Rehydration key to prevent production and health issues (Feb 25)

All cattle – milkers, fresh calvers and calves – can benefit from hydration support, and strategic use of products to replace lost fluids and electrolytes can offer myriad benefits.

TEXT PHIL EADES

Paying close attention to hydrating cows and calves is vital because dehydration impacts the performance, health and welfare of milking and calving cows, and calves.

So says Trouw Nutrition GB’s Tom Jarvis, adding that water is essential for all aspects of metabolism. “A dehydrated animal will be reluctant to eat, which reduces dry matter and milk replacer intakes, before becoming listless and lethargic. This will have a direct impact on milk production and growth rates. Dehydration can also lead to an increase in inflammation, leaving the animal at greater risk of infections,” he explains.

Producers have made significant improvements to reduce the risk of hydration issues, based on Cow Signals and Calf Signals, when designing housing and facilities. But the limiting factor for adequate hydration during pressure periods still remains the ability and desire of the animal to drink.

He urges producers to consider using rehydration supplements to help reduce the impact of dehydration, particularly in pre-weaned calves and calving cows.

“Enteric infection from scours or dehydration in calves is the single biggest cause of calf losses in the first three weeks of life,” he says. “Calves are particularly vulnerable to dehydration due to their body size and composition, and high metabolic rate.

“Calves lose fluids more easily than older animals because a higher proportion of their body’s fluids are outside body cells, which means they are lost more quickly.”

Figure 1: Calves have a higher proportion of bodily fluids outside cells (extracellular), which makes them more prone to dehydration than mature cows

Figure 1 demonstrates the increased risk of dehydration in calves, from birth to three weeks old, and the importance of spotting the signs early and intervening with an effective rehydration formula. Early identification can prevent significant fluid losses and not only save time treating but also maximise growth rates in early life.

Early signs

“Pay close attention to calf behaviour for early signs of sickness,” says Mr Jarvis. “Reduced milk intakes, slower drinking speeds or not drinking at all are early indicators of a problem. Other signs will include droopy ears, sunken eyes and a reduction in activity.

“Any change in behaviour indicates a problem and will typically be seen four or five days before obvious physical symptoms, like changes in faecal consistency, are seen. As soon as any of these signs are seen, it is time to intervene with the priority being rapid and effective rehydration.”

Trouw Nutrition OsmoFit is an oral rehydration solution designed for use alongside continued feeding of milk or milk replacer. A hypotonic solution containing carefully formulated levels of sodium and glucose, it helps stabilise the water and electrolyte balance.

“It is important that sick calves continue to be fed milk because rehydration and electrolyte products will not have sufficient feed values or energy intake to replace milk feeds,” stresses Mr Jarvis.

Between feeds

“The product should be provided between milk feeds, typically for between one and two days, and when the calf returns to taking its full allocation of milk. You cannot over hydrate a calf.”

The formulation and research behind quality oral calf rehydration solutions means they should be fed as a separate feed mixed with water and should not be mixed into milk. “Mixing an oral rehydration supplement in milk will create a solution that is hypertonic and that will reduce the effectiveness of the rehydration, potentially leading to more scour and more persistent dehydration,” he adds.

“It is also important to remember that any stressful event such as group changes, weaning, dehorning or medicine administration can all predispose calves to dehydration. The use of a hydration product before and after these events can significantly help to prevent the onset of dehydration and scour.”

When it comes to cows, he says that all are dehydrated to some extent at calving. In cases of severe dehydration, cows will not want to stand after calving and will certainly refuse feed. The greater the calving stress, the greater the extent of dehydration and the more reluctant the cow will be to start eating, delaying the restoration of dry matter intakes and prolonging the impact of post-calving negative energy balance.

“Post-calving dehydration is due to a combination of two factors. The first is that cows will lose about 60 litres of fluids and salts when they calve, made up of blood and intra-uterine fluids. At the same time, cows reduce food and water intakes in the hours leading up to calving making post-calving dehydration extremely likely.

“The sooner she is able to drink after calving, the sooner the balance is restored. Rehydrated cows are more vigorous and will eat sooner, which can help reduce problems with milk fever and metabolic diseases.”

Feed intake is also significant because cows extract a lot of liquid from their diet. A 30% dry matter silage is, after all, 70% water.

“Palatability is the key to effective rehydration in the two hours immediately post calving, ensuring cows replace lost fluids and electrolytes,” says Mr Jarvis.

“If a fresh-calved cow will not drink the supplement when they are dehydrated it will be because it is not palatable enough.”

Electrolyte levels

Water only has very low levels of electrolytes so won’t rehydrate cows as well as a product that supplies the necessary salts. The latest research also shows that oral supplementation with calcium helps restore calcium homeostasis more effectively.

Farm-O-San Reviva is a proven highly palatable post-calving drink providing a balance of glucose, electrolytes, vitamins and trace elements to support the immune function and rehydrate cows effectively. It consistently achieves high voluntary intakes. Studies have shown that cows are more enthusiastic to drink this product compared to water.

Simply mixed with warm water, it should be offered within 30 minutes of calving. As well as rehydrating the cow, a big drink helps fill the ‘void’ inside the cow immediately after calving, which in turns helps reduce the risk of metabolic disorders. “Effective rehydration also encourages increased dry matter intakes immediately post-calving, which are vital to help minimise negative energy balance. Trials with Reviva have shown a 1kg per day increase in dry matter intakes,” adds Mr Jarvis.

Being ready to rehydrate cows and calves at the first signs of dehydration or at events when dehydration is a risk can help to reduce its impact on performance.

“Ensuring appropriate supplements are available, and that staff are trained to mix and feed them, can help limit the consequences of dehydration for all cattle.”