Blood metabolites and their relationship with production variables in dual-purpose cows in Venezuela

Effect of a feed supplementation during the mid-lactating period on body condition, milk yield, metabolic profile and pregnancy rate of grazing dual-purpose cows in the Mexican humid tropic

“…Comparison with optimum values, the degree of variation from them and comparisons between groups within herds have provided information about nutritional constraints on productivity (Whitaker et al 1999). In our study, serum albumin concentration was comparable to those obtained in previous studies in dairy cows (31 ± 4.4 and 34 ± 3.3 g/L, Contreras et al 1996, 28.7 ± 0.5 g/L, Rajora et al 1997) and dual-purpose (29.8 ± 0.6 to 36.8 ± 6 g/L, Corro et al 1999, 33.6 ± 4.4 g/L, Parra et al 1999). However, albumin concentration was lower in the rainy season.…”

“…The higher concentrations of serum copper and zinc in the rainy season might indicate an effect of the rain on the soil composition and consequently in the forage mineral content, although this was not analyzed in our study. Serum inorganic phosphorus level was not different by FS or SY; however, it was comparable to some reports in dairy cows (1.51 ± 0.4 and 1.55 ± 0.4 mmol/L, Contreras et al 1996, 1.56 ± 0.03 mmol/L, Rajora et al 1997), and was lower than the values reported in other studies in dual-purpose cows (1.99 ± 0.3 mmol/L, Parra et al 1999). Blood metabolite levels are influenced by nutritional status of the animal, feed intake and nutrients requirements, which fluctuate largely throughout the parturition and lactation periods (Sato et al 1999).…”

“…ships were not proven. Milk yield was comparable to that obtained by Romero (1999) in dual-purpose cows in the dry (4.45 kg/cow/day) and rainy (4.25 kg/cow/day) seasons, but was lower than other reports in dual-purpose cows receiving FS, such as 5.0 ± 1.5 kg/cow/day (Corro et al 1999), and 6.5 kg/cow/day (Parra et al 1999). In dual-purpose cows, greater milk production was obtained in the rainy season McDowell 1984, Corro et al 1999), contrary to the results of our study.…”

“…As with BCS and milk yield, this might have been because of a reduced feed intake as a consequence of the FS. Serum urea concentration was lower than some reports in dairy (5.31 ± 1.48 and 5.39 ± 1.83 mmol/L, Contreras et al 1996) and dual-purpose (5.4 ± 1.5 to 7.9 ± 0.4 mmol/L, Corro et al 1999; 5.4 ± 1.6 mmol/L, Parra et al 1999) cows. Urea concentration was higher at the end of the FS period in both groups, with and without FS, which might indicate no effect of FS.…”

Indicators of the Internal Environment of Beef Cattle during Fattening and their Correlation to the Quality of Beef

“…If we are to create optimal conditions that would correspond to the current requirements of individual animals, we must draw as much information as possible about the internal environment, which reflects these effects and, above all, indicates the level of nutrient, mineral and vitamin supply required, which at the same time shows the functional condition of the animal. Changes in haematological and biochemical blood indicators of various cattle categories are well known (Dubreuil and Lapierre 1997;Parra et al 1999;Whitaker et al 1999;Knowles et al 2000;Jorritsma et al 2003;Kumar and Pachauri 2000;Accorsi et al 2005;Cavestany et al 2005;Fontaneli et al 2005). However, the authors mostly focus on evaluations of the internal environment of dairy cattle breeds, or some categories of cattle intended for fattening.…”