ContentsA study was designed to determine pelvic-size parameters, age and weight at puberty, growth rates, and the interrelationships between all these parameters in dairy heifers. A total of 108 dairy heifers from five dairy herds (two Jersey herds with 40, two Friesian herds with 49, and one Illawarra herd with 19 heifers), which were born at different times of the year, were used. Pelvic height and width were measured with a Rice pelvimeter and pelvic area was calculated. The ratio of pelvic area to wither height and the daily increase in pelvic area were also calculated. Plasma progesterone concentrations in all heifers were estimated from 210 days of age until the onset of puberty. The percentage gain in body weight from birth to 15 months of age was recorded. Pelvic parameters, age, weight at puberty, and growth rates were different (p < 0.05) between herds and breeds. Pelvic height and width increased (p < 0.05) with advancing age in all herds, with the smallest increases observed in the Jersey herds and the largest in the Friesian herds. There was a linear rate of increase in pelvic area from 12 to 18 months of age in all herds except one Jersey herd. Heifers in the Illawarra herd tended to have the same pelvic area as Friesians but the same rate of increase in pelvic area as the Jerseys. Significant (p < 0.05) positive correlations were found between pelvic height, area and the ratio of pelvic area to height at 12 and 15 months of age and percentage gain in body weight at 15 months in Jersey herds; significant (p<0.05) negative correlations with age at puberty were also found with these pelvic parameters in the Jersey herds. When the data were pooled, there were positive correlations (p < 0.01) between pelvic parameters and body weight at puberty, which indicates that pelvic measurements are predictable in some breeds on the basis of body weight. The effects of percentage gain in body weight and age and weight at puberty on pelvic measurements were found to be significant (p < 0.05). It was concluded that the predictability of pelvic parameters varied between breeds. InhaltBeziehungen zwischen BeckenmaRen, Wachstumsrate und Pubertat bei jungen Milchkuhen In einer Studie wurden die Beziehungen zwischen Becken-maBen, Wachstumsrate und Pubertat bei jungen Milchkuhen analysiert. Es wurden 108 Farsen in fiinf Milchkuhherden (zwei Jersey-Herden rnit 40 Tieren, zwei Holstein-Friesian Herden rnit 49 Farsen und eine Illawarra-Herde rnit 19 Farsen) in die Untersuchungen einbezogen. Die Farsen wurden zu unterschiedlichen Jahreszeiten geboren. Mit einem Rice-Pelvimeter wurden Hohe und Breite des Becken gemessen und hieraus der Beckendurchmesser berechnet. Zusatzlich wurden die taglichen Zunahmen dieser MeBgroBen registriert. Plasma-Progesteron-Konzentrationen aller Farsen wurden ab Tag 210 nach der Geburt bis zum Erreichen der Pubertat bestimmt. Die prozentualen Korperzunahmeraten wurden vom Geburtszeitpunkt bis zum 15. Lebensmonat aufgezeichnet. Die Ergebnisse der Beckenmessungen, Alter, Gewicht zum Zeitpunkt der P...

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A study was made of the effects of exogenous adrenocorticotropin (ACTH) on the levels of blood components in 109 dairy replacement calves and the statistical correlations between these effects and the growth rates of the calves from birth to six months. Blood samples were taken from a jugular vein before ACTH was injected and then at two, four, six and eight hours afterwards, and analysed for plasma cortisol concentration, total white cell counts, packed cell volume, haemoglobin, plasma glucose, sodium, potassium, magnesium and inorganic phosphorus, erythrocyte sodium, potassium and magnesium, serum ionised calcium and total protein and total plasma calcium concentration. The injection of 1.1 +/- 0.02 iu/kg of ACTH intramuscularly resulted in a peak plasma cortisol concentration after two hours which had not returned to normal after eight hours. It also resulted in leucocytosis, lymphopenia, neutrophilia, eosinopenia and hypophosphataemia; the mean changes were repeatable (P < 0.05) in 49 of the calves tested two months later. The weight gains to six months of age could be predicted from the degree of the changes in several blood constituents. Significant partial regression coefficients were found for the change in glucose concentration (0 to four hours), absolute neutrophil count (0 to two hours), absolute lymphocyte count (0 to four hours) and loge absolute eosinophil count (0 to two hours). The multiple regression sum of squares was highly significant (P < 0.0001), and the multiple coefficient of determination was 0.305. It was concluded that the changes in these blood components after an injection of ACTH might be used to predict the weight gains of dairy replacement calves.