The Effects of Castration, Implant Protocol, and Supplementation of Bos indicus-Influenced Beef Cattle under Tropical Savanna Conditions on Growth Performance, Carcass Characteristics, and Meat Quality.

The effects of castration, supplementation, and implant protocol (IP) on growth, carcass characteristics, and meat quality of grass-fed cattle were evaluated. Two experiments followed a two-way ANOVA and a 2 × 2 factorial arrangement. Experiment-I, 99 bulls were evaluated for: (a) supplementation (mineral (MS) or strategic protein-energy supplementation (SS), and (b) IP (repeated (day-0 and day-90) Zeranol-72 mg implantation (Zeranol-Zeranol) or Trenbolone Acetate-140 mg/Estradiol-20 mg (day-0) followed by Zeranol-72 mg (day-90) (TBA/E2-Zeranol). Experiment II, 50 animals were evaluated for: (a) IP (like Experiment-I), and (b) male class (steers vs. bulls). In Experiment-I, SS bulls had greater growth rate, carcass yield, and yield of high-valued boneless lean cuts than MS bulls, while decreasing (p < 0.05) time to harvest. Steaks from SS-bulls on TBA/E2-Zeranol IP were more (p = 0.05) tender than SS/Zeranol-Zeranol counterparts. Experiment-II bulls had greater growth than steers, but decreased (p < 0.05) carcass quality aspects. Zeranol-Zeranol increased (p < 0.01) meat tenderness of steers. Interactions (p < 0.05) affected cutability (Experiment-II) and meat sensory traits (Experiment-I/II). The SS improved growth, carcass yield, and shortened days until harvest of bulls, while TBA/E2-Zeranol IP positively affected tenderness in bull meat only. Castration improved carcass quality while the implant effects on cutability and tenderness were male-class dependent.

Effects of Sex Class, a Combined Androgen and Estrogen Implant, and Pasture Supplementation on Growth and Carcass Performance and Meat Quality of Zebu-Type Grass-Fed Cattle.

Forty-seven Zebu calves were used to determine the effects of class (bull or steer), supplementation (SUPPL, a poultry litter-based supplement or mineral supplementation), and implant (20 mg estradiol combined with 120 mg of trenbolone acetate or no implant) on growth and carcass performance and beef eating quality. The average daily gain (ADG) of implanted cattle significantly increased for steers, but not for bulls. The SUPPL treatment increased ADG by 8.63% from day 0 to end, and shortened in 73.3 d the time to reach 480 kg BW (p < 0.01). Compared to bulls, the steer carcasses exhibited more desirable maturity and finish scores, thicker back fat (p < 0.05), and yielded greater (p < 0.01) percentages of high-value boneless subprimals (HVBLS) (+1.64%) and total cuts (1.35%). The SUPPL bulls dressed 2.63 and 1.63% greater than non-supplemented bulls and SUPPL steers, respectively (p < 0.05). Meat sensory quality was subtly affected (p < 0.05) by sex class or supplementation. The implant did not affect (p > 0.05) shear force or sensory ratings. The supplementation improved key growth performance traits while it adversely affected tenderness-related sensory traits. The implant enhanced the rate of gain of steers only, without improving cut-out yields or inducing adverse effects on palatability traits in both steers and bulls.

Cholesterol and fatty acid composition of longissimus thoracis from water buffalo (Bubalus bubalis) and Brahman-influenced cattle raised under savannah conditions.

Male (n=66) water buffalo (Buffalo) and Brahman-influenced cattle (Brahman) were born, raised, weaned, fattened on grazing savannah and harvested at two different ages (19 and 24months) to compare lipid composition of the longissimus thoracis muscle. Half of the animals were castrated at seven months of age (MOA) to examine the castration effects. At 24 MOA Brahman steers showed the highest content of total lipids (P<0.05). No significant variation was detected in cholesterol content for either the main or interaction effects in the age groups. Some individual fatty acids varied with the species (P<0.05), however, interspecific similarities were found in fatty acid ratios. For health-related indices, only atherogenic index (AI) showed lower values in favor of Buffalo meat (P<0.05) at both harvesting ages. Although, meat derived from both bovid groups was leaner and showed lower cholesterol level, AI indicates that Buffalo meat might be beneficial from a human health standpoint.

Efecto de la suplementación estratégica, régimen de implantes y condición sexual sobre la composición proximal y mineral de carne de bovinos cruda y cocida / Effect of strategic supplementation, implant regime and gender on the proximate and mineral composition of raw and cooked bovine meat

Se evaluó el efecto de suplementación, régimen de implantes (RI) y condición sexual (CS) sobre la composición proximal y mineral del longissimus dorsi crudo y cocido, de 89 animales (77 toros y 12 novillos) alimentados al azar con pasto (NSUE) o con suplementación estratégica (SUE). Un grupo (n= 49) fueron implantado con una doble dosis de Ralgro® (2Ralgro), con reimplante a los 90 d.; a otro (n=40), con un tratamiento mixto: Revalor® por 90 d., luego 2Ralgro (Revalor-2Ralgro). El análisis de varianza (ANOVA) reveló que la carne cruda de los toros SUE, mostró mayor contenido de humedad (HUM) (P<0,05) (74,23 vs. 73,88 g/100g de muestra), mientras que el Na fue el único mineral afectado (P<0,05) en las muestras cocidas de los NSUE (71,32 vs. 69,16 mg/100g de muestra). RI sólo afectó el contenido de Na y Cu observándose un aumento (P<0,05) en la carne cocida de toros implantados con Revalor-2Ralgro. CS afectó a HUM (P<0,05), mostrando la carne cocida de novillos el mayor contenido. La SUE x RI incrementó(P<0,05) el contenido de proteínas (PC) en la carne cocida de los toros SUE implantados con Revalor-2Ralgro, mientras que la CS x RI incrementó el contenido de lípidos (LIP) y la concentración de K de la carne cruda de novillos. Se observó que ni SUE ni IR produjeron los resultados esperados, es decir, un aumento del PC, y la disminución en LIP en las muestras de carne consideradas; los incrementos observados en la carne cocida se debieron probablemente a la pérdida del agua durante la cocción. Los resultados sugieren que la suplementación estratégica, la administración de implantes hormonales y la castración utilizados para maximizar los índices productivos del ganado, si bien no produjeron un beneficio adicional en lacomposición química de las carnes, tampoco disminuyeron la calidad nutricional de las mismas.

The effect of supplementation, implant regime (IR) and gender (G) on the proximal and mineral composition of the raw and cooked longissimus dorsi muscle, from 89 animals (77 bulls and 12 steers) was studied. A randomly selected group of animals was grass-fed (NSUE) and other was strategically supplemented (SUE). One group (n= 49) was implanted with one double dose of Ralgro® (2Ralgro) and then reimplanted to the 90 d. Another one (n= 40) was treated with a mixture: Revalor® for 90 d. then 2Ralgro before the slaughter (Revalor-2Ralgro). The analysis of the variance (ANOVA) detected a higher moisture (M) content in the raw SUE bull meat (74.23 vs. 73.88 g/100g of sample), while only Na from NSUE was the mineral affected in the cooked meat (71.32 vs. 69.16 g/100g of sample). IR only affected (P<0.05) the Na and Cu content; an increase in the cooked bull meat reimplanted with Revalor-2Ralgro was observed. Gender (G) affected (P<0.05) M, being higher in the cooked steers meat samples. SUE x IR interaction significantly (P<0.05) increased the protein content (PC) in the cooked bull meat (SUE) implanted with Revalor-2Ralgro, while G x IR interaction had provoked an increase in LIP and K contents of the raw steers meat. It is inferred that neither SUE nor IR caused the expected results, it is to say, an increase in PC nor a decrease in LIP in the meat samples considered; the increments observed in the cooked meat was probably due to loss of the water during cooking. Results suggest of SUE, IR and castration used for maximize the cattle productive index, although they did not produce an additional benefit in the chemical composition of the meat samples, did not diminish their nutritional quality either.

Características al sacrificio rasgos del canal y rendimiento carnicero de novillos criollo limonero sometidos a suplementación durante la fase de ceba a pastoreo / Slaugter characteristics carcass traits and cutability of criollo limonero steers fattened on pasture with supplementation regimes

Se estudiaron efectos de dos tipos de suplementación a pastoreo sobre caracaterísticas al sacrificio, rasgos en canal y rendimiento carnicero de 23 novillos de la raza Criollo Limonero. A los 36 meses de edad, éstos se distribuyeron aleatoriamente a tres grupos durante 158 d: T1= Pastoreo (Echinochloa polystachia) no suplementado, como testigo; T2= Pastoreo más 1,0 Kg/animal/día de concentrado al 11% PC y T3= Pastoreo más 1 h/día ramoneando Leucaena leucocephala. Análisis de varianza covarianza por el método de mínimos cuadrados indicaron que ningún tratamiento de suplementación (T2, T3), afectó (P>0,05) el rendimiento en canal, los rasgos de la canal y variables de rendimiento en cortes. Solo se observó una menor proporción de víceras blancas frente al testigo del grupo suplementado con Leucaena (7.98% vs 7,07%). Se sugiere estudiar otras alternativas de manejo y de alimentación con alta energía que permitan mejorar la calidad de la canal y el rendimiento cárnico de novillos de esta raza Bos taurus lechera tropical.

Evaluación de las propiedades físicas de carne para hamburguesas de res bajas en grasas elaboradas con ß-glucano / Evaluation of physical properties of of low fat meat for hamburger beef formulated with ß-glucan

En la presente investigación se evaluó el efecto de la sustitución de grasa sobre el rendimiento a la cocción (RC), la reducción del diámetro (RD), retención de grasa (RG), retención de humedad (RH), y fuerza de corte (FC) en carne para hamburguesas de res "bajas en grasa", elabordas con diferentes proporciones de un concentrado de ß-glucano. Se formularon carne para hamburguesa con tres niveles de sustitución de grasa (A) 50 por ciento; (B) 70 por ciento y (C) 90 por ciento, comparando con un control de un 20 por ciento de grasa. Las muestras fueron pasadas antes y después de la cocción. La fuerza de corte se evaluó con un equipo Warner-Bratzler. Las formulaciones con mayor concentración de ß-glucano (B y C) resultaron ser más blandas y con mayor retención de humedad (P<0,05) en relación al control. No se encontró diferencias significativas entre formulaciones para el RC y la RD. La ausencia de ß-glucano en el control disminuyó significativamente (P<0,05) la retención de grasa. Sin embargo, los tres tratamientos con ß-glucano mantienen porcentajes similares de RG, RD y RC (P>0,05). Los hallazgos sugieren que el ß-glucano es un ingrediente funcional que puede ser efectivamente usado para mejorar las propiedades físicas de las carnes para hamburguesas "bajas en grasa"