Main altered characteristics in the meat of young cattle of different sexual conditions supplemented in tropical pasture.

The aim was to identify the predominant variables in the differentiation of meat quality of cattle submitted to surgical castration, immunocastration, or non-castration and finished in a tropical pasture. Thirty-nine crossbred cattle were used and distributed in three treatments: i) surgical castration; ii) immunocastration; and iii) non-castration, with an initial mean age of 14.06±0.72 months and a mean weight of 284.10±31.40 kg. We used the principal component analysis to differentiate the qualitative meat characteristics between the treatments. Based on that analysis, we found that the first three principal components explained 71.44% of the total variation in the meat quality data, which ensures that the variation found is associated with the effect of the treatments. The characteristics correlated with the first three principal components and responsible for the discrimination between sexual conditions were subcutaneous fat thickness, instrumental meat color, cooking loss and shear force. These characteristics were similar among castrated animals, regardless of the methods. Therefore, immunological castration preserves the attributes of the meat and prevents possible damage to the physical and mental integrity of the animals. Finally, principal component analysis is an important methodology in the objective investigation of beef meat attributes.

Qualitative characteristics of meat from cull cows of different genotypes and age class slaughter under different finishing systems: a meta-analytic approach.

The aim of this study was to evaluate, by meta-analysis, the quality of the meat of the cows according to genotype, termination system and age class slaughter. During an online research were identified 15 articles with information related to meat quality of slaughtered cows. The data were grouped according of the genotype of cows being: zebu or continental defined, crossed zebu x british or zebu x continental; according to termination system: feedlot or grassland; according to age of slaughter, where: up to 4 years old (young), 4-8 years old (adult) or more than 8 years old (old). The meat of the continental crossbred cows was softer than the other genotypes, both panel of evaluators and by Shear. The meat of cows finished in feedlot showed higher marbling degree in relation to meat of females finished on grassland. The reduction of the slaughter age of cows improved the meat color. The cow's genotype affects the organoleptic aspects of meat while the finished system and slaughter age affects the sensory aspects of meat.

Non-carcass components of cattle finished in feedlot with high grain diet / Componentes não integrantes da carcaça de bovinos terminados em confinamento com dieta de alto grão

The objective of this study was to quantify the non-carcass components of steers and heifers finished in feedlot and fed with high grain diets. Altogether, 45 Charolais and Nellore crossbred cattle of two categories, 21 heifers with an initial age of 32 months and 24 steers with an initial age of 20 months, were used. The animals were fed with diets of 100% concentrate and divided in groups according to the energy source used in the form of rice, white oat, or corn; each diet group had seven heifers and eight steers. The experimental design was completely randomized with a factorial 3 × 2 arrangement, using P<0.05. The slaughter weight and empty body weight were higher in animals fed with corn (430.4 and 379.1 kg, respectively) or white oat (449.3 and 378.0 kg, respectively) as compared to animals fed with rice (401.9 and 341.0 kg, respectively). With the exception of heart and abomasum fat, all other adipose tissue deposits were lower in animals fed with rice. The steers showed higher development of internal organs (3.67% versus 3.24%), feet (2.33% versus 2.06%), and total peripheral components (15.9% versus 15.1%), while heifers presented higher total fat deposition (6.45% versus 5.75%), as expressed in relation to empty body weight. Thus, the use of high grain diets based on corn or white oat in the finishing of cattle leads to higher development of internal organs and digestive tract, while feed with rice grain provides less deposition of adipose tissue.

O presente estudo teve por objetivo quantificar as partes não-integrantes da carcaça de novilhos e novilhas, terminados em confinamento alimentados com dietas de alto grão. Utilizaram-se 45 bovinos de duas categorias, sendo 21 novilhas com idade inicial de 32 meses e 24 novilhos com idade inicial de 20 meses, oriundos do cruzamento entre as raças Charolês e Nelore. Os animais receberam dietas de 100% concentrado e foram distribuídos nos tratamentos conforme a fonte energética utilizada, sendo essas: arroz; aveia branca ou milho, sendo utilizados sete novilhas e oito novilhos para cada dieta alimentar. O delineamento experimental foi o inteiramente casualizado, com arranjo fatorial 3 x 2, utilizando P<0,05. Os pesos de abate e de corpo vazio foram superiores nos animais alimentados com milho (430,4 kg e 379,1 kg, respectivamente) ou aveia branca (449,3 kg e 378,0 kg, respectivamente) em relação aos animais que receberam arroz (401,9 kg e 341,0 kg, respectivamente). A exceção da gordura de coração e da gordura abomasal, para os demais depósitos de tecido adiposo, os animais alimentados com arroz apresentaram menores valores. Os novilhos apresentaram maior desenvolvimento dos órgãos internos (3,67% contra 3,24%), das patas (2,33% contra 2,06%) e total de componentes periféricos (15,9% contra 15,1%), enquanto as novilhas apresentaram maior deposição no total de gorduras (6,45% contra 5,75%), expressos em relação ao peso de corpo vazio. A utilização de dietas de alto grão a base de milho ou aveia branca na terminação de bovinos acarreta maior desenvolvimento de órgãos internos e do trato digestório, enquanto a alimentação com grãos de arroz proporciona menor deposição de tecido adiposo.

Gorduras de descarte e componentes externos do corpo de novilhos e vacas de descarte de diferentes grupos genéticos / Trim fat and external components of the body of steers and cull cows from different genetic groups

Objetivou-se com esse estudo avaliar as proporções das diferentes gorduras de descarte e os componentes externos do corpo de novilhos e vacas de descarte 5/8Charolês (Ch) 3/8Nelore (Ne) e 5/8Ne 3/8Ch. A idade média dos animais ao final do período experimental foi de 23 meses para os novilhos e 68 meses para as vacas de descarte. Os animais foram terminados em confinamento até atingirem acabamento para o abate. A dieta alimentar continha relação volumoso:concentrado de 40:60 (base na matéria seca), com 14,2 por cento de proteína bruta e 2.869kcal de energia digestível kg-1 de matéria seca. O delineamento experimental foi o inteiramente casualizado, em um arranjo fatorial 2x2 (2 categorias x 2 grupos genéticos). Houve maior peso de abate (PAB) (509,67 contra 414,50kg) e de corpo vazio (PCVZ) (433,01 contra 355,27kg) para as vacas em relação aos novilhos. Quando os componentes foram expressos em valores absolutos e ajustados para PCVZ e PAB, as vacas apresentaram maiores pesos de gordura inguinal/úbere, gordura renal e no total de gordura interna. Quando os pesos dos componentes foram ajustados para PAB e PCVZ, os novilhos foram superiores no peso da cabeça, patas, vassoura da cauda e no total dos componentes externos. Os animais 5/8Ch 3/8Ne apresentaram maior peso absoluto da cabeça e maior peso relativo ao PCVZ da gordura ruminal, em relação aos 5/8Ne 3/8Ch. Por outro lado, os 5/8N e 3/8Ch apresentaram maiores pesos relativos ao PAB e PCVZ do couro e do PAB do total de componentes externos, quando comparados aos 5/8Ch 3/8Ne. Não houve correlação entre o rendimento de carcaça e os componentes não integrantes da carcaça.

The objective of this research was to evaluate the trim fat and external components of the body of two categories, steers and cull cows, from two genetic groups: 5/8 Charolais (Ch) 3/8 Nellore (Ne) and 5/8Ne 3/8Ch. The average age of animals at the end of the experimental period was of 23 and 68 months, for steers and cull cows, respectively. The animals were maintained at feedlot finished until they reached the finishing degree for slaughter. The experimental diet had a roughage concentrate ratio of 40:60 (dry matter basis), containing 14.2 percent of crude protein and 2,869kcal of digestible energy kg-1 dry matter. The experimental design was complete randomized in a 2x2 (two categories and two genetic groups) factorial scheme. The slaughter weight (PAB) (509.67 versus 414.50kg) and the empty body weight (PCVZ) (433.01 versus 355.27kg, respectively) were higher for cows in relation to steers. When the components were expreseds in absolutes values and adjusted for PCVZ and PAB, cull cows showed higher inguinal fat, renal fat and internal total fat weights. When the components weights were adjusted for PAB e PCVZ, the steers showed higher head, foots, tail broom and total external components. The 5/8Ch 3/8Ne animals showed higher head absolute weight and ruminal fat in relation to PCVZ, while the 5/8Ne 3/8Ch showed higher rawhide weight in relation to PAB and PCVZ, and in relation to PAB higher total extern components weight. The carcass dressing percentage and non integrants body parts of carcass didn't show any correlation.