Biological control of the toxic shrub juniper.

et al. 2005

Goats avoid eating redberry juniper (Juniperus pinchottii Sudw.) when other palatable forages are available but will increase intake of juniper when exposed to the plant for several days. Intake of redberry juniper also differs among breeds and individual goats. Selection based on foraging habits could further improve juniper intake. The purpose of this study was to determine the influence of sires on juniper consumption. Heritability of redberry juniper intake was assessed for 3 years (1997, 1998, 2000) by placing male Boer-Spanish cross goats from 4-8 sires (the number of sires differed among years) in individual pens and feeding juniper (200 g) daily for 2 hours over 5 to 10 days. Feeding juniper was done after weaning kid goats each year. Juniper intake was similar among sire groups within years. Heritability of juniper consumption was low (11%) across the 3 years of this study. Goats increased juniper intake daily while in individual pens. These results suggest that an acceptance of juniper by goats can be conditioned through exposure to the plant after weaning, and that juniper consumption does not appear to be a highly heritable trait. Resumen Las cabras evitan comer ''Redberry juniper'' (Juniperus pinchottii Sudw.) cuando otros forrajes más apetecibles está n disponibles, pero incrementan el consumo de ''juniper'' cuando está n expuestas a él por varios días. El consumo de ''Redberry juniper'' también varia entre razas y cabras individuales. La selecció n basada en los há bitos de forrajeo pudiera mejorar má s el consumo de ''juniper''. El propó sito de este estudio fue determinar la influencia del padre en el consumo del ''juniper''. La heredabilidad del consumo de ''Redberry juniper'' fue evaluado por 3 añ os (1997, 1998 y 2000) colocando machos cruzados de Boer-Spanish (provenientes de 4-8 padres y el nú mero de padres difirió entre añ os), en corrales individuales y alimentá ndolos con ''juniper'' (200 g) diariamente por 2 h durante 5 a 10 días. La alimentació n con ''juniper'' fue hecha después de destetar los cabritos cada añ o. El consumo de ''juniper'' fue similar entre grupos de padres dentro de añ os. La heredabilidad del consumo de ''juniper'' fue baja (11%) a través de los tres añ os del estudio. Las cabras incrementaron el consumo diario de ''juniper'' mientras estuvieron en los corrales individuales. Estos resultados sugieren que una aceptació n del ''juniper'' por las cabras puede ser condicionada a través de la exposició n a la planta después del destete, y que el consumo de ''juniper'' no parece ser una característica de alta heredabilidad.

Section: Introductionmentioning

confidence: 99%

Sire Influence on Juniper Consumption by Goats

Ellis

Jones

et al. 2005

“…At higher dose levels (0.36 g oil ? kg 21 BW), cellular necrosis and lobular encapsulation were evident (Straka et al 2004). Goats typically avoid juniper during the spring and summer and when alternative herbaceous forage is available (monoterpene levels are also reportedly higher; Riddle et al 1996;Owens et al 1998b).…”

mentioning

confidence: 99%

Feeding Redberry Juniper (Juniperus pinchotii) at Weaning Increases Juniper Consumption by Goats on Pasture

Dietz

Campbell³

et al. 2010

Redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus ashei Buchh.) juniper dominate rangelands throughout central Texas. Our objective was to attempt to improve the efficacy of goats as a biological control mechanism for juniper through behavioral training. Conditioning sheep and goats to increase the palatability of chemically defended plants can be a useful tool in brush control. Previous research illustrated that goats can be conditioned to consume more juniper while in individual pens when foraging choices are limited. To test whether this creates a longer-lasting increase in juniper preference, we determined if goats would continue to consume juniper on pasture for one year after being fed juniper in individual pens for 14 d. Female Boer-cross goats (n 5 40) were randomly divided into two treatments: conditioned and naive to juniper. At approximately 12 mo of age, conditioned goats were placed in individual pens and fed redberry juniper 1 h daily for 14 d, while naive goats received only alfalfa pellets to meet maintenance requirements. After the pen-feeding phase of the study, goats were placed in one of four pastures (10 goats ? pasture 21) for 12 mo. Two pastures housed conditioned goats, and two pastures housed naive goats at a moderate stocking rate (1 animal unit ? yr 21 ? 8 ha 21). Bite count surveys were conducted twice per month, while herbaceous standing crop and monoterpene levels were measured once per month. Juniper preference varied monthly; however, conditioned goats consistently ate more (P , 0.05) juniper than naive goats except for April, when the study began, and March, when the study ended. When selection of herbaceous forages decreased, conditioned goats increased selection of juniper, while naive goats increased selection of other palatable shrubs. Seasonal changes of monoterpene levels in juniper had no apparent effect on juniper preference. We contend that feeding juniper at weaning will increase use of the plant in grazing situations. Resumen Juniperus pinchotii Sudw y J. ashei Buchh son dominantes en pastizales naturales del centro de Texas. Nuestro objetivo fue intentar mejorar la eficacia del pastoreo de caprinos como mecanismo de control biológico de Juniperus mediante entrenamiento de comportamiento ingestivo. El condicionamiento de ovejas y cabras para que incrementen la palatabilidad de plantas que contienen defensas químicas podría ser una herramienta útil en el control de especies arbustivas. Trabajos de investigación previos demostraron que se puede condicionar un incremento en el consumo de Juniperus en cabras mantenidas en bretes individuales cuando las opciones de forrajeo son limitadas. A fin de determinar si este protocolo crea un incremento duradero en la preferencia de Juniperus, determinamos si las cabras continuarían consumiendo Juniperus en condiciones de pastoreo durante un añ o luego de haber recibido Juniperus en bretes individuales por 14 días. Hembras cruza Boer (n 5 40) se dividieron al azar en 2 tratamientos, uno condicionado y el otro sin experiencia p...

“…Arguably, if intake had exceeded 30% of the diet for longer periods of time, juniper may have affected meat quality or flavor. In previous studies, juniper intake typically did not exceed 30% of the diet for any length of time (Bisson et al 2001;Ellis et al 2005;Dunson et al 2007) apparently because rumen microbial death occurs when intake exceeds 30% of the diet (Straka et al 2004). It is unknown why juniper intake apparently affects the flavor of some wildlife species but not goats.…”

Section: Discussionmentioning

confidence: 97%

Juniper Consumption Does Not Adversely Affect Meat Quality in Boer-Cross Goats

Menchaca

Braden

et al. 2011

Goat browsing can be used as an alternative brush management option for redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus asheii Buch) juniper instead of more expensive and invasive brush control methods, assuming consumption of juniper does not adversely affect the marketability of offspring. Some wildlife species reportedly retain juniper flavor when consumed. We determined if juniper consumption affected meat quality or flavoring of Boer-cross kid carcasses. Twenty recently weaned, Boer-cross wethers were randomly assigned to one of four treatments with treatments fed different amounts of juniper (0%, 10%, 20%, 30% juniper in the diet). All goats were fed juniper for 28 d at the Angelo State University (ASU) Management, Instruction, and Research Center. All goats were also fed a feedlot ration to meet maintenance requirements (2% body weight). Juniper intake varied (P , 0.05) between all treatments (0%, 10%, 20%, 30%) primarily because treatments were fed different amounts of juniper. Following a 28-d trial, goats were harvested at the ASU Food Safety and Product Development Laboratory. Carcass characteristics including live weight, hot carcass weight, dressing percentage, loineye area, body wall fat thickness, and leg circumference were similar (P. 0.05) among treatments. Sensory characteristics including tenderness, juiciness, flavor intensity, off-flavor, and overall acceptability were also similar (P. 0.05) among treatments. Landowners can utilize goats as a biological management tool without adversely affecting goat meat quality or flavoring. Resumen El ramoneo con cabras puede ser usado como una opción alternativa de manejo de arbustivas de junípero rojo (Juniperus pinchotii Sudw.) y junípero cenizo (Juniperus asheii Buch) en lugar de me´todos de control de arbustivas más caros e invasivos, asumiendo que el consumo de junípero no afecta el mercado del cabritos. Algunas especies de fauna silvestre se ha reportado, que mantienen el sabor de junípero cuando son consumidas. Determinamos sí el consumo de junípero afecta la calidad y el sabor de la carne de cabritos de la cruza con Boer. Veinte cabritos recie´n destetados cruzados con Boer fueron asignados aleatoriamente a 1 de 4 tratamientos con alimentación con diferentes cantidades de junípero (0%, 10%, 20%, 30% de junípero en la dieta). Todos los cabritos fueron alimentados con junípero por 28 d en el Centro de Manejo, Instrucción e Investigación de Angelo State University (ASU). Todos los cabritos tambie´n recibieron una ración de engorda para cubrir los requerimientos de mantenimiento (2% PV). El consumo de junípero varió (P , 0.05) entre todos los tratamientos (0%, 10%, 20%, 30%). Principalmente, por que los tratamientos suministraban diferentes cantidades de junípero. Despue´s de 28 d de experimentación los cabritos fueron sacrificados en