Abstract The aim of this study was to evaluate the influence of two sub-periods of the calving season and two cow maturity stages on the efficiency of beef cows and their calves. A total of 159 cow-calf pairs were divided by calving time (early or late) within the calving season and maturity stage (young or adult). Calves were weaned at 42 or 63 days after birth and evaluated until 210 days of age. Cows and calves had their development examined based on their weight and body condition score at calving, at weaning, and at 210 days. Reproductive performance was evaluated on the basis of time to become pregnant again. Milk yield was assessed by the direct method on three occasions spaced 21 days apart. Adult cows were heavier than young cows, at calving (398.5 vs 327.5 kg, respectively), weaning (397.3 vs 324.1 kg, respectively) at the end breeding season (424.1 vs 342.1 kg, respectively). Reproductive performance was influenced by calving time. Adult cows had higher pregnancy rates (83.75 and 69.17%, for early and for late calving, respectively) than young cows (57.03 and 35.01% for early and for late-calving, respectively). Calves from early-calving young cows weighed 158.8 kg at 210 days of age vs. 123.7 kg for those born from late-calving adult cows. However, late-calving cows produced 10.7% more milk than those that calved early in the season (227.0 vs 205.0 liters, respectively). Early calving associated with non-requirement of growth determine higher productivity efficiency in beef cows.

The electrochemical properties of the one-dimensional coordination polymers [{CuX}2(YNC10H14O)]n (X=Cl: Y=NMe2 1a, Y=NHMe 1b, Y=NH2 1c; X=Br: Y=NH2 2c) and dimers [{Cu(YNC10H14O)}2(μ-X)2] (X=Cl: Y=NMe2 3a; Y=NHMe 3b; X=Br: Y=NMe2 4a; Y=NHMe 4b) were studied by cyclic voltammetry (CV) and controlled potential electrolysis (CPE). All complexes display anodic and cathodic processes. The anodic processes involve the oxidation of the metal site (Cu(I)→Cu(II)), while the cathodic processes are based on the ligand. The substituent (Y) at the camphor hydrazones (YNC10H14O) plays a relevant role in the electrochemical properties and reactivity of Cu(I) coordination polymers and Cu(I) dimmers, as corroborated by CPE.