Gelson Luís Dias Feijó

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.

Desempenho animal e avaliação do potencial produtivo de forragens para ensilagem, por intermédio de diferentes fontes de suplementação nitrogenada

This study was conducted to evaluate the corn (Zea mays L.) AG 1051 and the sorghums (Sorghum bicolor (L.) Moench) AG 2006 and BR 303, for silage production, and the effect of substitution of soybean meal by urea (0,50 and 100%) in the concentrated diets for feedlot cattle. The silages were used in two experiments and the animals were alloted to a completely experimental design. In the first, 72 F1 crossbred Brown Swiss x Nellore bulls, with 20 months of age and 412 kg LW were distributed to a 3x3 factorial arrangement (corn silage and sorghums silage and level of substitution of soybean meal by urea). In the second, 48 Nellore steers, with 34 month of age and 378 kg LW, were allotted to a 2 x 3 factorial arrangement (sorghum silage and level of substitution of soybean by urea). There were no differences between the forages as for production/ha of total dry matter and leaves, stem and of ear/panicle ratio. The corn and sorghum BR 303 plants presented about 53% of ear/panicle ratio as compared to 45% of the sorghum AG 2006. There was no interaction between the silage and the nitrogen source. The corn silage provided better performance for the crossbred bulls. Economically, the highest profit was obtained by using corn silage and soybean meal. The performance of Nellore steers was not affected by silage type or nitrogen source. There were no differences in the economic return for the silages. However, for the nitrogen source, the higher economic return was obtained by the use of urea followed by soybean meal + urea mixture and, finally, by soybean meal.

Efeito de idade à castração e de grupos genéticos sobre o desempenho em confinamento e características de carcaça

Seventy-one animals from two genetic groups, ½ Angus - ½ Nellore (AN) and ½ Simmental ¾ ½ Nellore (SN) with different growth potential, which belonged to the Projeto Cruzamento Embrapa 1 were used. These groups were submitted to seven castration treatments. It was observed that the SN animals delayed 14 more days in feedlot in order to be slaughtered in the same degree of finishing as the AN (131 days versus 117 days, respectively) animals. The other evaluated traits, slaughter weight, cold carcass weight, carcass dressing, longissimus muscle area, were not affected by genetic group. The averages for these traits in this same sequence were 471 kg and 476 kg, 266 kg and 274 kg, 58.13% and 57.46% and 72.71 cm2 and 75.79 cm2 for AN and SN animals, respectively. The comparisons among treatment means were carried out through six different contrasts. It was observed that young bulls delayed under feedlot confinement 25 more days than those castrated at birth (136 days versus 111 days, respectively). However, these animals showed heavier slaughter weight than those castrated at birth (515 kg versus 463 kg, respectively). Animals castrated at birth stayed longer in feedlot than those castrated at weaning or castrated as yearling (111 days versus 95 days, respectively). Animals feedlot confined just after weaning, as it should be expected, were those that delayed longer under feedlot confinement (181 days). Since these animals were one year younger than the other animals, the longer time required for them to attain the end point did not result in heavier slaughter weights (455 kg). The average carcass dressing independent on genetic group and treatment was 57.79%.

Avaliação das carcaças de novilhos F1 Angus-Nelore em pastagens de Brachiaria decumbens submetidos a diferentes regimes alimentares

This trial was conducted at National Beef Cattle Research Center of Brazilian Agricultural Research Corporation (Embrapa Beef Cattle). Forty five F1 Aberdeen Angus-Nellore steers were used to evaluate the effects of different dry seasons feeding schemes on carcass characteristics. The treatments were: control, without supplementation (S/S); supplementation in 2nd dry period (S2S); supplementation in 1st dry period (S1S); supplementation in 1st and 2nd dry periods (S12S) and supplementation in 1st dry period and confinament in 2nd one (S1C2). Animals were slaughtered at 460-480 kg of live weight and the treatments effects were evaluated by least square means. Steers with higher nutritional levels in 2nd dry season (S1C2; S2S; S12S) showed more dressing percentage and higher hot and cold carcass weights than those supplemented only in 1st dry period or non supplemented. Animals supplemented only in 1st dry season showed similar carcasses than non supplemented. It was concluded that increasing the 2nd dry season nutritional level is primary to expand the dressing percentage. Supplementation in 1st dry period solitarily does not affect dressing percentage neither carcass quality.

Identification of KCNJ11 as a functional candidate gene for bovine meat tenderness

The potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11) gene was investigated as a candidate for meat tenderness based on the effects reported on muscle for KCNJ11 gene knockout in rat models and its position in a quantitative trait locus (QTL) for meat tenderness in the bovine genome. Sequence variations in the KCNJ11 gene were described by sequencing six amplified fragments, covering almost the entire gene. We identified single nucleotide polymorphisms (SNP) and validated them by different approaches, taking advantage of simultaneous projects that are being developed with the same Nelore population. By sequencing the KCNJ11 in Nelore steers representing extreme phenotypes for Warner-Bratzler shear force (WBSF), it was possible to identify 22 SNPs. We validated two of the identified markers by genotyping the whole population (n = 460). Analysis of association between genotypes and WBSF values revealed a significant additive effect of a SNP at different meat aging times (P ≤ 0.05). In addition, an association between the expression levels of KCNJ11 and WBSF was found, with lower expression levels of KCNJ11 associated with more tender meat (P ≤ 0.05). The results showed that the KCNJ11 gene is a candidate mapped to a QTL for meat tenderness previously identified on BTA15 and may be useful to identify animals with genetic potential to produce tender meat. The effect of KCNJ11 observed on muscle is potentially due to changes in activity of KATP channels, which in turn influence the flow of potassium in the intracellular space, allowing establishment of the membrane potential necessary for muscle contraction.

Association of polymorphisms in the leptin and thyroglobulin genes with meat quality and carcass traits in beef cattle

The objective of the present study was to estimate the allelic and genotypic frequencies of the polymorphisms E2FB (AY138588.1: c.305C> T), located in the leptin gene (LEP), and TG5 (X05380.1:g.-422C>T), located in the thyroglobulin gene (TG), and evaluate the association of these polymorphisms in crossbred cattle of seven distinct genetic groups with the following traits: slaughter weight (SW), hot carcass weight (HCW), hot carcass yield (HCY), carcass fat thickness (CFT), ribeye area (REA), marbling (MARM) and shear force (SF). The animals were genotyped using the PCR-RFLP (Polymorphism Chain Reaction-Restriction Fragment Length Polymorphism) technique, using 201 products obtained from F1 Caracu × Nellore, Angus × Nellore and Valdostana × Nellore cows, mated to Canchim, Caracu and Red Angus bulls (only Caracu × Nellore cows were used with Red Angus bulls). The allelic and genotypic frequencies were compared using the Chi-squared test. Associations between the genotype of each polymorphism and the traits were analyzed using the General Linear Model (GLM) of statistical software SAS. The least squares means of genotypes of the polymorphisms were compared using Students t test. The E2FB polymorphism in the LEP gene was associated with CFT, showing the potential for use in national programs for genetic improvement of beef cattle, through the inclusion of SNP in genotyping commercial tests. The TG5 polymorphism in the TG gene was not associated with any of the evaluated traits and was considered ineffective for selection of beef cattle in Brazilian herds.

Marinados com soluções alcalinas para a melhoria da qualidade da carne suína

The objective of this work was to evaluate the effects of alkaline solution marinades on the characteristics of pork subjected to post-mortem pH decrease in pig muscle. The pH of carcasses was measured in a commercial slaughterhouse (n = 526), 45 min after slaughtering (pH45) and, then, the carcasses were divided into the groups with pH45 5.7. Ten samples of the longissimus dorsi muscles of each group were collected and distributed in an entirely randomized design, in a 2x4 factorial arrangement, with two conditions (pH45 5.7), and four marinade solutions: TC, no marinade; TM1, sodium bicarbonate and sodium chloride; TM2, sodium tripolyphosphate and sodium chloride; TM3, sodium bicarbonate, sodium tripolyphosphate and sodium chloride. There was no interaction between pH45 of the meat and the marinade treatments. Meat with pH45<5.7 showed higher values for lightness, and for purge loss (PL), exudate loss (EL), cooking loss (CL) and shear force (SF). Marinating increased the pH, reduced the lightness, EL, CL and SF, and improved tenderness, juiciness and flavor of meat. Marinades with solutions containing chloride, bicarbonate, and sodium tripolyphosphate are effective in the improvement of pork quality, making physical characteristics of marinated meat similar to those of fresh pork, as a consequence of accelerated postmortem glycolysis.

Weight gain and control of endo- and ectoparasites of beef heifers treated with allopathic, herbal and homeopathic drugs.

UNLABELLED The aim of this study was to evaluate the efficacy of herbal, homeopathic and allopathic treatments for parasites in beef heifers during two experimental cycles of 318 and 313 days. TREATMENTS NC - negative control (untreated); HH - treated with homeopathic preparation Homeo bovis Parasitário®; PC - (positive control) - treated with 10% moxidectina® and an acaricide formulation of cypermethrin, chlorpyrifos and piperonyl butoxide®; HF - treated with homeopathic preparation Fator C&MC®; and FN - treated with neem cake (torta de neem®) and with neem oil (óleo de neem®). Parasite egg count (EPG), horn fly (Haematobia irritans) and tick (Rhipicephalus (Boophilus) microplus) assessment and animal weighting were performed at 28-day intervals. Blood samples were collected at the first cycle to assess the immune response. Horn fly infestation was not affected by any treatment (P>0.05). The mean number of ticks, which was low in both cycles, was lower (P<0.05) in the first cycle in animals that received PC treatment. In both experimental cycles, the mean EPG of the PC-treated animals was lower (P<0.05) than the animals receiving other treatments. TREATMENTS had no effect on the immune response (P>0.05). The animals treated with allopathic drugs were 22 to 30 kg heavier (P<0.05) than untreated animals or animals treated with alternative drugs.

Características quantitativas e qualitativas da carcaça e da carne de cordeiros alimentados com torta de girassol

This study aimed to evaluate the quantitative and qualitative characteristics of carcass and meat of lambs fed sunflower cake. Were used 28 Suffolk crossbred lambs, with 4 months of age and average weight of 21.00 ± 0.74 kg, divided into four treatments: 0% (control), 10%, 20% and 30% of sunflower cake inclusion (% DM). The criteria adopted for the slaughter was body condition score (3, on scale of 1 to 5). The inclusion of sunflower cake did not influence the measurement of length and carcass depth (P>0.05), pH 24 hours (P>0.05), yields of commercial cuts (P>0.05), as well as fat distribution, fat thickness and marbling (P>0.05). There was a linear effect (P 0.05). In relation to the control treatment, the inclusion of 20% and 30% of sunflower cake influenced negatively the ribeye area (12.00 and 11.43 cm2, respectively) (P<0.05), cold carcass weight (13.19 and 12.58 kg, respectively) (P<0.05), and confinement time (136.85 and 138.39 days, respectively) (P<0.05). The inclusion of 10% of sunflower cake can be recommended for use in diets of feedlot lambs, since it allows the production of meat and carcasses with quantitative and qualitative characteristics satisfactory, without adversely affecting the performance characteristics.