Supplementation of DHA-Gold pre and/or postnatally to goat kids modifies in vitro methane production and rumen morphology until 6 mo old 1

• Published in: Journal of animal science 2018-11, Vol.96 (11), p.4845-4858
• Main Authors: Ruiz-González, A, Debruyne, S, Dewanckele, L, Escobar, M, Vandaele, L, Van Den Broeck, W, Fievez, V
• Format: Article
• Language: English
• Subjects: Algae; Animal growth; Body weight; Diet; Fatty acids; Fermentation; Goats; Gold; Inoculum; Methane; Methanogenesis; Morphology; Papillae; Potassium; Pregnancy; Reduction; Rumen; Supplements; Volatile fatty acids
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/sky307

This study aimed to investigate the effect of pre and/or postnatal supplementation of a dry whole cell algae (DHA-Gold) to goat kids, on in vitro methane (CH4) production, animal growth, and rumen morphology at the age of 6 mo. Furthermore, the in vitro retreatment effect of DHA-Gold was evaluated. Twenty pregnant Saanen goats giving birth to 2 male kids were used. Half of these does were supplemented (D+) with 18.2 g/d of DHA-Gold in the last 3 wk of pregnancy, whereas the other half was not (D...). After kidding, one goat kid per doe in both groups was supplemented daily with 0.28 g/kg of body weight of DHA-Gold (k+) until 12 wk, whereas the other goat kids were untreated (k...). This resulted in 4 experimental groups D+k+, D+k..., D...k+, and D...k... In vitro incubations were performed at the ages of 4 wk, 11 wk, and 6 mo. At the age of 6 mo, goat kids were euthanized and additional incubations were performed supplementing 4 doses of DHA-Gold (0, 0.4, 0.8, and 1.6 mg/mL). Additionally, rumen tissue of the atrium ruminis, ventral rumen, and dorsal blind sac were collected to assess rumen morphology. Rumen inocula of 4-wk-old goat kids supplemented D+ showed lower (P < 0.05) in vitro CH4 production, however, this was mainly due to a reduction in the overall fermentation, while CH4 expressed relatively to total volatile fatty acids (VFA) was higher when goat kids were treated D+ or k+. The detrimental D+ effect on VFA production diminished at 11 wk old but remained a tendency (0.05 < P < 0.1). As for 4 wk D+ as well as k+ supplementation of DHA-Gold stimulated rather than inhibited in vitro CH4 production expressed relative to total VFA. Supplementation of DHA-Gold either D+ or k+ decreased density, width, and surface area of the ruminal papillae. However, no effect on animal growth was observed. Moreover, detrimental effects of D+ or k+ treatment on VFA production or stimulation of relative CH4 production were no longer observed at 6 mo old. Nevertheless, direct exposure of DHA-Gold to 6-mo-old inoculum linearly (P < 0.05) decreased CH4 and VFA production, which tended (P = 0.06) to be greater when using D-rumen inoculum. Accordingly, neither D+ nor k+ DHA-Gold supplementation showed potential for reduction of rumen methanogenesis. Furthermore, this early life intervention could represent some risk for impaired rumen papillae development, which, however, did not impair animal performance.