Rodrigo Augusto Cortêz Passetti

Propolis or cashew and castor oils effects on composition of Longissimus muscle of crossbred bulls finished in feedlot

The natural additive products (propolis or essential oils), in replacing antibiotics, could be used as an alternative for feed strategies to improve animal production. This work was performed to evaluate the effect of natural additives as propolis or essential oils on meat quality of crossbred (Aberdeen Angus vs. Nellore) bulls. Thirty bulls were kept in feedlot (individual pen) for 55 d and randomly assigned to one of three diets (n = 10): control (CON), propolis (PRO), or essential oils (OIL). CON diet consists of corn silage (45% DM) and concentrate (cracked corn, soybean meal, glycerin, limestone, and mineral salt, 55% DM). The PRO group received same CON diet plus 3 g animal-1 d-1 of propolis premix added to the concentrate. The OIL group received same CON diet and 3 g animal-1 d-1 of a premix (cashew Anacardium occidentale L. and castor Ricinus communis L. oils) added to the concentrate. Fat thickness (5.0 mm), pH (5.9), Longissimus muscle area 58.0 cm2, marbling, texture, color (L* = 36.6, a* = 17.3, and b* = 5.9), lipid oxidation (0.08 malonaldehyde kg-1 meat), and Warner-Bratzler shear force (3.3 kg) were unaffected by the diet. PRO and OIL diets had no effect neither on moisture (73.7%), ashes (1.1%), protein (23.8%), and lipids (1.7%), fatty acid composition or polyunsaturated/saturated fatty acid (PUFA/ SFA, 0.13), and n-6/n-3 ratio (6.9) on Longissimus muscle. Addition of natural additives as propolis extract or cashew and castor oils in the diet of bulls when they are finished in a feedlot did not change meat qualities.

Carcass Composition and Cuts of Bulls and Steers Fed with Three Concentrate Levels in the Diets

In this paper, weight, carcass dressing, weights of the primary cuts, weights of the physical components of the primary cuts, and weights of the main commercial cuts of 66 Purunã animals, of which 33 were bulls and 33 were steers were evaluated. These animals, with an average age of 19 months at the beginning of the experiment, were finished in a feedlot system during 116 days, and were fed with diets containing three levels of concentrate (0.8%, 1.1%, and 1.4% of body weight). The concentrate was formulated with 25% soybean meal, 73% ground corn grain, 1% of a mineral mix, and 1% of limestone. The interaction between sexual groups and the concentrate level was not significant for any of the variables. Likewise, no effect of the concentrate level was detected on the same variable traits. The bulls demonstrated higher hot carcass weights (265.1 vs 221.7 kg) and a higher proportion of forequarter (38.4% vs 36.1%) however the steers presented with higher proportions of side (19.7% vs 18.5%) and hindquarter (44.2% vs 43.1%). The bulls produced higher yields of muscle in the three primary cuts, there by resulting in higher yields of edible portions of the carcass. The bulls also produced higher weights of tenderloin, knuckle, topside, flat, eye round, rump, and rump cover. The finishing of young bulls in feedlot is to be recommended, since the animals produce carcasses with higher amounts of edible meat and higher yields of commercial cuts, thus allowing for a better price for the carcass. Low concentrate level could be used due to the lower cost of production for farmers.

Animal Performance and Carcass Characteristics of Bulls (1/2 Purunã vs 1/2 Canchim) Slaughtered at 16 and 22 Months Old, and Three Different Weights

Current study aimed to evaluate the performance of bulls (1/2 Purunã vs 1/2 Canchim) slaughtered at two ages and three different weights. One hundred and thirteen bulls were divided into two slaughter ages (16 and 22 months) and three different slaughter weights (light, 422 kg; medium, 470 kg; and heavy, 550 kg). The body weight was higher for bulls slaughtered at 16 months. Daily gain, carcass weight and dressing were higher for bulls slaughtered at 16 months. Feed intake was higher for bulls slaughtered at 22 months although feed efficiency was better for bulls slaughtered at 16 months. Carcass characteristics were better for bulls slaughtered at 16 months. The percentages of muscle, fat and bone and meat characteristics were similar between two slaughter ages. Feed intake and animal performance was lower for lighter animals. Feed conversion and carcass dressing were similar in the three slaughter weights. Muscle percentage was higher for heavier animals but fat and bone percentages were lower. Slaughter weight had no effect on meat characteristics.

Validation of photographs usage to evaluate meat visual acceptability of young bulls finished in feedlot fed with or without essential oils

Forty ½ Brown Swiss×½ Nellore crossbred bulls were distributed into three experimental groups: CON - diet without addition of essential oils; CLO - diet with average 5,000mg/animal/day of clove essential oils and CIN - diet with average 5,000mg/animal/day of cinnamon essential oils to evaluate three methodologies of visual acceptability: with steaks directly in Trays and Sequential and Random photos. Seventeen consumers evaluated visual appearance of meat using a 9-point structured hedonic scale. CON group presented higher shelf-life than essential oils groups. Trays and Sequential scores were similar in the majority of days; thus digital images could be used to evaluate colour evolution. However, Random photos resulted in lower scores and slower acceptability decrease than Trays and Sequential photos (p<0.05) among the second and fifth day of display. Random photos presented a lower and more constant standard deviation than Trays and Sequential photos (p<0.01) indicating that this methodology promoted a higher standard situation for meat colour evaluation.

How dietary cottonseed hull affects the performance of young bulls finished in a high-concentrate system

This study aimed to evaluate the effects of diets composed of cottonseed hull on feed intake, in vitro digestibility, animal performance, carcass characteristics and ingestive behaviour of young bulls (1/2 Simmental × 1/2 Nellore) fed in a high-concentrate system. Thirty crossbred young bulls (319 ± 12.5 kg of bodyweight, and 11 ± 0.8 months old) were assigned to a complete randomised experimental design of three diets (CH21: cottonseed hull 210 g/kg on a DM, basis; CH27: cottonseed hull 270 g/kg on a DM basis; CH33: cottonseed hull 330 g/kg on a DM basis) with 10 animals per group. The animals were kept in a feedlot for 162 days. The cottonseed hull diets had effects on DM intake and neutral detergent fibre intake. The CH21 diet reduced the DM and detergent fibre intakes (kg/day and kg/100 kg bodyweight) and increased the in vitro digestibility of DM. However, the in vitro digestibility of neutral detergent fibre was greater with the CH27 diet. The cottonseed hull diets did not have effects on animal performance or the carcass characteristics of young bulls. However, the CH33 diet reduced the feed efficiency of the animals. A cottonseed hull level up to 270 g/kg of dietary DM may be utilised as a non-forage fibre in high-concentrate diets for young bulls in feedlots.