Abstract
A total of 933 mixed-parity sows (Line 1050, PIC) and their litters were used to evaluate the effect of calcium administration protocols around farrowing on sow performance. Sows were blocked by parity category and past stillbirth record then allotted to 1 of 3 treatments with 310-312 replications per treatment. Treatments included: 1) Control in which sows received no intervention; 2) calcium chloride feed top-dress (CaCl; TRIAD, Alltech, Inc., Nicholasville, KY) provided daily at the morning feeding from the time of entry (approximately d 112) until the sow farrowed; or 3) calcium gluconate injection (CaG; VetOne; Boise, ID) where multiparous and primiparous sows received a 20 or 15 mL injection, respectively, if a sow had more than 16 piglets, longer than 1 h since the birth of the last piglet, she had 2 or more stillbirths, or farrowing duration exceeded 4 h. On a subset of females (n=74/treatment), farrowing duration, sow blood metabolite analysis, sow urine pH, and piglet blood immunocrit were analyzed. Sow blood, sow urine, and piglet blood were collected within 4, 6, and 24 h of the end of farrowing. Multiparous females were categorized into past average stillbirth groups of < 0.5, ≥0.5 and ≤1, or >1. Females were categorized in parity groups of P1 (n=194), P2-P4 (n=489), or P5+ (n=250). Parity category, treatment, and their interaction were included as fixed effects while stillbirth category was a random effect in the model. There were no differences in total born, percentage born alive, or percentage stillbirths between treatments. Parity 5+ sows had reduced percentage of pigs born alive due to increased percentage stillbirth (P< 0.05) compared to other parity categories. There was an interaction between farrowing calcium protocol and parity category for birth to cross foster mortality (P=0.035) where mortality was lowest in P1 Control sows (P< 0.05) compared to all other combinations of TRT × parity category except for P1 CaG sows which were intermediate. Parity 1 sows had decreased birth to cross foster mortality (P< 0.05) when compared to other parity categories. Sows fed CaCl had increased blood Cl and ionized Ca (P< 0.05) compared to Control or CaG sows. Parity 5+ sows had decreased ionized blood Ca (P< 0.05) when compared to other parity categories. Sows injected with CaG had increased blood glucose levels (P< 0.05) compared to Control sows with sows fed CaCl intermediate. Sows provided CaCl and CaG had decreased urine pH (P< 0.05) compared to Control sows. There was a tendency for a farrowing Ca protocol effect on piglet immunocrit (P=0.068) where offspring from CaG sows had numerically higher immunocrit ratios. In conclusion, topdressing CaCl before farrowing or administering CaG injections peripartum altered sow metabolites during farrowing but did not influence farrowing performance.