The objectives of this trial were to evaluate the association between corn processing, glucose-dependent insulinotropic polypeptide (GIP) concentration, and intramuscular (IM) fat deposition. We hypothesized that steers fed whole shelled corn (WSC) would have a greater IM fat deposition than steers fed cracked corn (CC) due to an increase in plasma GIP concentration. Backgrounded, Angus-cross cattle (initial body weight [BW] = 279 ± 9.8 kg) were used in a randomized complete block design in a feedlot setting for an average of 230 d. Cattle were allotted in 12 pens (6 pens per treatment with 8 animals per pen). There were three blocks: heifers (n = 32, initial BW = 265 ± 1.3 kg), small steers (n = 32, initial BW = 262 ± 1.3 kg), and large steers (n = 32, initial BW = 310 ± 1.4 kg). Two pens within each block were randomly assigned to one of the following treatments: 1) CC or 2) WSC. Animal growth performance, carcass characteristics, and plasma hormone and metabolite concentrations were analyzed using the MIXED procedure of SAS, including the fixed effects of treatment, or treatment, time, and their interaction. Pen and block were included as random effects. Carcass yield and quality grade distributions were compared using the GLIMMIX procedure of SAS. including the fixed effects of treatment and time with pen and block as random effects. Linear regression was used to evaluate the association of plasma GIP concentration and IM fat content. Average daily gain (P = 0.57) and final BW (P = 0.34) were similar, regardless of treatment. Cattle fed CC had reduced (P < 0.01) dry matter intake (DMI) when compared with those fed WSC. This lesser DMI resulted in improved gain:feed ratio (P < 0.01) for cattle fed CC compared with cattle fed WSC. There was no effect (P ≤ 0.33) of corn processing on plasma glucose, plasma GIP concentrations, hot carcass weight, dressing percentage, or marbling score. There was a positive linear relationship (P = 0.03) between IM fat concentration and plasma GIP concentration. In conclusion, feeding CC increased gain:feed ratio compared with WSC, but there was no difference in plasma GIP concentration, whereas plasma GIP concentration appears to be related to IM fat deposition.

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ABSTRACT. This study was realized to evaluate the production and economic viability of finished beef cattle in feedlot in the Cerrado biome of Piauí State, Brazil. One hundred and fifty cattle -50 bulls (B) with an body weight of 283.0 ± 20.82 kg, at 30 months of age; and 100 cull cows (CC) with an body weight of 296.1 ± 17.80 kg, at 100 months of age-were used in a completely randomized design. The animal performance indicators for the evaluation of economic viability were initial age (months), slaughter age (months), was initial body weight (kg), final body weight (kg), daily feed intake (kg animal produced), and average price of the kg of meat for finishing (R$). The CC consumed more sorghum silage and concentrate than B (p < 0.05).There was a difference between the categories (p < 0.05) for gross revenue, balance, opportunity cost, and net revenue per animal, with higher values found for the steer category. The animal category did not affect the profitability of the system, although the bulls provided lower revenues than cull cows.Keywords: performance, production systems, rate of return.Produção e economicidade de categorias de bovinos de corte em confinamento RESUMO. Objetivou-se avaliar a produção e a viabilidade econômica de bovinos de corte confinados no bioma Cerrado do estado do Piauí, Brasil. Cento e cinquenta bovinos -50 novilhos não castrados (NNC) com peso corporal de 283,0 ± 20,82 kg, aos 30 meses de idade; e100 vacas de descarte (VD) com peso corporal de 296,1 ± 17,80 kg, aos 100 meses de idade -foram utilizados em delineamento inteiramente casualizado. Os indicadores de desempenho animal para a avaliação da viabilidade econômica foram idade inicial (meses), idade de abate (meses), peso corporal inicial (kg), peso corporal final (kg), ingestão diária de alimento (kg animal produzido) e preço médio do kg de carne para acabamento. Essas variáveis foram obtidas a partir da coleta de dados realizada durante o experimento. As VD consumiram mais silagem e concentrado de sorgo do que os NNC (p < 0,05). Houve diferença entre as categorias (p < 0,05) para a receita bruta, o saldo, o custo de oportunidade e a receita líquida por animal, com maiores valores encontrados para NNC. A categoria de animais não afetou a rentabilidade do sistema, embora os novilhos tenham fornecido menores receitas do que as vacas de descarte.Palavras-chave: desempenho, sistemas de produção, taxa de retorno.

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SUMMARY The objectives of this trial were to evaluate intake and nutrient digestibility, weight gain, and carcass characteristics of grazing lambs supplemented with increasing dietary inclusion of castor bean meal (CBM). Thirty-six Santa Inês-crossed, non-castrated, 120 ± 15 d old lambs (initial BW = 21.8 ± 3.4 kg) were randomly allotted to 1 of 4 dietary treatments. The treatments consisted of 4 levels of soybean meal substitution with lime treated CBM (0, 33, 67, and 100%) on the DM basis. The experimental design was a completely randomized design with 4 treatments and 9 replicates (lambs) for each treatment. Supplementation level was 1.6% BW per animal/d. There was a linear decrease (P<0.01) for total DM intake and a quadratic effect (negative; P = 0.05) for pasture intake as CBM was increased in the supplement. There was a negative quadratic effect of CBM inclusion on NDFap intake, both in g/d (P = 0.01) and as in BW % (P = 0.05). There was a linear effect (negative; P<0.01) on DM and NDFap digestibility coefficients. There were no effects (P≥0.48) of treatments on HCW, dressing percentage, carcass conformation, back fat or carcass length. Despite some negative effects on intake and nutrient digestibility, increasing CBM inclusion in the supplement, up to the substitution of all the soybean meal in the supplement, did not affect weight gain of grazing lambs or carcass characteristics.

Objectives were to determine the dietary inclusion level of NaOH in a dried distillers grains with solubles (DDGS)-based diet needed to improve growth performance and carcass characteristics of feedlot steers, and to determine the effects of NaOH treatment of DDGS on pattern of feed intake. Based on previous research regarding the acidity of DDGS, we hypothesized that using NaOH in cattle fed 50% DDGS-based diets to neutralize the acidity inherent in DDGS would improve growth performance of cattle but shift intake patterns. Angus-cross steers (120 total) were blocked into 2 BW blocks (light, initial BW = 211 ± 27 kg; and heavy, initial BW = 261 ± 27 kg) and allotted randomly within block to 20 pens (6 steers per pen; = 30). Pens within block were assigned randomly to 1 of 4 dietary treatments: 1) 50% DDGS, untreated; 2) 50% DDGS, treated with 0.5% NaOH (DM basis); 3) 50% DDGS, treated with 1.0% NaOH (DM basis); or 4) 50% DDGS, treated with 1.5% NaOH (DM basis). The remainder of the diets contained 20% dry-rolled corn, 20% corn silage, and 10% mineral and vitamin supplement, on a DM basis. Cattle were fed in a GrowSafe system. There were no effects ( ≥ 0.21) of increasing NaOH inclusion on final BW, ADG, or G:F. Increasing NaOH in the diet increased meal duration (linear; = 0.02) and tended to increase meal size (linear; = 0.06), but did not affect overall number of meals per day (linear; = 0.21) or overall DMI ( ≥ 0.40) for the course of the trial. Relative to cattle fed DDGS treated with 0, 0.5 or 1% NaOH (DM basis), steers fed DDGS treated with 1.5% NaOH consumed a larger proportion of their meals in the afternoon. However, regardless of treatment, all steers consumed 78% or more of their feed in the first 12 h post-feeding. There were no effects ( ≥ 0.19) of increasing NaOH inclusion on HCW, LM area, dressing percentage, KPH, back fat thickness, and marbling. There was a linear ( = 0.02) decrease in USDA Yield Grade (YG) 3 and a tendency ( = 0.09) for a quadratic response in carcasses grading USDA YG 4 as NaOH concentration increased in the diets; however, there were no other YG differences. The quality grade response followed marbling score and was not different ( ≥ 0.11) among treatments. Thus, there were no effects of feeding DDGS treated with NaOH on growing cattle performance or carcass characteristics. However, NaOH inclusion shifted the pattern of intake slightly to the afternoon hours, and increased meal duration without increasing the total number of meals per day.

The objectives were to determine the optimum inclusion of NaOH necessary to buffer the acidity of dried distillers' grains with solubles (DDGS) and its effects on digestibility, ruminal metabolism, and metabolic acidosis in feedlot steers. Rumen cannulated Angus-crossed steers were blocked by BW (small: 555 ± 42 kg initial BW, = 4; large: 703 ± 85 kg initial BW, = 4) over four 21-d periods in a replicated 4 × 4 Latin square design. Steers were assigned to 1 of 4 dietary treatments: 1) 50% untreated DDGS, 2) 50% DDGS treated with 0.5% (DM basis) sodium hydroxide (NaOH), 3) 50% DDGS treated with 1.0% (DM basis) NaOH, and 4) 50% DDGS treated with 1.5% (DM basis) NaOH. The remainder of the diets, on a DM basis, was composed of 20% corn silage, 20% dry-rolled corn, and 10% supplement. Ruminal pH was not affected by treatments ( = 0.56) or by a treatment × time interaction ( = 0.15). In situ NDF and ruminal DM disappearance did not differ ( ≥ 0.49 and ≥ 0.47, respectively) among treatments. Similar to in situ results, apparent total tract DM and NDF digestibility were not affected ( ≥ 0.33 and ≥ 0.21, respectively) by increasing NaOH inclusion in the diets. Urinary pH increased (linear, < 0.01) with increasing NaOH concentration in the diet. Blood pH was not affected ( ≥ 0.20), and blood total CO and partial pressure of CO were similar ( ≥ 0.56 and ≥ 0.17, respectively) as NaOH increased in the diet. Increasing NaOH in the diet did not affect ( ≥ 0.21) ruminal concentrations of total VFA. There were no linear ( = 0.20) or quadratic ( = 0.20) effects of treatment on ruminal acetate concentrations, nor was there a treatment × time interaction ( = 0.22) for acetate. Furthermore, there were no effects ( ≥ 0.90) of NaOH inclusion on ruminal propionate concentration. However, there was a quadratic response ( = 0.01) of ruminal butyrate concentrations as NaOH inclusion increased in the diet; ruminal butyrate concentrations were greatest with the 0.5 and 1.0% NaOH treatments of DDGS. In the current study, feeding DDGS treated with NaOH did not increase fiber digestibility nor was it necessary to alleviate a possible metabolic acidosis. Alkali treatment of DDGS did not increase average ruminal pH or blood pH.

The objective of this study was to evaluate productive traits in sheep fed roughage-free diets by multivariate analysis. Forty lambs were used in this study: 20 Santa Inês animals, consisting of 10 uncastrated males and 10 females; and 20 crossbreds (½ Santa Inês × Dorper), consisting of 10 uncastrated males and 10 females, at an average age of five months. Lambs were randomly allocated into the following treatments: Santa Inês males fed once daily (SM1); Santa Inês males fed twice daily (SM2); Santa Inês females fed once daily (SF1); Santa Inês females fed twice daily (SF2); crossbred males fed once daily (CM1); crossbred males fed twice daily (CM2); crossbred females fed once daily (CF1); and crossbred females fed twice daily (CF2). In the multivariate analysis, a difference was detected between the mean values for production classes and feeding-behavior variables (Wilks, Pillai, Hotelling-Lawley, and Roy tests). Tocher's optimization method had two groups formed: Group I, comprising treatments SM1, SM2, SF1, SF2, CF1, and CF2; and Group II, containing treatments CM1 and CM2 (crossbred males). When production and cud chews per day were evaluated, neutral detergent fiber digestibility and final weight were the performance-digestibility variables that most contributed to explaining the variation between treatments. When the feeding behavior was assessed, the time spent on other activities was the variable that most contributed. The crossbred genotype (½ Santa Inês × Dorper) and the male sex have superior performance for weight-related traits. However, when these animals are confined with females, it is recommended to supply the feed only once daily, irrespective of the genetic group.