Management6 min read

Inside the Transition Period — The Six Weeks That Shape the Whole Lactation

By Vikas Industrial Corporation, Khanna, Punjab

What happens inside a cow from 3 weeks before to 3 weeks after calving, why straw-based feeding makes it harder, and a simple daily fresh-cow check that catches trouble early.

The six weeks that matter most

The transition period runs from 3 weeks before calving to 3 weeks after it. Drackley (1999) described it as critically important to a cow's health, milk production and profit, and noted that most health disorders occur during this window. Goff and Horst (1997) add that milk fever, ketosis, retained placenta and displaced abomasum nearly all appear within the first 2 weeks of lactation, and that mastitis also becomes visible in those same 2 weeks. That is why this short window deserves more attention than its length suggests.

Three jobs the cow must get right

Goff and Horst (1997) describe three basic jobs that must keep working around calving: the rumen must adapt to a diet rich in energy, blood calcium must stay normal, and the immune system must stay strong. When any one of them fails, the risk of both metabolic and infectious disease rises. The rest of this article follows those three jobs, and ends with a daily check you can do yourself.

Job one: eating enough

In the last 3 weeks before calving, feed intake usually falls by 30 to 35 percent, and a cow that eats well before calving tends to eat well after it, so the effort to protect intake must start before the calf arrives (Grummer, 1995). Over-conditioned cows may be more prone to the drop. Feeding more fermentable carbohydrate in the close-up period helps the rumen microbes and the rumen lining adapt to the richer diet that follows calving. Wheat and paddy straw are abundant in Punjab's rice–wheat belt (Solovyev et al., 2018). If a dry cow has been living mostly on straw and green fodder, her rumen is not ready for a heavy concentrate, so the change should be gradual, over days and weeks, not at the door of the calving pen.

Job two: keeping blood calcium up

At the start of lactation a cow's daily calcium loss jumps from about 10 g to about 30 g, and blood calcium can fall well below normal (MSD Veterinary Manual). Clinical milk fever, with a cow that cannot stand, is only the visible end of the problem. A US survey of 1,462 cows sampled within 48 hours of calving found low blood calcium (below 2.0 mmol/L) in 25 percent of first-calf cows, rising to between 49 and 54 percent of cows in their 3rd to 5th lactations (Reinhardt et al., 2011). We did not find a comparable survey of Punjab herds, so treat these figures as a warning about how common the hidden form can be, not as a Punjab number. Low calcium also raises the risk of retained placenta, metritis, displaced abomasum and mastitis, which is why the calcium plan matters even when no cow goes down.

A forage trap: berseem, potassium and phosphorus

Researchers found that the potassium in a dry cow's ration may matter even more than its calcium in deciding whether she gets milk fever (Horst et al., 1997). Berseem, a common winter fodder in the northern plains, averages about 1.9 percent calcium, and the one potassium analysis listed shows about 4.6 percent, against roughly 0.5 percent calcium and 1.1 percent potassium for wheat straw (Feedipedia). Feeding berseem freely in the final weeks works against the aim of the close-up diet, which is to keep the cow's own calcium-mobilising system switched on (MSD Veterinary Manual). Wheat straw has the opposite weakness: only about 0.07 percent phosphorus and 4 percent protein, so it must be balanced with a proper concentrate. Forage minerals vary from field to field, so ask your vet to help set the close-up ration.

Job three: staying free of infection

Around calving the cow's immune defences are weaker, which is why mastitis and uterine infection show up so often in the first 2 weeks (Goff and Horst, 1997). Sheldon and colleagues report that uterine infection affects about half of all dairy cattle after calving and lowers fertility by disturbing the ovary as well as the womb (Sheldon et al., 2009). Heat adds to the load. At NDRI Karnal, the immune cells of Sahiwal cows that calved in summer, at a temperature-humidity index (THI) of 79.9, showed more signs of programmed cell death than those of cows that calved at a THI of 67.3 (Somal et al., 2015). That study had only 12 cows, so it is a pointer rather than proof. Our articles on cooling dry animals and on retained placenta cover the practical steps.

A daily fresh-cow check for the first 10 days

Check every fresh cow or buffalo once a day, at the same time. Note whether she has eaten, whether her left flank looks full, how much milk she gave, and whether she passed the placenta; normal expulsion takes 3 to 8 hours (MSD Veterinary Manual). Take her rectal temperature. A reading above 39.5°C together with a foul, watery, reddish-brown discharge and dullness is the definition of puerperal metritis in the first 21 days and needs a vet the same day (Sheldon et al., 2006). Ask your vet about a blood ketone meter. In a study of 1,717 cows tested between 3 and 16 days after calving, 43.2 percent had at least one reading of 1.2 to 2.9 mmol/L, the range used to define subclinical ketosis, and new cases peaked at day 5. Cows that first tested positive at 3 to 5 days were 6.1 times more likely to develop a displaced abomasum, so early testing pays (McArt et al., 2012).

Set the stage before calving: dry period and body condition

A dry period of 51 to 60 days has been the industry standard for decades. A review of random-assignment trials found that cutting the dry period from about 50 to 57 days to 30 to 34 days changed next-lactation milk by anything from a 10 percent loss to a 1 percent gain, while giving no dry period at all clearly lowers the next lactation (Bachman and Schairer, 2003). Body condition at calving matters just as much. The best calving score is 3.0 to 3.25 on the 5-point scale, and a score of 3.5 or more is linked with lower intake, lower milk and more metabolic disease (Roche et al., 2009). A cow or buffalo that gets no real dry period, or is allowed to put on condition during pregnancy, starts the transition at a disadvantage.

Does feeding for the transition pay on Indian farms?

A field trial on 85 pregnant buffaloes in tribal villages of Gujarat gives an Indian answer. Buffaloes that received 1.5 kg a day of a 22 percent protein concentrate plus 50 g of a chelated area-specific mineral mixture for 2 months before and 2 months after calving came back into heat sooner (67.7 against 79.4 days) and had a shorter service period (90.9 against 105.1 days), both statistically significant differences. Conception rate was 55 against 40 percent (Kalasariya et al., 2017). It was one trial in one region and a trial protocol, not a feeding recommendation, so ask your vet or Krishi Vigyan Kendra to adapt it to your animals. It does show that planned feeding around calving can pay off in village herds.

✦ Key Takeaway

The transition period is three jobs: eat enough, keep blood calcium up, and stay free of infection. Prepare the cow before calving with a proper dry period, a calving condition of 3.0 to 3.25 and a gradual change of ration, then check every fresh animal daily for 10 days.

Sources

Figures in this article come from the published sources below. Each link opens the original paper or reference page.

PreviousBody Condition Score (BCS) Guide for Dairy Farmers NextMurrah Buffalo Transition Problems — Milk Fever and Red-Urine Disease