Einar Vargas-Bello-Pérez

Short communication: Chemical composition, fatty acid composition, and sensory characteristics of Chanco cheese from dairy cows supplemented with soybean and hydrogenated vegetable oils

Lipid supplements can be used to alter fatty acid (FA) profiles of dairy products. For Chanco cheese, however, little information is available concerning effects of lipid supplements on sensorial properties. The objective of this study was to examine effects of supplementation of dairy cow diets with soybean (SO) and hydrogenated vegetable (HVO) oils on chemical and FA composition of milk and cheese and sensory characteristics of cheese. Nine multiparous Holstein cows averaging 169±24d in milk at the beginning of the study were used in a replicated (n=3) 3×3 Latin square design that included 3 periods of 21d. All cows received a basal diet formulated with a 56:44 forage:concentrate ratio. Dietary treatments consisted of the basal diet (control; no fat supplement), and the basal diet supplemented with SO (unrefined oil; 500g/d per cow) and HVO (manufactured from palm oil; 500g/d per cow). Milk fat yield was lower with HVO compared with control and SO. Cheese chemical composition and sensory profile were not affected by dietary treatment. Vaccenic (C18:1 trans-11) and oleic (C18:1 cis-9) acids were higher for SO than for control and HVO. Compared with control and HVO, SO decreased saturated FA and increased monounsaturated FA. The thrombogenic index of milk and cheese produced when cows were fed SO was lower than when cows were fed on control and HVO. The outcome of this study showed that, compared with control and HVO, supplementing dairy cow diets with SO improves milk and cheese FA profile without detrimental effects on the chemical composition of milk and cheese and the sensory characteristics of cheese.

Quantitative analysis of ruminal bacterial populations involved in lipid metabolism in dairy cows fed different vegetable oils

Vegetable oils are used to increase energy density of dairy cow diets, although they can provoke changes in rumen bacteria populations and have repercussions on the biohydrogenation process. The aim of this study was to evaluate the effect of two sources of dietary lipids: soybean oil (SO, an unsaturated source) and hydrogenated palm oil (HPO, a saturated source) on bacterial populations and the fatty acid profile of ruminal digesta. Three non-lactating Holstein cows fitted with ruminal cannulae were used in a 3×3 Latin square design with three periods consisting of 21 days. Dietary treatments consisted of a basal diet (Control, no fat supplement) and the basal diet supplemented with SO (2.7% of dry matter (DM)) or HPO (2.7% of DM). Ruminal digesta pH, NH3-N and volatile fatty acids were not affected by dietary treatments. Compared with control and HPO, total bacteria measured as copies of 16S ribosomal DNA/ml by quantitative PCR was decreased (P<0.05) by SO. Fibrobacter succinogenes, Butyrivibrio proteoclasticus and Anaerovibrio lipolytica loads were not affected by dietary treatments. In contrast, compared with control, load of Prevotella bryantii was increased (P<0.05) with HPO diet. Compared with control and SO, HPO decreased (P<0.05) C18:2 cis n-6 in ruminal digesta. Contents of C15:0 iso, C18:11 trans-11 and C18:2 cis-9, trans-11 were increased (P<0.05) in ruminal digesta by SO compared with control and HPO. In conclusion, supplementation of SO or HPO do not affect ruminal fermentation parameters, whereas HPO can increase load of ruminal P. bryantii. Also, results observed in our targeted bacteria may have depended on the saturation degree of dietary oils.

Chilean consumers’ perception about animal welfare in dairy production systems: short communication

Information on animal welfare and ways that farm animals are kept has gained more and more importance with regard to the consumers’ behaviour and expectations when buying food products. In certain countries, animal welfare is considered as an important extrinsic quality attribute of animal products. Until now, hardly any studies have been conducted in Latin America on consumers’ expectations and knowledge regarding animal welfare aspects of the products they buy. The objective of this study was to determine the knowledge and expectations of consumers in Chile regarding information about dairy production systems and animal welfare, and the main aspects they considered when buying dairy products. A face-to-face interview was conducted on a sample of 501 persons from the Province of Santiago, Chile. The survey was conducted in major supermarkets from 15 different municipalities of Santiago in November and December 2012. The main aspects considered before purchasing dairy products were fat content (30%) and price (26%). It was shown that 66.9% of the participants associated the term animal welfare with responsible pet ownership, 12.4% to farm animal care, 11.6% to vegetarianism and 9.2% to the freedom and nature of animals. Age, educational level and family income were related (P < 0.001) to responsible pet ownership whereas gender did not relate to the concept of animal welfare. From the total surveyed participants, 73% were interested in receiving more information about animal welfare; 62% of these were women between 18 and 30 years of age. Information about the conditions of milk production and animal welfare were considered to be an important aspect to be included in dairy products’ labelling for 86% of the participants. Also, 68% of the participants declared a willingness to pay more for an animal welfare friendly dairy product. Data from this study may be useful in order to include animal welfare as an extrinsic quality attribute of dairy products in Chile and to define a market-oriented strategy including animal welfare.

Short communication: Discrimination between retail bovine milks with different fat contents using chemometrics and fatty acid profiling

We used a multivariate chemometric approach to differentiate or associate retail bovine milks with different fat contents and non-dairy beverages, using fatty acid profiles and statistical analysis. We collected samples of bovine milk (whole, semi-skim, and skim; n = 62) and non-dairy beverages (n = 27), and we analyzed them using gas-liquid chromatography. Principal component analysis of the fatty acid data yielded 3 significant principal components, which accounted for 72% of the total variance in the data set. Principal component 1 was related to saturated fatty acids (C4:0, C6:0, C8:0, C12:0, C14:0, C17:0, and C18:0) and monounsaturated fatty acids (C14:1 cis-9, C16:1 cis-9, C17:1 cis-9, and C18:1 trans-11); whole milk samples were clearly differentiated from the rest using this principal component. Principal component 2 differentiated semi-skim milk samples by n-3 fatty acid content (C20:3n-3, C20:5n-3, and C22:6n-3). Principal component 3 was related to C18:2 trans-9,trans-12 and C20:4n-6, and its lower scores were observed in skim milk and non-dairy beverages. A cluster analysis yielded 3 groups: group 1 consisted of only whole milk samples, group 2 was represented mainly by semi-skim milks, and group 3 included skim milk and non-dairy beverages. Overall, the present study showed that a multivariate chemometric approach is a useful tool for differentiating or associating retail bovine milks and non-dairy beverages using their fatty acid profile.

Feeding extruded linseed to dairy ewes under extensive grazing conditions

The aim of this trial was to evaluate the effect of dietary supplementation of extruded linseed on the milk and cheese fatty acid (FA) profiles of ewes under extensive grazing conditions. Over 26 days, a group of nine lactating ewes (Latxa × Milchaf × Corriedale) in mid-lactation were managed under grazing conditions and given supplements during each manual milking (0830 and 1800 h) of 50% corn and 50% oats (500 g ewe -1 milking -1 ; control, TC) for the first 6 days. From day 7 to 20, the supplement was 25% corn, 25% oats and 50% extruded linseed (500 g ewe -1 milking -1 ) (extruded linseed; TEL). From day 21 to 26, the ewes were fed TC. The saturated FA content in milk was reduced (3.6%), and the monounsaturated, polyunsaturated and n-3 FA (7, 10 and 25%, respectively) were increased when the ewes were supplemented with extruded linseed. A correlation between rumenic acid with vaccenic acid (R 2 =0.68) was found in the milk fat from ewes fed TEL. In cheese obtained from TEL, the contents of n-3 and polyunsaturated FA were increased (21 and 7%, respectively). In conclusion, a supplement of extruded linseed in ewes under grazing conditions could be an alternative lipid source to produce cheese with additional nutritional value. However, the effect of extruded linseed supplementation in ewes under the same conditions with longer experimental periods and a more suitable statistical design must be investigated. El objetivo de este ensayo fue evaluar el efecto de suplementar extruido de linaza en el perfil de acidos grasos de leche y queso de ovejas en pastoreo extensivo. Durante 26 dias, un grupo de nueve ovejas lactantes (Latxa × Milchaf × Corriedale) fueron manejadas en pastoreo extensivo y suplementadas durante cada ordeno manual (830 y 1800 h) con 50% maiz + 50% avena (500 g oveja -1 ordeno -1 ) durante los primeros 6 dias (control; TC), de los dias 7 al 20 se suplementaron con 25% maiz + 25% avena + 50% extruido de linaza (500 g/oveja/ordeno) (extruido de linaza; TEL), y finalmente, del dia 21 al 26 las ovejas fueron alimentadas con TC. El contenido de acidos grasos saturados en leche fue reducido (3,6%) mientras que los acido grasos monoinsaturados, polinsaturados y n-3 fueron incrementados (7, 10 y 25%) en aquellas ovejas alimentadas con TEL. Se observo una correlacion de acido rumenico con acido vaccenico (R 2 =0,68) en leche de ovejas alimentadas con TEL. Los quesos elaborados de ovejas alimentadas con TEL, aumentaron su contenido de n-3 y acidos grasos poliinsaturados (21 y 7%). En conclusion, el suplementar ovejas en pastoreo extensivo con extruido de linaza puede ser una alternativa que puede resultar en la elaboracion de quesos con un valor nutricional mas saludable desde el punto de vista humano. Ademas resulta necesario investigar mas sobre el uso del extruido de linaza bajo las mismas condiciones con periodos mas largos de experimentacion usando un diseno estadistico mas apropiado.

Characterization of cheese consumers in Santiago Province, Chile

A high demand for Chilean cheese has resulted in increased cheese production. This increase represents an opportunity to promote the development of new markets, such as for small ruminant cheeses. However, little has been discussed regarding the extent to which cheese consumers consider small ruminant cheeses. We hypothesized that price is the main determining factor for purchasing cheese. The present study examined this previously unexplored aspect. The objective of this study was to identify the factors that contribute to the purchaser’s response behavior, including purchase, usage and product possession. This study also aimed to provide preliminary information on cheese consumption in the Province of Santiago, Chile. A personal interview was conducted in a sample of 323 individuals in major supermarkets from five municipalities (Santiago, La Florida, Las Condes, Pudahuel, and Recoleta) of Santiago city between March and May 2012. The largest proportion of surveyed individuals were female (62%) who were between 20 to 25 years (34%). The main cheese purchaser of the household was more often the woman (52%; P<0.01). The brand and origin (70%; P≤0.01) and price (30%; P≤0.01) of the cheese were the main aspects considered before making a purchase. Cow’s milk cheese was the predominant cheese type consumed (77%), followed by goat’s milk cheese (6%), cow’s and goat’s milk cheese (15%) and cow’s, goat’s and sheep’s milk cheese (2%). Of the individuals surveyed, 35% consumed cheese three times per week as a sandwich ingredient. We conclude that consumer fidelity is driven by brand and origin and a preference to use the cheese in sandwiches (81%). Data from this study may be used to determine the most adequate strategy for promoting the sales of small ruminant cheeses. La produccion de queso en Chile esta creciendo debido a un alza en su demanda; este fenomeno podria representar una oportunidad para promover el desarrollo de nuevos mercados (quesos de rumiantes menores), sin embargo, poco se ha investigado sobre el consumo de quesos. La hipotesis que se contrasta es que los sujetos que compran queso en el mercado lo hacen con un grado debil de implicacion, donde el precio del producto es la variable mas importante en el comportamiento de compra. Este estudio tiene por objetivo identificar funciones de respuesta comportamental, para analizar los procesos de adquisicion, utilizacion, y posesion del producto en la Provincia de Santiago en Chile. Un cuestionario personal fue realizado a una muestra de 323 personas en supermercados de cinco comunas (Santiago, La Florida, Las Condes, Pudahuel y Recoleta) de la ciudad de Santiago entre marzo y mayo del 2012. La mayor proporcion de personas encuestadas resulto ser mujeres (62%) entre 20 y 25 anos de edad (34%). Las mujeres (52%; P≤0.01) resultaron ser las personas que se encargan de comprar el queso mientras que marca y origen (70%; P≤0.01) y precio (30%; P≤0.01) fueron los aspectos mas importantes que el consumidor considera antes de realizar la compra de queso. El queso de origen vacuno fue el queso que mas se consume (77%), la diferencia se distribuye en queso de cabra (6%), queso de vaca y queso de cabra (15%) y quienes consumieron queso de vaca, cabra y oveja (2%). Del total de encuestados, el 35% consume queso tres veces a la semana como un ingrediente en sandwiches. Se puede concluir que la accion de compra de queso tiene una debil implicacion, como generalmente se asume, con una aprehension complementaria entre racional y emocional. Ello se explica por una presumible alta tasa de fidelidad a marca/origen en quesos cuya principal caracteristica es ser suave, caracteristica que lo hace apropiado para el fin que se utiliza (81%): sandwich. Los resultados de este estudio podrian ser utilizados para encontrar la forma mas apropiada de ingresar al mercado de quesos de pequenos rumiantes: un uso practico y habitual.

Utilisation of a mix of powdered oils as fat supplement in nursery- and growing-pig diets

Two experiments were conducted to challenge nursery and growing pigs to increased levels of dietary fat (5–10% as fed), using a crystallised powdered oil mix (CPOM), produced by a modified freeze-drying process. Growth performance of nursery pigs was determined and a digestibility trial was also conducted with growing pigs (Experiment 2). The CPOM was compared, at similar levels of lipid inclusion (10% total lipids), with other fat sources commonly used in swine diet, namely soybean oil (SBO) and hydrogenated palm oil. For the growth assay (Experiment 1), the CPOM was prepared and added at different levels (0%, 2.6% and 3.8%) commonly used in commercial diets (Phase 1–4 diets). Seventy-five weaning pigs (28 days of age) were housed in 15 pens (5 pigs per pen) and randomly assigned into the three dietary treatments until 70 days of age. Growth performance and feed utilisation were compared weekly among experimental groups. The use of CPOM improved average daily gain (~60%), and increased average daily feed intake by 40% and 50% at the 2.6% and 3.8% CPOM levels respectively. In the digestibility trial (Experiment 2), pigs fed with 5% incorporation of CPOM (10% of total lipid content) had digestibility of energy and ether extract similar to those fed the SBO-supplemented diet, although the SBO diet had a significantly greater polyunsaturated fatty acid concentration. The powdered crystallisation process of the CPOM fat allowed an equivalent digestibility of this fat source with more saturated fatty acids, and the physical-property effect of this processed oil source on apparent total-tract digestibility should be further studied.

EFFECT OF GENUS AND GROWTH STAGE ON THE CHEMICAL AND MINERAL COMPOSITION OF TROPICAL GRASSES USED TO FEED DAIRY COWS

In tropical production systems, dairy cows are rarely supplemented with minerals, which often lead to mineral imbalances. Grasses grown together in the same soil type and sampled at the same growth stage can vary widely in chemical and mineral composition; therefore, the objective of this study was to characterize the chemical and mineral composition of Urochloa spp., Megathyrsus spp., and Andropogon spp. at three different stages of growth in the same soil type. The content of dry matter (DM; g 100 g-1) was higher (P≤0.05) in Urochloa spp. than in Andropogon spp. and Megathyrsus spp. Hemicellulose, non-fiber carbohydrates and slowly degraded true protein contents were higher (P≤0.05) in Andropogon spp. than in Urochloa spp. and Megathyrsus spp. Ether extract, crude protein, rapidly degraded true protein and unavailable protein contents were not affected by genus, whereas ether extract, ash, neutral detergent fiber, non-fiber carbohydrates, rapidly degraded true protein and unavailable protein contents were not affected by growth stage. Compared with Urochloa spp. and Andropogon spp., Megathyrsus spp. had higher (P≤0.05) contents of Na and Mg, intermediate (P≤0.05) contents of Mn and lower (P≤0.05) contents of Zn. P, Na, and K contents were affected by growth stage. Compared with Megathyrsus spp. and Andropogon spp., Urochloa spp. Was higher (P≤0.05) in P and Na contents. Results from this study may be useful in predicting the nutrient and mineral supply from forages in dairy production systems in tropical areas. En los sistemas de produccion tropical, las vacas lecheras rara vez se suplementan con minerales y frecuentemente esto provoca un desequilibrio mineral. Los pastos que crecen en las mismas condiciones de suelo y que son muestreados en la misma etapa de crecimiento pueden variar en su composicion quimica y mineral, por lo tanto el objetivo de este estudio es caracterizar la composicion quimica y mineral de Urochloa spp., Megathyrsus spp., and Andropogon spp., en tres etapas distintas de crecimiento con las mismas condiciones de suelo. El contenido de materia seca (g 100 g-1) fue mayor (P≤0.05) en Urochloa spp., que en Andropogon spp., y Megathyrsus spp. Los contenidos de hemicelulosa, carbohidratos no estructurales y proteina verdadera de degradacion lenta, fueron mayores en (P≤0.05) Andropogon spp., que en Urochloa spp., y Megathyrsus spp. Los contenidos de extracto etereo, proteina cruda, proteina verdadera de rapida degradacion no fueron afectados por el genero del pasto; mientras que el extracto etereo, ceniza, fibra detergente neutra, contenido celular, carbohidratos no estructurales, proteina verdadera de rapida degradacion y proteina no degradables tampoco fueron afectados por la etapa de crecimiento de los pastos. En comparacion con Urochloa spp., y Andropogon spp., Megathyrsus spp., tuvo mayor (P≤0.05) cantidad de P, Na y Mg, valores intermedios (P≤0.05) para Mn y valores menores (P≤0.05) para Zn. P, Na y K fueron afectados por la etapa de crecimiento de los pastos. Comparado con Megathyrsus spp., y Andropogon spp., Urochloa spp., presentaron contenidos mas altos (P≤0.05) de P y Na. Los contenidos de K fueron menores (P≤0.05) en Andropogon spp., que aquellos observados en Megathyrsus spp., y Urochloa spp. Los resultados de este estudio podrian ser utilizados para calcular o predecir el consumo de nutrientes y minerales de vacas lecheras en sistemas de pastoreo tropical.

Effect of dietary vegetable oils on the fatty acid profile of plasma lipoproteins in dairy cows

ABSTRACT The aim of this study was to elucidate the effect of dietary supplementation of soybean oil (SO) and hydrogenated palm oil (HPO) on the transport of fatty acids (FA) within plasma lipoproteins in lactating and non-lactating cows. Three lactating and three non-lactating Holstein cows were used in two different 3 × 3 Latin square experiments that included three periods of 21 d. Dietary treatments for lactating cows consisted of a basal diet (control; no fat supplement) and fat-supplemented diets containing SO (500 g/d per cow) or HPO (500 g/d per cow). For non-lactating cows, dietary treatments consisted of a basal diet (control; no fat supplement) and fat-supplemented diets containing SO (170 g/d per cow) or HPO (170 g/d per cow). Compared with the control and SO diet, HPO addition increased (p < 0.05) the concentration of C16:0, C18:0, C18:2cis-9,12, C18:3cis-9,12,15 and total saturated and polyunsaturated FA in the plasma of lactating cows. In non-lactating cows, the SO addition increased the plasma concentration of C18:1trans-11. In lactating cows, concentrations of C16:0, C18:0 and total saturated FA were increased (p < 0.05) by HPO addition in the high-density lipoprotein (HDL). Total saturated FA were increased (p < 0.05) by HPO in very-low-density lipoprotein (VLDL). In non-lactating cows, the concentration of C18:0 was increased (p < 0.05) by HPO in HDL, whereas C18:1trans-11 was increased (p < 0.05) by SO in the low-density lipoprotein. Overall, it was found that distribution and transport of FA within the bovine plasma lipoproteins may be influenced by chain length and degree of unsaturation of dietary lipids. Also, the distribution of individual FA isomers such as C18:1trans-11 and C18:2cis-9,trans-11 may vary depending on the physiological state of the cow (lactating or non-lactating), and are increased in plasma (lactating cows) and the HDL (non-lactating cows) when cows are fed SO.