Nutrient intake from grazing is not the only issue that needs addressing when managing livestock during the current wet weather, according to Rumenco technical services manager Dr Derek McIlmoyle. Even under normal conditions, grazed grass contains a poor balance of the minerals and trace elements needed for optimum production, but it's a problem exaggerated by the current high moisture content of grass.
"Not only is the wet grass and poor weather limiting overall intakes, but actual grass mineral content will also be lower," he claims. "Many farmers are finding that beef cattle and dairy youngstock have virtually stopped growing, with dairy performance also suffering. It's not just through a lack of nutrients, supplying the correct level of minerals is critical if livestock are to make the most of those nutrients they do consume."
The graph below clearly demonstrates how poorly grass alone meets the needs of dairy cows for the main essential minerals and trace elements during an average year, and the picture will be much poorer this summer. Failure to provide the supplements needed to correct this imbalance can very quickly lead to problems, such as rapid drops in fertility and increased mastitis in dairy cows, or reduced growth and increased health problems in growing cattle.
Figure 1 – Comparison of mineral supply and requirements during grazing (dairy cow producing 35 litres of milk)
"Traditional compounds will contain many of the extra minerals needed, but only if sufficient volume is fed," Dr McIlmoyle continues. "Where production from forage is being maximised, and minimal levels of concentrate are being offered, some deficiencies may remain.
"By all means tackle the problems of nutrient supply by buffer feeding with silage if forage stocks allow, combined with supplements high in digestible fibre and low in rumen degradable protein to help balance the lush grass. But don't forget to also increase the supply of minerals, and for grazing livestock not receiving additional feeds, that means using a controlled intake mineral block designed specifically for the purpose, such as Rumenco's TAB Cattle Plus."