USask study aims to gain understanding of finishing diets for bison

The term “finishing diet” refers to the rations given to put weight on market animals in the last few months before slaughter. Over two years, Dr. Diego Moya and his collaborators will analyze how the proportion of starch in the finishing diet affects the bison’s performance and the animal’s welfare as well as carcass quality and meat quality.

“There is a need for the industry to characterize the effect of these diets in the final meat product,” says Moya, an assistant professor at the Western College of Veterinary Medicine (WCVM) and the study’s lead investigator. “And then we also wanted to contribute … to further optimize and make this industry more profitable. 

Saskatchewan’s bison ranchers produce the second-largest number of bison in Canada with only Alberta having higher production numbers in the country.

“In Saskatchewan, the bison industry consists of approximately 40,000 bison and is worth $36 million to $42 million per year,” says Dr. Gabriel Ribeiro, one of the study’s collaborators.

Ribeiro and Dr. Greg Penner — both faculty members in the university’s College of Agriculture and Bioresources — are working with Moya on the project. Ribeiro holds the Saskatchewan Beef Industry Chair while Penner is the university’s Centennial Enhancement Chair in Ruminant Nutritional Physiology.

The idea for a study focused on finishing diets for bison first came about during a conversation with Murray Feist, the provincial livestock specialist in feed and bison for the Saskatchewan Ministry of Agriculture.

“Based on his experience with bison producers and formulating diets for bison, he saw a huge need to do more research in the field,” says Ribeiro.

As Ribeiro explains, most of the information available for guiding bison nutrition is based on beef cattle studies, which fail to consider the large differences between these two ruminant species.

While bison and cattle are both ruminants, they are very different creatures. Bison are more excitable and aggressive and have a much larger flight zone than cattle. They also have a stronger preference for foraging and they are better at digesting low-quality fibre.

The study is taking place over two four-month periods, with Moya using 32 bison in each period of the study. The bison will be housed at the university’s Livestock and Forage Centre of Excellence (LFCE), southeast of Saskatoon.

For each period, the study’s bison will be split into two groups of 16 with each group receiving a different diet type: one with high starch content and the second with moderate starch content. The diet’s specific content will be determined closer to the study’s start date, but it will be based on what’s available in Saskatchewan and the grain diets that are already fed to bison in Western Canada.

“We will assess how these diets affect not only the performance from a productivity standpoint, but also the health,” says Moya. “We’re going to monitor their behaviour to see whether different diets will change the feeding pattern of these animals.”

Ribeiro says the study’s results will provide Canadian bison producers with the tools they need to make more informed decisions when trying to optimize their productivity or the quality of their end products.

“This project will provide a guideline for producers that are interested in improving bison feed efficiency, carcass quality and at the same time, maximizing its [the bison’s] health and welfare,” says Ribeiro. 

Moya says this study will hopefully increase the industry’s understanding about bison and their finishing diets not only for veterinarians and producers but also for consumers. 

“From a consumer perspective, they’re going to have better products … and become more aware of how the products that they’re consuming are produced in Saskatchewan,” says Moya.

As part of the study, the team members will also assess the animals’ rumen pH levels as there are some risk factors for the development of rumen acidosis depending on the starch content of the bison’s diet. Rumen acidosis is a metabolic disease characterized by a decreased ruminal pH level, which is usually associated to the ingestion of large quantities of highly fermentable carbohydrates such as starchy foods like corn.

“This is the first of a series of studies that we have planned to define the best feeding strategies for bison raised in confined systems,” says Ribeiro.

The Agriculture Development Fund (ADF) is providing funding for this study, which Moya says was pivotal to getting the project started.

“I’ve been tempted before about doing some work with bison,” says Moya. “And this raises [an] opportunity … to assess and to work with bison and to help the bison industry in Saskatchewan. I’m very, very keen to start this project.”

“The funding from ADF is essential,” adds Ribeiro. “Without this funding and the support from the LFCE, we would not have the means to do this work. We are excited that it was funded and that we will be starting on it soon.”