Herbage utilisation efficiency of continuously stocked pastures during periods of restricted pasture growth     

Tiago Miqueloto  Cauby de Medeiros Neto  Clovis David Medeiros Martins  Rodrigo Amorim Barbosa  Sila Carneiro Da Silva  André Fischer Sbrissia 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2020,70(3):208-214

ABSTRACT

The aim of this study was to evaluate the defoliation patterns of individual tillers, efficiency of herbage utilisation, and forage production in continuously stocked Brachiaria humidicola cv. Comum swards during periods of the year of restricted pasture growth. The experiment was conducted at the Embrapa, Campo Grande-MS, Brazil, from April to October 2012. Treatments consisted of two grazing management strategies, defined by two ranges of sward height (10–15 and 20–25 cm) managed under continuous and variable stocking rates. The experiment was conducted as a completely randomised block design with three replications. During periods of resource constraints, grazing management strategies based on ‘steady state’ sward heights did not alter defoliation patterns, herbage utilisation efficiency (HUE), and forage production in Brachiaria humidicola swards under a continuous stocking method. A direct implication of our results is that grazing management strategies during the driest and coldest periods of the year in the tropics should be developed based on the conditions most suitable for better promoting faster pasture recovery and a return to production in the following spring; it is unlikely that any grazing management strategy would be successful in increasing herbage production and/or HUE in periods of restricted pasture growth.  相似文献   

Mixtures of grasses: An alternative to traditional pasture monocultures in the tropics     

Cauby Medeiros-Neto  Rodrigo Amorim Barbosa  Daniel Schmitt  Tiago Miqueloto  Sila Carneiro da Silva  André Fischer Sbrissia 《Grass and Forage Science》2023,78(2):296-305

A two-year experiment assessed herbage production and above- and below-ground characteristics of a highly productive monoculture (‘BRS Zuri’ guineagrass [Panicum maximum Jacq.]) and two mixtures of three grasses (Mixture 1: ‘BRS Zuri’ guineagrass, ‘BRS Xaraés’ palisadegrass [Brachiaria brizantha Stapf.], and ‘Basilisk’ signalgrass [Brachiaria decumbens Stapf.]; Mixture 2: ‘BRS Quênia’ guineagrass [Panicum maximum Jacq.], ‘Marandu’ palisadegrass [Brachiaria brizantha Stapf.], and ‘BRS Paiaguás’ palisadegrass [Brachiaria brizantha Stapf.]), cultivated in the Brazilian tropical savanna. Mixtures 1 and 2 were subjected to two grazing intensities (removal of 40 or 60% of pre-grazing height) and ‘BRS Zuri’ guineagrass monoculture was defoliated to a single grazing intensity of 50%. Treatments were randomly assigned to fifteen 0.25-ha plots and managed under intermittent stocking by cattle. Herbage accumulation rate was similar among pastures and years (p > .1). The root mass in the tussocks did not differ (p > .1), with mean values ranging between 0.62 to 1.81 kg DM m⁻². Root density in the tussock interspaces was greater in the mixtures (p < .001), regardless of seasons (p = .405) and years (p = .292). The mixtures were dominated by guineagrass (70%) and palisadegrass (30%) at the end of the experiment, with the population of ‘Basilisk’ and ‘BRS Paiaguás’ being completely suppressed throughout the experimental period. Mixing guineagrass and brachiariagrasses can be an alternative to the traditional pastoral systems in the tropics, as it does not compromise herbage production and presents a capacity to produce more roots than a very productive monoculture of ‘BRS Zuri’ guineagrass.  相似文献   

Efficacy of avridine as an adjuvant for Newcastle disease virus antigen in chickens     

M M Rweyemamu  O Umehara  D de Lucca-Neto  M C Baltazar  F E Vicente  R da R Medeiros-Neto 《American journal of veterinary research》1986,47(6):1243-1248

Avridine, a lipoidal amine with interferon-inducing and adjuvant properties, was an effective adjuvant for Newcastle disease antigen (NDA) in chickens. Eleven vaccine lots were evaluated: 2 commercial water-in-oil vaccines, 4 experimental oil emulsion vaccines, 4 avridine-containing vaccines, and a control lot of nonadjuvanted antigen. Avridine significantly enhanced the immunologic responses of chickens against NDA. Chickens vaccinated with the avridine-containing vaccines had significantly higher antibody titers (hemagglutination inhibition) than did chickens vaccinated with the commercial vaccines. Experimental oil emulsion vaccines prepared from the same antigens as avridine-adjuvanted vaccines induced higher hemagglutination inhibition antibody titers after primary but not after booster vaccination. Use of avridine as an adjuvant for NDA in vaccines for chickens induced immunologic protection rates similar to those induced by oil emulsion vaccines, without causing the reactogenic and tissue residue problems associated with the use of oil vaccines in chickens.  相似文献