Nutrient supplementation of beef female calves at pre-weaning enhances the commitment of fibro-adipogenic progenitor cells to preadipocytes

We aimed to evaluate the impact of nutrient supplementation of beef female calves at pre-weaning on adipogenic determination. Thirty-four female calves were assigned to two experimental treatments: Control (CON, n = 17), where animals were supplemented only with mineral mixture; Supplemented (SUP, n = 17), where animals received energy-protein supplement containing minerals (5 g/kg of BW per day) of their body weight. Animals were supplemented from 100 to 250 days of age, and muscle samples were biopsied at the end of the supplementation period. Regarding the performance variables, there were no differences between treatments for initial body weight (P = 0.75). The final body weight (P = 0.07), average daily gain (P = 0.07), rib eye area (P = 0.03), and rib fat thickness (P = 0.08) were greater in SUP female calves compared with CON treatment. The number of fibro-adipogenic progenitor cells (P = 0.69) did not differ between treatments, while a greater number of intramuscular pre-adipocytes were observed in SUP than CON female calves (P = 0.01). The expression of miRNA-4429 (P = 0.20) did not differ between treatments, while the expression of miRNA-129-5p (P = 0.09) and miRNA-129-2-3p (P = 0.05) was greater in CON than SUP female calves. Our results suggest that nutrient supplementation at early postnatal stages of development enhances the commitment of fibro-adipogenic progenitor cells into the adipogenic lineages allowing to an increase in intramuscular fat deposition potential of the animals later in life.

Protein dietary efficiency and methane emission in cattle fed soybean meal treated with tannins

Adding tannins to the dietary protein source will cause complexation between the tannin and protein, which may increase dietary ruminal undegraded protein. Thus, this study aimed to evaluate the effects of replacing soybean meal (SM) with soybean meal treated with tannin (SMT) on the intake, partial and total nutrient digestibility, and protein dietary efficiency of young cattle fed a high-concentrate diet. Five Nellore bulls with bodyweights of 290 ± 11.2 kg were fitted with ruminal and abomasal cannulas and were used in the study. The experimental diets included 7.5% SM, with a proportion of that SM (0%, 33%, 66% or 100%) replaced with SMT. Another treatment (SMT+urea) with only 2.5% SM treated with tannins was tested. The intake of ether extract and the intake of neutral detergent fibre ash and protein were the only parameters related to feed intake that were affected by the replacement of SM with SMT. Ruminal and intestinal digestibility each showed a linear effect on crude protein, which decreased with ruminal digestibility and increased with intestinal digestibility. The intake of ruminal undegraded protein and metabolisable protein showed a positive linear correlation with the amount of SMT in the diet. SMT substitution showed no effect on methane emission. The replacement of traditional SM with SM treated with 2.5% tannins (85% condensed tannins and 15% hydrolysable tannins) for cattle that were fed high-concentrate diets showed increased amounts of metabolisable protein and decreased nitrogen loss per unit of crude protein, without changing the methane emission.

Performance of beef Guzerat and Guzerat-cross bulls during the feedlot, and carcass traits of Guzerat-cross groups

Two experiments were conducted to evaluate performance and carcass traits of Guzerat-based beef bulls. In experiment 1, Guzerat; F1 Guzerat × Holstein (‘Guzholstein’); F1 Guzerat × Nellore (‘Guzonell’); and 1/2 Simmental + 1/4 Guzerat + 1/4 Nellore (Three-Cross) bulls (n = 12 each group) were kept in a feedlot for 84 days, receiving sorghum silage and concentrate supplement. ‘Guzholstein’ bulls had greater average daily gain (ADG; 1.7 kg/day) compared with ‘Guzonell’ (1.4 kg/day), but similar to Three-Cross and Guzerat (1.6 and 1.5 kg/day respectively). ‘Guzonell’ bulls gained less bodyweight (BW; 85.8 kg); however, the gain : feed ratio did not differ among groups. Dry matter intake (DMI) was less for Guzerat (11.8 kg) compared with other groups (12.4, 12.4, and 12.6 kg for ‘Guzholstein’, ‘Guzonell’, and Three-Cross respectively); DMI, as a percentage of BW, was lesser for Three-Cross bulls (2.5%) compared with other groups (2.7%, 2.8%, and 2.6% for Guzerat, ‘Guzholstein’, and ‘Guzonell’ respectively). In experiment 2, 18 bulls from experiment 1 were randomly selected from ‘Guzonell’, ‘Guzholstein’ and Three-Cross groups (n = 6, each breed group), transferred to a state-inspected slaughterhouse, and humanely slaughtered. Three-Cross bulls had greater carcass weight gain (80 kg), greater striploin yield (2.39%), and lesser leg yield (1.86%). ‘Guzholstein’ bulls had lesser dressing-out percentage and greater liver yield (51.6 and 1.28% respectively), whereas ‘Guzonell’ bulls had greater rump yield (1.47%). Forequarter yield, hindquarter weight and yield, eye round, flank steak, rump skirt, topside, rump cap, head, heart, lungs and trachea, spleen, tail, and tongue yield did not differ among groups. Despite the limited number of animals used in these experiments, we can conclude that all breed groups have potential for meat production because carcass traits meet the Brazilian beef industry standards, and ‘Guzholstein’ bulls could be an option for producers to diversify revenues.

Effects of pregnancy and feeding level on carcass and meat quality traits of Nellore cows

Carcass and meat quality traits of 16 pregnant and 5 non-pregnant cows fed at 1.2 times maintenance and 16 pregnant and 6 non-pregnant fed ad libitum were evaluated. Pregnancy did not affect final body weight (FBW; P=0.0923), cold carcass yield (CCY; P=0.0513), longissimus muscle area (LMA; P=0.8260), rib fat thickness (RFT; P=0.1873) and shear force (WBSF; P=0.9707). A lower FBW (P=0.0028), LMA (P=0.0048) and RFT (P=0.0001) were observed in feed restricted cows. However, no differences were found for CCY (P=0.7243) and WBSF (P=0.0759) among feeding level groups. These data suggests that carcass and meat quality traits are not affected by pregnancy status in Nellore cows. Moreover, although cows experiencing feed restriction did have reduced deposition of subcutaneous fat and lean tissue, there were no major impacts on meat quality traits.