Effect of the Hydrological Keyline Design on the Growth and Quality of the Naturalized Grassland in the Dry Central Zone of Chile

The effect of climate change in the central, semi-arid zone of Chile has altered precipitation patterns, shortening the growing season of the naturalized annual grasslands and reducing forage yields. Water harvesting techniques such as the hydrological keyline design, may improve the distribution of precipitation, reduce erosion, and enhance soil water harvesting. It may therefore reduce the impact of climate change in rainfed areas. A trial was implemented to evaluate the effect of the keyline water harvesting practice on soil variables, and pasture production and quality in three farms of the semi-arid O\u27Higgins region. Rains began in April and amounted to a total of 399 mm. Pasture species germinated in August, and growth peaked in October. The keyline design influenced soil moisture and temperature, crude protein (CP), neutral detergent fiber, and acid detergent fiber of the grasses. Yields varied between months and locations. Overall, keyline management significantly increased compressed forage height and yield by 44 and 25% respectively, relative to the control. Considering that there was an effect of location it is necessary to determine the effects of variables such as soil fertility, slope, and orientation, among others

Relationship between Semi-Arid Rangelands Quality Parameters and Vegetation Indexes

A large portion of the sheep production systems in the semi-arid zone of Central Chile base their feeding on the rangelands, adjusting both the production cycle and the use of supplementary feed to the natural supply of fodder. In this way, knowledge of the rangeland quantity and quality at the farm level emerges as an essential input for the decision-making of feed management. The objective of the study was to relate the herbage quality parameters of the semi-arid zone rangeland with Vegetation Indices (VI) and to determine which vegetation index report the best results. Vegetative indexes were obtained from aerial images multispectral captured by a drone. During the 2018 growing season (Oct to Dec), in three farms of the semi-arid zone of Central Chile, three plots of exclusion (per farm) of 100 m2 each were installed and monitored. Samples were taken once a month to determine the contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) of rangeland herbage. Regressions were developed between the rangeland herbage quality parameters and the calculated VI. Most of the regressions obtained were significant (p \u3c 0.05). In DM, the index that presented the best R2 (0.84) was Plant Senescence Reflectance Index (PSRI). In CP, the highest value of R2 was only 0.38 for PSRI. For NDF, a maximum value of R2 of 0.56 was obtained using Red Edge Chlorophyll Index (CI red edge). Finally, for ADF, the highest value of R2 was 0.72 obtained in Green Normalized Difference Vegetation Index (GNDVI), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and Green Chlorophyll Index (CI green)

Characterisation of dairy female calf management practices in southern Chile

The objective of this study was to characterise husbandry and technical-productive practices at the calf rearing stage in dairy farms in Los Lagos Region, southern Chile. A face-to-face survey was applied to 22 dairy farms in Los Lagos Region in 2017. All farms performed artificial calf rearing under either of two systems: total barn confinement (48%) or a mixed system that considers the first stage with confinement and the second stage in open-air paddocks (52%). More than half (52%) of the farms supplied fresh colostrum to the calf from its dam and the rest of the farms used bottle or oesophageal tube. Only 30% of the farms evaluated colostrum quality using colostrometer (densimeter) or refractometer. After the colostrum supply, milk replacers, waste milk, or a mixture of both were used for calf feeding. Most of the farms (66.7%) did not have automated milk-feeding systems and used bottles (88.9%) and buckets (11.1%) instead. On average, calves were handled by 1.5 caretakers (SD: 0.63) of which 63.4% (SD: 40.2) were men. The average age for caretakers was 43.9 years (SD: 12.7), with 23.8% being less than 35 years old. Overall, results from this study can be used to identify key managements that could improve calves’ rearing productive traits

Estudio comparativo del perfil de ácidos grasos de quesos de oveja comerciales

The present study was carried out to characterize the FA profile of sheep cheese marketed in Chile. Fifty-eight cheeses were collected from supermarkets of 5 different Chilean cities including 34 sheep cheeses, 7 from goat’s milk, 11 from cow’s milk, 4 from a mixture of sheep, goat and cow’s milk and 2 from a mixture of sheep and cow’s milk. Compared to the cow and goat cheese (3.4 and 2.5 g·100g−1), the sheep cheese (3.8 g·100g−1) contained higher contents of C18:1t. The saturated and polyunsatured FA contents were greater in goat cheese than in sheep and cow cheese. The n6/n3 ratio was greater in goat (6.1) cheese than in sheep and cow cheese (3.8 and 5.2). The atherogenicity index was unaffected by cheese type, however, the thrombogenic index was lower in sheep cheese (2.8) than in goat and cow cheese (3.1 and 2.9). The n6/n3 ratio and thrombogenic index were lower in Chilean sheep cheese than in those imported from Europe. The fatty acid profile of cheese can be used to differentiate animal species from which the cheese is made and to some extent the geographical origin that may give some insight as to animal feed and production management.Este estudio fue llevado a cabo para caracterizar el perfil de AG de quesos de oveja que se comercializan en Chile. Cincuenta y ocho quesos fueron recogidos de supermercados de 5 ciudades de Chile de los cuales 34 fueron de oveja, 7 de cabra, 11 de vaca, 4 de mezcla de leche de oveja, cabra y vaca y 2 de mezcla de leche de oveja y vaca. Comparado con quesos de vaca y cabra (3.4 y 2.5 g·100g−1), los quesos de oveja (3.8 g·100g−1) presentaron mayor contenido de C18:1t. Los AG saturados y poliinsaturados tuvieron concentraciones más altas en los quesos de cabra que en los quesos de oveja y vaca. La relación n6/n3 fue más alta en quesos de cabra (6.1) que en quesos de oveja y vaca (3.8 y 5.2). El índice aterogénico no fue afectado por el tipo de queso, sin embargo, el índice trombogénico fue menor en quesos de oveja (2.8) que en quesos de cabra y vaca (3.8 y 5.2). La relación n6/n3 y el índice trombogénico fueron menores en quesos chilenos que en quesos importados de Europa. El perfil de AG de quesos puede ser usado para diferenciar entre especies animales de las cuales proviene el queso y hasta cierto grado, el origen geográfico, ofreciendo indicios sobre el tipo de alimento y sistema productivo animal del cual provienen los quesos

Effect of olive oil in dairy cow diets on the fatty acid profile and sensory characteristics of cheese

The effect of dietary unrefined olive oil (OO) residues and hydrogenated vegetable oil (HVO) on the fatty acid profiles of milk and cheese and the sensory characteristics of cheeses was determined. For 9 weeks, animals were fed a control diet with no added lipid (n = 5 cows), or fat-supplemented diets containing OO or HVO (in both cases n = 5 cows; 30 g kg-1 dry matter). Compared with control and HVO, OO increased C18:1 cis-9, and C18:3 cis-9, cis-12, cis-15 fatty acids in milk; and also increased C18:1 trans-10, C18:1 trans-11, C18:1 cis-9, C18:2 cis-9, trans-11 and C18:3 cis-9, cis-12, cis-15 fatty acids in cheeses. OO reduced the number of holes, overall odour and acidity of cheeses, whereas HVO increased the cow milk odour, bitterness and acidity of cheeses. Overall, OO can improve the cheese fatty acid profile, but with adverse effects on sensory attributes