Seasonal changes in one seed juniper intake by sheep and goats in relation to dietary protein and plant secondary metabolites

TitleSeasonal changes in one seed juniper intake by sheep and goats in relation to dietary protein and plant secondary metabolites
Publication TypeJournal Article
Year of Publication2009
AuthorsUtsumi S.A., Cibils AF, Estell RE, Soto-Navarro S., VanLeeuwen D
JournalSmall Ruminant Research
Volume81
Pagination152-162
Date Published2009/02/19
ARIS Log Number232654
Keywordsgoats, journal, juniper, protein supplements, ruminant, secondary metabolites, sheep
AbstractSeasonal variation in plant secondary metabolites (PSM) can influence voluntary intake levels of one-seed juniper (Juniperus monosperma Englem. Sarg.) of sheep and goats. Supplemental nutrients could mitigate the deterrent effects of juniper PSM. We determined the concentration of mono-and sesqui- terpenes, total phenolics and condensed tannins in one-seed juniper leaves in summer, fall, winter, and spring, and tested their effects on juniper intake of 12 Western White Face ewes (74.9 ± 1.23 kg) and 12 Boer-Spanish does (46.7 ± 1.25 kg) fed isoenergetic diets (1.6% BW) with no supplemental protein (Control, 5% CP) or with addition of a rumen degradable (RDP, 12.5% CP) or undegradable (RUP, 12.5% CP) protein supplement. Animals were fed unrestricted amounts of freshly harvested juniper branches for 30 min and short-term juniper intake was determined for 10 d per season. Total terpenes, total phenolics, and condensed tannins varied across seasons (P<0.05), and were positively correlated to each other (P<0.05). Juniper intake was greater for goats than sheep (P<0.05), and twice as high for supplemented vs. control animals (P<0.05). Juniper intake in the fall, when levels of plant secondary metabolites were highest, was 41, 58, and 52% less than in summer, winter, and spring (P<0.05), respectively. Supplements with RDP and RUP promoted different patterns of juniper intake among seasons (P<0.05), herbivores (P<0.05), and individual animals (P<0.05). This study suggests that supplemental protein can increase voluntary intake of one-seed juniper of small ruminants during seasons when plant secondary metabolite levels are low. Proteins of different degradability appear to affect seasonal patterns of juniper intake differently.
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