Influence of predeprivation diet nutrient density and sodium chloride content on nutrient losses and repletion in lambs.

Six crossbred lambs (32+/-2 kg) in a 6 x 6 Latin square design were used to determine the effects of predeprivation diet nutrient density and NaCl content on nutrient losses during periods of feed and water deprivation and nutrient repletion. Treatments consisted of two predeprivation dietary nutrient densities (low [LOW] and moderate [MOD]) and three NaCI intakes (0, 2, or 4 g/d) in a 2 x 3 factorial arrangement. During the 4-d predeprivation phase, lambs fed the M0D diet had greater (P < .05) K retention and lower (P < .01) Na retention than lambs fed the LOW diet. Retention of Na increased linearly (P< .01), whereas retention of K decreased linearly (P < .O01) with increasing NaCl intakes. During the 3-d deprivation phase, lambs fed the MOD diet had lower (P < .01) Na losses than lambs fed the LOW diet. Losses of Na increased linearly (P < .01), whereas losses of K decreased linearly (P < .05) with increasing NaCl intakes. During the predeprivation and deprivation phases, cumulative losses of K were greater (P < .05) and cumulative losses of Na were lower (P < .05) in lambs fed the LOW diet than in lambs fed the MOD diet. Cumulative losses of K increased linearly (P < .05) as predeprivation NaCl intake increased. Predeprivation NaCl intakes did not affect (P > .10) total retention of water, Na, or K for the overall 14-d sampling period. Predeprivation salt intakes affected Na and K losses during a simulated marketing-transport period. However, after 7 d on the realimentation diet, predeprivation diet nutrient density and NaCl intake did not affect the balance of these nutrients.