DAILY MILK INTAKE AND BODY-WATER TURNOVER IN SUCKLING MINK (MUSTELA-VISON) KITS

Daily (24 h) milk intake and body water turnover were measured in eigh t litters of suckling mink (Mustela vison) kits (6-9 kits litter(-1)) during weeks 1-4 post partum using the tritiated water ((HHO)-H-3) dil ution technique. The biological half-life of body water turnover in th e mink kits increased linearly from 0.9 days in week 1 (3-5 days post partum) to 1.9 days in week 4 (22-24 days post partum). The daily milk intake varied markedly among the mink kits within a litter and increa sed significantly with increasing body mass from (mean +/- SEM) 10.9 /- 0.4 g per kit during week 1 to 27.7 +/- 1.0 g per kit during week 4 . Throughout the study, male kits were similar to 10% heavier and had a significantly higher milk intake than female kits. The results were corrected for water recycling between the dam and her kits, ranging fr om similar to 4 to 15% of the daily milk water intake, and the calcula ted daily milk yield of the 2 year old lactating mink dams increased f rom 87 +/- 7 g day(-1) in week 1 to 190 +/- 15 g day(-1) in week 4 pos t partum. The average body growth rate of the mink kits ranged from 2. 9 g kit(-1) per day in week 1 to 5.4 g kit(-1) per day in week 4, and the calculated mean intake of mink milk per unit of body weight gain w as remarkably stable at 4.0 (g g(-1)) during weeks 1-3 post partum, bu t increased to 5.6 (g g(-1)) in week 4 post partum. The amount of meta bolizable energy supplied to the kits by the daily milk yield of the d am increased from approximate to 450 to approximate to 990 kJ day(-1) which corresponded well with the calculated daily energy requirements ai. the kits. The tritiated water dilution technique was found feasibl e and reliable for repeated measurements of milk intake in suckling mi nk kits up to 4 weeks of age. (C) 1998 Elsevier Science Inc. All right s reserved.