Published August 6, 2015 Effects of Juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics W. C. Stewart,*† T. R. Whitney,*1 E. J. Scholljegerdes,† H. D. Naumann,‡ N. M Cherry,§ J. P. Muir,§ %'/DPEHUW-::DONHU 53$GDPV.':HOFKŒ'5*DUGQHUŒDQG5((VWHOO *Texas A&M AgriLife Research, 7887 U.S. Hwy 87 N, San Angelo 76901; †Animal and Range Sciences Department, New Mexico State University, Box 30003, Las Cruces 88003; ‡Division of Plant Sciences, University of Missouri, 116 Waters Hall, Columbia 65211; §Texas A&M AgriLife Research, 1229 N. U.S. Hwy 281, 6WHSKHQYLOOH%LRORJ\'HSDUWPHQW%D\ORU8QLYHUVLW\%R[:DFR7;Œ86'$$563RLVRQRXV Plant Research Laboratory, Logan, UT 84341; and ¶USDA-ARS Jornada Experimental Range, Las Cruces, NM 88003 ABSTACT: Rising feed costs and recurring feed short- did not differ in mature plant material across species. ages necessitate the investigation into alternative and Condensed tannins (CT) were greater (P < 0.001) in underutilized feed resources. Nutritional characteristics immature J. pinchotii and J. ashei than mature plants; of Juniperus species are either unknown or limited to differences in CT concentrations among immature spe- leaves and ground material from small stems. Therefore, cies were also detected (P < 0.04). Volatile oil yields the objective was to quantify nutritional characteristics, were similar across maturity and species with 1 excep- 48-h true IVDMD (tIVDMD), microbial gas pro- tion: immature J. pinchotii yielded more (P < 0.02) duction, and secondary compound characteristics of volatile oil than mature material. Volatile oil composi- entire woody plant material of 4 Juniperus species— tion across species varied and contained a range of 65 to Juniperus pinchotii, Juniperus monosperma, Juniperus 70 terpene compounds. The dominant terpenes across ashei, and Juniperus virginiana—at immature and species were generally greater (P < 0.05) in immature mature stages of growth. Immature plants had greater vs. mature plant material with the exception of J. vir- CP concentrations and lower NDF concentrations (P < giniana. Labdane acids were negligible in J. pinchotii, 0.001) than mature plants regardless of species. Mature J. ashei, and J. virginiana and greater in J. monosperma plants also had greater (P < 0.001) concentrations of (P < 0.001). Ground material from mature juniper spe- ADF compared with immature plants with the excep- cies, although inferior in nutritional quality compared tion of J. virginiana. In general, immature J. pinchotii, with immature plants, is comparable to traditional low- J. monosperma, and J. ashei had greater (P < 0.02) quality roughage ingredients. Given that J. pinchotii tIVDMD and total 48-h and asymptotic gas production has been successfully fed in lamb feedlot diets, the than mature plants. Immature J. monosperma and J. pin- similarities of J. pinchotii, J. ashei and J. monosperma chotii plants were more digested (tIVDMD; P < 0.001) suggest that all three species have potential to be effec- than immature J. virginiana and J. ashei, but tIVDMD tive roughage ingredients. Key words: in vitro digestibility, juniper, nutritional quality, secondary compounds, sheep, woody plants © 2015 American Society of Animal Science. All rights reserved -$QLP6FL± doi:10.2527/jas2015-9274 INTRODUCTION dients. Woody plants from the genus Juniperus have worldwide distributions (Hora, 1981) and cover over Rising feed costs and recurring feed shortages 50 million ha in the western United States (Van Auken necessitate the investigation of alternative feed ingre- and Smeins, 2008). Juniperus virginiana is the most common juniper species in the eastern United States and is found on all states east of the 100th meridian 1 Corresponding author: [email protected] (Van Auken and Smeins, 2008). Leaves (Whitney and Received May 6, 2015. Muir, 2010) or leaves and small stems (Whitney et al., Accepted June 11, 2015. 4034 Juniper species nutritional comparison 4035 2014) of these increasingly abundant plants can be used One mature male and 1 mature female tree (height as a roughage ingredient in mixed diets for ruminant of >3 m) and 2 male and 2 female immature plants livestock. Use of woody biomass as a feed resource is (height of 1 to 1.8 m) from each plot were mechanical- not entirely novel nor is it limited to certain geograph- ly harvested and transported to a central location and ic regions; however, research with these nontraditional processed within 72 h. Immature trees were chipped feeds receives greatest consideration during times of feed using an ECHO Bear Cat chipper (ECHO Bear Cat, shortages and high feed costs but diminishes when feed West Fargo, ND). Due to the large amount of biomass, related inputs and feed availability stabilize (NRC, 1983). mature plants were initially chipped through a coarse Secondary compounds such as volatile oil and shredder (Vermeer X1500; Vermeer Corp., Pella, IA) condensed tannins (CT) present in Juniperus species and then a 90-kg random sample was chipped once can either positively or negatively affect animal per- more using the ECHO Bear Cat chipper. All chipped formance and rumen function. Preliminary research material from immature and mature plants was then regarding the feeding value of ground juniper plants VXEVDPSOHG ¿QH JURXQG WKURXJK D KDPPHUPLOO WR is promising, but information is limited to ground pass a 4.76-mm sieve (Sentry, model 100; Mix-Mill Juniperus pinchotii leaves and small stems (<3.6 cm). Feed Processing Systems, Bluffton, IN), dried at 55°C Widespread use of juniper species in U.S. feeding sys- in a forced-air oven for 48 h, ground through a Wiley tems requires approval by appropriate federal agencies mill (Arthur H. Thomas Co., Philadelphia, PA) to pass based in part on baseline information regarding their DPPVFUHHQDQGVWRUHGDW±& nutritional, in vitro digestibility, and plant secondary compound characteristics. We hypothesized that plant Laboratory Analyses biomass from immature plants (height of 1 to 1.8 m) will possess superior nutritional characteristics com- Dry matter of ground juniper subsamples was calcu- pared with mature plants (height of >3 m) whereas lated by drying chipped material at 105°C in a forced-air plant secondary compound characteristics would vary oven for 24 h. For all other nutrient, in vitro digestibility, across species and maturity. The objective of this study and plant secondary compound analyses, material dried was to quantify nutritional, in vitro digestibility, and at 55°C in a forced-air oven was used. Nitrogen was plant secondary compound characteristics of J. pin- analyzed (Method 990.03; AOAC, 2006; Leco Corp., St. chotii, Juniperus monosperma, Juniperus ashei, and Joseph, MI) and CP was calculated as 6.25 × N. The NDF J. virginiana at mature and immature growth stages to and ADF were sequentially analyzed according to Van assess their suitability as a feed ingredient. 6RHVWHWDO PRGL¿HGIRUDQ$1.20)LEHU Analyzer (Ankom Technology Corp., Fairport, NY), cor- MATERIALS AND METHODS UHFWLQJIRUUHVLGXDODVKDQGXVLQJĮDP\ODVHDQGVRGLXP VXO¿WHDFFRUGLQJWR0HUWHQV /LJQLQZDVDQDO\]HG by a standard method ( AOAC 973.18; AOAC, 2006). Study Design and Harvesting Protocol $VKZDVTXDQWL¿HG 0HWKRG$2$& DQG Juniper species were collected over a 4-wk pe- minerals were analyzed by a Thermo Jarrell Ash IRIS riod in March 2012 at 4 separate geographic loca- Advantage (Thermo Jarrell Ash Corp., Franklin, MA) in- tions. Juniperus pinchotii was collected in Tom Green ductively coupled plasma radial spectrometer. &RXQW\ 7; ƍƎ 1 ƍƎ : RQ 7KH SURWRFRO IRU FROOHFWLQJ UXPLQDO ÀXLG ZDV DS- a Cho Association loamy, capionatic, thermic, shal- proved by the Texas A&M University Institutional low Petrocalcic Calciustolls site. Juniperus ashei was $QLPDO &DUH DQG 8VH &RPPLWWHH 5XPLQDO ÀXLG IURP FROOHFWHG LQ (GZDUGV &RXQW\ 7; ƍƎ 1 sheep (n = 4) fed a low-quality basal hay diet and 125 g ƍƎ: RQDQ(FNUDQWFOD\H\VNHOHWDOVPHF- of a 12% CP supplement daily was collected via oral la- titic, thermic Lithic Haplustolls site. Juniperus virginiana vage into a prewarmed thermos purged with CO2¿OWHUHG ZDV FROOHFWHG LQ %DVWURS &RXQW\7; ƍƎ 1 through 4 layers of cheesecloth, combined, and continu- ƍƎ: RQD6LOVWLGORDP\VLOLFHRXVVHPLDFWLYH ously purged with CO2 until added to prewarmed gas pro- thermic Arenic Paleustalfs site. Juniperus monosperma duction modules. For each jar, 56 mL McDougal’s buffer ZDV FROOHFWHG LQ 7RUUDQFH &RXQW\ 10 ƍƎ VROXWLRQ JRIXUHD/ DQGP/RIUXPLQDOÀXLGZDV 1 ƍƎ : RQ 3LQRQ ORDP\ PL[HG VXSHU DGGHGWRJRIMXQLSHUPDWHULDO-DUVZHUHÀXVKHGZLWK active, mesic Lithic Ustic Haplocalcids site. At each of CO2 and ANKOM gas production modules were secured the 4 sites, 4 plots, separated by a minimum of 165 m, and then incubated for 48 h at 39°C. Recording of gas were designated as harvest sites. Plots for each species SURGXFWLRQFRPPHQFHGPLQDIWHUUXPLQDOÀXLGZDV were the experimental unit and were maintained separate added to jars. All species and maturities within plot were throughout the study, as plot was the experimental unit. analyzed in duplicate; therefore, 4 separate gas produc- 4036 Stewart et al. tion runs were evaluated. In addition, 2 blanks that did in which Y is gas produced in milliliters, a is the asymp- not contain a feed substrate were used in each run. tote in milliliters, b is the fractional degradation rate After 48 h, undigested feed material was rinsed out per hour, t is time in hours, c is lag time in hours, d is of each jar and analyzed by NDF procedures according