‘Florigraze’ rhizoma peanut (Arachis glabrata Benth.) is a perennial legume of high forage quality adapted to warm climates, but there has been no comprehensive evaluation of its responses to grazing management. In 1988 and 1989, the effects of grazing frequency and intensity on Florigraze persistence and herbage accumulation (HA) were evaluated on a loamy, siliceous, hyperthermic Grossarenic Paleudults soil. All 12 combinations of three levels of residual dry matter after grazing (RDM, 500, 1500, and 2500 kg ha‐') and four grazing cycle lengths (GC; 7, 21, 42, and 63 d between grazings, including a 0.5‐ to 2‐d grazing period) were replicated twice. Data were analyzed by fitting multiple regression equations starting with a second order polynomial model. In 1988, rhizoma peanut HA ranged from 6130 to 10 240 kg ha− and increased linearly as GC and RDM increased. There was a GC‐by‐RDM interaction for rhizoma peanut HA in 1989, whereby at low RDM, increasing GC increased HA, but GC had less effect as RDM increased. In 1989, rhizoma peanut HA of at least 8800 kg ha− was estimated to occur with GC of 42 d or longer when RDM was 1500 kg ha− or greater. Rhizoma peanut percentage in HA was greatest with high RDM and long GC, but values of 80% or greater in the second year were estimated for RDM as low as 1300 kg ha− when GC was 63 d, or with GC as low as 7 d when RDM was above 2300 kg ha−. Lowest values were obtained with low RDM and short GC. These data indicate that unlike most tropical legumes, rhizoma peanut is productive and persistent over a relatively wide range of grazing management practices.

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‘Florigraze’ rhizoma peanut (Arachis glabrata Benth.) is a promising pasture legume for warm climates. In 1988 and 1989, the effect of grazing management on rhizoma peanut canopy light interception (LI) and the role of rhizome reserves in regrowth were studied on a Sparr fine sand (loamy, siliceous, hyperthermic Grossarenic Paleudults). Treatments were replicated twice and included all combinations of three levels of residual dry matter (RDM; 500, 1500, and 2500 kg ha−1) and four grazing cycle lengths (GC; 7, 21, 42, and 63 d between grazings, including a 0.5 to 2‐d grazing period). Data were analyzed by fitting multiple regression equations starting with a second order polynomial model. Canopy LI before grazing ranged from 24 to more than 90% and was lowest for low RDM and short GC treatments, while canopy LI after grazing ranged from 9 to 79% and increased at a decreasing rate as RDM increased. When grazed to 500, 1500, and 2500 kg ha−1, RP required an average of 49, 24, and 12 d to reach 85% LI. At season‐end 1989, rhizome mass (range of 450‐4100 kg ha−1) and total nonstructural carbohydrate (TNC; range of 58‐210 g kg−) concentration were lowest at low RDM and short GC, increased with increasing GC when RDM was low, and changed only slightly with changes in GC at RDM above 1700 kg ha−1. Low postgraze light interception and depletion of rhizome mass and total nonstructural carbohydrate with close grazing suggest that reserves were mobilized for rhizoma peanut regrowth. In contrast, postgraze light interception and rhizome mass and reserve status remained high when residual dry matter was 1700 kg ha−1 or greater suggesting that residual leaf area was primarily responsible for regrowth under more lenient grazing.

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BACKGROUND: The grey squirrel, Sciurus carolinensis Gmelin, is an invasive alien species introduced into Great Britain in the late nineteenth century and into Northern Italy during the early twentieth century. Grey squirrels have displaced the native European red squirrel, Sciurus vulgaris L., throughout much of Great Britain and have a significant impact on trees and woodlands through bark-stripping activity. In Britain, eradication is no longer an option at a regional scale, but fertility control offers a non-lethal approach to reducing negative impacts. The cholesterol mimic DiazaCon  has been successfully used to inhibit reproduction in some species. These studies aimed to evaluate whether DiazaCon  is effective in inhibiting reproduction in grey squirrels. RESULTS: DiazaCon reduced serum cholesterol levels in female grey squirrels at a range of doses. The period of effect increased with increasing dose. Reproduction rate was not significantly different between treatment and control groups owing to a lack of breeding in controls. CONCLUSIONS: DiazaCon has potential to reduce serum cholesterol levels enough and for a sufficient period to reduce fertility in female grey squirrels. Information on baseline physiology and blood chemistry of grey squirrels is required to inform interpretation of the level of significance of the effect.

ABSTRACT:The suitability of white-tailed deer (Odocoileus virginianus) as hosts for the cattle ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus (Boophilus) annulatus, has been well documented. These ticks have a wide host range, and both transmit Babesia bovis and Babesia bigemina, the agents responsible for bovine babesiosis. Although this disease and its vectors have been eradicated from the United States and some states in northern Mexico, it still is a problem in other Mexican states. It is not known if wild cervids like white-tailed deer can act as reservoirs for bovine babesiosis. The purpose of this study was to determine if B. bovis and B. bigemina or antibodies against them occur in white-tailed deer in the states of Nuevo Leon and Tamaulipas, Mexico. Twenty blood samples from white-tailed deer from two ranches were collected and tested with a nested polymerase chain reaction (nested PCR) and indirect immunofluorescence antibody test (IFAT) for B. bovis and B. bigemina. Eleven samples were positive for B. bigemina and four for B. bovis by nested PCR; amplicon sequences were identical to those reported in GenBank for B. bovis (Rap 1) and B. bigemina. Results of the IFA test showed the presence of specific antibodies in serum samples. This is the first report of the presence of B. bovis and B. bigemina in white-tailed deer using these techniques and underscores the importance of cervids as possible reservoirs for bovine babesiosis.

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Thermal cover may influence habitat selection by white-tailed deer Odocoileus virginianus in subtropical climates with hot summers. We 1) tested the hypothesis that thermal environment is more important in habitat selection at midday during summer than forage quality or quantity and concealment cover and 2) determined whether operative temperature, vegetation height, or woody plant canopy cover (or some combination of these) explain habitat selection at midday. We predicted that during crepuscular periods and at night habitat use increases with increasing forage quality and quantity and concealment cover and is unrelated to thermal environment. Male white-tailed deer were fitted with GPS collars to determine resources selected within habitats during June and July 2008 and 2009. A generalized linear mixed model using logistic regression was used to estimate resource selection functions. We used the first principal component in a principal components analysis (PCA) of forage standing crop, crude protein, and acid detergent fiber (ADF) to create a 'forage index'. This index and vegetation height, operative temperature and concealment cover, together with their interactions with activity period, were used to develop a priori candidate models. Akaike weights were used to compare candidate models. A model that included the forage index, vegetation height, operative temperature, concealment cover and their interactions with activity period was the best model out of 97 candidate models for explaining habitat selection by adult male white-tailed deer. Male white-tailed deer selected areas with taller vegetation in morning and midday activity periods but selected shorter vegetation during evening and nighttime. Forage quality was important in habitat selection in all activity periods. Male white-tailed deer did not select areas with greater concealment cover during any activity period. A combination of operative temperature, vegetation height, and woody plant canopy cover predicted midday habitat use better than any of these three variables alone. Thermoregulatory behavior in male white-tailed appears to include a combination of seeking cooler environments during midday but at the same time using areas with greater forage quality.