Autochthonous Sarda pigs are usually bred in mountainous areas of Sardinia where they use mainly feeding resources in shrublands and forests. The aim of the study was to evaluate the effect of different feeding systems on some performances of Sarda pigs. Twelve, castrated male pigs, homogeneous for body weight (98.4±13.8 kg) and age (15 months) were randomly assigned to the following three feeding systems: A, reared en plein-air system in the woods and fed ad libitum with a commercial concentrate; B, reared en plein-air in the woods and fed with ground barley (1.8 kg/head/day), with an automatic feeder; C, fed at pasture in the woods and receiving 500 g/head/day of barley grain. Morphological measures and weight were recorded fortnightly until slaughtering (22 months of age). Preliminary results showed differences between feeding systems, with best performance in group A: weight and fat thickness were higher (294 kg and 84.5 mm respectively) than group B (170.7 kg and 29.7 mm) and group C (202.0 kg and 39.7 mm). Therefore extensive feeding systems is a right compromise between good performances and farming profit.

Article available on line / Article disponible en ligne à l’adresse : -------------------------------------------------------------------------------------------------------------------------------------------------------------------------http://om.ciheam.org/article.php?IDPDF=800367 --------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Milk samples with low (<500,000/ml), medium (500,000-1,000,000/ml) and high (1,000,000-2,000,000/ml) Somatic Cell Counts (SCC) were obtained from a flock of 120 Sarda breed ewes. Milk was analysed for chemical composition and rheological properties (Formagraph), and used for a laboratory scale cheesemaking. The milk of the three groups showed differences (P<0.01) in pH, lactose, whey protein and total Na content. Soluble casein, casein to protein ratio, soluble Ca and total K content were significantly different at P<0.05. Rennet clotting time (R), rate of curd firming (K 20 ) and curd firmness (A 2R ), in milk with nonstandardised pH value, were significantly different (P<0.01). Protein recovery rate was higher in cheese from low SCC milk (P<0.01), while adjusted cheese yield did not show significant differences. Protein losses in whey were greater (P<0.05) when medium or high SCC milk was processed. Neither 1 d-old nor fully ripened cheeses showed significant differences in chemical composition or rheological characteristics.

Los resultados obtenidos hasta ahora demuestran que existe una relacion directa entre el contenido de las celulas somaticas y la composicion de la leche de oveja. En particular, se puede senalar una estrecha relacion entre el RCS, el valor del pH y el contenido de proteina soluble de la leche, ademas de con algunos elementos minerales. Tambien la evolucion de la coagulacion por cuajo resulta diferente dependiendo del contenido en celulas somaticas, su aumento implica notables atrasos en la coagulacion e importantes dificultades en la estructura del coagulo y, por lo tanto, una prolongacion en el tiempo de transformacion de la leche. Todo esto puede ser mejorado estandarizando el pH de la leche en valores de 6,5-6,6, como demuestran los resultados obtenidos. Los datos relativos a la composicion de los quesos no muestran diferencias significativas, tan solo una tendencia a obtener quesos con mayor cantidad de agua y con menos grasa cuando la leche de elaboracion presenta un elevado contenido en celulas somaticas. Tampoco la evolucion de la proteolisis secundaria ha estado afectada por el contenido en celulas somaticas de la leche transformada. Como consecuencia, las caracteristicas reologicas de estos quesos han resultado practicamente identicas. Parece, por lo tanto, segun los resultados obtenidos, que el contenido en celulas somaticas de la leche no influye de manera significativa en las caracteristicas cualitativas del producto final.

The effects of sheep alpha s1-casein CC, CD and DD genotypes on milk composition and cheese yield were studied. Processed bulk milk was collected from three groups of 15 ewes, carrying alpha s1-casein CC, CD and DD genotypes. CC milk was higher in casein content than CD or DD milk (+3.5 and +8.6% respectively), and had a higher protein: fat ratio and a smaller casein micelle diameter. In addition, DD milk had a significantly lower alpha s1-casein content. The main differences were in curd formation: CC milk had better renneting properties. Cheesemaking trials, carried out in a pilot plant, showed that CC milk had better cheesemaking characteristics than DD milk, while CD milk was intermediate. Both 1 d old and fully ripened cheeses had different fat: dry matter ratios and alpha s1-I-casein electrophoretic mobilities: these were lower for DD cheese. As a consequence, these genotypes could be considered as markers of milk and/or cheese quality.

SUMMARY - A survey was carried out on three Sarda goat herds (A, B and C) during the milking period, with the aim to investigate the effect of different feeding systems on milk composition, with particular emphasis to fatty acid (FA) and volatile compound contents. Herd A was stall-fed with hay and concentrate whereas herds B and C were fed at pasture, with woody and herbaceous species in B and only herbaceous species in C. Milk yield and composition including FA and volatile compounds, as well as feeding behaviour were measured monthly. Individual milk yield and composition were different in the three herds (P<0.05), as well as the bulk milk FA composition, particularly the long chain fatty acids (C17:0-C18:3). The levels of CLA (C18:2 c-9, t-11) and vaccenic acid (C18:1 t-11) were higher in B (11.10±0.9 and 23.01±1.9 g/kg of fat respectively; P<0.05) as compared to the other herds. When pooling all data, a relationship was found between CLA and vaccenic acid (Y=0.38X+1.90, R2=0.79, P<0.05). The profile of total volatile compounds in the bulk milk of the three herds was