Effects of Juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics

Authors: STEWART, W - New Mexico State University; WHITNEY, T - Texas A&M University; SCHOLLJEGERDES, E - New Mexico State University; NAUMANN, H - University Of Missouri; CHERRY, N - Texas A&M University; MUIR, J - Texas A&M University; LAMBERT, B - Texas A&M University; WALKER, J - Texas A&M University; ADAMS, R - Baylor University; Welch, Kevin; Gardner, Dale; Estell, Richard - Rick

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/11/2015
Publication Date: 8/6/2015
Citation: Stewart, W.C., Whitney, T.R., Scholljegerdes, E.J., Naumann, H.D., Cherry, N.M., Muir, J., Lambert, B., Walker, J.W., Adams, R.P., Welch, K.D., Gardner, D.R., Estell, R.E. 2015. Effects of Juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics. Journal of Animal Science. 93:4034-4047.

Interpretive Summary: Alternative low-cost feed ingredients for livestock are needed. Several species of junipers cover millions of acres in the western US and may have potential as an alternative feed. We examined the nutritional properties of four juniper species found in Texas and New Mexico. Nutritional and digestive properties of juniper (whole plants, dried and ground) were generally of comparable quality to other traditional roughage sources. Secondary compounds (antiquality chemicals) in dried juniper were not present in concentrations that should impair animal health or digestion. Processed whole juniper plants may be a viable low-cost feed ingredient.

Technical Abstract: Rising feed costs and recurring feed shortages necessitate the investigation into alternative and underutilized feed resources. Nutritional characteristics of Juniperus species are either unknown or limited to leaves and ground material from small stems. Thus, the objective was to quantify nutritional characteristics, 48-h true IVDMD (tIVDMD), microbial gas production, and secondary compound characteristics of entire woody plant material of four Juniperus species: J. pinchotii, J. monosperma, J. ashei, J. virginiana, at immature and mature stages of growth. Immature plants had greater CP concentrations and lower NDF concentrations (P < 0.001) than mature plants regardless of species. Mature plants also had greater (P < 0.001) concentrations of ADF compared to immature plants with the exception of J.virginiana. In general, immature J. pinchotii, J. monosperma and J.ashei had greater (P < 0.02) tIVDMD, total 48-h and asymptotic gas production than mature plants. Immature J.monosperma and J.pinchotii plants were more digested (tIVDMD: P < 0.001) than immature J.virginiana and J.ashei but tIVDMD did not differ in mature plant material across species. Condensed tannins (CT) were greater (P < 0.001) in immature J.pinchotii and J.ashei than mature plants; differences in CT concentrations among immature species were also detected (P < 0.04). Volatile oil yields were similar across maturity and species with one exception; immature J.pinchotii yielded greater (P < 0.02) volatile oil than mature material. Volatile oil composition across species varied and contained a range of 65 to 70 terpene compounds. The dominant terpenes across species were generally greater (P < 0.05) in immature vs. mature plant material with the exception of J.virginiana. Labdane acids were negligible in J.pinchotii, J.ashei, and J.virginiana, and greater in J.monosperma (P < 0.001). Ground material from mature juniper species, although inferior in nutritional quality compared to immature plants, is comparable to traditional low-quality roughage ingredients. Given that ground J.pinchotii has been successfully fed in lamb feedlot diets and nutritional similarities of J.monosperma and J.ashei to J. pinchotii 47 combine to suggest potential of J.monosperma and J.ashei as effective roughage ingredient alternatives.