Challenged to increase efficiency of production to help offset the current squeeze on margins while looking to improve sustainability of production, milk producers should look to make full use of available science rather than waiting for new developments, according to speakers at the British Society of Animal Science conference.
Conference delegates were told that more than 80% of ingredients in typical ruminant diets were not human edible, a combination of forages, co-products and so on.
If animal products were taken out of human diets, there would not be enough key nutrients to meet human dietary requirements.
Dr Phil Holder, ofED&F Man, said: “Animalsplayavitalrolein the circular economy of efficient food production, utilising products which would otherwise go to waste and converting non-human into human food.
“However, production must be as efficient as possible while also meeting requirements for greater sustainability.
“We must focus on utilising forages more efficiently and become more precise in the way we feed animals. This will become more important as regulations make products such as soya less acceptable.
“Rather than just replacing soya, can we be more precise in how protein is fed to reduce dietary protein levels, increase nitrogen use efficiency [NUE] and reduce nitrogen excretion? This would reduce costs and also cut nitrogen emissions, increase NUE and sustainability of production.”
Amino acid
Dr Sion Richards, of Adisseo, said ensuring amino acid requirements were more precisely met was an effective way to reduce the crude protein content in diets. He said: “The supply of amino acids allows cows to synthesise milk protein or body protein. All proteins are made up of a combination of amino acids.
“There are 20 amino acids and 10 are classed as essential, meaning they need to be supplied through the diet of the cow.”
As soon as an amino acid becomes limiting, in other words, there is not enough to meet requirements, Dr Richard said performance was affected.
He said: “Cows will divert the available amino acid from functions like the immune system, fertility and milk protein to maintain production. The usual approach when formulating diets is to overfeed metabolisable protein to try and ensure the cow is supplied with all the amino acids required.
“This imprecise ‘shotgun’ approach pushes up protein use and costs, while also depressing NUE.
“There is no guarantee that feeding more protein in total will meet cow amino acid requirements.”
He reported on trials with milking sheep showing that supplementing ewes with methionine in the transition and early lactation periods increased both milk yield and milk protein.
He said: “By being more precise, we can ensure animals get exactly what they need as efficiently as possible. Milking ewes are no different to cows and we have seen the same response in dairy cows.”
In addition to meeting nutrient requirements more precisely, research shows the need to ensure cows can utilise those nutrients for production.
Keeping cows healthy and minimising the frequency of immune responses will have a direct impact on energy availability.
Dr Sophie Parker-Norman, of Volac, said: “An immune response to an infection diverts energy from production. Maintaining an immune response over a 12-hour period will use lkg of glucose, which is equivalent to 20MJ, the energy required for about three-and-a-half litres of milk.”
Any infection or health challenge will trigger an immune response, so it is vital to keep cows as healthy as possible to optimise efficiency of nutrient use and production.
This includes visible conditions, including mastitis, metritis and lameness, but also conditions such as acidosis.
Dr Parker-Norman said: “We know that feed additives can play a significant role in supporting the immune system and offer a proven way to help nutritionists improve efficiency of diet utilisation.”
Summarising the session, Dr Holder argued that while there was no silver bullet to increasing efficiency and no one product can address all the issues, there is a great deal of science already available.
Requirements
Dr Holder said: “We know a great deal about how to make better quality, more productive forages. We have a better understanding of cows’ requirements and how these can be met. Improved production efficiency leads to reduced emissions per unit of output.
“We also know that the application of existing science can play a crucial role in helping reduce emissions and moving towards more sustainable production.
“The good news is that this information is already available and producers can start to fine-tune their systems to reap the benefits.”
