Studies^1,2,3,4 carried out with Selko IntelliBond hydroxy trace minerals in beef cattle have shown differences in bioavailability compared to copper sulphate and zinc sulphate. In the case of copper, this is more obvious in the face of antagonists in the diet.

In a study carried out by Jalali and others⁵, two different trace mineral sources were fed as a free choice mineral supplement to two groups of beef cattle. In one group, the supplement was fed with 100% of the copper, zinc and manganese coming from Selko IntelliBond hydroxychloride sources, in the other group, a supplement with a combination of 75% of the copper, zinc and manganese coming from sulphate and 25% from an organic source was fed. Both groups of beef cattle were included in the study for two consecutive production cycles.

Liver copper concentration and zinc copper concentration were improved after one and two years of supplementation with the Selko IntelliBond hydroxychloride sources of trace minerals compared to the combination treatments. There was a clear difference in relative bioavailability for the two different sources of trace mineral supplementation for beef cattle (see figure 1). Pregnancy rate to artificial insemination in the beef cattle fed Selko IntelliBond hydroxy trace minerals was improved numerically (see Figure 2).

Ranch cattle are often fed two times or three times the NRC requirements for beef cattle with sulphate trace mineral sources, because sulphates are cheap. In a study by Stanton and others⁶ in beef cattle, three treatments were compared: a low-level sulphate treatment, where about 50% of the copper requirement was being met with copper sulphate, a high-level sulphate treatment where 100% of the NRC requirement was being met with sulphate, and a high-level organic treatment were 100% of the NRC requirement was met with an organic source of trace minerals. Beef cattle was included in the trial from calving through weaning. Liver copper status was improved with the two higher levels of supplementation, both for high-level sulphate and high-level organic. Pregnancy rate to artificial insemination in the high-level sulphate did not improve, compared to the organic source. Cows fed the high level of sulphates lost significantly more body weight relative to the other treatments in this trial.

The study suggests that feeding beef cattle high levels of sulphate trace mineral sources could have a negative effect on beef cattle production.

A study in beef cattle was carried out at the CSU Eastern Colorado Research center in North-east Colorado. The objective of this study was to determine the effects of copper, manganese and zinc source and concentration in free choice mineral supplements for beef cattle. Mineral status, reproduction and performance of the cows was included in the experiment and their offspring were tested during three production cycles.

Three treatments were compared. Copper, zinc and manganese NASEM requirements for beef were targeted either with sulphates or with Selko IntelliBond hydroxychloride trace minerals. The third group was fed half the amount of Selko IntelliBond hydroxychloride trace minerals advised by NASEM. All 3 mineral treatments for beef cattle were offered to the cows via a free choice mineral supplement. To increase the risk of antagonism, sulphur was included in each of the 3 supplements at a level of 12%.

Cows were blocked by weight, body condition, age, gestation and liver trace mineral status before they were randomly assigned to a treatment. Cows were synchronized and timed AI was used. Two AI technicians randomly bred half of the cows across the treatments to try to make sure the number of cows bred with AI was even between the 3 groups. After the timed AI, all cows were exposed to cleanup bulls for 46 days. Mineral intake was recorded monthly, body weight, condition score, and pregnancy rates were scored annually. Liver samples were collected and analysed and weaning weight of the calves was recorded.

Results, mineral intake off the beef cattle included in the trial

The trial aimed at an intake of 114 grams of supplement per head per day, to target the 1 times NASEM sulphate treatment, the 1 times NASEM hydroxy treatment and 50% of the NASEM requirements for the second hydroxy trace mineral group. Assumptions about trace mineral levels in the graze forage were taken into account and the aim was to feed 1000 ppm copper, 3000 ppm zinc, and 2000 ppm manganese for the 2 groups at 100% of the NASEM requirements for beef cattle and 500 ppm copper, ppm 1500 zinc, and a 1000 ppm manganese for the third group. In year 1, it turned out that almost double of the amount intended was fed, this was adjusted for years 2 and 3. Over the full 3-year timeframe, 2 groups were fed 1.5 times the NASEM requirements for beef cattle, 1 group was fed close to 75% of NASEM requirements for beef cattle (see Figure 3). Copper level in graze forage was low, zinc level was below requirement. Molybdenum levels were fairly high, which resulted in a risk of antagonism, particularly with copper.

Results, body weight and Body Condition Score

Body weight and body condition score of beef cattle included in the trial were similar between all 3 groups for the full 3-year study period, despite the fact that there was one year with extreme drought and another year with limited amounts of rainfall.

Results, trace mineral status and pregnancy rates

Trace mineral status of beef cattle at the beginning of the trial was good and was not different in year 1, but in years 2 and 3, there were highly significant differences for copper, zinc and manganese. Both Selko IntelliBond hydroxy trace mineral treatments were superior to the sulphate treatment (see figure 4, 5, 6).

In year 1 pregnancy rates to artificial insemination were not different, there was only a small numerical increase for the 1x hydroxy trace mineral group relative to sulphate group. In year 2 and 3, there were significant differences. Both Selko IntelliBond hydroxy trace mineral groups outperformed the sulphate group. As a result, more calves were born earlier in the calving season (see Figure 7).

Weaning weights of beef calves were not different in year 1, differences were close to significant in year 2 and highly significant in year 3, with both Selko IntelliBond hydroxy trace mineral groups outperforming the sulphate group (see Figure 8).

It was concluded that compared to supplementation with sulphate sources of copper, zinc and manganese, supplementation of beef cattle with Selko IntelliBond hydroxy trace mineral sources of copper, zinc and manganese improved liver copper zinc and manganese levels, resulting in improved pregnancy rate to AI of beef cattle and higher weaning weights of beef calves.