Feednavigator caught up with Dr Luis Tedeschi, research nutritionist and associate professor in the department of animal science at Texas A & M University, to hear how these models help producers understand nutrient requirements and feed utilization to improve cattle performance and profitability while protecting the environment.
He reckons nutrition modeling is “more important than ever because it gives users the ability to quickly evaluate multiple scenarios of production and choose options that are more acceptable, sustainable and resilient.”
Precision feeding model
And the programs developed at Texas A & M can be used to mitigate greenhouse gas emissions in several ways, said Tedeschi.
“The first way is by reducing the amount of feed fed to the animals by better matching their energy and protein demands through precision feeding.”
Nutritionists, he said, have typically formulated cattle rations to contain excess nutrients to ensure that growth rate was maximized, which often increased nutrient excretion and contributed to adverse effects on water and air quality.
Texas A & M’s Large Ruminant Nutrition System (LRNS), said Tedeschi, supports the precision feeding approach to reducing methane emissions by estimating beef and dairy cattle nutrient requirements and supply under specific conditions of animal type, climatic factors, management, and physicochemical composition of available feeds.
“Taking into account farm-specific management, environmental, and dietary characteristics has enabled more accurate prediction of cattle growth, milk production, and nutrient excretion in diverse production situations,” he continued.
The Small Ruminant Nutrition System (SRNS) also helps producers reduce emissions, in that it calculates energy, protein, calcium and phosphorus needs, accounting for factors such as body weight, age, insulation, movement, milk production and composition, body reserves, and pregnancy and environmental parameters including temperature, wind, and rainfall, said the assistant professor.
“Feed biological values are predicted based on the pool size and fractional degradation and passage rates of carbohydrate and protein fractions, ruminal microbial growth, and physically effective fiber,” he said.
Feedstuffs that generate less methane
Another way of reducing the environmental impact of cattle production is to select feedstuffs that generate less methane per organic matter consumed or fermented by the ruminant animal and yet still yield the same productivity, said Tedeschi.
“The in vitro gas production (IVGP) technique we use in our modelling systems helps evaluate how much methane is generated in a formulated feed ration. It has a faster turnaround than in vivo systems, which are more laborious, expensive, and time consuming,” he told us.
The IVGP assesses digestion characteristics and biological values of feeds based on their pattern of accumulated gas during incubation with rumen fluid under anaerobic conditions, he said.
“The data collected from these samples is imported into a spreadsheet, which automatically calculates fractional degradation rates of fiber and non-fiber carbohydrates to estimate total digestible nutrients (TDN) and metabolized energy (ME) of feeds. Methane production for each ration ingredient is also collated,” said Tedeschi.
Feed sector interest
The Texas A & M team has been trialing their modelling systems with feed manufacturers.
“Selected participants have been identified to work with us. Their main interest is in evaluating their products in terms of how they will help reduce greenhouse gas emissions and their level of digestibility,” said Tedeschi.
Most of the funding for this research has been through federal and state agencies as well as industry partners and supporters, said the academic.
The models are not limited to US feedlots either. “Because of how they account for different animal, feed, and environmental factors, the systems can be used globally,” he said.