PS4-15. The Impact of Water Additives on the Growth Performance and Water Disappearance of Newly Weaned Pigs.

Abstract Weaning places many stressors on the young pig, which can reduce feed intake and body weight gain. A practical approach to stimulate early nutrient intake is to add nutrients to the water supply; however, comparative efficacy data among commercial products remain limited. The objective of this study was to investigate the impact of three water additives on early post-weaning feed intake, water disappearance, and performance. This 42-day study was conducted at the Iowa State University Swine Nutrition Farm and utilized 480 newly weaned pigs randomly allocated to 48 mixed sex pens. Treatments were provided for 5 days after placement, were randomly assigned to pens, and included: standard water (Control), two commercially available water additives (Product 1, Product 2), and one experimental water additive (Exp product). Products 1 and 2 are Liquid supplements with carbohydrates and functional proteins. Additionally, Product 1 contains trace minerals, and Product 2 includes palatability enhancers. All supplements were composed of commercially available GRAS status ingredients and were administered through nipple waterers at a 1:128 dilution. A three-phase standard nursery diet, formulated to meet or exceed the NRC (2012) nutrient requirements, was provided ad libitum to all treatments. Data were collected on days 0, 3, 7, 21, and 42 and were analyzed across four periods: period 1 (days 0-7), period 2 (days 8-21), period 3 (days 22-42), and overall performance (days 0-42). Performance measurements included body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (G:F), and water disappearance. Statistical analysis was performed in R Version 4.5.1. Linear mixed models were used to evaluate the effect of treatment on performance metrics, with treatment and day 0 body weight as fixed effects and pen and block as random effects. The significance of treatment was determined by analysis of variance (ANOVA), and significant effects were further evaluated using Tukey's post hoc test for multiple comparisons. In period 1, the Control had significantly (P < 0.05) higher day 3 BW, ADG, G:F, and water disappearance, and day 7 ADFI than Product 1, but did not differ from Product 2 or Exp product (P > 0.10). Exp Product had significantly higher day 3 ADFI (P = 0.047) than Product 1, but not compared to Control or Product 2 (P > 0.10). In period 3, Exp Product didn't differ from Product 2 or Control, but had higher (P = 0.034) BW than Product 1. Overall, Exp Product grew faster (P = 0.034) than Product 1, but not than Control or Product 2 (P > 0.10). These findings support the use of water additives as a strategy to promote nutrient intake and sustain post-weaning growth; however, product efficacy may vary among water additives and across pig populations.