James F. Gallagher

Nutrition of the collared peccary in south Texas

Effects of growth, reproduction, sex, age, season, and diet quality on collared peccary (Tayassu tajacu) digestion and assimilation efficiencies, and on nutrient requirements of peccaries in south Texas are presented. Five metabolism trials were conducted with 10 collared peccaries fed either a concentrate diet or a forage diet representing the seasonal diet of free-living peccaries. Dry matter digestibility ranged from 49-72% for natural diets and was 84% for concentrate. Mean true digestibilities for energy, nitrogen, and phosphorus were 68, 46, and 70%, respectively, for natural diets and 89, 81, and 87%, respectively, for concentrate. Digestibility of the diet was directly related to nitrogen in the diet and the age of the animal and inversely related to consumption, gross energy, phosphorus, fiber, and ash in the diet. Mean true assimilation efficiencies for energy, nitrogen, and phosphorus were 64, 31, and 84%, respectively, for natural diets and 86, 58, and 84%, respectively, for concentrate. Maintenance requirements for adult, nonreproductive animals were 148.5 kcal/kg MBW/day of digestible energy (136.9 kcal/kg MBW/day of assimilated energy), 0.837 g/kg MBW/day of digestible nitrogen, and 0.844 g/kg MBW/day of digestible phosphorus. Daily energy requirements were directly related to growth and reproductive activity (increasing with duration of pregnancy and lactation) and inversely related to ambient temperature and age of animal. J. WILDL. MANAGE. 48(3):749-761 Information concerning the nutrient requirements of collared peccaries in Texas is sparse. Lindheimer pricklypear (Opuntia lindheimeri) is common in the diet (Jennings and Harris 1953), but the proportion in the diet varies seasonally (Low 1970, Everitt et al. 1981). Although digestibility of pricklypear for peccaries has been reported as 80% (Zervanos 1972, Shively 1979), the seasonal variation in diet digestibility is unknown. Zervanos (1972) determined that an average peccary in Arizona required 104 kcal/kg MBW/day in winter and 90 kcal/ kg MBW/day in summer. Similar estimates for peccaries in south Texas are not available. Information concerning the effects of physiological status of the animal and diet quality on consumption also is lacking. This paper describes and quantifies effects of growth, reproduction, sex, age, season, and diet quality on peccary digestion and assimilation efficiencies and on n trient requirements in south Texas. Support and funding for this research were provided by the Caesar Kleberg Res. Program in Wildl. Ecol., Dep. of Wildl. and Fish. Sci., Tex. A&M Univ. We thank t e staff of the Tex. Agric. Exp. Stn. at Uvalde for their assistance during this study, particularly L. H. Blankenship for advice on handling the animals. We also acknowledge the assistance of the staff of the Chaparosa Ranch, particularly P. O. Reardon, and the personnel of the Chaparral Wildl. Manage. Area, particularly C. E. Davis, for their cooperation and advice.

Impacts of buffelgrass (Pennisetum ciliare) on a forb community in south Texas.

Abstract Since the 1950s, many south Texas rangelands have been seeded with buffelgrass, a perennial C4 bunchgrass native to Africa that is believed to contribute to reductions in biodiversity. Forb species represent a critical habitat component throughout the breeding period for many wildlife species as seed (summer to fall), as green vegetative material (spring to summer), and as habitat for arthropods (spring to summer). Reductions in richness and diversity of crucial ecosystem components such as forbs and arthropods have large implications for grassland birds and other wildlife. We sampled annual and perennial forbs within 1-m2 quadrats on 15 study plots (1 ha; n  =  20 quadrats/plot) at Chaparral Wildlife Management Area, in LaSalle and Dimmit counties, Texas, during 2005 and 2006. Study plots were divided into five light-buffelgrass plots (0 to 5% buffelgrass canopy coverage), five moderate-buffelgrass plots (5 to 25% buffelgrass canopy coverage), and five heavy-buffelgrass plots (> 25% buffelgrass canopy coverage). Buffelgrass in study plots was composed of naturalized plants, and was not deliberately planted. During 2005 we observed that plots with > 25% buffelgrass had a 73% reduction in forb canopy of native species, a 64% reduction in native forb species richness, and a 77% reduction in native forb stem density compared to plots with 0 to 5% buffelgrass. These trends in native forb reduction (−79% native forb canopy, −65% forb species richness, −80% forb stem density) were nearly identical in 2006, even with greatly reduced rainfall. Simple linear regression revealed negative relationships between buffelgrass cover, total exotic grass cover (buffelgrass and Lehmann lovegrass), and total grass cover and the richness, coverage, and density of forbs/m2. Reductions in diversity may have larger implications regarding ecosystem function and available useable space and densities of desired bird species such as northern bobwhite. Nomenclature: Buffelgrass, Pennisetum ciliare (L.) Link; Lehmann lovegrass, Eragrostis lehmanniana Nees.

Woody vegetation response to various burning regimes in South Texas

Responses of woody plant communities on native rangelands in the western South Texas Plains to fire are not clearly understood. Our objective was to compare woody plant cover, density, and diversity on burned and nontreated rangelands. Five rangeland sites that received 2 dormant-season burns, 5 rangeland sites that received a combination of 1 dormant-season and 1 growing-season burn, and 5 sites of nontreated rangeland were selected on the Chaparral Wildlife Management Area, Dimmit and La Salle Counties, Tex. Woody plant cover was estimated using the line intercept method, and stem density was estimated in 25-x 1.5-m plots. Species richness did not differ among treatments. Percent woody plant cover was reduced by 50 and 41 % on winter and winter-summer combination burned sites, respectively. Honey mesquite (Prosopis glandulosa Torr.), twisted acacia (Acacia schaffneri S. Wats.), Texas persimmon (Diospyros texana Scheele), lotebush [Ziziphus obtusifolia (Hook.) T. & G.], wolfberry (Lycium berlandieri Dunal), and tasajillo (Opuntia leptocaulis Cand.) canopy cover was greatest on nontreated sites. Woody plant density declined by 29 and 23% on winter and winter-summer combination burned sites, respectively. Density of guayacan (Guajacum angustifolium Engelm.), wolfberry, and tasajillo was less on all burning treatments. Percent cover of spiny hackberry (Celtis pallida Torr.) and density of Texas pricklypear (Opuntia engelmannii Salm-Reif.-Dyck) declined on winter burned sites. Inclusion of summer fire into the burning regime did not increase declines in woody plants. Fire created a post-fire environment which resulted in the decline of many woody plant species. It is unclear to what degree other environmental factors such as herbivory and competition between woody plants and among woody and herbaceous vegetation may have interacted with fire in producing woody plant declines. Fire may be a useful tool in managing woody vegetation on native south Texas rangelands, while maintaining woody plant diversity.

Digestibility of guajillo for white-tailed deer.

A study was conducted from May 1986 to June 1987 with white-tailed deer (Odocoileus virginianus) to determine seasonal nutritive value and nutrient digestibilities of guajillo (Acacia berlandieri) and a pelleted diet. In vivo dry matter digestibility (DMD) of guajillo varied seasonally from 35.2 to 48.1% and was inversely correlated to levels of condensed tannins in the forage. Apparent protein digestibility varied seasonally from 13.7 to 45.8% and was a highly dependent function R2 = 0.97) of the amount of neutral detergent fiber nitrogen (NDFN) digested and the negative impact of condensed tannins. Cellulose and hemicellulose digestibilities also varied seasonally (0.6 to 13.5% and 52.3 to 71.1%, respectively). Nutrient digestibilities of the pelleted diet did not vary by season, sex, or age. Dry matter digestibility of the pelleted diet was 75.6% +/- 0.9 and true protein digestibility was 95.0 +/- 0.04. Results suggest summer is a stressful period for south Texas deer due to low protein and energy digestibility and high levels of condensed tannins.

Immobilization of Collared Peccaries with Ketamine Hydrochloride

A variety of agents have been used to immobilize collared peccaries (Tayassu tajacu) (Neal 1959, Day 1969, Low 1970), but none have provided the combination of quick action, broad safety margin, and quick recovery. Although ketamine hydrochloride is usually regarded as a safe and effective immobilizing agent for a variety of wildlife species (Addison and Kolenosky 1979, Hash and Hornocker 1980, Baber and Coblentz 1982), overdoses can result in heat stress, death, and drug wastage, and underdoses may result in the need for multiple injections. This paper reports the use of ketamine to immobilize wild and captive collared peccaries. Nineteen collared peccaries were captured from the Chaparral Wildlife Management Area located in Dimmitt and La Salle counties, Texas, and the Chaparrosa Ranch located in Zavala County, Texas, using Clover deer traps baited with whole corn. A variety of techniques was used to administer ketamine hydrochloride (Ketalar, Parke, Davis & Co.; and Ketoset, Bristol Laboratories; 100 mg/ml): Cap-Chur gun, jab stick, blowgun syringe (Lochmiller and Grant 1983), and hand injection. All injections were made intramuscularly (IM) in the upper thigh. Time to first effects was defined as unsteadiness, lowered head, and salivation. Onset of immobilization was defined as the time from injection until the animal became recumbent. Immobilization time was the period during which the animal could be handled safely. Recovery time was the time from injection until the animal first stood up. Influences of dose, sex, and injection technique on time to first effects, onset of immobilization, immobilization time, and recovery time were evaluated using the General Linear Models procedure of the Statistical Analysis System (Helwig and Council 1979). Response to the drug generally was rapid, first effects were observed in under 5 minutes but varied (N = 19, x = 3.1 min, SE = 0.9) and were not related to dosage (2 = 18.4 mg/kg, SE = 3.0) (Table 1). The average immobilization period was 71.7 minutes (SE = 29.7). Some animals were given multiple doses to prolong immobilization during transportation. Multiple doses were often required to induce immobilization because of poor delivery when using projectile darts (darts ejected before delivering full dose). This might account for some of the variability observed in response times. Injection of the drug generally was followed by a brief period of excitability (<15 sec). Undisturbed animals gradually lay down and passed into a cataleptoid state (f for onset of immobilization = 6.0 min, N = 19, SE = 1.6)

Indigestible Particulate Passage in White-Tailed Deer

Relationships among intake, digestion, and passage rates for white–tailed deer (Odocoileus virginianus) eating guajillo (Acacia berlandieri) were examined in a completely randomized balanced design metabolism experiment. Dry matter intake was positively correlated (P = 0.0005) with rate of indigestible particle disappearance from the rumen. The more highly digested diets had longer ruminal and total tract mean retention times (MRT). There were seasonal differences in ruminal and total tract MRT. Differences in total tract MRT were a function of ruminal turnover rates, not of time spent in the lower tract. No chemical or physical criteria were related directly to ruminal or total tract MRT. Dietary NDF concentrations varied seasonally, but permanganate lignin concentration was similar across seasons. Passage rates were not a function of permanganate lignin concentration; rather, low cell wall content of the forage allowed for rapid excretion of indigestible particles.

Separating leaves from browse for use in nutritional studies with herbivores.

A technique has ban developed that facilitates removal of green leafy material from stems of shrub speciea using a thresher. Use of this technique makes possible the rapid removal of leaves from woody species that would otherwise require excessive band labor.