Evaluation of glucose supplement provided with enrichment to reduce hunger induced stress in gestating sows
This study aimed to evaluate the effect of glucose supplementation via alginate hydrogel beads (AHBs) using enrichment using measures of behavior, farrowing performance, and physiology of feed restricted pregnant sows. First parity pregnant sows (N =36) with an average weight of 200 kg were randomly assigned into three treatment groups: negative control group sows were not provided with AHBs with enrichment (NEG), positive control sows were provided with AHBs without glucose with enrichment (POS), and the treatment group sows were provided with a glucose source via AHBs with enrichment (TRT). A total of 1 kg of AHBs were provided to POS and TRT sows for 1 week and the daily bead consumption was measured. Blood samples were taken on day 0 (baseline) and day 7 to evaluate the change in hematological and blood chemical parameters between the treatment groups. Behavior data were analyzed using GLM procedure in SAS. The non-parametric Kruskal Wallis test was used to analyze the farrowing performance. Statistical analysis was performed using repeated ANOVA measures following linear mixed model for blood data in R studio. A non-parametric Wilcoxon signed rank test was performed for AHB consumption data. The AHB consumption results revealed that the median bead consumption for the POS group was significantly higher than for the TRT group (P < 0.01). The hematological data showed a significantly higher lymphocyte count (LYM) in NEG than TRT sows on Day 7 (P < 0.05) but did not differ from the POS group at Day 7. Similarly, monocytes (MON) were higher for TRT sows at day 0 and day 7 (P = 0.04 and P = 0.003) compared to NEG group, whereas LYM in TRT was higher than POS on day 7 (P < 0.001) only. The Platelet distribution width was greater for POS sows than NEG sows (P = 0.04) but did not differ from the TRT sows. For the blood chemistry, TP (P = 0.003) and AST (P = 0.01) values showed a significant treatment by time interaction. TRT sows showed a higher total plasma protein (TP) level than NEG and POS groups (P = 0.01 and P = 0.03 respectively). Similarly, AST was significantly higher for POS sows than NEG sows on day 7 (P = 0.01). In conclusion, the blood parameters that are significant in this study are not definitive indicators of stress associated with hunger and are within the reference interval for pregnant sows. In conclusion, the increased blood parameters results could be the result of physiological coping mechanism in response to new material in the environment. There was no significant difference in the number of born alive, still born and mummified fetuses among the treatment groups. The behavior data showed higher active behaviors in TRT sows than POS and NEG sows during the first and second hour whereas standing behaviors and interacting behaviors in TRT sows was higher than POS and NEG sows during the second hour after providing AHBs and did not differ at any time after the second hour. In summary, the glucose supplement in AHBs increased feed motivation but did not significantly influence stress related blood parameters and did not affect farrowing performance.