Emma Serrano

Effect of tannic acid on rumen degradation and intestinal digestion of treated soya bean meals in sheep

The current experiment was conducted to study the effect of different doses of tannic acid, a hydrolysable tannin, on ruminal degradation and post-ruminal digestion of treated soya bean meals (SBM) in sheep. Samples of SBM were prepared by spraying 100 g SBM with 100 ml distilled water containing 0, 1, 5, 10, 15 or 25 g of commercial tannic acid (So, S TA1 , S TA2 , S TA3 , S TA4 and S TA5 , respectively). Three ruminally cannulated ewes, that had never consumed tannic acid previously, were used to determine in situ degradability of tannic acid-treated SBM. Intestinal digestibility of protein remaining after 16 h rumen incubation was estimated in vitro. Extent of rumen degradation of SBMs was significantly (P < 0.05) affected by the tannic acid treatment. All doses of tannic acid used in this experiment, even the lowest one (S TA1 ), significantly decreased the extent of N degradation but only doses higher than that used to treat S TA3 reduced the extent of DM degradation. This reduction in the extent of DM and N degradation was mainly due to a marked decrease in the immediately degradable fraction (a), which was observed in all treated SBM, and to a lower rate of degradation (c), observed in meals S TA3 , S TA4 and S TA5 , Intestinal digestion of the non-degraded protein was decreased (P < 0.05) by treatment with the two highest doses of tannic acid (those used to treat meals S TA4 and S TA5 ). It was therefore concluded that tannic acid can exert a negative effect both on rumen degradation and on intestinal digestion of SBM, this effect being clearly dependent on the dose used to treat the SBM.

Effects of feeding strategy during a short finishing period on performance, carcass and meat quality in previously-grazed young bulls

Twenty-one Brown Swiss×Limousin young bulls reared on pasture were housed for a short finishing period (60 days). CA group (concentrate-ad libitum group) received concentrate and straw ad libitum for the whole finishing period. CR group (concentrate-restricted group) received 4kg of concentrate/animal per day and ad libitum alfalfa hay throughout the 60days. CRA group (concentrate-restricted/ad libitum group) received the same diet as CR group for the first 30days and the same diet as CA group for the last 30days. CA and CRA groups presented higher fatness values. Myoglobin concentration in muscle was highest in CA group (P<0.05) and carotene content in subcutaneous fat was highest in CR group (P<0.01), while Warner-Bratzler shear force and sensory traits were unaffected (P>0.05). It is concluded that, in this type of young animal, 4kg concentrate plus ad libitum alfalfa hay for a 60-day finishing period, despite lower fatness, provides carcasses and meat with acceptable quality characteristics, similar to those obtained from ad libitum fed animals for the same period.

Censos de ganado y de explotaciones, distribución de la población y uso del territorio en la provincia de León: situación actual y evolución

En este trabajo se estudia la distribucion actual y la evolucion, en las dos ultimas decadas, del uso del territorio, de los censos de ganado y explotaciones y de la poblacion, en las diez comarcas que componen la provincia de Leon. La evolucion reciente del uso del territorio revela una disminucion en las tierras de cultivo y un incremento del territorio catalogado como otras superficies. En las dos ultimas decadas se han incrementado los censos de ganado y ha disminuido el numero de explotaciones. En la evolucion de los censos ganaderos, ha sido especialmente llamativa la disminucion en el censo de ganado vacuno de leche y el incremento en el censo de ganado vacuno de carne. En la decada de los 80, la poblacion disminuyo en todas las comarcas de la provincia de Leon, salvo en la de Tierras de Leon. En la decada de los 90, la perdida de poblacion afecto incluso a esta comarca.