Effects of clay on toxin binding capacity, ruminal fermentation, diet digestibility, and growth of steers fed high-concentrate diets1,2

Abstract

Three experiments were conducted to determine the effect of increasing concentrations of a smectite clay on toxin binding capacity, ruminal fermentation, diet digestibility, and growth of feedlot cattle. In Exp. 1, 72 Angus × Simmental steers were blocked by BW (395 ± 9.9 kg) and randomly allotted to 3 treatments (4 pens/treatment and 6 steers/pen) to determine the effects of increasing amounts of clay (0, 1, or 2%) on performance. The clay was top-dressed on an 80% concentrate diet at a rate of 0, 113, or 226 g/steer daily to achieve the 0, 1, and 2% treatments, respectively. Steers were slaughtered at a target BW of 606 kg. In Exp. 2, 6 steers (596 ± 22.2 kg initial BW) were randomly allotted to the same 3 treatments in a replicated 3 × 3 Latin square design (21-d periods) to determine the effects of increasing amounts of clay on ruminal pH, VFA, and nutrient digestibility. In Exp. 3, 150 mg of clay was incubated in 10 mL of rumen fluid with 3 incremental concentrations (6 replicates per concentration) of aflatoxin B (AFB) or ergotamine tartate (ET) to determine binding capacity. During the first 33-d period, there was a quadratic effect of clay on ADG ( < 0.01) and G:F ( < 0.01), increasing from 0 to 1% clay and then decreasing from 1 to 2% clay. However, during the second 30-d period, clay linearly decreased ADG and G:F ( ≤ 0.03) and overall ADG, DMI, and G:F were not impacted ( ≥ 0.46). Clay linearly decreased marbling score ( = 0.05). Hepatic enzyme activity did not differ among treatments on d 0 or at slaughter ( ≥ 0.15). Clay linearly decreased ruminal lactate and propionate, linearly increased formate and the acetate:propionate ratio ( ≤ 0.04), and tended ( = 0.07) to linearly increase butyrate. Clay tended to linearly increase ( = 0.06) OM and CP apparent digestibility. Ruminal pH, urine pH, and other digestibility measures did not differ among treatments ( ≥ 0.15). Clay was able to effectively bind AFB and ET at concentrations above the normal physiological range (52 and 520 μg/mL), but proportional adsorption was decreased to 35.5 and 91.1% at 5,200 μg/mL ( < 0.01) for AFB and ET, respectively. In conclusion, clay effectively binds ruminal toxins, decreases ruminal lactate, and improves performance only during adaptation to a high-concentrate feedlot diet.

A Systematic Review of the Efficacy of Interventions to Control Aflatoxins in the Dairy Production Chain—Feed Production and Animal Feeding Interventions

“…In the studies of Maki et al (2016a) [34], and Maki et al (2016b) [35], a clear clay dose-dependent reduction of aflatoxin concentration was shown. Antonelo et al (2017) [33] proved a linear toxin dose effect, while Xiong et al (2015) [50] showed that the adsorbent at high AFB1 concentrations was not effective. Weatherly et al (2018) [44] found a quadratic decrease in AFB1 reduction by the adsorbent treatment in faeces.…”

Invited review: Determination of large-scale individual dry matter intake phenotypes in dairy cattle

“…Although this technique is simple and inexpensive when only a small number of animals are tested, it is labor intensive. Furthermore, this technique works well in a tiestall setting, where separate feed bunks can be allocated to each animal, but fails when animals are group housed with access to a communal bunk, where only a group average can be determined effectively (e.g., Silva Antonelo et al, 2017), can be used to roughly estimate feed intakes, although these are more suitable for management than for research or genetic selection.…”