Skin and coat traits in sheep in Brazil and their relation with heat tolerance   总被引：1，自引：1，他引：0  

Concepta McManus  Helder Louvandini  Rosilene Gugel  Luiz Cláudio Bastos Sasaki  Eliandra Bianchini  Francisco Ernesto Moreno Bernal  Samuel Rezende Paiva  Tiago Prado Paim 《Tropical animal health and production》2011,43(1):121-126

The objective of this study was to evaluate and compare physical parameters in groups of sheep with different phenotypic characteristics in the Centre-west region of Brazil. Five groups of sheep, with nine animals per group, were selected, three groups of Santa Inês animals with different coat colours (white, brown and black), one group with crossbred animals (Santa Inês × Bergamasca) and one group with animals of the Bergamasca breed. The following traits were evaluated: coat thickness, number and length of hair, pigmentation level in the coat and the skin as well as the percentage area of sweats glands in the skin tissue, carried out by histological analysis. The number of hairs and the area of sweats glands were not significantly different between the evaluated groups. The Bergamasca breed showed low pigmentation of the skin and long hairs. The levels of pigmentation of the hair and of the skin were highly correlated. Between the Santa Inês groups, the group with white hair showed the better parameters for heat adaptation, while the brown hair group showed the lower heat adaptation when compared with another hair breed groups.  相似文献   

Fatty acid profile of hair lambs and their crossbreds slaughtered at different weights     

Landim AV  Cardoso MT  Castanheira M  Fioravanti MC  Louvandini H  McManus C 《Tropical animal health and production》2011,43(8):1561-1566

This study aims to investigate the effect of breed and slaughter weight on fatty the acid profile of the Longissimus dorsi muscle in lambs. Twenty-four Santa Inês (SI), 24.5 Ile de France × 0.5 Santa Inês (Ile × SI) and 12.5 Texel × 0.5 Santa Inês (Te × SI), slaughtered at different weights (30, 35, 40, and 45 kg), were evaluated. The animals were reared with creep feeding to weaning and were feedlot finished, receiving a diet composed of 30% hay and 70% concentrate. The analyses of fatty acids were carried out on the Longissimus muscle of the 13th rib. The experiment was in a three by four factorial design. The total mean saturated fatty acid level was 44.88%, with 43.30% monounsaturated fats and 1.72% polyunsaturated. The major fatty acids found included oleic (43%), palmitic (22%), and stearic (18%). The concentration of desirable fatty acids varied from 61.56% to 66.78%, with Te × SI (66.78%) having the highest levels (P < 0.05). The slaughter weight affected (P < 0.05) the saturated and unsaturated (both mono and poly) fatty acid profiles. The 35-kg slaughter weight showed the most desirable fatty acid profile. The saturated myristic and stearic fatty acids decreased with an increase in the slaughter weight, but oleic acid increased. In the conditions of the present study, the meat from Santa Ines and Texel × Santa Ines lambs had fatty acid profiles more beneficial for human health due to the higher levels of unsaturated fatty acids.  相似文献   

Comparison of acid phosphatases in two genotypes of white clover with different responses to applied phosphate     

Donal A. Hunter  Michael T. McManus 《Journal of plant nutrition》2013,36(4-5):679-692

Two white clover (Trifolium repens L.) genotypes, identified by their differing ability to increase in biomass in response to added phosphorus (P) (high P responder, low P responder) were subjected to P deprivation and examined for differences in root growth, root surface acid phosphatase activity, and soluble and ionically‐bound root cell wall isoform profile. As leaf P levels declined, the high P responder showed a greater increase in biomass allocated to the roots, and highest root surface acid phosphatase activity. However, these differences were not statistically significant. The onset of P deprivation enhanced the intensity of several acid phosphatase isoforms in the P deprived root extracts from both genotypes. After 11 days, one basic isoform (resolved atpH4.5) was enhanced in the cell wall extract, an enhancement that was also observed after 26 days. However, for the soluble isoforms, a temporal separation of response was observed in both genotypes. After 11 days, there was no discernable enhancement of the major staining basic isoform or in the major staining acidic isoform (resolved at pH 8.8) in extracts from P‐deprived roots. After 26 days, these isoforms were enhanced in extracts from P‐derived root tissues. Further, a second acidic isoform could now be discerned as a major staining enzyme in P‐derived root extracts from both genotypes.  相似文献   

THE EFFECT OF PHYSIOLOGICAL STATUS ON DIET SELECTION BY GRAZING EWES     

W. R. McManus  G. W. Arnold  Judith Ball 《Grass and Forage Science》1968,23(3):223-227

The effect of the physiological status of grazing ewes on diet selection was studied, using ewes with oesophageal fistulae. The diets of dry ewes grazing Phalaris annual grasses and subterranean clover pastures, over a range of availabilities, were compared with those of ewes in various stages of pregnancy and lactation. There were no significant differences at any stage of reproduction in the botanical composition of the diets. However, small differences in diet digestibility, soluble carbohydrate and nitrogen content were found during pregnancy and lactation. These occurred at all levels of availability of pasture. The differences did not appear to have nutritional significance in the particular pasture ecosystems studied because levels of N, soluble carbohydrates and digestibility of the diet were such that selection for survival was unlikely to be necessary.
It is concluded that dry fistulated ewes can be used to obtain samples for assessing diet N and soluble carbohydrate contents for ewes in other physiological states. The use of in vitro digestibility tests of diets of dry ewes to assess diet digestibility for ewes in other physiological states may be subject to error.  相似文献   

The Embeddedness of Collective Action in Nepalese Community Forestry     

Krishna K. Shrestha  Phil McManus 《Small-Scale Forestry》2007,6(3):273-290

Collective action by local communities has been recognised as crucial for effective management of natural resources, particularly the management of forests in rural settings in developing countries. However, the processes and outcomes of collective action in forest management are often analysed through a narrow rational choice model, ignoring the impacts of wider social, political and economic processes in conditioning peoples’ decisions to act (or not to act) collectively. Optimistic assumptions are made for collective action being instrumental to enhance both social and ecological outcomes, but there is a paucity of empirical evidence on how and why the condition of forests has improved (or deteriorated) under collective action, and what impacts the change in forest condition has on various groups within local communities. This study critically examines the emergence, evolution and outcomes of collective action in a case of community forestry in Nepal. A mix of qualitative and quantitative methods has been used to collect primary data from the forest, households, key informants and focus groups. The emergence and outcomes of collective action is found to be embedded in social, economic and political relationships, where powerful actors control the use of forests in order to ensure conservation, thereby resulting in the underutilisation of forest products. Poor users, who depend heavily on forests, are found to be worse off economically under community forestry, but still engage in collective action for a variety of socio-political reasons. This contradicts the conventional wisdom which assumes that people only cooperate when they benefit from cooperation. It is concluded that a deeper understanding of the embeddedness of community forestry is needed in order to achieve the potential of collective action.

Krishna K. ShresthaEmail:

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Bioactivity of extracts and isolated compounds from Vitex polygama (Verbenaceae) and Siphoneugena densiflora (Myrtaceae) against Spodoptera frugiperda (Lepidoptera: Noctuidae)     

Gallo MB  Rocha WC  da Cunha US  Diogo FA  da Silva FC  Vieira PC  Vendramim JD  Fernandes JB  da Silva MF  Batista-Pereira LG 《Pest management science》2006,62(11):1072-1081

The effects of crude extracts, fractions and isolated compounds from Vitex polygama Cham. and Siphoneugena densiflora Berg were evaluated on the development of Spodoptera frugiperda JE Smith, a destructive insect pest of corn and several other crops. The extracts and fractions were incorporated into an artificial diet at 1 mg g(-1) and offered to the insect during its larval stage. Length and viability of larval and pupal stages as well as pupal weight were assessed. Isolated compounds were tested through superficial contamination of the diet at 0.1 mg g(-1). Weight and viability of ten-day-old larvae were determined. Methanolic and hydroalcoholic S. densiflora extracts caused 100% larval mortality, while leaf and fruit hydroalcoholic extracts from V. polygama were the most active. Among the isolated compounds, flavonoids presented the best insecticidal results, and tannins the best larval growth inhibition.  相似文献   

A simulation model of a breeding ewe flock     

D.H. White  P.J. Bowman  F.H.W. Morley  W.R. McManus  S.J. Filan 《Agricultural Systems》1983,10(3):149-189

A simulation model was constructed of a self-replacing flock of Merino ewes grazing a predominantly Wimmera ryegrass and subterranean clover pasture in the Eppalock catchment of northern Victoria, Australia. The model was used to predict the likely physical, biological and economic consequences of changes in stocking rate and date of lambing.Routines for simulating the local climate, together with expected levels of pasture production, were based on available local data. The herbage produced was utilised for animal maintenance, growth, pregnancy, lactation and wool production. Predictions were made of the ovulation and fertilisation rates of the breeding ewes and the subsequent survival of embryos and lambs. Lamb growth rates were determined relative to their predicted intake levels of milk and herbage.The economic consequences of different combinations of ewe stocking rate and date of lambing were evaluated by simulating the cash flow of the property. Financial returns were obtained from the sale of wool, cast-for-age and culled ewes, and wether lambs.  相似文献   

Encapsulated nitrate replacing soybean meal changes in vitro ruminal fermentation and methane production in diets differing in concentrate to forage ratio     

Andressa Santanna Natel  Adibe Luiz Abdalla  Rafael Canonenco de Araujo  Concepta McManus  Tiago do Prado Paim  Adibe Luiz de Abdalla Filho  Patrícia Louvandini  Carina Nazato 《Animal Science Journal》2019,90(10):1350-1361

The objective of this study was to evaluate the effects of using encapsulated nitrate product (ENP) replacing soybean meal in diets differing in concentrate to forage ratio on ruminal fermentation and methane production in vitro using a semi‐automatic gas production technique. Eight treatments were used in a randomized complete design with a 2 × 4 factorial arrangement: two diet (20C:80F and 80C:20F concentrate to forage ratio) and four levels of ENP addition (0%, 1.5%, 3.0%, and 4.5% of DM) replacing soybean meal. There was a diet × ENP interaction (p = 0.02) for methane production. According to ENP addition, diets with 80C:20F showed more intense reduction on methane production that 20C:80F. A negative linear effect was observed for propionate production with ENP addition in diet with 80C:20F and to the relative abundance of methanogens Archaea, in both diet. The replacement of soybean meal by ENP in levels up to 3% of DM inhibited methane production due to a reduction in the methanogens community without affecting the organic matter degradability. However, ENP at 4.5% of DM level affected fiber degradability, abundance of cellulolytic bacteria, and propionic acid production, indicating that this level of inclusion is not recommended for ruminant production.  相似文献   

First report on the distribution of microsporidian infections of browntail moth (Euproctis chrysorrhoea L.) populations in Bulgaria     

D. Pilarska  A. Linde  D. Goertz  M. McManus  L. Solter  N. Bochev  M. Rajkova 《Anzeiger für Sch?dlingskunde》2001,17(5):37-39

The distribution of microsporidian infections of browntail moth (Euproctis chrysorrhoea L.) populations in Bulgaria was studied. Of the 72 browntail moth populations in the regions of Balkan, Sredna Gora, Sakar Mountains, and Rodope Mountains, 21 were infected by Microsporidia. The Microsporidia belong to two genera – Nosema (Dihaplophasea, Nosematidae) and Endoreticulatus (Haplophasea, Encephalitozoonidae). Microsporidial infections caused by a Nosema were found in 14 populations, by an Endoreticulatus in 8 populations, and mixed infections of Nosema and Endoreticulatus were recorded from 3 populations. Endoreticulatus was present in Balkan, Sredna Gora, and the Sakar Mountains. Nosema infections were found in Sakar Mountains and Rodope, and mixed infections were recorded only from the Sakar Mountain populations.  相似文献   

The effect of Cryphonectria parasitica on water relations of American chestnut     

Patricia S. McManus  Frank W. Ewers 《Physiological and Molecular Plant Pathology》1990,36(6)

Chestnut blight has commonly been regarded as a phloem disease due to conspicuous stem cankers that result from infection by the fungal pathogen Cryphonectria (Endothia) parasitica. Stomatal conductance (g_s), transpiration rate (E) and leaf water potential were measured throughout the day on leaves distal to naturally-occurring virulent (sunken bark with abundant stromata) or hypovirulent (swollen bark lacking stromata) cankers and cankers induced by inoculation with virulent or hypovirulent strains of C. parasitica. Relative to control stems, hydraulic conductivity (K_h), g_s and E were reduced significantly (α = 0·05) for both natural virulent cankers, and cankers that were induced by a virulent strain. These effects were less pronounced for both natural and induced hypovirulent cankers. Isolation experiments revealed that the percentage of xylem tissue chips yielding C. parasitica was greater for virulent than for hypovirulent cankers. The data provide evidence that the localized presence of C. parasitica in cankers of American chestnut results in stomatal closure, possibly as a direct result of xylem dysfunction.  相似文献