Effects of infrequent drinking on the nitrogen metabolism of Bedouin goats maintained on different diets

The effect of infrequent drinking on nitrogen metabolism was studied in Bedouin goats, a breed herded in the extreme deserts of the Middle East. The goats were given water either daily or only once every 4 days, while being maintained on roughages of different quality: lucerne hay (19% protein), Rhodes grass (10% protein) or wheat straw (3.7%). On lucerne hay and Rhodes grass the goats kept their body mass constant, whether given water daily or only once every 4 days. When on wheat straw the body mass was maintained constant only when given water once every 4 days. Infrequent drinking was found to hamper considerably the food intake of the goats when fed on high quality roughage. When on the wheat straw, the nitrogen intake of the goats (only 12% of that recorded when fed lucerne hay and given water daily) was, however, not affected by the drinking regime. Infrequent drinking improved nitrogen digestibility on all the diets, but more so on those of low quality than on the lucerne hay. When tested on the low quality feeds, urea excretion was low and urea retention and recycling were maintained at high rates. Infrequent drinking had no adverse effect on these capacities.