| Popis: |
In two trials, pigs were given lucerne juice (LJ) as the only protein supplement from 20–90 kg liveweight. The effects of reducing the mineral supplementation of the meal given with LJ and of increasing water intake were studied. In Trial 1, a total of 45 pigs were given either control diets with 7% white-fish meal to 54 kg liveweight and 3.5% thereafter, or diets in which the fish meal provided by the control diets was replaced with LJ. The meal mixture given with LJ was either supplemented or unsupplemented with limestone flour, dicalcium phosphate and salt. In the former case, as in previous studies, the Ca, P and Na content of LJ was not taken into account in formulating the meal mixture; in the latter treatment, taking these into account eliminated the need for supplements. In Trial 2, 18 pigs received LJ at a similar level to that given in Trial 1, together with a meal mixture without the mineral supplements. The water intake of half the pigs was restricted to 2.5 l/kg meal, including the water in LJ. The remaining pigs had, in addition, a supply of water ad libitum. The pigs given LJ in Trial 1 had much lower growth rates and feed: gain ratios than the controls given white-fish meal. A significant, but relatively small, improvement in performance was achieved by giving LJ with the unsupplemented meal rather than with meal supplemented with minerals. In Trial 2, supplying additional water ad libitum significantly increased feed intake. There was a tendency for this to increase daily gain, although the difference was not significant. Despite the improvements due to adjustments of mineral and water intake, the performance of the pigs given LJ as the only protein supplement was unsatisfactory. This may be due to the very high level of potassium in LJ. This cannot be taken into account in formulating a practical basal meal mixture. |
