With all herds containing higher yielding and more efficient dairy cows it is important to make sure they are getting adequate supplies of trace elements in a form that can be utilised most effectively.
While modern diets have been revised to meet the requirements of today’s higher genetic merit dairy cows, Dr Huw McConochie from Zinpro Corporation argues that a failure to review trace mineral requirements may be stopping cows achieving their potential.
“A cow’s trace mineral requirements are determined principally by their bodyweight and milk yield,” he said.
“In addition, more efficient cows may produce more milk from a lower DMI and a small metabolic size which means they could be receiving less supplementation but yet have greater metabolic demands.”
He added that bigger cows have a higher maintenance allowance and there are known energy and protein levels per litre of yield. However, while modern rationing systems take account of increased energy and protein needs of higher yielding cows, there is less consideration for their trace element requirements.
Furthermore, today’s higher producing cows benefit from diets variously ‘fine-tuned’ with amino acid balancing, rumen protected amino acids, glucose precursors, liver function enhancers, yeasts etc. But, in most cases, they are still only fed less effective inorganic trace minerals.
“There are herds averaging more than 40kg of milk which are still being supplemented according to recommendations formulated in 2001,” said Dr McConochie.
He said that advances in animal nutrition are one of the main reasons why modern cows are performing better than their predecessors, but argues a reluctance to provide a reliable and adequate supply of a superior source of organic trace elements is becoming a bottle neck which prevents cows milking to their potential.
“It is probable that sub-optimal mineral nutrition is causing more of the issues we see on farm. We know that things like lameness, reproduction and mastitis can be caused by insufficient levels of trace minerals in the diet without having clinical deficiencies signs. Just because an animal is not showing deficiencies does not mean it has the required nutrition.
“The problem is that many rationing systems are not making sufficient allowance for mineral requirements and by so doing may be holding cows back.”
He also stressed the importance of the form of mineral fed and says that high performing animals need a proportion of minerals in a form that can be used more effectively.
Dr McConochie added that inorganic minerals are utilised less efficiently.
“The problem is that a large proportion of inorganic minerals, and some low-quality organic trace minerals, get inactivated in the gut, are not absorbed to make them available to the animal and are just excreted.
“Cows need performance minerals which remain active in the gut and can be absorbed more effectively, meaning they are able to participate in metabolic functions and help cows perform to their potential.
Instead, he advised producers to pay closer attention to trace mineral levels in the diet and the sources of those minerals to ensure performance and fertility are not being compromised by a shortage of key trace minerals. He emphasised the need for an appropriate proportion of performance trace minerals.
Zinpro offers a comprehensive mineral evaluation service through its network of suppliers, providing detailed forage and water mineral analysis which, combined with details of the diet, allow a full mineral audit to be carried out taking into account minerals in the diet and any effects of antagonism.
“This process allows a bespoke recommendation to be created based on a cost-effective mix of inorganic and performance minerals that can help to maximise herd health and performance and achieve better margins from today’s highly efficient cows. At the same time, it will ensure that individual trace minerals are not being over-supplied,” concluded Dr McConochie.