Testing different devices to assess the meat tenderness: preliminary results.

Meat tenderness is one of the principal attribute associated with consumer preferences. This study describes tenderness measurements at three final endpoint cooking temperatures (51, 61 and 71 °C) using a mechanical Warner-Bratzler (WBSF) as the standard instrument versus digital texturometer (CT3) and penetrometer (FHT) devices. Thirty-six cross-breed heifers (Bos indicus) with initial body weight 330 ± 40 kg, 20-24 months of age, were slaughtered after 100 days on feed. Subsequently, 48 h post-slaughter, Longissimus thoracis (LT) samples were collected between the 10th and 13th ribs. Six LT samples from each animal were used to evaluate tenderness and cooking losses through analysis of variance and regression analyses. No interaction between device × temperature was observed (p = 0.57). Shear force values were greater (p < 0.05) as endpoint cooking increased and the results from CT3 were close to the ones using the WBSF (R2 = 0.76; p < 0.0001). In conclusion, the digital CT3 can replace the mechanical WBSF because these devices were strongly correlated (r = 0.85; p < 0.00). However, the results from FHT were underestimated (R2 = 0.19; p < 0.006), indicating that FHT device should not be used for the evaluation of meat tenderness.

Effect of different roughages sources on performance, milk composition, fatty acid profile, and milk cholesterol content of feedlot feed crossbred cows (Holstein × Zebu).

The aim of the study was to evaluate the effect of different forage sources in diets for feedlot dairy cows and their implications on production, composition, fatty acid profile, and milk cholesterol content. Nine Holstein × Zebu crossbred cows were distributed in three 3 × 3 Latin squares, in three periods of 21 days each, and three diets: elephant grass silage + concentrate, briquette from Brachiaria + concentrate, and sugarcane + concentrate. Elephant grass silage resulted in lower milk production and milk protein content. Cows fed elephant grass silage had lower concentrations of the saturated fatty acids C10:0, C11:0, C12:0, and C15:0 in the milk and higher of the unsaturated fatty acids C15:1, C16:1, C18:1n-9t, C18:1n-9c, C18:3n-6, CLAc9t11, and CLAt10c12 in relation to the other diets. Data were analyzed using the GLM procedure of the Statistical Analysis System (SAS) and the means were compared by the Tukey's test (P = 0.05). It is recommended to use the briquette from Brachiaria as a forage source for lactating cows, since it led to higher milk yield. On the other hand, the use of elephant grass silage as a forage source is recommended if the farmer is paid for milk with higher concentration of monounsaturated and polyunsaturated (CLA) fatty acids, which exerts beneficial effects on human health.

Inclusion of licuri meal in the diet of pasture dairy cows.

The objective of this study was to evaluate the inclusion of increasing levels of licuri meal as a substitute for soybean bran in the diet of pasture-based dairy cows and its effects on the intake, nutrient digestibility, and milk production and composition. Eight crossbred Holstein/Zebu cows were used in two 4 × 4 Latin square plots. The diets contained increasing percentage of licuri meal (0.0, 4.16, 7.09, and 9.45%) in the total diet, replacing soybean bran. The inclusion of licuri meal in the diet affected total dry matter intake and dry matter intake in relation to body weight, which presented a quadratic effect. The same behavior was observed for the consumption of EE, CP, TDN, and NDFap. The NFC consumption showed a linear decrease with the addition of the by-product in the diet. There was no influence of the inclusion of the licuri meal on the digestibility of the DM, CP, NFC, and TDN, while the digestibility of the NDFap and EE presented increasing linear effect. There was a reduction of milk production and food efficiency with the inclusion of increasing levels of the meal. The fat content in milk showed a linear increasing effect. Ditto for cholesterol. It is recommended to include not more than 7.00% of licuri meal for lactating cows with an average production of 20 kg day-1.

Comparison of Dental Carcass Maturity in Non-Castrated Male F1 Angus-Nellore Cattle Finished in Feedlot.

Dental classification of carcasses is used as a parameter of cattle maturity at slaughter, and it can influence carcass and meat quality traits. Brazilian beef-packing companies use the number of permanent incisor (PI) teeth as a parameter for bonus and certification of carcasses with superior quality. However, when non-castrated male such as F1 Angus-Nellore (Bos taurus×Bos indicus) are slaughtered, only animals without PI teeth are subsidized by the breed association. We evaluated these animals finished in feedlot for 180 days with zero versus two PI teeth on the carcass and meat quality traits. At the time of slaughter, 88 carcasses were selected, forming two treatments according to dental carcass maturity (0 versus 2 PI teeth; 44 animals per category). It was demonstrated that the number of PI teeth (0 versus 2 PI) did not influence (p>0.05) carcass (weights, yield, cooling loss, ribeye area and the backfat thickness) and meat quality traits (Longissimus thoracis chemical composition, color, cooking losses, shear force and pH). Thus, dental carcass maturity (zero versus two PI teeth) does not influence non-castrated male F1 Angus-Nellore finished in feedlot for 180 days. This is the first study to demonstrate that carcasses of non-castrated male F1 Angus-Nellore with two PI teeth should be subsidized in a similar way to those with zero PI teeth. Moreover, Brazilian beef-packing companies could produce heavier and leaner carcasses of acceptable quality though the use of crossbred cattle such as non-castrated F1 Angus Nellore.