Effect of diet energy concentration and of age of Holstein-Friesian bull calves on growth rate, urea space and fat deposition, and ruminal volume

Abstract

Holstein-Friesian bull calves were fed diets of three metabolizable energy concentrations: 11.7, 10.9, and 10.0 MJ/kg of DM, and the same content of CP, 145 g/kg. Two trials were carried out. Initial weights were 195 and 180 kg and final weights were 490 and 600 kg for Trials 1 and 2, respectively. The live weight gains (kg/d) were .93, 1.06, and 1.16 in Trial 1 and .98, 1.11, and 1.16 in Trial 2 on the low-, medium-, and high-energy diet, respectively. In Trial 2, measurements were made of ruminal fluid volume and urea space, which expresses the protein mass in the body. Ruminal fluid volume of young calves was high, exceeding 250 mL/kg live weight. Proportional to live weight, it tends to decrease from the age of 213 d to slaughter. It was higher on the lower-energy diet (P < .01). Rate of fat deposition between 250 and 600 kg body weight did not increase even on the diet with 11.7 MJ/kg, although these calves were fatter (P < .05) at slaughter than those on the low-energy diets. The ratios of depot fats (g of fat/kg of hot carcass) in both trials were close for each energy level, in spite of a 100-kg difference in live weight at slaughter. It was 24.0, 29.8, and 40.7 for calves fed low-, medium-, and high-energy diets, respectively, in Trial 1 and 27.7, 37.1, and 40.4, respectively, in Trial 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of low- and high-forage diets on meat quality and fatty acid composition of Alentejana and Barrosã beef breeds

“…It seems reasonable that the LF scheme could have exacerbated the deposition of IMF to a larger extent in the BA breed than in the AL breed. Indeed, it is known that the level of energy available in the diet influences largely carcass fat deposition in early-maturing breeds (Brosh et al, 1995;Aldai et al, 2006). In agreement, our research group found that BA had a higher level of cod fat expressed as g/kg carcass weight (P , 0.01) and lower slaughter weight than the AL breed (A.S.H.…”

Social Behavior and Productive and Stress Parameters in Holstein Steers Fattened in Three Contrasting Production Systems

“…The same conclusions can be extracted from ADG, as those obtained in this experiment are within the same range in the three treatments. Nevertheless, these ADG are lower than those reported by other authors such as Brosh et al (1995) and Nielsen et al (2004), although they worked with wider ranges of live weight and its difficult to know in which point of the growing curve animals are. Nevertheless the feed conversion is one of the most economic traits and in this sense, feed efficiency rate was worse in T2.…”

Developmental changes in clearance of intravenous doses of glucose, acetate and β-hydroxybutyrate from plasma of calves

“…Volumes of BHB distribution according to the best fitting model, 1 pool from 3 min onwards, averaged 0.63 L/kg (Table 5), which is close to the total water content of a calf. Urea distribution space ranged from 0.46 to 0.59 L/kg in calves (Brosh et al, 1995), while acetate space tanged from 0.35 to 0.56 L/kg in lambs (Cronjé et al, 1991) and from 0.13 to 0.53 L/kg in dogs (Pouteau et al, 1998). β-Hydroxybutyrate might be expected to exhibit a similar volume to acetate into which it distributes, so an average of 0.63 L/kg appears too high.…”