Effect of Dietary Anhydrous Calcium Chloride in Early and Late Finishing on Pig Performance and Body Composition

Abstract Understanding how to control pig growth is critical during market disruptions, including foreign animal disease and harvest facility shutdowns. In times of severe market disruptions, feeding acidogenic salts such as anhydrous calcium chloride to suppress appetite is an effective way to manage pig growth. Therefore, the aim of this study was to understand the impact of feeding calcium chloride during early and late growth stages on grow-finish growth and body composition of pigs. Barrows and gilts (n = 240; 52 ± 6.9 kg BW) were allotted by sex across 60 pens and to one of three treatments fed in 3 diet phases (Phase 1, d 1-28; Phase 2 d 28-56; Phase 3 d 57-87). Treatment included: 1) Control corn-soy diets in phases 1-3, 2) 3% CaCl2 intervention in phase 1, control diet fed in phases 2 and 3 (IP1), and 3) Control diet fed in phases 1 and 2, and 3% CaCl2 intervention in phase 3 (IP3). All diets were formulated to meet or exceed amino acid and energy requirements and pigs were fed ad libitum. Pig BW were recorded at the start and end of each phase, and pen feed disappearance was recorded to calculate pen ADG, ADFI, and G: F. Loin eye area and fat depth were measured using real-time ultrasound at the end of phases 1 and 3. Data were analyzed with pen as the experimental unit and treatment, gender, and their interaction as fixed effects. No noteworthy gender by diet interactions were demonstrated and only the diet treatment, overall performance, and ultrasound trait means are reported (Table 1). Compared with the Control and IP3, IP1 reduced ADFI and ADG by 42% and 60%, respectively, in phase 1 (P< 0.05). Feed efficiency, loin eye area, and fat depth were also reduced in the IP1 compared with the Control and IP3 pigs in phase 1 (P< 0.05). In phase 2, the IP1 pigs did not have a significant difference in feed intake and their ADG increased by 22% compared with the Control and IP3 pigs (P< 0.05) and therefore were more feed efficient. Implementation of CaCl2 in phase 3, the IP3 pigs reduced ADFI, ADG, and G: F compared with the control and IP1. Further, phase 3 loin eye area and fat depth were 13% and 17% less, respectively, in the IP3 pigs compared with the control. Overall, the IP3 treatment had the most severe reductions in ADG, ADFI, and feed efficiency (P< 0.05). Early intervention (IP1) also attenuated overall G: F, ADFI, and ADG compared with the Control (P< 0.05). These results demonstrate the efficacy of calcium chloride in attenuating pig feed intake and growth performance during early and late finishing.