Effects of dairy husbandry practices and farm types on raw milk quality collected by different categories of dairy processors in the Peruvian Andes

In developing countries, milk quality is often mismanaged in relation to husbandry practices, collection logistics, and the production of small batches. This paper investigates how the management of milk quality from farm to dairy processor impacts on both chemical and hygienic indicators, in a context characterized by farm scale diversity, the co-existence of formal and informal markets, and high milk demand. It is based on an analysis of the chemical and hygienic quality of milk samples collected over a 12-month period from 20 farms and three dairy processors. Data from the farmers’ husbandry practices and the logistics of milk collection were also collected. A large range of quality profiles and farming practices were observed. This diversity is explained by rainfall and temperature pattern, farm size which affects hygienic quality, and lack of efficient logistics between farms and dairy processors. The findings indicate that in a context of high demand for milk and poor private and public regulations, milk quality is impacted upon by poor stakeholders’ management practices.     

The Weedy Rice Complex in Costa Rica. I. Morphological Study of Relationships Between Commercial Rice Varieties,Wild <Emphasis Type="Italic">Oryza</Emphasis> Relatives and Weedy Types

Weedy rice is a complex of Oryza morphotypes widely distributed in commercial rice fields, which interfere with rice cultivation, seed production, industrial processing and commercialization of this crop in several countries. The objective of this study was to characterize the weedy rice complex of Costa Rica by comparing it with the cultivated and wild rice species found in the country. A collection of weedy rice accessions, representative of the morphotypes found in the country, was established and characterized. Their morphometric relationships were established by comparing 27 morphological traits with commercial rice cultivars, landraces and wild Oryza species and by performing a multivariate analysis. Twenty-one weedy rice morphotypes were identified among 735 weedy accessions by using a three-digit code based on seed characters. Three principal components (PCs) explained 66.25% of the variation observed. The first PC accounted for 36.21% of the variation and separated CCDD genome type Oryza latifolia and O. grandiglumis from AA genome species O. sativa, O. glumaepatula, O. rufipogon and O. glaberrima. The second (18.9%) and third (11.14%) PCs separated the weedy morphotype groups from the AA genome species O.sativa, O. glaberrima and O. rufipogon. The weedy morphotypes were scattered between the indica commercial rice varieties, the cluster landraces–glaberrima and O. rufipogon. Additionally, a group of morphotypes showed intermediate characteristics between O. sativa and O. rufipogon, suggesting that hybridization could have taken place in the past between these species. None of the morphotypes collected in Costa Rica clustered with the allotetraploids CCDD species or O. glumaepatula.     

Development and use of microsatellite markers for genetic diversity analysis of cañahua (<Emphasis Type="Italic">Chenopodium pallidicaule</Emphasis> Aellen)

Cañahua (Chenopodium pallidicaule Aellen) is a poorly studied, annual subsistence crop of the high Andes of South America. Its nutritional value (high in protein and mineral content) and ability to thrive in harsh climates make it an important regional food crop throughout the Andean region. The objectives of this study were to develop genetic markers and to quantify genetic diversity within cañahua. A set of 43 wild and cultivated cañahua genotypes and two related species (Chenopodium quinoa Willd. and Chenopodium petiolare Kunth) were evaluated for polymorphism using 192 microsatellite markers derived from random genomic cañahua sequences produced by 454 pyrosequencing of cañahua genomic DNA. Another 424 microsatellite markers from C. quinoa were also evaluated for cross-species amplification and polymorphism in cañahua. A total of 34 polymorphic microsatellite marker loci were identified which detected a total of 154 alleles with an average of 4.5 alleles per marker locus and an average heterozygosity value of 0.49. A cluster analysis, based on Nei genetic distance, clearly separated from wild cañahua genotypes from the cultivated genotypes. Within the cultivated genotypes, subclades were partitioned by AMOVA analysis into six model-based clusters, including a subclade consisting sole of erect morphotypes. The isolation by distance test displayed no significant correlation between geographic collection origin and genotypic data, suggesting that cañahua populations have moved extensively, presumably via ancient food exchange strategies among native peoples of the Andean region. The molecular markers reported here are a significant resource for ongoing efforts to characterize the extensive Bolivian and Peruvian cañahua germplasm banks, including the development of core germplasm collections needed to support emerging breeding programs.     

Diversity of native rhizobia isolated in south Brazil and their growth promotion effect on white clover (Trifolium repens) and rice (Oryza sativa) plants

In this study, rhizobia strains isolated from white clover (Trifolium repens) root nodules were evaluated in an effort to identify an efficient nitrogen-fixing rhizobia strain that can also improve the growth of rice plants (Oryza sativa). White clover plants were collected from seven sites in south Brazil, and 78 native rhizobia isolates were obtained. The genetic diversity analysis of those isolates was carried out by BOX-polymerase chain reaction. Overall, the native rhizobia isolated showed a high genetic diversity, but when the bacterial isolates from the same site were compared, the diversity was lower. One native rhizobia, POA3 (isolated from the Porto Alegre locality), was able to promote the growth of both plants and is therefore a good candidate for new inoculant formulation. Finally, we can conclude that the community of native rhizobia symbiont of white clover plants in southern Brazil is highly diverse and the growth promotion effect of rhizobia inoculation on rice plants was more pronounced in a poor nutrient substrate condition than in a rich nutrient substrate condition.     

Mathematical modeling for extraction of essential oil from Baccharis spp. by steam distillation

Baccharis (Compositae-Asteraceae) is a large genus of plants distributed from the USA to Argentina, of which 90% are located in South America. In recent decades, species of the genus have been studied, due to their importance as sources of novel active components with possible applications in the pharmaceutical and chemical industries. This work studied three species of Baccharis: Baccharis uncinella DC, Baccharis anomala DC and Baccharis dentata (Vell) G.M. Barroso collected in São Francisco de Paula in southern Brazil. The aim of this work is the evaluation of the aromatic potential of the essential oil obtained by steam distillation method and the simulation of the extraction data by means of a mathematical model. A mathematical model based on mass transfer fundamentals is developed and applied to correlate the experimental data. This model is based on the existence of the broken and intact cells, in which the oil located in the broken cells is rapidly extracted and the oil from intact cells diffuses slowly to the surface of the vegetal material. The analysis of the essential oil was carried through by GC-MS and the major compounds identified to both processes were α-pinene, β-pinene, and spathulenol (B. uncinella), spathulenol, β-caryophyllene, and β-selinene (B. anomala), and germacrene-D, caryophyllene oxide, and spathulenol (B. dentata).     

Otter (Lutra lutra) distribution modeling at two resolution scales suited to conservation planning in the Iberian Peninsula

We used the results of the Spanish Otter Survey of 1994-1996, a Geographic Information System and stepwise multiple logistic regression to model otter presence/absence data in the continental Spanish UTM 10×10-km squares. Geographic situation, indicators of human activity such as highways and major urban centers, and environmental variables related with productivity, water availability, altitude, and environmental energy were included in a logistic model that correctly classified about 73% of otter presences and absences. We extrapolated the model to the adjacent territory of Portugal, and increased the model's spatial resolution by extrapolating it to 1×1-km squares in the whole Iberian Peninsula. The model turned out to be rather flexible, predicting, for instance, the species to be very restricted to the courses of rivers in some areas, and more widespread in others. This allowed us to determine areas where otter populations may be more vulnerable to habitat changes or harmful human interventions.     

Pathological changes in the lungs and mammary glands of sheep and their relationship with maedi-visna infection.

Maedi-visna, a multisystemic disease of adult sheep, was first described in Spain in 1984. To get an idea of the seroprevalence of the disease locally and to estimate the number of seropositive animals with lesions, samples of blood, lungs and mammary glands were taken from 124 randomly selected sheep killed in the main slaughterhouse of Zaragoza. In the agar gel immunodiffusion test, 74 (59.7 per cent) of the sheep were positive and 50 were negative. Among the 74 seropositive animals, 19 (25.6 per cent) had no lesions in any organ, 12 (16.2 per cent) had lesions in the lungs only, 15 (20.2 per cent) had lesions in the mammary glands and 28 (37.8 per cent) had lesions in both organs. In the lungs hyperplasia of lymphoid follicles was more evident than an interstitial infiltrate but in the mammary glands this relationship was not observed. Even when the lesions occurred in both organs, they did not show the expected proportion in terms of either type or severity. Among the 50 seronegative sheep, eight (16 per cent) showed maedi-like lesions, formed exclusively by the hyperplasia of lymphoid follicles.     

A new variant of arcelin in wild common bean, Phaseolus vulgaris L., from southern Mexico

Arcelin, a seed protein discovered in wild Phaseolus vulgaris L. accessions, gives high levels of resistance to the Mexican bean weevil [MBW; Zabrotes subfasciatus (Boheman)]. Six variants of arcelin have been described. In this paper we report on a new variant, arcelin 7, found in six wild bean accessions collected in the southern state of Chiapas in Mexico. The new variant is clearly distinct from previously reported ones. It confers high levels of resistance to MBW, comparable to those due to the presence of arcelin 1, arcelin 2 and arcelin 4. Accessions containing arcelin 7 were not as resistant as the one containing arcelin 5 but significantly better in terms of resistance than arcelins 3 and 6. Arcelin 7 was found in a poorly sampled area of Mexico threatened with genetic erosion due to expanding agricultural operations. This exemplifies the need for urgent additional collecting efforts.