Garlic's impact on fly management and feedlot cattle performance

Garlic’s impact on fly management & feedlot cattle performance

Debates about the impact of feeding garlic products to cattle have plagued producers for years. A good number of producers argue that feeding garlic-infused minerals or salt to their cattle has measurably reduced the abundance of flies or increased the amount of minerals they consume or both. Other producers, just as passionate, claim that garlic had no impact on their herds.

Two years ago, researchers at Lakeland College set out to collect objective data to clear up the claims. The most surprising thing about their results? Both those who swear on garlic’s efficacy and those who don’t are probably correct – and it might all come down to the type of garlic used. An initial pilot study led by Dr. Obioha Durunna in Saskatchewan, with support from the Saskatchewan Ministry of Agriculture and some cattle producers, evaluated the fly-repellence impact of garlic-infused-salt supplement in grazing cows. In that study, they worked with three groups of cow-calf pairs over two years, where some groups received salt supplements infused with garlic powder, and some did not. While the study's findings showed significantly lower fly abundance and defensive behaviours in one of the two groups that received the garlic-infused treatments, the other group that received the same treatment was not as strong. The results from the Saskatchewan study were published in the Sustainable Agriculture Research Journal. For Dr. Durunna, the initial study raised more questions than it answered, and he wanted to look deeper into the impact of feeding garlic on the cow’s overall health with intake and growth performance. His research team at Lakeland received funding from the Government of Saskatchewan’s Agriculture Development Fund and Canadian Agriculture Partnership (through the Government of Alberta) to closely study the animal performance outcomes associated with supplementation practices. “It’s a step further,” Dr. Durunna explains. “We wanted to collect additional information that we couldn't collect in the initial study, for example, the actual mineral intake and feed intake, with their growth and efficiency performance in the different groups, which are important information for beef producers. In addition to the control group with no garlic product, we evaluated two levels of garlic powder at 2.5% and 5%, then a 0.3% garlic-oil-based premix. The study will help us answer some important and basic questions everybody wants to know: do garlic products improve growth performance? Which levels stimulate animals to eat more minerals? Does the inclusion affect the rumen microbiome and overall health of the animal? What are the recommended feeding levels, and how much are they eating?” Studying the impact of garlic supplementation on an animal’s mineral intake can provide essential information to producers who may be dealing with nutrient-deficient cows or in regions where the soil lacks the essential nutrients for optimum cattle production and reproduction. “Because mineral supplementation can ensure the adequate supply of some nutrients to cattle, it’s critical for producers to ensure that the animals are consuming the supplements. If infusing garlic products into supplements can stimulate the animals to consume enough of such supplements, that will give producers another tool that will ensure their animals are receiving all the nutrients they need for excellent health and productivity.” In the first year, the researchers were excited about the results. After the second year, however, they began to suspect the garlic question was more complicated than they’d first assumed. “We crunched the numbers for that first year and saw 19 to 50 percent increase in mineral intake in the groups that received the garlic powder when compared to the control group. It was exciting,” says Dr. Durunna. “But then, fast forward to the second year, and we didn’t see the difference between the treatment groups and the control group. But overall, groups receiving garlic-infused mineral supplement had about 30% greater supplement intake than the control”. The group looked for an explanation for the discrepancy between the two years and found something interesting — the brand of garlic used in each year was different. The researchers sent samples of both garlic brands to a lab in the United States for in-depth profiling to determine if some of the garlic’s active compounds differed between the two years. The results also showed that one of the brands had higher allicin content by about 1000 ppm, but it is unclear about the differences in the observed outcomes given that allicin is quickly decomposed to more stable sulfuric compounds. The results also showed over 90% reduction in allicin if the garlic powder was exposed and would suggest that better storage is required to maintain the integrity of the allicin. The group that received a higher inclusion rate of 5% garlic powder in the mineral supplement had a daily garlic powder intake of about 10 g of garlic powder. There were no adverse health incidents or abnormal blood test results associated with any of the treatment groups. There was no difference in feed intake or growth, or other efficiency measures. “It’s about understanding why the garlic products work for some groups and not for others,” Dr. Durunna says. Based on their findings, they plan to conduct a supplementary trial in the fall. The main messages from their studies show that: 1. All garlic products do not contain the same level of active compounds, affecting their efficacy. 2. Storage conditions affect the quality of garlic powder 3. The study in grazing cows showed lower fly abundance in the groups receiving garlic 4. The study in feedlot steers showed higher supplement intake than the control, but there was no difference in body and growth performance. 5. There was no adverse health associated with feeding garlic products at the recommended inclusion rates.