 0.34 – that’s up 11%.” He added that feed and methane ‘costs’ of rearing are, therefore, spread across more kilogrammes of milk, further improving production efficiencies.


The key to improving whole-farm feed efficiency is to improve milk yield per hectare. “Improving quality and utilisation of grass and forage allows dairy businesses to increase livestock numbers and manage feed better to reduce wastage.


“Youngstock must be managed to achieve weight targets, with a focus on maximising fertility and health to reduce animal wastage and reduce replacement rates.


“Heifer losses and age at first calving also impact efficiency, but the biggest drive is fertility culls. It has a huge effect on the overall efficiency of the herd and business because it affects how many heifers are on the unit and how many litres cows produce during their lifetime.”


He said that sexed semen had been a gamechanger for producing female replacements. “According to AHDB, it now accounts for 70% of dairy inseminations, and this means each cow can now produce 1.95 potential heifer replacements. This still doesn’t overcome the effect of replacement rate on efficiency though,” he stressed. Professor Garnsworthy ended his session by encouraging delegates to consider the three pillars of sustainability – society, economics, and the environment – and said that improving fertility has positive effects on all three.


Tackling methane


Microbiome-driven breeding has potential to reduce methane emissions and improve feed efficiency, according to Scotland’s Rural College’s (SRUC) Rainer Roehe. The rumen is home to billions of bacteria, millions of protozoa, and thousands of fungi, as well as the archaea, which facilitate fermentation. “There is a symbiotic relationship between the host animal and the rumen microbiome,” said Professor Roehe.


Work at SRUC found that improving the efficiency of fermentation, in a bid to reduce the amount of hydrogen produced, led to lower methane emissions. By studying different progeny groups researchers discovered huge differences between animals of the same breed, and under the same management including nutrition.


“There is a lot of variation between animals so we can breed for reduced methane production.”


Researchers also discovered a link between the abundance of archaea micro-organisms in the rumen and methane emissions. “We can use the microbial information to breed animals that produce less methane without measuring emissions, which is more cost-effective.


“The advantage of microbial-driven breeding is that we are tackling the ‘cause’ of methane – excess of hydrogen – to reduce excess methane. This is a significant advantage in comparison to using feed additives to reduce emissions. These prevent the final step of methane production but don’t tackle its cause,” he concluded.


More data


Pieter van Goor: breeding for feed efficiency reduces feed costs and methane emissions


CRV’s Pieter van Goor and dairy producer Wietse Duursma shared their experiences of improving feed efficiency in The Netherlands. “The 25% best cows for feed efficiency in a herd need 25% less feed to produce the same amount of fat-and-protein-corrected milk as the lower yielding cows,” Mr van Goor explained to delegates. “As well as lower feed costs, this also means lower methane emissions and less manure.”


Mr Wietse said that collecting data had been central to his success with improving feed efficiency on his dairy unit. “I’m extremely focused on running a high-input system, with good health and fertility, because that puts extra money on the table.”


Flintshire-based producer Rhys Davies shared his findings from a Farming Connect-funded study tour, with delegates. He visited seven grass-based units in Ireland. The trip inspired him to examine the management of his own herd in more detail, and implement some changes including weekly grass measuring and genomic testing.


“Not genomic testing heifer calves would be like not walking the paddocks once a week. It leaves you in the dark and unable to make sound decisions,” Mr Davies says. When making breeding decisions protein percentage is more important to him than kilogrammes, and good fertility is also high on his list.


Walford College’s farm manager Tom Moore and LIC’s Sean Chubb discussed the significant changes they’ve recently made to ensure the future of the college’s dairy herd.


Tom took on the management of the unit in 2018 and was faced with several challenges concerning costs and herd health. Working with Mr Chubb he implemented plans that focused on reducing costs and increasing milk value. These included turning the cows out for between nine and 10 months each year, moving to an autumn-calving block, and increasing milk from forage. This led to decisions to move to a milk-solids-based contract and implement a cross-breeding policy, bringing in Jersey genetics.


“The main reason for this was to add hybrid vigour,” said Mr Chubb. “To put it simply, hybrid vigour means one plus one equals three. In the first year we halved the herd’s £4,500 annual loss, and we’ve been getting progressively better. The past couple of seasons have seen the business break even.


“As more of the cross-bred Jersey genetics come through, milk constituent and quality will improve, and we will be able to increase milk value and further improve profitability.”

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