Procjena tjelesne kondicije, dnevne proizvodnje mlijeka i nekih biokemijskih parametara tijekom puerperija prema sezoni teljenja u montbeliard pasmine mliječnih krava uzgojenih u polusušnom području - Alžir

The aim of this study was to evaluate the effect of calving season on postpartum changes of certain blood metabolites and minerals and of the body condition score evaluation (BCS) in Montbeliard dairy cows reared under semi-arid conditions. Blood samples were collected from 74 clinically healthy dairy cows of 10 semi-intensive Algerian dairy herds once month during a whole year. Animals were grouped according to the occurrence of their calving to four different seasons (autumn, winter, spring and summer). Albumin, urea, glucose, total cholesterol, calcium, phosphorus and magnesium plasma levels were analysed using the colorometric method adapted to each biochemical parameter. One-way repeated measures analysis of variance (ANOVA) showed a significant effect of season (P<0.05, P<0.01 and at P<0.001) on all parameters, except BCS. The highest plasma concentrations of urea nitrogen, albumin, total cholesterol, and phosphorus were recorded in summer, though calcium was significantly lower during this period. A significant negative correlation was found between blood glucose, total cholesterol and phosphorus during winter calving, urea nitrogen in spring calving, and magnesium and calcium in summer calving. The results of this study highlight the evolutionary pattern of blood biochemical metabolites and electrolytes, BCS and daily milk production of Montbeliard dairy cows during the postpartum period according to calving season. They provide reliable information to assess the risk of metabolic activity failures during these very important productive stages, i.e., open days, ascending and peak production periods.Cilj je ove studije bio procijeniti učinak sezone teljenja na promjene nekih metabolita i minerala u krvi nakon teljenja, kao i na tjelesnu kondiciju (BCS) u montbeliard mliječnih krava uzgojenih u polusušnim uvjetima. Kednom mjesečno tijekom cijele godine prikupljeni su uzorci krvi od 74 klinički zdravih krava 10 poluintenzivnih alžirskih mliječnih krda. Životinje su prema teljenju raspoređene na sva četiri godišnja doba, tj. jesen, zima, proljeće i ljeto. Analizirane su: razine albumina, uree, glukoze, ukupnog kolesterola, kalcija, fosfora i magnezija u plazmi uporabom kolorimetrijske metode prilagođene svakom biokemijskom parametru. Jednosmjerna analiza varijance ponovljenih mjerenja (ANOVA) pokazala je značajan učinak sezone (P<0,05, P<0,01 te P