360 Effect of the administration of a protected source of calcium gluconate on growth, feed efficiency, nutrient digestibility, and health in beef cattle

Abstract The gastrointestinal tract has a central role in production efficiency due to its involvement in the digestive function as well as in immunological, nervous, and metabolic functions. In ruminants, a great deal of attention is placed on ruminal functionality and safety. However, it is now recognized that the hindgut is involved in the onset of some metabolic issues, normally associated with ruminal imbalances, as well as in the digestion efficiency. Thus, the application of nutritional strategies that target the hindgut are gaining interest in cattle nutrition. The study evaluated the effects of a protected source of calcium gluconate on performance, digestibility, and health in beef cattle. Charolaise bulls (n = 241) were randomly divided into two groups: i) Control (n = 120) basal diets + 10g/head/day of a placebo of wheat bran; ii) Treatment (n = 121) basal diets + 10 g·bull⁻¹·d⁻¹of a protected source of calcium gluconate (Lactibute, Selko Trouw Nutrition). The population was further divided into two subgroups: i) “Overall population” (n = 201) housed in pens of 7to 8 animals each; ii) “Beefmonitor population” (n = 40). The latter was housed in two pens (Control and Treatment) with 20 animals each equipped with two automatic scales for BW located at the drinkers, to evaluate the daily growth trends. Growth performance, feed intake (FI), feed conversion ratio (FCR), were evaluated with specific approaches in the two populations. The incidence of diseases was evaluated equally in the two populations. The apparent total tract digestibility (aTTD) was evaluated on 10 representative pens per group using a portable near-infrared system that compares the composition of the diets and the correlated feces. All the data were analyzed statistically using the SAS software and applying specific models. The average daily gain (ADG) was improved by the Treatment (+40 and +43 g·bull⁻¹·d⁻¹compared with the Control group, in the “Overall” and “Beefmonitor” populations; Table 1 and Figure 1; P = 0.0084 and 0.0001, respectively), and the final BW were also heavier (706.82 and 705.83 vs 699.75 and 697.33 kg in the “Overall” and “Beefmonitor” populations; P = 0.0084 and 0.037, respectively). The treatment improved both, FCR (6.90 and 7.03 vs 7.51 and 7.28 in the “Overall” and “Beefmonitor” populations; P = 0.0008 and 0.0001 respectively; Table 1 and Figure 1) and the aTTDs of starch (97.05 vs 95.71%; P 0.0001), cellulose (57.91 vs 52.95%; P 0.0001) and NDF (52.02 vs 50.02%; P = 0.020). The incidence of lameness was reduced in the Treatment group (0.99 vs 7%; P = 0.0282). Including protected sources of calcium gluconate can be functional to improve production efficiency and animal health, as a consequence of its proactive role on intestinal health, functionality and epithelial integrity.