Ruminal fermentation characteristics of goats selectively bred to have greater consumption of juniper foliage

•Rumen fermentation characteristics were evaluated in goats selected for HIGH or LOW juniper consumption.•Isovalerate and NH3-N was greatest in rumen fluid of HIGH goats when collected after grazing juniper predominated rangelands.•VFA production tended to differ in HIGH and LOW selection lines when diets changed across the 3 periods.•HIGH goats did not consume more juniper foliage in pen setting. The objective of this study was to determine if ruminal fermentation characteristics differed in goat lines selectively bred for high or low consumption of J. pinchotii foliage. Ten Boer × Spanish-composite bucks (age = 2 yr; initial body weight (BW) = 67.2 ± 4.3 kg) previously selected for high (High; n = 5) or low (LOW; n = 5) juniper consumption selected from each line were subjected to three periods: Period 1, d 0, grazing native range predominated by Juniperus spp; Period 2, d 1 to 26, group fed for ad libitum intake of sorghum × sudan hay; and Period 3, d 27 to 63, indivually fed sorghum × sudan hay at 3% of body weight (BW) and offered fresh J. pinchotii foliage for ad libitum intake. During each period, rumen fluid was evaluated for pH, VFA, ammonia N (NH3-N), and juniper foliage was evaluated for 48-hr true IVDMD (tIVDMD). There was a Selection line × Period interaction observed for total VFA (P