GM 13. Neonatal weakness and its sequels in tropical crossbred calves

Abstract

Neonatal morbidity and mortality cause significant economic and genetic losses in cattle. This study analyzed aspects associated with weakness in newborn crossbred calves. They were analyzed in 675 yearling crossbred calves with 9 genotypes of milk and meat races. The calves were evaluated clinically between birth and 24 h. The data were collected from 1990-1994 in a commercial dual-purpose farm in Mene Grande, Zulia State, Venezuela. The effect of sire breed on weakness occurrence and seasonal effects on the occurrence of pathological conditions and weakness were analyzed using Chi-Squares. Analyzed variables were: perinatal clinical condition (PCC) in levels good (G), affected (A) and bad (B); perinatal pathologies (PP) (weakness=W; diarrhea=D, omphalitis=O and blindness=B); and perinatal mortality (PM) Effect of sire breed (SB) on the occurrence of W and season of birth (S) on CCP, PP and occurrence of DB. CCP was distributed in G (78.81 %), A (18.22 %) and B (1.32 %). W (87.87 %) were the greater exponent of PP, followed of D (6.81 %)), O (4.54%) and B (0.75%). PM was 0.43 %. Neonatal weakness was associated (P<.001) with sire breed, but not with season of birth, being Jersey (35.70 %), Holstein (26.10 %), red Brahman (25.60 %), Swiss Brown (18.40 %) and Limousin (16.60 %) the genotypes with greater incidence. And S was not associate with PCC nor a W, but it was associated (P<.05) to the PP incidence. It is concluded that neonatal weakness must be reviewed like the main predisposing of morbidity and mortality and that its relation with genetic factors must be carefully analyzed.