Régis Augusto Carvalho Bernardes

Carcass Traits of Young Red Angus Steers Slaughtered with Different Weights

The carcass quantitative characteristics of feedlot finished Red Angus steers, with initial age of eight months and 189 kg, slaughtered with 340, 370, 400 or 430 kg (SW), were evaluated. The number of days to reach the respective weight was 114, 144, 173 and 213 days. The diet contained 13.13% crude protein, 2.7 Mcal digestible energy/kg DM and a roughage:concentrate ratio of 56:44. Carcass dressing percentage and conformation were not affected by the slaughter weight. The saw cut weight although increasing linearly in weight (91.73; 103.26; 106.20 and 116.66 kg) as the slaughter weight increased, declined linearly when expressed in relation to cold carcass weight. Side cut percentage showed the highest increase (23.36; 25.40; 28.50 and 35%) as the slaughter weight increased, following the increase of subcutaneous fat thickness (3.91; 6.16; 6.16 and 9.58 mm). The Longissimus dorsi muscle (LMA) increased linearly as the slaughter weight increased (LMA = 27.48 + 0.083SW) while the LMA/100 kg of cold carcass weight declined linearly (LMA/100 kg carc. = 45.14 - 0.0425SW). According to the regression equation the minimum subcutaneous fat thickness required by the slaughter weights (3 mm) would be reached at 327 kg of live weight. Considering the minimum carcass weight of 180 kg, it would be reached with the slaughter weight of 337 kg. Using Red Angus breed to produce steers to be slaughtered at young age the slaughter weight should not surpass 400 kg, in order to not exceed the 6 mm of subcutaneous fat thickness, to avoid the carcass trimming for fat excess.

Características de carcaça de bovinos de corte inteiros ou castrados de diferentes composições aciais Charolês x Nelore

The carcass characteristics from young bulls or steers from different breed compositions of Charolais x Nellore were the objective of this study. Seventy beef males from three breeding systems: straightbreds (Charolais (Ch) and Nellore (Ne)), G1 crossbreds (1/2 Ch 1/2 Ne and 1/2 Ne 1/2 Ch) and G2 crossbreds (3/4 Ch 1/4 Ne and 3/4 Ne 1/4 Ch) were used. Thirty-five males were castrated (steers) at seven months and 35 were kept entire (young bulls). The animals were confined from 20 month to the slaughter time, at 24 months of age. No interaction was observed between breed composition and sexual condition, for any of the studied variables. The young bulls showed higher slaughter and carcass weight, forequarter and muscle percentage and conformation, while the steers showed higher fat thickness, fat, pistol cut and sidecut percentage. Among breeding systems, crossbreds animals showed higher values for slaughter weight, carcass weight, dressing percentage, carcass length, leg length, cushion thickness and arm perimeter, and the heterosis values were 16.36, 20.10, 3.08, 3.71, 4.09, 6.04 and 4.56% in G1, and, in G2, of 10.03, 11.48, 1.09, 3.02, 2.49, 6.08 and 4.56%, respectively. Comparing the Ch and Ne breeds, the first showed higher slaughter and carcass weight, while the dressing percentage and carcass fat thickness were better in Ne animals. There was no difference among 1/2 Ch 1/2 Ne and 1/2 Ne 1/2 Ch animals for any one of the studied traits.

Desenvolvimento de bovinos de corte de diferentes grupos genéticos desmamados aos 3 ou 7 meses de idade

The objective of this experiment was to evaluate the performance up to 24 months of age of males from two breeding systems, straightbred (Charolais - C and Nellore - N) and crossbred (1/2 CN, 1/2 NC), submitted to two ages of weaning: T3-weaning at three months of age; T7-weaning at 7 months of age. The calves were maintained from birth to the weaning time with the cows on native pasture and, after weaning, both animals from T3 and T7 were maintained during a period of 30 days in a feedlot. The animals from T3, from 4 to 7 months, were maintained on pearl millet pasture (Pennisetum americanum). The weights at 3, 7, 12, 18 and 24 months of age and the average daily gain (ADG) among the different ages were collected. There was no interaction between the breeding system and genetic group within breeding system and age at weaning for the studied variables. The average daily gain of the T3 calves was lower from 3 to 7 months and higher from 7 to 12 months, afterward no difference was observed in the ADG. The only difference for weight was at 7 months, when T7 calves showed higher weight. The weight at 24 months was 424 and 423 kg, respectively, for T3 and T7. The crossbred animals showed higher ADG from 7 to 18 months and were heavier at 18 and 24 months. The heterosis for ADG ranged from .6 to 29.9%, and for weight at different ages ranged from -.68 to 12.41%. When the nutrition conditions are adequate, the weaning at 3 months does not affect slaughter weight at 24 months of age.

Desempenho na fase de crescimento de machos bovinos inteiros ou castrados de diferentes grupos genéticos

ABSTRACT - The objective of the experiment was to evaluate, during the growth phase, the dry matter intake, weight gain and feed to gainconversion of young bulls and steers, castrated at eight month, from two breeding systems, straightbred (Charolais - C and Nell ore - N) and crossbred( 1 / 2 CN, 1 / 2 NC), as well as to measure the resulting heterosis. The animals were confined from nine to twelve months and fed a 15% crude p roteindiet and a 70:30 forage to concentrate ratio. There was no difference between bulls and steers for dry matter intake (DMI) in k g/animal.day (DMID),DMI per unit of metabolic weight (DMIM) and DMI per 100 kg of live weight (DMIP). The bulls showed a 13,7% higher average daily weightgain (ADG) and were more efficient in the feed to gain conversion (4.66 vs 4.99 kg of DMI/kg of gain) than the steers. The effe ct of castrationon the weight gain was more pronounced in calves sired by C bulls (1.00 vs 1.19 kg) than in calves sired by N bulls (.91 vs .97 kg). The F1 animalsshowed higher ADG than the average of the straightbreds, resulting in 9.28% heterosis. The C calves presented higher DMID and A DG than theN. However, DMIM and DMIP were similar between the two straightbred groups. The F1

Evaluation of Different Sorghum Hybrids (Sorghum bicolor, L. Moench) Related to Plant Components and Produced Silages

The experiment was conducted with the purpose to evaluate the qualitative traits of the plant components and fermentation characteristics of silages from different sorghum hybrids AGX-213, AG-2002 (forage) and AGX-217, AG-2005E (double purpose). The panicle component showed higher percentages of dry matter (DM), crude protein (CP), mineral material (MM) and in vitro dry matter digestibility (IVDMD), and lower percentages of plant cell wall than the stems and leaves. No differences were observed among the sorghum silages for MM and IVDMD percentages. The AG-2005E silage showed higher contents of DM (35.5%), CP (6.69%), ether extract (2.28%) and nitrogen-free extract (58.56%) in comparison with the other genotypes. No difference was observed among the sorghum silages for acid detergent insoluble nitrogen (ADIN) content. The silages of the forage hybrids (AGX-213 and AG-2002) showed lower pH and N-NH3 (% of total N) in comparison with the double purpose (AGX-217 and AG-2005E) hybrids.

Desempenho de vacas Charolês e Nelore desterneiradas aos três ou sete meses

The experiment evaluated the performance of Charolais (C) and Nellore (N) cows of three age classes, young (3 and 4 years), adult (5 to 7 years) and old (8 or more years), weaned at three (early weaning) or seven months in the fall (traditional weaning). The weight of the cows at the fall was 45 kg higher for the cows weaned at three months (T3) than for the cows weaned at seven months (T7). The body condition at seven months was also better for T3 cows (3.3 vs. 2.1 points). The T3 cows had higher weight gain from calving to the end of the reproductive period and showed higher percentage of estrus (81 vs. 51%), of pregnancy (67.2 vs. 37.3%) and shorter interval between calving and first estrus (102 vs. 114 days) than T7 cows. Adult cows displayed better body condition at seven months and showed higher reproductive performance than young and old cows. The difference in pregnancy rate between T3 and T7 was more evident in young cows (42.11 vs. 12.5%) and old cows (51.72 vs. 35.71%) than in adult cows (62.5 vs. 53.33%). The C cows were heavier then N cows, at calving, at three and seven months, and displayed better body condition at seven months. The effect of early weaning on reproductive performance was more evident for C cows. The pregnancy rate of C cows was 80.6% for the T3 and 41.9% for the T7, while for the N cows the percentages were 45.5 and 30.0%, respectively, for T3 and T7. For C cows, milk production and the calves (presence and suckling) showed a stronger suppression on reproduction, than for N cows.

Aspectos quantitativos de carcaças de bovinos de diferentes raças, alimentados com diferentes níveis de energia

The objective of the experiment was to evaluate the carcass quantitative characteristics of feedlot finished steers, slaughtered at 13-14 months of age. Sixteen calves with nine months of age and average initial weight of 220 kg, being eight Aberdeen Angus - AA and eight Hereford - HE, were used. The animals were submitted to two levels of energy, 3.07 or 3.18 Mcal/kg of DM. The complete randomized experimental design was used, with a 2 x 2 factorial arrangement (two breeds vs. two energy levels). Corn silage with 36% of grain in DM was used as roughage. In the treatments with the lower energy level, the concentrate level was 12% and in the higher energy level, 32% of the diet DM. The animals were slaughtered when the average estimated carcass weight reached 190 kg. The AA animals showed higher hot carcass dressing percentage (54.95 vs. 53.75%), higher leg length (64.12 vs. 62.12 cm) and larger Longissimus muscle area per 100 kg of carcass (29.31 vs. 27.41 cm2). The animals fed higher energy level in the diet showed higher leg length (71.75 vs. 64.50 cm) and better carcass conformation score (11.25 vs. 10.12 points). Significant interaction between breed and energy level was observed for subcutaneous fat thickness, and the higher fat thickness was observed for the carcasses of HE animals, that were fed the lowest energy level.

Efeitos de Raça e Heterose na Composição Física da Carcaça e na Qualidade da Carne de Novilhos da Primeira Geração de Cruzamento entre Charolês e Nelore

Carcass characteristics of 463 steers, born during 1984 to 1996, from two breeding systems: straightbreds (S) and F1 crossbreds were studied. The S breeding system included the 188 Charolais (C) and 125 Nellore (N) steers and the F1 included 72 1/2 C 1/2 N and 78 1/2 N 1/2 C steers. F1 steers were superior than the purebreds in carcass fat percentage, muscle / bone relation, muscle + fat / bone relation and marbling score, being heterosis levels of 3.33, 2.92, 3.67, and 23.64%, respectively. Comparing the two breeding systems, it was observed that the straightbred animals were superior than F1 in carcass muscle percentage, being the heterosis level of -3.08%. Within the S breeding system the Charolais showed higher carcass muscle percentage (68.4 vs. 64.4%), muscle / bone relation (3.57 vs. 3.29), muscle + fat / bone relation (4.43 vs. 4.30), texture (3.80 vs. 3.58 points), tenderness (6.81 vs. 4.89 points), flavor (5.82 vs. 5.41 points) and juiciness (6.28 vs. 5.66 points), while the Nellore steers showed higher values for carcass fat percentage (19.6 vs. 16.3%), carcass bone percentage (19.7 vs. 19.2%), Shear force (9.29 vs. 6.01 kg), thawing losses (8.54 vs. 6.79%) and cooking losses (30.72 vs. 28.12%). The crossbreeding between Charolais and Nellore resulted in positive heterosis and additive genetic complementarily for carcass and meat characteristics important to the slaughterhouses and to the consumers.

Características de carcaça e da carne de vacas de descarte de diferentes genótipos charolês x nelore, terminadas em confinamento

The objective of this work was to study the carcass and meat characteristics of cull cows, of different Charolais (C) X Nellore (N) compositions, finished in feedlot. Twenty-five C, 3/4 C + 1/4 N, 1/2 C + 1/2 N cull cows, were used. The dressing percentage was higher for 3/4 C + 1/4 N (51.1%) and 1/2 C + 1/2 N (50.8%) cows than for C (49.0%) cows. Nevertheless, the cold carcass weight was higher for 3/4 C + 1/4 N (272kg) than the C (250kg) cows. Subcutaneous fat thickness was higher for 1/2 C + 1/2 N than for C and 3/4 C + 1/4 N cows, being 6.86, 4.86 and 4.92mm, respectively. The arm perimeter was higher for C (37.4cm) than 1/2 C + 1/2 N (35.3cm) cows. The 1/2 C + 1/2 N cows showed less muscle percentage than the other genotypes and less bone percentage than C cows, and higher fat percentage than 3/4 C + 1/4 N and C, being also superior in muscle + fat / bone ratio (6.52) than C (5.56).

Desempenho e características da carcaça de cordeiros de três grupos genéticos abatidos ao mesmo estágio de maturidade

The objective of this study was to compare the performance and carcass characteristics of lambs from three genetic groups slaughtered at the same stage of maturity, reared in feedlot (confinament). Twenty-three castred male lambs were used. Seven were of the Ideal breed (I), eight were ½ Texel + ½ Ideal (F1) and eight were ¾ Texel = ¼ Ideal (F2). The average age of the lambs was three to four months. The lambs were slaughtered at the moment in wich they attained 65% of the mature weigth of the ewes in their respective genetic group, which corresponded to 25.5kg for Ideal, 30.9kg for F1 and 31.7kg for F2. No significant difference (P>.05) was observed between the three genetic groups for the following parameter: dry matter consumption (g/UTM/day and kg/100kg PV), feed conversion, number of days in confinement, coefficient of loss due to chilling, carcass yeld. The Ideal lambs presented a smaller average daily gain, live weight at slaughter (P .05). The F2 lambs presented higher hot and cold carcass weights (P .05). In relation to the consumption, the F2 cross-bred lambs presented higher consumption (P .05).