By Lawton Stewart and Uttam Saha
This year has proved to be quite an interesting one. Many parts of the state have seen periods with above-average amounts of rain, but also periods of well below-average amounts. Most producers were able to put up plenty of hay. However, based on the samples submitted to the UGA Feed and Environmental Water Laboratory, there is quite a range in forage quality. For producers with late winter/spring calving season, this could cause potential issues. Combining this with a few other observations, here are a few situations we are seeing, and the potential ramifications.
1.I will restrict feed in the last trimester to decrease calf birth weights.
2.I need more protein to go with my hay
3.There is a tendency to underestimate crude protein and overestimate energy.
I will restrict feed in the last trimester to decrease calf birth weights. Is this correct? Absolutely! The problem is that birth weight is not the only thing it will affect. Recent research has focused on fetal programming. Fetal programming is the concept that maternal stimuli or insults during fetal development have long-term effects on the offspring. One of the most critical aspects of fetal programming involves the adequate nutrition, or lack thereof, of the dam. Research has shown minimal impact on calf birth weights; however, the restricted nutrition during the last trimester decreased weaning weights, finishing weights, and hot carcass weights. Additionally, research from Nebraska indicated that heifers from
nutritionally restricted cows reached puberty 14 days later than those with proper
nutrition.
I need more protein to go with my hay. Is this correct? Possibly, however, protein is only half of the equation. From April 1 to October 1 of this year, 773 bermudagrass hay samples were submitted to the UGA lab. The mean crude protein and energy (TDN) value was 11.1%. and 55.7%, respectively. Figure 1 represents the CP and TDN requirements of a brood cow throughout the production year. As you can see, as cows are entering the final trimester, their CP requirement is exceeded by the average bermudagrass sample, but the energy requirement falls short. More importantly, as they calve, enter peak lactation, and the breeding season, the CP requirement is met, but the TDN falls tremendously short.