Brian J. Rude

Use of a commercial probiotic supplement in meat goats.

Sixty-three Boer crossbred goats were used in 5 separate experiments (Exp. 1 to 5) to evaluate the effects of a commercial probiotic supplement on growth performance (Exp. 1 to 4), diet digestibility (Exp. 5), carcass traits (Exp. 3), and fecal bacterial populations (Exp. 4). Goats were either fed a commercially pelleted concentrate diet and supplemented with a commercial probiotic (PRO) that had shown anecdotal positive effects on goat growth and performance according to local goat producers, or they remained as controls. The dose of PRO used was within the labeled dose for sheep for all studies. For Exp. 1, goat BW and feed intake were measured and G:F was calculated every 7 d for 56 d. For Exp. 2 to 4, BW and feed intake were measured and G:F was calculated every 14 d. The first day of supplementation was considered d 0. Carcass traits were also collected at slaughter on d 57 for Exp. 3, and fecal samples were collected every 14 d for microbial culture for Exp. 4. For Exp. 5, which was a digestibility trial that lasted for 10 d, animals were placed in metabolic pens for collection of feces and orts. Growth performance of goats was not affected by probiotic supplementation, with the exception of performance in Exp. 2, in which ADG and G:F were improved (P < 0.03) in PRO goats compared with control goats on d 56 only (treatment x day interaction; P < 0.05), averaging 0.21 +/- 0.02 kg/d for PRO goats and 0.11 +/- 0.02 kg/d for control goats for ADG and 0.17 +/- 0.02 for PRO goats and 0.10 +/- 0.02 for control goats for G:F. Carcass weights and weights of fabricated cuts (shoulder, loin, leg, rack, shank, and total parts) as well as carcass length, leg circumference, loin eye area, and backfat were not influenced by PRO supplementation. Apparent digestibilities of OM, DM, NDF, ADF, CP, and GE (on a DM basis) were similar for the PRO and control treatments. Fecal culture analysis of Escherichia coli and coliforms, Lactobacillus, and Bifidobacterium populations were not influenced by the PRO treatment. Overall, although the PRO treatment affected goat ADG and G:F in Exp. 2, no PRO treatment effects were noted on growth performance for Exp. 1, 3, and 4. Furthermore, the PRO treatment did not affect diet digestibility, carcass traits, or fecal microbial populations in goats. In conclusion, no consistent benefits were noted from supplementing healthy, growing meat goats with PRO.

Soils and forage quality as predictors of white-tailed deer Odocoileus virginianus morphometrics

Abstract Biologists tasked with managing cervids could benefit from models predicting physical characteristics. Differences in white-tailed deer Odocoileus virginianus morphometrics across soil resource areas in Mississippi, USA, provide opportunity to test the predictive capacity of soil chemical and forage quality variables. Using principal components analysis (PCA), we modeled variation in body mass and antler score of ≥ 1.5-year-old male deer against seven soil chemical variables and 12 forage quality variables to elucidate potential nutritional factors corresponding with physical variation among 21 deer populations. We developed separate sets of models at the levels of state and soil resource area (Delta, Thin Loess and Lower Coastal Plain) and compared statewide models with general linear models (GLM) that related deer morphometrics to nominal classification variables representing the three soil resource areas. PCA distinguished a gradient of increasing soil fertility and forage quality that explained 58% of body mass and 52% of antler score variation statewide. However, the GLM using soil resource area as the explanatory variable explained 78 and 61%, respectively, indicating that management models should use soil resource area to designate areas with broadly similar nutritional planes. Within soil resource areas, the region with the greatest soil fertility and forage quality (Delta) did not model successfully for either body mass or antler score. The Thin Loess was successfully modeled for antler score, but only the Lower Coastal Plain, which had the lowest level of soil and forage quality, was successfully modeled for both morphometric variables. The Delta may have represented an area with habitat quality sufficiently high to render small variations non-influential. In contrast, the generally poorer soil quality of Thin Loess and Lower Coastal Plain soils and forages may act as a limiting factor on physical expression, which allowed some response to relatively small fluctuations in range quality. The potential utility of soil and forage metrics within soil resource areas to estimate deer physical qualities appears to be primarily for fine-tuning estimates largely determined by factors such as density and land use.

Deer Forage Response to Herbicide and Fire in Mid-Rotation Pine Plantations

Abstract Mid-rotation management practices for pine (Pinus spp.) plantations enrolled in cost-share programs have not been widely evaluated for wildlife. Mid-rotation pine plantations often have a substantial hardwood mid-story that limits growth of desirable understory forage species important to white-tailed deer (Odocoileus virginianus; deer). We treated with imazapyr herbicide and prescribed burning (HB) 11 thinned, 13–22-year-old loblolly pine (P. taeda) plantations in the Upper Coastal Plain (UCP; n = 5) and the Lower Coastal Plain (LCP; n = 6) of Mississippi, USA, enrolled in cost-share programs. We then sampled these plantations for production of important deer forages during July of 2003 and 2004, years 1 and 2 posttreatment. Deer foraging habitat was clearly improved by the HB treatment in both regions by year 2. Forb species of annual importance to deer increased in percent cover and biomass in the UCP and in biomass in the LCP. We estimated nutritional carrying capacity using a target diet quality of 14% crude protein; estimates in HB plots were 3 times greater than controls in the UCP and 19 times greater in the LCP. Although UCP sites had baseline carrying capacities nearly 8 times greater than LCP sites, the greater relative response to HB in the LCP eliminated the regional difference. Our results indicate that imazapyr herbicide treatment followed by prescribed fire is a beneficial tool for deer management in mid-rotation pine plantations.

Condensed Tannins' Effect on White-Tailed Deer Forage Digestibility in Mississippi

Abstract Condensed tannins (CT) can reduce digestibility of forages for white-tailed deer (Odocoileus virginianus), potentially confounding estimates of diet quality and nutritional carrying capacity. We collected 143 spring and 142 summer samples of 8 important deer forage species from 22 properties in Mississippi, USA, and tested for CT content using a modified butanol-HCl assay. Three species (partridge pea [Chamaecrista fasciculata], southern dewberry [Rubus trivialis], and roundleaf greenbrier [Smilax rotundifolia]) contained CT, ranging from 0.11% to 6.46% dry weight. Summer CT concentration was greater than in spring for 2 species. We ranked soil samples from least to most fertile using 8 chemical characteristics and found a positive correlation between fertility and CT concentration for 1 species and no correlation for 2 species. We tested effects of CT concentration on in vitro dry matter disappearance (IVDMD) and in vitro protein digestibility using samples of partridge pea and roundleaf greenbrier and rumen fluid from 3 free-ranging deer. Average IVDMD was reduced 1.9% for each 1% increase in CT concentration. In vitro protein digestibility was reduced 2.5% for each 1% increase in CT concentration. Assuming that our methods reflect the effects of CT on in vivo digestibility, maximum loss of available crude protein (CP) in our samples was 3.0 g/100 g dry-weight forage, and only 13 of the 112 CT-containing forage samples (12%) would have decreased available CP by >1 g/100 g dry-weight forage. Deer consuming equal portions of sampled forages would lose <1% of dietary CP to CT. Comparisons of foraging area quality using crude protein estimates should be unaffected by CT under reasonable restrictions of similar habitat types, soil fertility, and time. Given the ability of deer to forage selectively and the abundance of alternative forages in Mississippi, the potential for CT to substantially affect spring or summer diet quality of deer appears minimal.

Dietary l-Arginine Supplementation during Gestation in Mice Enhances Reproductive Performance and Vegfr2 Transcription Activity in the Fetoplacental Unit

Regarded as one of the most versatile amino acids, arginine serves as a precursor for many molecules and has been reported to improve the reproductive performance of rats and pigs. To this end, we sought to determine if dietary L-arginine alters fetoplacental vascular endothelial growth factor receptor-2 (Vegfr2) transcription activity. Eighteen wild-type FVB/N female mice were bred to homozygous FVB/N-Tg(Vegfr2-luc)-Xen male mice. Bred female mice received 1 of 2 experimental diets: one supplemented with 2.00% (wt:wt) L-arginine (+Arg) or 1 supplemented with 4.10% (wt:wt) alanine (+Ala) to serve as an isonitrogenous control for +Arg. In addition, 6 mice were fed a nonsupplemented control (Con) diet to normalize bioluminescent imaging data. All data were analyzed using ANOVA followed by Fishers least significant difference. Total feed intake did not differ between groups; however, mice in the +Arg group consumed more arginine (P < 0.05). Arginine supplementation increased weight gain during the latter one-third of gestation (d 12- 18), total litter size, number of pups born alive, number of placental attachment sites, litter birth weight, and litter weight of pups born alive but decreased the individual birth weights (P < 0.05). During d 12-18, arginine supplementation increased (P < 0.05) the mean total Vegfr2 transcription activity and Vegfr2 transcription activity corrected for fetoplacental mass. Moreover, mice in the +Arg group had an earlier rise in Vegfr2 transcription activity. In conclusion, our results demonstrate that the beneficial effect of dietary L-arginine supplementation on mammalian reproduction is associated with enhanced Vegfr2 transcription activity in fetoplacental tissues.

In vivo monitoring of fetoplacental Vegfr2 gene activity in a murine pregnancy model using a Vegfr2-luc reporter gene and bioluminescent imaging

BackgroundVascular endothelial growth factor receptor-2 (VEGFR2) plays a pivotal role in angiogenesis by eliciting vascular endothelial cell growth when bound to VEGF, a powerful pro-angiogenic ligand. While Vegf and Vegfr2 are expressed throughout gestation, the latter third of gestation in mice is characterized by a marked increase in fetoplacental angiogenesis. Thus, the objective of this study was to determine the feasibility of monitoring fetoplacental Vegfr2 gene activity non-invasively using a Vegfr2-luc reporter transgenic mouse and bioluminescent imaging.MethodsImaging parameters were optimized using two wild-type (WT) females, bearing Vegfr2-luc fetuses. Then, seven WT females, bred to Vegfr2-luc males, were imaged from gestational day (GD) 12 to 18 to determine the usefulness of the Vegfr2-luc mouse as a model for studying fetoplacental Vegfr2 activity during pregnancy. Semi-quantitative RT-PCR of Vegfr2 was also performed on whole fetoplacental units during this time. Additionally, resultant neonates were imaged at postnatal day (PND) 7, 14 and 21 to monitor Vegfr2 activity during post-natal development.ResultsFetoplacental Vegfr2 gene activity was detected as light emissions beginning on GD 12 of gestation and increased throughout the imaging period (P < 0.05), and this paralleled the Vegfr2 mRNA data obtained from RT-PCR analysis. A decline in fetoplacental light emissions was associated with a poor pregnancy outcome in one pregnancy, indicating that this approach has potential use for studies monitoring pregnancy well being. Additionally, neonatal Vegfr2 activity was detected at PND 7, 14 and 21 but declined with time (P < 0.0001).ConclusionsIn utero fetoplacental Vegfr2 gene activity was monitored longitudinally in a quantitative manner using a luciferase reporter gene and bioluminescent imaging during the latter third of gestation. This study demonstrates the feasibility of using the Vegfr2-luc mouse to monitor late gestation fetoplacental angiogenic activity under normal and experimental conditions. Additionally, neonatal Vegfr2 gene activity was monitored for three weeks postpartum, allowing continuous monitoring of Vegfr2 activity during the latter third of gestation and postnatal development within the same animals.

Determination of bamboo-diet digestibility and fecal output by giant pandas

Abstract The goals of this study were to determine digestibility of a bamboo diet by giant pandas (Ailuropoda melanoleuca) and to evaluate potential internal markers (naturally occurring markers in their diet) for their ability to estimate fecal output and digestibility. Digestibility predictions using internal markers were based on either feed offered or feed consumed. Two giant pandas were used in 1-, 2-, and 3-day digestibility trials with total collection of feces. In the 3-day trial, animals were fed 100% bamboo with no dietary supplements. In all other trials, supplements were included in addition to bamboo. The 3 internal markers chosen for evaluation were acid insoluble ash (AIA), acid detergent lignin (ADL), and acid detergent insoluble nitrogen (ADIN). Results from digestibility trials indicated that apparent nutrient digestibility could be determined with no differences (P > 0.05) between pandas. Six apparent dry matter (DM) digestibility values ranged from 6.9 to 38.5%. Apparent DM digestibility for the male and female panda in the unsupplemented (3-day) trial were 6.9 and 12.4%, respectively. Among the 3 potential internal markers evaluated, AIA more accurately predicted fecal output (r  =  0.99; P < 0.01) than ADL (r  =  0.84; P < 0.02) or ADIN (r  =  0.85; P < 0.02). Calculations using AIA and feed consumed more accurately predicted nutrient digestibility than did feed offered calculations for all 3 internal markers. Apparent crude protein (CP) digestibility was 33.8% and was predicted by AIA and feed consumed calculations to be 35.5% (r  =  0.88; P  =  0.009). Acid insoluble ash and feed consumed calculations predicted fiber digestibility to be 35.1% compared to apparent fiber digestibility (31.8%; r  =  0.97, P < 0.001). Methods and data presented in this study may be used to predict nutrient digestibility in wild pandas in their native habitat.

Energy digestibility of giant pandas on bamboo-only and on supplemented diets.

Endangered giant pandas (Ailuropoda melanoleuca) are bears (Family Ursidae), within the order Carnivora. They specialize on an herbivorous diet of bamboo yet retain a gastrointestinal tract typical of their carnivorous ancestry. The evolutionary constraints of their digestive tract result in a low extraction efficiency from bamboo (<40% in reported studies). The goal of this study was to determine the energy digestibility of bamboo by giant pandas used in digestibility trials and through subsequent analyses with bomb calorimetry. Seven digestibility trials were conducted (three with bamboo-only diets and four with supplemental diets). Energy digestibilities ranged from 7.5-38.9% for mixed diets and 9.2-34.0% for bamboo-only diets. The bamboo-only trials summarized here represent, to our knowledge, the first empirical data available for energy digestibility on a bamboo diet for giant pandas.

Delayed Flowering in Bamboo: Evidence from Fargesia qinlingensis in the Qinling Mountains of China

Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a 5-year period (2003–2007) after a mast flowering event (2003). We examined flowering culm and seedling characteristics in relation to questions regarding the evolution of delayed flowering. Density of live culms decreased over the 5 years in both flowering sites and un-flowered patches. New shoots regenerated only in un-flowered patches. Chemical constituent allocation varied among culm parts (stems, branches, and leaves). Crude protein and extract ether in branches and leaves were less in flowering culms than in un-flowered culms. Seedling density was lower than expected based on floret counts, suggesting predation of seeds. Seedling density was significantly greater in flowering sites than in un-flowered patches and decreased over time. Seedlings performed better in flowering sites than in un-flowered patches based on their height, leaf number per seedling, and average leaf length, while fertilization on flowering sites had no significant effect on seedling growth, suggesting a saturation of resources. This study suggested that the characteristics of bamboos and bamboo stands were dramatically altered during this flowering event, enhancing seedling establishment and growth, and supporting mostly the habitat modification hypothesis of delayed reproduction.

Nutritive Value Response of Native Warm-Season Forage Grasses to Harvest Intervals and Durations in Mixed Stands

Interest in management of native warm-season grasses for multiple uses is growing in southeastern USA. Forage quality response of early-succession mixed stands of big bluestem (BB, Andropogon gerardii), indiangrass (IG, Sorghastrum nutans), and little bluestem (SG, Schizachyrium scoparium) to harvest intervals (30-, 40-, 60-, 90 or 120-d) and durations (one or two years) were assessed in crop-field buffers. Over three years, phased harvestings were initiated in May, on sets of randomized plots, ≥90 cm apart, in five replications (blocks) to produce one-, two-, and three-year-old stands, by the third year. Whole-plot regrowths were machine-harvested after collecting species (IG and LB) sample tillers for leafiness estimates. Species-specific leaf area (SLA) and leaf-to-stem ratio (LSR) were greater for early-season harvests and shorter intervals. In a similar pattern, whole-plot crude protein concentrations were greatest for the 30-d (74 g·kg−1 DM) and the least (40 g·kg−1 DM) for the 120-d interval. Corresponding neutral detergent fiber (NDF) values were the lowest (620 g·kg−1 DM) and highest (710 g·kg−1 DM), respectively. In vitro dry matter and NDF digestibility were greater for early-season harvests at shorter intervals (63 and 720 g·kg−1 DM). With strategic harvesting, similar stands may produce quality hay for beef cattle weight gain.