Green Grass Calving

There are many advantages to green grass calving when compared to late winter early spring calving.
Green Grass Calving - Articles


Cows with calves on grass

A recent review of bulls delivered bulls to the Pennsylvania Bull Test revealed that the bulls are now more often born in March and April as compared to earlier years of the bull test. The review revealed the bulls were born earlier in the year.

The conventional wisdom has been that calves born earlier in the spring (January through March) will make more money because they will be bigger at weaning and return more dollars at the feeder calf sale. Is this still sound thinking?

Heavier calves

A recent review of the weekly summary of feeder calf prices in Pennsylvania at the time of the writing of this fact sheet indicates M1 grade feeder steers weighing 500 > 700 lbs have been averaging $2.45 and those averaging 300 > 500 lbs. average $2.65 making the heavier calves worth about $20.00 per 100 wt more for the extra 60 pounds in weight. This difference in sale weight could occur in some herds with a difference in calving date from February to late April. The prevailing question what is the additional cost for calving cows in February as compared to late April, and is the cost more than the $20.00 that is realized by the older possibility heavier calf. An additional hidden expense is the potential calf losses associated with cold weather calving.

Feed cost

For cows calving in February in the Mid-Atlantic region you can expect to feed about $200 worth of hay until pasture availability. Secondly, since the nutritional needs of the cows will increase following calving, hay consumption will often double for the lactating cow. Additionally, average quality hay may not have sufficient feed value to meet the nutritional needs of the late gestation early lactation cows with average or better milk production. Conservatively adding a pound of protein to the diet for 60 days will add an additional feed cost of $15-$20 per cow. Most research shows beef cows have a peak in milk production 60-90 days after calving, so a calf born in February may have the most milk available before pastures are ready. This results in feeding additional harvested feed to the cows to reach peak milk production. As the cost of feed inputs increase it is important to compare the weaning weight and value advantages compared to the cost for feeding more harvested feed to the early calving cow.

Calf Health

Consider the view of a calving area in February in the Mid-Atlantic region compared to one in late April, May, snow and mud compared to green grass. Obviously, cows will usually be more confined, they will be concentrated around a hay feeder, and there is little opportunity to separate cows after they calve in March or earlier. This scenario leads to udders being dirty and resulting scours in the calves, injury to calves, and mud and aggravation for farmers. Compare that scenario if you will to the Sandhills calving system developed by researchers at the University of Nebraska Sandhills Research Station. This system was developed to help prevent scours and other disease issues in young calves. In this protocol cows that have not calved in the herd are moved to a new location every two weeks, while cows with calves stay together. This prevents older calves from transmitting bugs to newborn calves, and also prevents the buildup of pathogens at a single location. In the Mid-Atlantic region this system can only be used if there are functional paddocks available to keep moving the cows. Absent a number of hay feeders being available, winter water available in multiple locations, and access to facilities if needed, this implies healthier calves may be available when calving closer to when pasture is available.

Replacement heifers

There is a legitimate question of whether heifers born in May will be reproductively mature to be bred the next spring. Experience with heifers for the past three years in the Heifer Development Program in Pennsylvania has shown us heifers born in April and bred around May 1 to a synchronized estrus did not differ significantly in pregnancy rate from those born in earlier months. The key to breeding heifers at 12 months of age is with proper development so they reach a critical weight of 65% of mature weight, they are healthy, and the nutritional environment allows them to cycle, maintain adequate growth, and be fertile.

The downside

As with any management program there are going to be some compromises to make with green grass calving. First, haying and crop farming will be in high gear in most areas at the same time calves are hitting the ground. The division and availability of labor to effectively manage cows at calving while making hay and planting crops can be a problem for small breeders. This situation makes sire selection even more important. Producers must focus on calving ease bulls to help reduce the incidence of calving trouble. Secondly, the peak breeding season for the herd then becomes July and August-often the hottest and driest part of the summer in the region. Forage availability, grazing time, and breeding activity may be reduced.

Originally prepared by Dr. John Comerford, retired Penn State Professor