Beck, Matthew R.2020-11-092020-11-092020https://hdl.handle.net/10182/13051The objective of the outlined research was to determine how a fermented seaweed extract (SWO) and seaweed plus terrestrial plants (SWP) extract influenced ruminant health, productivity, environmental impacts (i.e. enteric methane and urinary N excretions), and the foraging ecology of young livestock. This was conducted over seven experiments. Chapter 3 implemented an in vitro methodology to determine the dose effect of SWO on fermentation parameters. The lowest dose implemented, which would relate to 5-mL/hd/d, reduced ammonia production by 6%, which may indicate lower urinary N excretions in vivo. Chapter 4 applied the determined dose (5-mL/d) to dairy cows during the last third of gestation with either SWO, SWP, or water (CON), and then the dose was increased to 100-mL per d after calving during the early lactation portion of the experiment. It was determined that the cows receiving SWO and SWP had reduced oxidative stress prior to calving and lower oxidative and metabolic stress 3-d after calving compared with the CON cows. Cows provided SWP after calving had 18% lower urinary N excretion, which is described in chapter 5. In chapter 6, pregnant ewes were either provided no supplement (CON-) or a grain based supplement with no plant extracts (CON+), with SWO (10-mL/hd/d), or SWP (10-mL/hd/d). At peak lactation (28 days-in-milk) grain supplementation (CON+) increased oxidative stress compared with CON-, and this effect was negated by SWO and SWP. Grain supplementation has been shown to induce oxidative stress in several animal models at peak lactation. In chapter 7, ewes were managed to lamb as yearlings, with their offspring precluded from consuming the same treatment supplements as in chapter 6. While SWO and SWP showed no benefit to oxidative stress of the ewes, possibly due to the low metabolic stress experienced, the lambs whose dams were provided SWO and SWP had lower oxidative stress one day after weaning. This indicates a greater maternal transmission of antioxidants from the SWO and SWP dams providing defense against oxidative stress induced from the physiological stress associated with weaning. The ram lambs born during chapter 6 continued to receive the supplement treatments of their dams until the start of the experiment described in chapter 8. The ram lambs were allocated to spatially separated strips sown to ryegrass (Lolium perenne), chicory, plantain, lucerne, and dock. Previous exposure to SWP reduced dietary neophobia, whereas the SWO and CON lambs exhibited substantial dietary neophobia to chicory and plantain. For chapter 9, the lambs born during chapter 7 were placed in the same paddocks as the ram lambs used in chapter 8. Similar to chapter 8, it was determined that lambs born to ewes provided SWP showed less dietary neophobia to chicory and lucerne compared with the lambs born to ewes provided SWO and CON. This chapter determined that dietary experience was obtained either from in utero or maternal milk exposure. Collectively, these experiments show the benefit of fermented plant extracts to improve animal health, reduce environmental impacts, and how foraging decisions of ruminants can be manipulated by previous exposure.enplant extractsseaweedbioactivesprobioticsruminant metabolismruminantsThesisANZSRC::07 Agricultural and Veterinary SciencesANZSRC::0702 Animal ProductionANZSRC::070204 Animal NutritionANZSRC::070202 Animal Growth and DevelopmentANZSRC::070203 Animal ManagementQ112183083https://creativecommons.org/licenses/by-nc-nd/4.0/Attribution-NonCommercial-NoDerivatives 4.0 International