Supplementation of beef cattle grazing Brachiariabrizantha during the dry and rainy seasons: performance and carcass ultrasound prediction

Abstract

The aim of this study was to evaluate the influence of genetic group, sex and level of protein-energy supplementation on the performance and carcass traitsultrasound prediction of weaned calves Nellore and crossbred animals ½ Nellore x ½ Aberdeen Angus. A completely randomized design in a factorial 2x2x2, were used, with two levels of protein-energy supplementation, two sex and two genetic groups. Fifty-six animals were used (28 Nellore and 28 crossbred ½ Nellore x ½ Aberdeen Angus), equally divided between males and females, maintained on grazing Brachiariabrizanthacv. Marandu and evaluated in three experimental periods: period 1 = protein-energy supplementation in the dry season; period 2 = protein-energy supplementation during the rainy season; period 3 = only mineral supplementation. In the dry season, they were supplemented with levels of 0.5 and 1% of body weight (BW) and in the rainy season with 0 and 1% BW. Dry matter intake (kg day -1 , % BW, g kgBW 0.75-1 ) was estimated. In vivo ultrasound measurements of carcass were: loin eye area (LEA), fat thickness (FT) and rump fat thickness (RFT). There was influence of genetic group and protein-energy supplementation levels on average daily gain (ADG) of animals in period 1 and 2 (P < 0.05). Sex affected the ADG only in period 2, and the males had 754 gday -1 and females, 582 g day -1 . There was no interaction of genetic group x sex x supplementation level. At the end of the experimental period (end of period 3), it was found that male animals and crossbred animals ½ Nellore x ½ Aberdeen Angus had higher ADG (716 and 748 g day -1 , respectively). The values of dry matter intake (DMI) were influenced by genetic group and sex, in all periods, verifying highest intake in crossbred animals ½ Nellore x ½ Aberdeen Angus, with better feed conversion for crossbred animals. Regarding ultrasound measurements taken on the carcass, the influence of sex on FT and RFT, it was observed, and the males showed higher values, 3.24 ResumoObjetivou-se neste estudo avaliar a influência do grupo genético, sexo e níveis de suplementação proteicoenergética sobre o desempenho e características de predição de carcaça de bezerros desmamados da raça Nelore e ½ Nelore x ½ Aberdeen Angus. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 2x2x2, sendo dois níveis de suplementação, dois sexos e dois grupos genéticos. Foram utilizados 56 animais (28 Nelore e 28 ½ Nelore x ½ Aberdeen Angus), divididos igualmente entre machos e fêmeas, mantidos em pastagem de Brachiariabrizantha cv. Marandu e avaliados em três períodos experimentais: período 1= suplementação proteico-energética na estação seca; período 2= suplementação proteico-energética na estação chuvosa; período 3= apenas suplementação mineral. Na estação seca, suplementou-se com níveis de 0,5 e 1% do peso corporal (PC) e na estação chuvosa 0 e 1% do peso corporal. Foram estimados o consumo de matéria seca (kg dia -1 , % PC, g kgPC 0,75-1). As mensurações ultrassonográficas de carcaça in vivo foram: área de o...

Nutritional evaluation of Brachiaria brizantha cv. Marandu cultivated in soils developed from basalt and sandstone in the state of Paraná

“…However, it should be considered that the tropical forages hardly present values below the recommended levels when the management and cutting height indicated for the species are adopted (PEREIRA et al, 2011). The results obtained are in agreement with the indications of Pereira et al 2011, Alencar et al (2014), and Guerra et al (2016), who verified that NDF values were always more than 60% in Brazilian pastures formed with different species of Brachiaria. High levels of NDF are a consequence of the proportional decrease in easily digestible molecules, mainly proteins, which play an important role in ruminant nutrition.…”

Efeito Dos Níveis De Suplementação No Desempenho De Bovinos Em Sistema De Semi-Confinamento

“…Neste contexto, Guerra et al (2016) ao trabalharem com suplementação de bovinos a pasto durante o período das chuvas, observaram maior área de olho de lombo para os bovinos que receberam o maior nível de suplementação, corroborando com os resultados desse trabalho. Porém, esses autores consideraram que esse fato estava correlacionado ao maior peso dos animais e ao maior aporte de nutrientes provindos da suplementação, já os animais deste experimento não diferiram no peso final.…”

Metabolic responses, performance, mammary gland development and gene expression in liver and muscle of Holstein × Gyr crossbred heifers grazing intensively-managed brachiaria decumbens supplemented with varied crude protein and association of housing and management practices with milk yield, milk composition, and fatty acid profile, predicted using fourier-transform mid-infrared spectroscopy, in farms with automated milking systems

“…In general, CP supplementation promotes greater performance and, consequently, high body gain and fat deposition rates in grazing cattle (Guerra et al, 2016;Machado et al, 2019;Machado et al, 2020). On the other hand, previous studies have demonstrated that dairy heifers submitted to a high-performance diet, without an adequate nutritional balance between energy and protein may cause damages to the development of the mammary gland due to excessive fat deposition (Weller et al, 2016;Albino et al, 2017b).…”