Ivan Luiz Brondani

Composição Física da Carcaça, Qualidade da Carne e Conteúdo de Colesterol no Músculo Longissimus dorsi de Novilhos Red Angus Superprecoces, Terminados em Confinamento e Abatidos com Diferentes Pesos

The carcass physical composition, meat quality and cholesterol content in the Longissimus dorsi muscle of 24 Red Angus steers finished in feedlot with different weights were evaluated. Steers average age and weight at the beginning of the feedlot were, respectively, eight months and 189 kg. The number of days on feed was 114, 144, 173 and 213 days to reach the slaughter weight (PA) of 340, 373, 400.6 or 433.6 kg. The carcass composition was affected by the slaugther weight, with a quadratic response for bone percentage (%bone= 92.81 ¾ 0.402PA + 0.0005PA2), being the minimum value of 12% at a PA of 402 kg. The muscle percentage decreased linearly (%musc.= 78.38 ¾ 0.042PA) while the fat percent increased (%fat= 3.92 + 0.052PA). The edible portion:bone ratio showed a quadratic relation with slaughter weight (EP:B= -31.88 + 0.194PA ¾ 0.0002PA2) showing the maximun value of 6.47 for the carcasses produced by animals slaughtered with 395 kg. Muscle:bone ratio did not change with slaughter weight, being the average of 4.4 for all slaughter weights. Meat color and texture were not affected by slaughter weight, while marbling score increased linearly (Marb.= -13.35 + 0.051667PA). Increasing the slaughter weight resulted in lower thawing losses and higher cooking losses. The meat tenderness was not affected by slaughter weight and was classified as tender and very tender. Meat juiciness and palatability were sligthtly above average. The Longissimus dorsi ether extract concentration and cholesterol content were not affected by slaughter weight being 2.35% and 43.07 mg of cholesterol/100 g of muscle, respectively.

Qualidade e composição química da carne de bovinos de corte inteiros ou castrados de diferentes grupos genéticos Charolês x Nelore

Seventy beef males of three breeding systems (BS), straightbreds Charolais (Ch) and Nellore (Ne), G1 crossbreds: 1/2 Ch + 1/2 Ne (1/2 Ch) and 1/2 Ne + 1/2 Ch (1/2 Ne) and G2 crossbreds: 3/4 Ch + 1/4 Ne (3/4 Ch) and 3/4 Ne + 1/4 Ch (3/4 Ne) were used. The number of animals by genetic group was, respectively, 15, 12, 8, 12, 14 and 9. Thirty-five males were castrated (C) at seven months and 35 were kept intact (I). The animals were feedlot finished from 20 to 24 months. The longissimus dorsi muscle was used for the meat evaluation. No significant interaction was observed between genetic composition and sexual condition, for the variables studied. The I males displayed meat with darker color (3.05 vs. 3.78 points) with less amount of marbling (4.26 vs. 5.75 points) and less amount of ether extract (1.73 vs. 2.88%). However they presented larger (66.03 vs. 60.50 cm2) longissimus dorsi area and meat with better palatability, juiciness and tenderness. Ch animals had larger longissimus dorsi than the Ne. In the G1 group, the 1/2 Ch meat showed larger amount of marbling and ether extract and less cooking losses than the 1/2 Ne meat. Between G2 animals, the 3/4 Ne showed meat with larger thawing losses and larger amount of ether extract. In G1 animals meat, the heterosis level reached 18.54% for longissimus dorsi area, 28.10% for ether extract and 64.01% for amount of marbling. In G2, the heterosis was -17.30% for lean texture and 10.40% for longissimus dorsi area.

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.

Características da carcaça de novilhos de gerações avançadas do cruzamento alternado entre as raças Charolês e Nelore, terminados em confinamento

The objective of this work was to evaluate the carcass characteristics of feedlot finished steers, straightbreds (Charolais - C and Nellore - N), and crossbreds from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generations of rotational crossbreeding. Crossbreds showed higher slaughter, hot and cold carcass weights than the average of the purebreds, being the total heterosis, respectively, 14.95; 18.72 and 18.39% in G2, 19.98; 24.16 and 24.59% in G3 and, 18.38; 22.55 and 22.88% in G4. Total heterosis for the three characteristics followed the fluctuation of individual heterozygosis. Heterosis for hot and cold carcass dressing percentage was significant in all generations, being the retained heterosis, respectively, 3.22 and 3.71%. Carcass chilling loss in G2 did not differ from purebreds, but was significantly lower in G3 (-16.73%) and G4 (-12.84%). For carcass physiological maturity, heterosis was negative and significant in G3 and G4. Subcutaneous fat thickness was higher for the crossbreds of the three generations, however, was only significant in G4. For the characteristics related to carcass muscling, heterosis was significant in the three generation for conformation and Longissimus dorsi area, for cushion thickness and arm perimeter, although positive in the three generations, reached significance only in G3 and G4, being the retained heterosis, respectively, 8.09; 11.33; 7.45 and 5.95%. The characteristics related to corporal development showed significant heterosis in all generations, being the retained heterosis 8.55; 5.73 and 4.99%, respectively, for carcass, leg and arm length. The proportion of commercial cuts of the carcass was not affected by heterozygosis, but for their absolute values, heterosis was significant following the carcass weight behavior.

Animal productivity and economic return in oat plus ryegrass pasture fertilized with sources of nitrogen

The objective of this experiment was to evaluate the animal productivity and economic return of the use of urea or ammonium sulfate for fertilization of oat (Avena strigosa Schreb) plus ryegrass (Lolium multiflorum Lam.) pasture. The pasture was established on 04/21/94 and the grazing period occured from 06/05 to 11/06/94. The continuous grazing method with variable stocking rate was used. The animals used were beef heifers, with 10 months of age. The amount of nitrogen used was 200 kg/ha, subdivided in three applications. The source of nitrogen did not significantly affect the average daily gain, .579 and .615 kg, the stocking rate, 873 and 842 kg of live weight/ha and the live weight gain/ha, 428 and 453 kg/ha, for urea and ammonium sulfate, respectively. Nitrogen fertilization represented 34.10 and 47.56% of the total cost of the pasture, when urea and ammonium sulfate were used, respectively. The gross income was of U

Órgãos internos e trato gastrintestinal de novilhos de gerações avançadas do cruzamento rotativo entre as raças Charolês e Nelore terminados em confinamento

299.50 and 318.00/ha and the net income was of U

Produção e Qualidade de Forragem da Mistura de Gramíneas Anuais de Estação Fria sob Pastejo Contínuo

47.90 and 1.90/ha, for urea and ammonium sulfate, respectively. Since no significant difference occurred in live weight gain/ha, the decision of using urea or ammonium sulfate for fertilization of annual winter pasture should be based on the price per kg of nitrogen.

Características quantitativas da carcaça de novilhos jovens e superjovens de diferentes grupos genéticos

The objective of this trial was to investigate the effect of heterosis and genetic group on the yield and weight of internal organs and gastrointestinal tract (GIT) of feedlot purebred (Charolais C and Nellore N) and crossbred steers from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generations of rotational crossbreeding slaughtered at 23 month of age. Crossbred steers from G2, G3 and G4 had, respectively, 14.95, 17.25 and 18.46% higher empty body weight (EBW) than that from purebred animals. A positive heterosis for cold carcass yield expressed as a proportion of EBW (CCYEBW) was observed in G2, G3, and G4. Weights of heart, lungs, and kidneys adjusted for EBW were lower on crossbred compared to purebred steers; the heterosis was significant for the weights of heart (-18.29%) and kidneys (-14.29%) in G3 and for that of lungs (-13.45%) in G4. Weights of all organs of the GIT either expressed as 100 kg of EBW or as proportion of slaughter body weight (SBW) were lower on crossbred than on purebred steers with the exception of rumen weight in G2. Retained heterosis was positive and significant for EBW, CCYEBW and liver weight. However, it was negative for amount of blood and weights of heart and small plus large intestines when expressed as 100 kg of EBW and SBW. Within purebred animals, N showed greater CCYEBW (61.64%) than C (57.09). Conversely, weights of rumen, abomasum, small plus large intestine, and GIT were all higher on C than N steers; excepting for small plus large intestine, the same was observed when weights of the remaining GIT components were expressed as proportion of EBW and SB. These differences partially explain the increased carcass yield on N steers.

Ingestive behavior of feedlot finished young bulls fed different concentrate levels in the diet

The production and quality of forage of annual temperate grasses mixtures under continuous grazing condition were evaluated. The mixtures used were: T1 - Triticale (X Triticosecale) plus ryegrass, T2 - Oat (Avena strigosa) plus ryegrass, and T3 - Triticale plus oat plus ryegrass. Broadrast sowing occurred at 04/21/95, being the area fertilized with 200 kg/ha (05-30-15). The broadcast fertilization was of 175 kg/ha of nitrogen in urea form and it was subdivided in four applications. The establishment of the pasture occurred from 04/21 to 06/08/95 and grazing period was extended in to 11/14/95. The component triticale and oat presented higher contribution in the initial evaluation of the botanical composition of the residue and the ryegrass in the final evaluations. The accumulation rate was 50.8, 55.6, and 42.1 kg DM/haday; crude protein content, 17.7, 18.1, and 16.2%, in vitro organic matter disappearance, 56.4, 56.7, and 57.5%, the % DM of the residue, 23.0, 21.2, and 23.2; and total forage production, 9,696, 10,273, and 8,041 kg DM/ha for T1, T2 and T3, respectively. The mixture of triticale plus ryegrass showed better distribution of production and higher stability in quality during the grazing period.

Efeito do Grupo Genético e da Heterose nas Características Quantitativas da Carcaça de Vacas de Descarte Terminadas em Confinamento

The objective of this trial was to evaluate the carcass quantitative characteristics of two categories: steers and young steers, from two genetic groups, 5/8Charolais (CH) 3/8Nelore (NE) and 5/8NE 3/8CH, and to evaluate the relation among studied variables. The animals were fedlot finished until reaching 430 kg of body weight. Steers were slaughtered averaging 22.8 months old and young steers 15.2 months old. The diet, roughage:concentrate ratio of 60:40 (dry matter basis), contained 10.25% crude protein and 3.18 Mcal of digestible energy/kg of dry matter. The experiment was analyzed as a complete randomized design with six replicates, according to a 2 x 2 (two categories x two genetic groups) factorial scheme. Significant interactions were verified for hot (HDP) and cold (CDP) dressing percentage. 5/8NE 3/8CH young steers showed higher HDP (57.51 vs. 54.10%) and CDP (54.84 vs. 52.62%) than 5/8CH 3/8NE of same category and in relation to 5/8NE 3/8CH steers (55.43 vs. 53.84%, respectively).Young steers showed carcasses with higher subcutaneous fat thickness in mm (6.29 vs. 3.22) and mm/100 kg cold carcass weight (2.71 vs. 1.39), cushion thickness (26.58 vs. 25.17 cm), sidecut percentage (13.45 vs. 11.34) and lower sawcut percentage (50.33 vs. 51.39) than steers. Between genetic groups, 5/8CH 3/8NE animals showed carcasses with higher conformation score (11.00 vs. 10.33 points), and 5/8NE 3/8CH higher leg length (72.46 vs. 69.92 cm), arm length (41.92 vs. 38.46 cm) and forequarter percentage (37.54 vs. 36.43). Carcass conformation was positively correlated with Longissimus dorsi area (r = 0.35), cushion thickness (r = 0.23) and arm perimeter (r = 0.15), and negatively with chilling loss of carcass (r = - 0.35). The correlation coefficient was of 0.55 between subcutaneous fat thickness and sidecut percentage.