排序方式： 共有35条查询结果，搜索用时 15 毫秒
1.
Sara Bellezza Oddon Ilaria Biasato Arianna Imarisio Miha Pipan Dominik Dekleva Elena Colombino Maria Teresa Capucchio Marco Meneguz Stefania Bergagna Raffaella Barbero Marta Gariglio Sihem Dabbou Edoardo Fiorilla Laura Gasco Achille Schiavone 《Journal of animal physiology and animal nutrition》2021,105(Z1):10-18
The commercial broiler chicken strains are the result of successful selection programmes. Most of the problems related to welfare arise from the high growth rate and body weight. The use of environmental enrichments in intensive farming could have a positive effect on birds by increasing animal welfare. The aim of the study was to evaluate the effects of Hermetia illucens (HI) and Tenebrio molitor (TM) live larvae in the diets of broiler chickens on growth performance, carcass yield and health status. A total of 180 four-day-old male broiler chickens (Ross 308) were randomly allotted to 18 pens. Each pen was assigned to one of the three dietary treatments (6 replicates/treatment, 10 birds/replicate) as follows: (i) control diet (C): commercial feed (two feeding phases: starter [4–11 days] and grower [12–38 days]), (ii) HI: C + 5% of the expected daily feed intake (DFI) HI live larvae (calculated on dry matter [DM]) and (iii) TM: C + 5% of DFI TM live larvae (DM). At 39 days of age, birds were slaughtered. Growth performance parameters were overall not affected by dietary treatments, except for the grower phase feed conversion ratio (FCR) and the overall FCR being better in the TM broilers than the others (p < 0.01). No differences were observed for slaughtering performance and haematological and serum parameters, except for the spleen relative weight being higher (p < 0.01) in the birds administered with larvae when compared to the C group. Gut morphometric indexes and histopathological alterations were not influenced by insect larvae administration. In conclusion, the administration in limited quantities of HI and TM live larvae as environmental enrichment has no negative effects on broiler chicken growth performance and health status. A behavioural study could confirm that live insect larvae represent a novel natural environmental enrichment in broiler farming. 相似文献
2.
3.
In this paper, an experimental procedure is proposed, in order to evaluate the machinability of different particleboards. A dedicated test stand has been built to measure the power consumption during the process for different typologies of particleboards. This methodology could constitute a quick particleboard grading system, in order to maximise the feeding rate during the working process, and, at the same time, minimise the tool wear and the loads on the shaft of the electrical spindle, with a considerable improvement in the overall production costs. 相似文献
4.
Adansonia digitata (baobab tree), a multipurpose tree species, occurs throughout semi-arid and arid zones of Africa. Its survival is, however,
threatened by bush fire, over-exploitation, grazing and a lack of natural regeneration. The extent of variation in fruit characteristics,
seed germination and seedling traits of the baobab tree in Benin, was evaluated at climatic zone level. 1,200 fruits were
sampled in each of the three climatic zones of Benin for morphological assessment and to assess germination rate and seedling
growth dynamics according to the climatic zones, the used substrate and the scarification of the seed coat. There were significant
differences in fruit characteristics not only between climatic zones but also between individuals from the same zone and within-trees.
Using mechanical scarification on freshly-collected baobab seeds negatively affected the germination rate of baobab seeds
sampled in the Guinean and Sudano-Guinean zones of Benin. The best-germination rate was recorded for non-treated seeds from
the Guinean zone, up to 57% on day 25. All seeds germinated best on the sand substrate, but supplying organic matter promoted
further seedling growth after 11 days of germination. Based on these observations we propose some strategies for efficient
ex situ conservation of baobab in Benin. 相似文献
5.
Allometric equations developed for the Lama forest, located in southern Benin, West Africa, were applied to estimate carbon stocks of three vegetation types:undisturbed forest, degraded forest, and fallow. Carbon stock of the undisturbed forest was 2.7 times higher than that in the degraded forest and 3.4 times higher than that in fallow. The structure of the forest suggests that the individual species were generally concentrated in lower diameter classes. Carbon stock was positively correlated to basal area and negatively related to tree density, suggesting that trees in higher diameter classes contributed significantly to the total carbon stock. The study demonstrated that large trees constitute an important component to include in the sampling approach to achieve accurate carbon quantification in forestry. Historical emissions from deforestation that converted more than 30% of the Lama forest into cropland between the years 1946 and 1987 amounted to 260,563.17 tons of carbon per year(t CO2/year) for the biomass pool only. The study explained the application of biomass models and ground truth data to estimate reference carbon stock of forests. 相似文献
6.
7.
R. Houehounha H. T. Avohou O. G. Gaoue A. E. Assogbadjo B. Sinsin 《Agroforestry Systems》2010,78(2):115-125
Daniellia oliveri is an indigenous tree with multiple coppicing that is harvested as firewood by local people from savannas and traditional
fallows in West Africa. We investigated the effects of periodic weed removal on D. oliveri resprouting and growth in traditional fallows and its use for firewood production by smallholder harvesters. Protected plots
were established in D. oliveri dominated fallows at four sites with contrasting soil types. The weedy control plots experienced periodic fires and grass
competition. Sizes of firewood logs were surveyed on local markets and used to estimate the quantity of marketable firewood
for each treatment. The species sprouted vigorously, forming pure stands. Leading shoot density on weed-free plots was three
times higher, reaching 7,250 ± 454 shoots ha−1 34 months after land clearance when compared to 2,425 ± 215 shoots ha−1 on weedy plots. The weed removal treatment increased shoot height from 18 to 34 months after land clearance, while shoot
diameter was not affected. After 24 months, 50% of the shoots were of marketable size for the weedy treatment, while this
was reached at 18 months for the weed-free treatment. 相似文献
8.
Dongmo Albert Nanfack Nguefack Julienne Dongmo Joseph Blaise Lekagne Fouelefack François Romain Azah Rene Udom Nkengfack Ephrem Augustin Stefani Emilio 《植物病害和植物保护杂志》2021,128(3):703-713
Journal of Plant Diseases and Protection - The high cost of chemical pesticides and their negative impact on the environment prompted the search for natural pesticides from plants. The objective of... 相似文献
9.
The baobab tree (Adansonia digitata L.) is a valued savannah tree. Although variation in fruit characteristics of this tree have been studied, no studies to our knowledge have been carried out on variation of leaf morphology which can be linked to drought adaptation mechanisms. Accessions of baobab from different ecosystems in Benin were characterised for leaf size and thickness, stomata size and density on the abaxial surface of leaves. Significant variation was found in leaf size and stomata characteristics. Trees from northern study sites had higher stomata density and smaller guard cell length than those from southern study sites. The results show that pruning has a significant effect on leaf size, but not on stomatal characteristics. Trees from northern study sites showed more xerophytic characteristics than those from the south. It seems that genetic and physiological effects may play a role in baobab drought adaptation. 相似文献
10.
Genomic prediction for yields,processing and nutritional quality traits in cultivated potato (Solanum tuberosum L.) 
下载免费PDF全文
下载免费PDF全文 Current potato breeding approaches are hampered by several factors including costly seed tubers, tetrasomic inheritance and inbreeding depression. Genomic selection (GS) demonstrated interesting results regardless of the ploidy level, and can be harnessed to circumvent these problems. In this work, three GS models were evaluated using 50,107 informative SilicoDArT markers and 11 traits in two values for cultivation and use (VCU) potato trials. Two key breeding problems modelled included predicting the performance of (i) new and unphenotyped clones (cross‐validation) and (ii) a VCU using another as training set (TS). GS models performed comparably. Cross‐validation accuracy was high for D35, D45, DMW and BVAL, in ascending order. Prediction accuracies of the VCUs were highly correlated, but the best prediction was obtained for the smaller VCU using the bigger as TS. Cross‐validation and VCU prediction accuracies were higher when bigger TSs were used. The findings herein indicate that GS can be attractively integrated in potato breeding, particularly in early clonal generations to predict and select for traits with low heritability which would otherwise require more testing years, environments and resources. 相似文献