Erythrocytometry and seric proteinogram of umbilical cord and jugular of foals at birth and respective mothers

Colheram-se amostras de sangue do cordão umbilical (SCU) e do sangue circulante de cinco eqüinos neonatos, imediatamente após o nascimento, e o sangue da própria mãe, utilizando-se um sistema a vácuo. O material foi submetido à contagem global de hemácias e leucócitos e à determinação do volume globular e da concentração de hemoglobina; à contagem diferencial de leucócitos em esfregaços sangüíneos; e ao cálculo dos índices eritrocitométricos. Foram realizadas a dosagem de proteínas séricas totais e a eletroforese das proteínas séricas em gel de agarose. Não houve diferenças significativas entre os parâmetros do SCU e do sangue da jugular dos potros. No SCU dos potros observaram-se valores mais elevados para contagem global de hemácias (9,75x106/µl), dosagem de hemoglobina (14,65g/dl) e concentração de hemoglobina corpuscular média (37,23g/dl); e valores menores para volume corpuscular médio (40,50fl), proteína total (4,37g/dl), a-globulinas (0,65g/dl), b-globulinas (1,10g/dl), g-globulinas (0g/dl) e contagens global (5,40 x 103/µl) e diferencial de leucócitos, exceto contagem de neutrófilos bastonetes e monócitos, quando comparados com os valores obtidos no sangue de suas mães. _________________________________________________________________________________________________________ ABSTRACTUmbilical cord blood (UCB) and systemic blood samples were collected from five equine neonates, immediately after birth. Systemic blood samples from their mothers were also collected at the same time, using a vacuum system. The samples were submitted to the following analyses: red blood cell and total white blood cell counts; determinations of packed cell volume and hemoglobin concentration; differential white cell count in blood smears; and determination of erythrocytometric values. Total serum proteins quantification and serum proteins electrophoresis in agarose gel were done. No significant difference (P<0.05) was noted between averages in neonate jugular blood and equine UCB. Equine UCB showed higher values of red blood cell count (9.75x106/µ), hemoglobin determination (14.65g/dl), and mean corpuscular hemoglobin concentration (37.23g/dl); but lower values of mean corpuscular volume (40.50fl), total protein (4.37g/dl), a-globulin (0.65 g/dl), b-globulin (1.10g/dl), g-globulin (0g/dl), total (5.40x103/µl), and differential leukocytes count, except for band neutrophils and monocytes counts, when compared to the blood of the mares

Estimates of genetic parameters and evaluation of genotype x environment interaction for weaning weight in Nellore cattle

Records of 105,645 Nellore calves born from 1977 to 1994 in eight different regions of Brazil were used to estimate genetic and environmental parameters and evaluate genotype x environmental interaction for weaning weight (kg). Estimates were obtained using MTDFREML with a sire model. Mathematical model included random effects of sire and dam, and fixed effects of sex, month and year of birth, herd, and age of dam at calving. Estimates of phenotypic variances were 375, 431, 431, 407, 409, 400, 413, and 336 for the eight different regions and 420 over all regions. Estimates of heritability were, respectively, 0.22, 0.26, 0.16, 0.29, 0.34, 0.38, 0.37, 0.26, and 0.26. Heritability estimates for weaning weights from two trait analyses with measurements in different regions considered as different traits varied from 0.17 to 0.38 and estimated genetic correlations among weaning weights in different regions varied from - 0.03 to 1.00. Spearman rank correlations between EPDs for weaning weight from different regions were calculated to verify whether sires ranked differently in different regions. The correlations ranged from - 0.25 to 1.00 between pairs of regions. Estimates of heritability suggest that mass selection could result in genetic gain under a breeding program that utilizes weaning weight as a selection criterion. The apparent importance of genotype x environment interaction detected by this study suggests a need to choose sires appropriate for the region where they will be used, since relative performance of progeny of a sire appears to change from one region to another