Dr. Laura Tennant Explains How Effective Rehydration Drives Transition Success
21 June 2019
Attention to detail is behind the high success rate in transitioning cows at one of the UK’s premier dairy farms
With around 40 -60 cows and heifers calving every week, smooth transition of cows back into the milking herd is a high priority for the 2,100 strong Grosvenor herd at Aldford in Cheshire.
“The herd is averaging 12500 litres on a three times a day milking system with a 384 calving interval,” comments farm manager Mark Farrall. “Fertility is running at a 28% pregnancy rate and the average is cows in calf by 110 days in milk. This performance puts pressure on our dry cow and transition management, but equally the fact we are achieving these results is evidence that cows are transitioning well.
“In total we calve around 2300 animals a year which is an average of about 60 per week.”
Since 2016, all dry and transition cows have been housed at a dedicated unit away from the milking herd which Mark believes is part of the success, allowing a dedicated and trained team to specialise in transition management.
Cows are dried off weekly from the milking herd and are moved every Wednesday to minimise movements. On the Monday prior, they are moved to once a day milking and are foot trimmed. They are dried off at 50 days before their next due to calve date and the farm follows a policy of selective dry cow therapy with antibiotic use determined by cell counts and clinical cases in the previous lactation.
At the transition unit they are housed on sand cubicles in two groups, far off dries and a close up group of cows less than 28 days from calving. Cows with known twins are kept in a separate group.
Between 21 and 28 days pre-calving targeted cows receive a Kexxtone bolus. “Our aim is to reduce potential problems so we routinely bolus all cows carrying twins,” explains transition unit manager Nigel Travers. “We also bolus any cows with a high body condition score and cows that had more than 400 days in milk in the previous lactation who will also often be carrying too much condition.”
One diet is used across both groups of dry cows, based on straw, wholecrop silage, barley and minerals. Nigel says this keeps the system simple. They used to feed two diets but were getting problems with larger calves.
All cows calve in individual calving boxes, allowing close observation. There are currently 11 pens but this is being increased to 16. A wipeboard on the side of the pen ensures all staff are aware of the status of the cow. Calves are removed from the cow around 40-60 minutes post-calving and are fed tested and pasteurised colostrum.
“To us a successful transition is allowing a cow to return to the main dairy soon after calving, with minimal metabolic problems and able to start producing within a short period,” Nigel continues. “To do this we need to help her recover from the considerable strain and stress of calving as quickly as possible and key to this is getting her rehydrated immediately.”
“We had tried a number of rehydration products but with mixed success and variable intakes. Following a discussion with Mark Pass from Beeston Animal Health we changed to Farm-O-San Reviva from Trouw Nutrition GB.”
Dr Laura Tennant, Ruminant Technical Specialist with Trouw Nutrition explains that post-calving dehydration, a condition that affects all calving cows is due to a combination of two factors. The first is that cows will lose around 50 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. With reduced intakes and increased losses, post-calving dehydration is likely.
“When a cow loses fluids and salts she needs to replace them and the immediate physiological response is to move fluids out of cells to balance concentrations in the blood,” she explains. “The sooner she is able to drink after calving, the sooner the balance is restored and the less has to be extracted from cells.
“Anyone who has watched a calving cow knows the considerable fluid loss but the dietary intake factor is also significant. In addition to drinking, cows extract a lot of liquid from the diet. A 30% dry matter silage is, after all, 70% water. While all cows will be dehydrated at the end of calving, the problem can be worse in cows which suffer a prolonged calving, mainly as they will have had lower feed intakes for a longer period.
“It is normally not difficult to get cows to drink a lot in the two hours immediately post-calving provided the drink is palatable, but it is important to make sure what they are drinking is the best replacement for lost fluids and this means supplying electrolytes.
“Water has no electrolytes in it and so won’t rehydrate cows as well as a product that supplies the necessary salts. New research also shows that oral supplementation with calcium helps restore calcium homeostasis more effectively. The cost of a rehydration supplement is very low compared to the benefits that will result.”
Dr Tennant says that rehydrated cows are more vigorous and will eat sooner which can help reduce problems with milk fevers and other metabolic problems. Restoring feed intakes is vital to help cows settle into lactation. She explains that getting cows eating and drinking quickly after calving can also reduce the risk of LDAs and other metabolic-related disorders by reducing the inevitable energy gap by improving intakes.
Post calving protocols
At Grosvenor Farms the protocol is that cows receive 30 litres of Reviva within 30 minutes of calving and before they eat or drink anything else. Nigel Travers says the bucket of solution is placed next to the calf, in many cases before the cow has stood up after calving.
“It is very palatable and we have no problem with cows taking it but sometimes we will sprinkle a little on the calf which encourages the cow to drink after she has licked the calf. It is vital that they have not had anything else to drink before they get the Reviva or else intakes will drop and we will lose the benefits.
“As well as rehydrating the cow, a big drink helps fill the hole left by the calf which in turns helps reduce the risk of a LDA. Once she has had the drink we give her access to food which is the milking cow diet and she will move back to the milking herd within 24 hours.”
Mark Farrall explains that cows initially move into a fresh cow group where they can be monitored daily for the first 21 days post calving.
He says rehydration is now a key part of fresh cow management for the herd. “In our experience getting a cow drinking and successfully rehydrated is the first step in reducing the bill associated with transition. LDAs, retained foetal membranes and the other metabolic conditions associated with calving all have a big bill attached. Then there is the hidden cost of increased time to cleanse and extended negative energy balance due to cows not eating.
“With effective rehydration we have managed to reduce milk fevers and retained foetal membranes to below 2% and cows are settling into lactation with minimal problems,” Mark Farrall concludes.