STUDIES ON THE PERFORMANCE, DEVELOPMENT AND CARCASS COMPOSITION OF THE GROWING PIG: EFFECTS OF SEX, FEEDING REGIME AND AGE ON BLOOD SERUM PARAMETERS

Abstract

Blood samples from 120 pigs serially slaughtered at five age groups, starting at 85 days of age with intervals of 2 wk, were used to study the effects of sex, feeding regime and age on a 12 component metabolic blood serum profile. The differences between barrows and gilts were small and only significant (P < 0.05) for blood urea. Pigs fed ad libitum had a significantly (P < 0.05) higher level of blood urea, calcium, inorganic phosphorus and alkaline phosphatase but a significantly (P < 0.01) lower level of creatinine than restricted fed pigs. Age had the most pronounced effects on the serum parameters studied, with blood urea, calcium, bilirubin, creatinine, total serum protein and albumin showing a significant (P < 0.01) increase per unit of serum with increasing age. The serum glucose, inorganic phosphorus, glutamic oxaloacetic transaminase and lactate dehydrogenase were also significantly (P < 0.01, P < 0.05 for glucose) influenced by age but did not show a consistent trend across the age groups. Serum alkaline phosphatase was the only component which significantly (P < 0.01) decreased with age. The results indicate that when these serum components are to be used for diagnostic or comparison purposes, age adjustment must be applied. Key words: Blood parameters, pigs, age, feeding regime, sex