Performance, carcass characteristics and gain cost of feedlot cattle fed a high level of concentrate and different feed additives

The objective of this study was to evaluate the effects of feeding cattle with isoprotein and isoenergetic diets, with and without the addition of polyclonal antibody preparation (PAP), yeasts (YST) or monensin sodium (MON) on performance, carcass characteristics and gain cost in feedlot. Ninety-five 20-month old bullocks (323.3±21.8 kg) were distributed in 25 pens. The completely randomized experimental design had a 2 × 2 + 1 factorial arrangement and the treatments were replicated 5 times. There was no effect of MON for DMI throughout the feedlot period; however, MON reduced the dry matter intake (DMI) in g/kg of BW in the first 28 days when compared with the other treatments. The gain cost decreased with MON addition in relation to the other treatments. Inclusion of YST decreased average daily gain (ADG), final body weight, hot carcass weight, carcass weight, gain to feed ratio and DMI in g/kg body weight, worsening feed conversion and increasing the gain cost in the feeding periods. Inclusion of PAP increased ADG and decreased the gain cost, besides improving feed conversion. For MON and PAP, a difference was found for kidney-pelvic fat and kidney-pelvic fat per 100 kg of hot carcass weight. For MON and YST, there was a difference in ADG, feed conversion, gain cost and carcass yield and kidney-pelvic fat per 100 kg of hot carcass. Treatment YST worsened performance in relation to the non-supplemented treatments. Feeding PAP to animals did not influence performance and carcass characteristics of bullocks in feedlot negatively. Thus, PAP shows potential to substitute MON in cattle feeding using isoprotein and isoenergetic diets.

Ruminal acidosis challenge impact on ruminal temperature in feedlot cattle

The objective of this experiment was to determine if ruminal temperature rise coincides with pH reduction using an acidosis challenge model. Twelve ruminally cannulated steers (518 ± 28 kg BW) were administered ruminal temperature-monitoring devices that recorded temperature every 2 min. Steers were fed a 63% concentrate diet at 1.6% BW for 20 d before being randomly assigned to 1 of 3 acidosis challenge treatments: no dietary change (CON), onehalf of daily DMI replaced with cracked corn (HALF), or all of daily DMI replaced with cracked corn (CORN). The challenge was initiated by ruminally dosing steers with their treatment diets. Ruminal pH and rectal temperatures (Trec) were recorded every 3 h for 72 h. All steers were offered CON diets at 24 and 48 h after challenge. Ruminal pH showed a treatment × day effect (P = 0.01). Ruminal pH of CORN steers was lower (P = 0.03) than that of HALF steers on d 1, was lower (P ≤ 0.004) than that of HALF and CON steers on d 2, and tended to be lower (P ≤ 0.10) than that of HALF and CON steers on d 3. Treatment did not affect (P ≥ 0.42) RecT. Ruminal temperature (Trum) showed a treatment · d-1 × h-1 after feeding interaction (P < 0.01). At 3 h after challenge, Trum of CORN and HALF steers was higher (P ≤ 0.01) than that of CON steers. On d 2, Trum of CORN steers was higher (P ≤ 0.03) than that of CON between 6 and 12 h after feeding. From 15 to 21 h after feeding on d 2, Trum of HALF steers was higher (P < 0.01) than that of CORN and CON steers. On d 3, at the time of feeding until 3 h later, Trum of CORN steers was lower (P ≤ 0.04) than that of all other steers. Rectal temperature was correlated (P ≤ 0.01) with Trum on all days for CON and CORN steers. Ruminal pH was negatively correlated (P ≤ 0.04) with Trec on d 2 and Trum on d 1 in CORN steers, and Trum was negatively correlated (P ≤ 0.02) with ruminal pH in HALF and CON steers on d 1 and 3, respectively. The amount of time above Trum of 39.0°C or 39.45°C was correlated (P ≤ 0.05) with the time spent below a ruminal pH of 5.5 in CORN steers; however, time above Trum of 39.0°C did not differ (P = 0.87) among treatments. Results indicate that there is a negative relationship between Trum and ruminal pH during an acidotic episode; therefore, Trum monitoring can detect a potential acidotic episode. © 2012 American Society of Animal Science. All rights reserved.

Survey of the nutritional recommendations and management practices adopted by feedlot cattle nutritionists in Brazil

Thirty-three feedlot cattle nutritionists were surveyed to evaluate the management practices and nutritional recommendations adopted by feedlots in Brazil. The web-based survey consisted of 81 questions that included: general information (n = 10); general commodity information (n = 15); use of coproducts (n = 5), roughage source and level (n = 5); adaptation methods (n = 7); feed mixers (n = 6); feeding management (n = 6); cattle management and type of cattle fed (n = 13); formulation practices (n = 9); information resources used for nutritional recommendations (n = 2); and additional questions (n = 3). In total, the 33 nutritionists were responsible for approximately 2,658,000 animals, and moreover, 65.5% of those participants had clients that feed less than 5000 animals yearly. Corn was the primary source of grain used in feedlot diets (87.9%) and cracking was the primary processing method recommended by nutritionists (57.6%). The average concentrate and roughage inclusion in finishing diets was 79.0% and 21.0%, respectively. The main challenges faced by nutritionists are the lack of available and precise equipment and lack of trained employees with respiratory diseases as the main health problem. This survey of nutrition and management practices should aid in the development of research for the feedlot industry in Brazil and similar tropical climates, as well as provide data to facilitate the broader application of future NRC models. (C) 2014 Elsevier B.V. All rights reserved.

Animal performance, feeding behaviour and carcass traits of feedlot cattle diet fed with agro-industrial by-product as fat source

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

BILL E. KUNKLE INTERDISCIPLINARY BEEF SYMPOSIUM: Temperament and acclimation to human handling influence growth, health, and reproductive responses in Bos taurus and Bos indicus cattle

Temperament in cattle is defined as the fear-related behavioral responses when exposed to human handling. Our group evaluates cattle temperament using 1) chute score on a 1 to 5 scale that increases according to excitable behavior during restraint in a squeeze chute, 2) exit velocity (speed of an animal exiting the squeeze chute), 3) exit score (dividing cattle according to exit velocity into quintiles using a 1 to 5 scale where 1 = cattle in the slowest quintile and 5 = cattle in the fastest quintile), and 4) temperament score (average of chute and exit scores). Subsequently, cattle are assigned a temperament type of adequate temperament (ADQ; temperament score <= 3) or excitable temperament (EXC; temperament score > 3). To assess the impacts of temperament on various beef production systems, our group associated these evaluation criteria with productive, reproductive, and health characteristics of Bos taurus and Bos indicus-influenced cattle. As expected, EXC cattle had greater plasma cortisol vs. ADQ cattle during handling, independent of breed type (B. indicus x B. taurus, P < 0.01; B. taurus, P < 0.01; B. indicus, P = 0.04) or age (cows, P < 0.01; heifers or steers, P < 0.01). In regards to reproduction, EXC females had reduced annual pregnancy rates vs. ADQ cohorts across breed types (B. taurus, P = 0.03; B. indicus, P = 0.05). Moreover, B. taurus EXC cows also had decreased calving rate (P = 0.04), weaning rate (P = 0.09), and kilograms of calf weaned/cow exposed to breeding (P = 0.08) vs. ADQ cohorts. In regards to feedlot cattle, B. indicus EXC steers had reduced ADG (P = 0.02) and G:F (P = 0.03) during a 109-d finishing period compared with ADQ cohorts. Bos taurus EXC cattle had reduced weaning BW (P = 0.04), greater acute-phase protein response on feedlot entry (P <= 0.05), impaired feedlot receiving ADG (P = 0.05), and reduced carcass weight (P = 0.07) vs. ADQ cohorts. Acclimating B. indicus x B. taurus or B. taurus heifers to human handling improved temperament (P <= 0.02), reduced plasma cortisol (P < 0.01), and hastened puberty attainment (P <= 0.02). However, no benefits were observed when mature cows or feeder cattle were acclimated to human handling. In conclusion, temperament impacts productive, reproductive, and health characteristics of beef cattle independent of breed type. Hence, strategies to improve herd temperament are imperative for optimal production efficiency of beef operations based on B. taurus and B. indicus-influenced cattle.

Ostecondrose em bovinos confinados

This paper reports the occurrence of osteochondrosis in feedlot cattle submitted to a high-caloric diet. About 11.6% of the animals showed symptoms that included lameness, tarsal hyperflexion, muscle fasciculations, reluctance to move and delayed recumbency. Necropsy and radiologic examination showed typical lesion of osteochondrosis, including cartilage discontinuity and osseous injury. The diet, age and high grow rate of the animals were considered to he factors in the development of osteochondrosis.

Desempenho e características da carcaça de bovinos alimentados com dietas com caroço de algodão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da suplementação com anticorpos policlonais e/ou monensina sódica sobre a saúde ruminal de bovinos jovens confinados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desempenho e características da carcaça de bovinos nelores terminados em confinamento com dietas a base de caroço de algodão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Glicerina associada a volumosos na dieta de bovinos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Créditos de nitrogênio, alterações nos atributos químicos do solo e nos componentes de produção da cultura do milho em função da aplicação de esterco bovino

Pós-graduação em Agronomia (Produção Vegetal) - FCAV