An evaluation of the performance of weaner pigs fed diets incorporating fresh sweet liquid whey

Three hundred and eighty-five pigs from 77 litters weaned at 5 weeks of age were used to evaluate the consumption and nutritive value of fresh sweet liquid whey over a 4 week period. The diets were: control weaner diet, fed dry (T1); weaner diet + water, fed as a slurry mixed at a ratio of 1:1 (T2); weaner diet + fresh whey, fed as a slurry mixed at a ratio of 1:1 (T3); weaner diet + fresh whey, fed as a slurry mixed at a ratio of 1:2 (T4); weaner diet + fresh whey, fed separately (T5). The pigs were fed to appetite at least five times a day. Treatments were replicated eight times, weekly, in groups of nine or ten pigs per treatment. Feeding slurry diets improved weaner diet intake by 3.8% in T2, 6.8% in T3 and 3.4% in T4 when compared with the dry meal control (T1). Feeding liquid whey ad libitum separately resulted in highest whey intake and reduced weaner diet consumption by 10.2%. Incidence of severe frothy diarrhoea during the first week after weaning was higher (P < 0.01) in pigs fed slurry diets or fresh whey separately (9–14%) than in those fed the control dry meal (5%). The proportion of pigs with severe diarrhoea decreased as the pigs grew older and diarrhoea had no adverse effects on pig performance. Daily liveweight gains were higher in whey supplemented treatments than in control treatments (T1 and T2) during the first and second week postweaning (P < 0.01), but did not differ during the third and fourth week after weaning. Weekly liveweights of pigs were higher with whey supplemented diets than of controls throughout the experimental period (P < 0.01). The liveweight advantage gained from whey supplementation persisted during the postexperimental period up to 12 weeks postweaning (P < 0.05). It is concluded that liquid fresh whey can be fed restricted or ad libitum to weaner pigs resulting in improved performance and with no risk of detrimental diarrhoea.