Weekly, Oklahoma State University Extension Beef Cattle Nutrition Specialist Paul Beck offers his expertise on the beef cattle industry. This is a part of the weekly series known as the “Cow-Calf Corner.” Today, he talks about increasing resilience of beef cattle.
In recent weeks I covered some of the impacts of drought on cow numbers and feeder cattle supply based on comments I made at a symposium at the American Society of Animal Science meeting held in Calgary “Increasing the Resilience of the Beef Cattle Feeder Supply”. This week I will cover some additional impacts of drought and changing weather patterns on performance and health of feeder calves.
Along with reduced cow rebreeding rates, heat stress or nutrient restriction of gestating cows will result in long-term reductions in productivity of their offspring. Last week I showed how heifer offspring of undernourished cows have lower fertility. The impacts affect growing and finishing performance as well. There has been a lot of research focusing on the impact of the environment the cow is experiencing during gestation on the offspring, this has been studied in humans, sheep, swine, cattle and other species. So, whether calf, lamb, piglet, or baby, adversity impacting the dam has profound effects on the next generation. This is called ‘Fetal Programming’. Severe nutritional restrictions during the last half to third of gestation are required to reduce calf body at birth, which is more pronounced in heifers than mature cows. But there are other effects that have been demonstrated on feeder cattle production. The post-weaning performance through finishing from calves produced by the same cowherd in 2009 (a wet year) and 2010 (a drought year) are presented below. Breeding and management of the cowherd were relatively consistent across years, but finishing performance (average daily gain), bodyweight at harvest, hot carcass weight, and carcass quality (percentage USDA Choice and greater) were all lower for calves impacted by the drought.
Yes, undernutrition of the dam has impacts on heifer fertility (as discussed last week) and finishing performance of offspring, but there are other impacts that are less visible. Colostrum production and quality is affected by undernutrition at calving, which can impact long-term health and productivity. There are more subtle effects of undernutrition on organ development (liver, lungs, heart, GI tract etc.) that can have long-term effects on health. In the Figure below is data from Shawn Walter, a data scientist from CattleFax, showing the feedlot mortalities in the last 60-days of the finishing period as a percentage of total death losses. There is a definite upward trend line over the last 10 years for both steers and heifers. Notice how the data points are above the trendline for the years following the drought in 2015 and 2016, before returning to baseline after a couple of year of ‘normal’ environmental conditions. Although not a scientific analysis this may indicate drought impacts on animal health and well-being through fetal programming.
Next week I will discuss potential steps we can take to manage our cowherds for overcoming the impacts of drought and changing weather patterns.
