When it comes to mineral supplementation for beef females, new research suggests that the source matters.
Studies from the University of Florida show that organic trace mineral supplementation for cows has benefits compared to inorganic trace minerals in areas such as increased pregnancy rates, weaning weight and calf immunity.
Dr. Matt Hersom is an associate professor and extension beef cattle specialist at the University of Florida’s department of animal sciences. Hersom spoke about mineral supplementation at this summer’s Canadian Beef Industry Conference in a presentation hosted by Alltech. Part of his research mandate focuses on developing nutritional and supplementation programs designed to improve performance on forage and roughage.
“Organic trace minerals have a place in that mineral supplementation program that’s going to have a positive or beneficial effect on your cow herd and your bottom line,” he says. “When we start to short our animals from a mineral standpoint, we see some insidious loss.”
This includes loss of immunity and fertility, which has major financial implications.
Hersom’s recent work on organic versus inorganic trace mineral supplementation used data from trials on two south Florida ranches. One group of cows was supplemented with an organic trace mineral formulation, replacing the inorganic trace mineral supplement that had previously been fed on these ranches. The new supplement was a loose trace mineral fed on a free-choice basis.
The second group of cows received an inorganic trace mineral supplement of sodium selenite and salt sulphates. Each trial took 340 days, starting about 90 days before the start of calving. Researchers collected two years’ worth of data, although one ranch didn’t participate in the second year.
Combining the data from both ranches, the pregnancy rate rose from 92.6 per cent for cows supplemented with inorganic trace minerals to 95.3 per cent when they were supplemented with organic trace minerals. While Hersom noted that the original pregnancy rate was quite high, he highlighted the value of that 2.7 per cent increase.
“When I went through a model utilizing this real-world data, real-world numbers, that difference… equates to about a three-to-one return on investment in terms of utilizing that organic trace mineral, because we had an increased pregnancy rate that was real. It was statistically significant. We could replicate it.”
The trials showed that older cows and those with better body condition scores saw increased performance with the change to organic trace minerals. These groups were more sensitive to this change than younger cattle.
The researchers then compared the effect of each type of supplementation on weaning weights and saw a difference. Using two years of data from one of the ranches, the average adjusted weaning weight of heifers whose dams were supplemented with organic trace minerals was 533 lbs., compared to 502 lbs. for heifers whose dams were supplemented with inorganic trace minerals.
For steers, the average adjusted weaning weight for those whose dams were supplemented with organic trace minerals was 562 lbs., while steers whose dams were supplemented with inorganic trace minerals were 544 lbs. on average.
Hersom and his team also conducted research on campus at the University of Florida. They divided the university’s Angus and Brangus cows into two groups, supplementing one group with inorganic trace minerals and the other with organic trace minerals. Researchers followed the cattle through two production cycles, also examining several areas including calf immunity and performance.
“Prior to the breeding season we put it in the commercial pellet that we fed on an every-other-day basis,” says Hersom. “Once the breeding season started… we put it in a loose trace mineral supplement that was out there for consumption on an everyday basis.”
They studied the effect on the immunoglobulins (IG) of the cows that were exposed to organic trace minerals by taking colostrum samples after calving. There was an increase in immunoglobulin M in cows supplemented with organic trace minerals, which benefits calves.
“Calves that came from dams that got organic trace minerals tended to have greater IG A concentrations 12 hours after calving, tended to have greater total IG concentrations, circulating IG concentrations, 24 hours after calving,” says Hersom. “Even 30 days after calving, we saw greater immunoglobulin G concentrations in those calves that came from dams that were supplemented with organic trace minerals 90 days before calving compared to cows that only got inorganic trace minerals.”
The implications of these findings are an opportunity for producers, he says.
“We’ve got a potential (way) to enhance calf immune status when we use the right mineral supplementation program. We get a better mineral supplement into those cows, we’re going to positively affect that cow’s colostrum and subsequent calf health and immunity.”
In addition to several other areas, the university trials focused on the effect of supplementation in dams on the age of puberty in their heifer calves. In the first year, they saw no difference in the age that the retained heifers attained puberty, despite the increase in weaning weight on the same heifers. However, in the second year heifers whose dams were supplemented with organic trace minerals reached puberty an average of 27 days earlier than those supplemented with inorganic trace minerals.
Questions remain on the effect of the dam’s mineral supplementation on her bull calf’s sexual development, though the study hinted at possible benefits.
“We’ve got a small number of bulls available to us, and so from a statistics standpoint we don’t have very good power,” Hersom explains.
“What I will tell you is bulls that came from dams that were supplemented with organic trace minerals were younger when they reached sexual maturity compared to bulls that came from the inorganic supplement. So we don’t have statistical power on that one; we need to do more research on bull sexual development,” he says. “I do think the trace mineral source does have an effect.”
Hersom and his team also examined the bulls’ semen characteristics, and found there were fewer secondary sperm abnormalities in bulls whose dams were supplemented with organic trace minerals. While this finding doesn’t have much statistical data, it’s another area to explore further.