Dietas alimentares dos bovinos Mirandeses: composição e variação ao longo do ano

A raça bovina Mirandesa é uma raça autóctone da região Nordeste de Portugal tendo um papel importante na manutenção dos espaços rurais, contribuindo para a fixação das populações e para a preservação do ambiente. Antigamente a criação dos animais dependia da abundância na Natureza para os alimentar e garantir a sua sobrevivência. No entanto, desde muito cedo que o homem passou a preocupar-se não só com a sua alimentação, mas também com a dos seus animais. Hoje sabemos que os alimentos são fontes de nutrientes para as funções fisiológicas que garantam não só a vida, mas também a saúde, o bem estar e a produção dos animais. Com este conhecimento, podemos agir activamente, plantando, comprando, armazenando e transformando os alimentos, de modo a produzirmos dietas equilibradas para os animais. Os conceitos de alimento e nutriente são importantes e devem estar claros para se entender a formulação de dietas. O alimento é um ingrediente da dieta e fornece os vários nutrientes. São alguns exemplos de alimentos: pastagens, fenos, milho, soja, bagaço de soja, trigo. Os nutrientes são os componentes activos dos alimentos e participam no processo bioquímico de formação dos tecidos animais. São exemplos de nutrientes: água, hidratos de carbono, proteínas, aminoácidos, vitaminas e minerais

Dynamics of pastures and fodder crops for Mirandesa cattle breed

Mirandesa cattle are a local breed from the Northeast region of Portugal, playing na important role on the maintenance of the rural spaces, contributing to the fixation of the populations ant to the environmental preservation. The aim of this study is to characterize the feed resources available along the year in this farming system. The animals graze natural pastures in Spring and beginning of Summer, being after fed with hays (of natural pasture or oat) and straws (oat, barley or wheat) and complemented with local feeds like squash or potatoes. Samples of feed were taken from three different farms in two consecutive years and analysed for crude protein (CP), cell wall components, minerals and in vitro organic matter digestibility (OMD). Data were evaluated using ANOVA statistical approach. Seasonal variations were observed in natural pastures with decreases of CP from Spring to Summer (16.0 to 9.4% DM) and increases of NDF content from 32 to 41% DM. Consequently a reduction of OMD from 69 to 58% was observed. Regarding hays composition, differences were observed for CP content which was lower for oat hay, compared with that from natural (2.4 vs. 4.6% DM). Straw quality varied between farms and type of straw

Nutritive value of meadows in the Northeast of Portugal

Meadows continue to be the most important source of pasture and hay for beef cattle production in the hill and upland areas in the NE region of Portugal. The aim of this study was to evaluate CP contents and IVOMD values during the year, in three harvests (spring, hay cut and autumn) under the effect of three rates of N fertilisation in seven mountain meadows. The results showed that the highest CP and IVOMD occurred in the beginning of spring when meadows are in active vegetative growth. Effects of N fertilisation on CP and IVOMD occurred only in oligotrophic meadows, but in an irregular way, and mainly on IVOMD

Determinación de la entrada en pubertad en cabras Serrana nacidas en verano e invierno mediante análisis de progesterona e observación de celos

The aim of this paper was to study the onset of puberty in Serrana - Ecotype Transmontano - female kids born at two different seasons of the year: summer and winter. The present study was performed in Bragança (latitude 41° 49' N, longitude 6° 40' W and altitude 720 meters), at the Agrarian Superior School farm of Sta Apolónia, using nineteen Serrana female kids born in summer and eighteen Serrana female kids born in winter. The puberty process is clearly influenced by the time of birth. Serrana female kids born in winter are more precocious than Serrana female kids born in summer. La entrada en pubertad esta marcada por varios factores como el grado de desarrollo corporal (influenciado por las condiciones alimentares), el fotoperiodo, el genotipo y las interacciones sociales. Según HUNTER (1980) Y TORRANO Y VALDERRABANO (1998), la pubertad depende fundamentalmente de la interacción entre el grado de desarrollo corporal y el fotoperiodo. En las especies estaciónales, la estación de nacimiento condiciona la edad a la que se produce la pubertad (KINDER et al., 1995) dado que es necesario que el grado de desarrollo corporal y el fotoperiodo sean simultáneamente adecuados. Este trabajo fue realizado con el objetivo de estudiar la entrada en pubertad en chatas de la raza portuguesa Serrana, ecotipo Transmontano, nacidas en dos periodos distintos deI ano: verano e invierno

Grazing regimes and fertilisation rates: effects on dry matter yields, crude protein content and digestibility of meadows in the Northeast of Portugal

The aim of this study was to evaluate the effect of two grazing regimes: the usual for the area and late spring grazing, and three rates of N fertilisation, on dry-matter (DM) yields and nutritive value in three mountain meadows (Anthemido-Cynosuretum cristati, Gaudinio-Agrostietum cristati and Bromo-Cynosuretum cristati). The results showed that the lowest DM yield was obtained on Bromo-Cynosuretum cristati meadow. Dry matter yields increased significantly with N fertilisation in all meadows, independent of grazing regimes. The highest nutritive values occurred at the beginning of spring, and decreased during the year as a result of maturation. This effect was favoured by N fertilisation and it was independent of grazing regimes. Nutritive values were sufficient to meet the daily requirements of beef cattle during the study

Characterization of collagen and fatty acid composition of “Carne Mirandesa-PDO” veal

The objective of this study was to evaluate chemical parameters related to meat quality, contributing to a better characterization of “Carne Mirandesa-PDO” veal. This study was made in three farms, from the Northeast region of Portugal (PG, FA1 and FA2), where calves were raised permanently indoors, nurse from their dams overnight, and fed with hay and concentrate made with local ingredients and soybean meal. Twenty five calves were slaughtered at 7 months old. Twenty four hours after slaughter, samples were collected from four different muscles: longissimus dorsi (LD), semimembranosus (SM), gluteus biceps femoris (GB) and triceps brachii caput longum (TBL), vacuum packaged and freeze-dried. Determinations of crude protein (CP), ether extract (EE), collagen and fatty acid were made. Collagen, CP and EE were significantly (p<0.001) affected by muscle type. Fatty acid composition was mostly affected by farm and by muscle type. The SM muscle was poor in saturated fatty acids (14:0, 15:0, 16:0, 17:0 and 18:0) and richer in polyunsaturated fatty acids than the other muscles. The ratio between n-3 and n-6 PUFA observed in this study are close to the usually found for pasture fed animals indicating the healthy value of “Carne-Mirandesa PDO” veal

Prediction of apparent digestibility of hays from natural pastures of the Northeast region of Portugal

In the Northeast region of Portugal hays from natural pastures are traditionally used as the main feed during the period of drought and the evaluation of its nutritive value is essential. The aim of this study was to predict the apparent organic matter digestibility (OMD) of 21 hays from natural pastures based on chemical composition, pepsin-cellulase solubility of organic matter (OMS) and in vitro organic matter digestibility. Chemical composition of hays showed a wide range of values and acid detergent lignin (ADL) was the component that presented the highest variation (CV = 18.4%). The OMD varied between 516 and 658 g/kg OM. The best single OMD predictor was OMS (RSD = 2.8%, R2 = 0.52, P<0.001). Using multiple regression to predict OMD, the variables included in the model were OMS and ADL (OMD = 21.51 + 0.94 OMS – 0.83 ADL; RSD = 2.75%; R2 = 0.54; P<0.0001). According to principal component analysis (PCA) hays were divided in 3 groups and the multiple regression established for the larger group of hays (n=10) was: OMD = 4.13 + 0.85 OMS – 1.03 ADL; RSD = 2.13%, R2 = 0.77, P<0.0001. The OMS method was superior to chemical composition and to the in vitro rumen fluid method in predicting OMD of hays from natural pastures. Results from PCA suggested that it may be useful to group these hays according to its chemical composition to accurately predict OMD

Efeito do regime de aleitamento sobre a duração do período de anestro pós-parto em cabras da raça Serrana – ecótipo Transmontano – paridas no outono

Este trabalho foi desenvolvido com o objectivo de estudar o efeito da aplicação de dois regimes diferentes de aleitamento (amamentação vs. amamentação “nocturna” + ordenha) sobre a duração do período anovulatório pós-parto, em cabras da raça Serrana, ecótipo Transmontano, paridas no final do Outono. A retoma da actividade sexual pós-parto não variou significativamente em função do regime de aleitamento empregue

Anestro post parto en cabras de la Raza autóctona portuguesa Serrana – ecótipo trasmontano – paridas en Otoño

El principal objetivo de este trabajo fue estudiar el anestro post parto en cabras de la raza autóctona portuguesa Serrana, ecótipo Transmontano, paridas a finales de Otoño. En estas cabras, la parición en Noviembre determinó una difícil retoma de la actividad reproductiva y la tentativa de utilización de la primera ovulación post parto tendría seguramente como resultado una bajísima tasa de fertilidad

Dynamics of pastures and fodder crops for Mirandesa cattle breed - II Mineral composition

Mirandesa cattle are a local breed from the Northeast region of Portugal, playing an important role on the maintenance of the rural spaces, contributing to the fixation of the populations and to the environmental preservation. The aim of this study is to characterize the feed resources (mineral composition) available along the year in this farming system. The animals graze natural pastures in Spring and beginning of Summer, being after fed with hays (of natural pasture or oat) and straws (oat, barley or wheat). Samples of feeds were taken from three different farms in two consecutive years and analysed for crude protein (CP), cell wall components, minerals and in vitro organic matter digestibility (OMD). Data were evaluated using ANOVA statistical approach. Results of organic composition of feeds were presented by Galvão et al. (EAAP, 2005). For mineral composition, seasonal variations were observed in natural pastures with decreases of K and P (from Spring to Summer 2 to 0.97 and 0.33 to 0.18% DM, respectively). Farm variations were observed for Ca, K and Mg. Regarding hays composition, differences were observed for Ca and Mg contents which was lower for oat hay, compared with that from natural pasture (0.16 vs 0.32 and 0.08 vs 0.15% DM, respectively). The composition of straws varied between farms and type of straw