[Influence of vitamin B 6 deficiency in early weaned piglets on the digestibility and conversion of protein and energy].
Early-weaned piglets were subjected during 2 metabolic periods (11th-18th and 32nd-39th days of the experiment) to conversion experiments to study the influence of vitamin B6 depletion on the digestibility of the crude nutrients, metabolizable energy and on nitrogen conversion using the difference procedure. The depleted piglets (0.4 mg vitamin B6/kh diet) and the pair-fed control animals raised under equal conditions (6.5 mg vitamin B6/kh diet) were first fed a pre-starter ration, and from the 24th experimental day, a starter feed. As the period of depletion increased, the vitamin B6 sub-provided piglets revealed deficiency symptoms such as reduced appetite, lethargic behaviour and less movement. Whilst in the first half of the experiment the control animals reached significantly higher weight gains at lower expenditure of dry matter and digestible energy per kg of weight gain, no differences were observed between both groups in the second period. On the other hand, during the 1st metabolic period the digestibility of all crude nutrients and energy in the depleted piglets proved slightly, but significantly higher than in the pair-fed control animals. In the second half of the experiment ther were just casual differences. After a 2-week vitamin B6 deficient nutrition, the piglets had a 4.1% lower nitrogen retention as compared with the pair-fed control. After a depletion period of 5 weeks, this difference reached 14.4%. As nitrogen excretion in the urine increased, a higher renal energy excretion was observed. Thus the vitamin B6 deficient animals had available less metabolizable energy (in % of digestible energy) than the control piglets.