Angélica Simone Cravo Pereira

Desempenho e características de carcaça de novilhos alimentados com dietas contendo diferentes fontes de lipídios

The objective of this trial was to evaluate the animal performance, carcass characteristics and meat tenderness of 36 crossbred steers averaging 14 months old and 320 kg body weight. The animals were fed high concentrate-based diets: control - without additional fat (CO); diet with 5% calcium salt of fatty acids (AG); and diet with 21% whole cottonseed (CA). Dry matter intake of AG treatment was lower (P=0,05) than CA, that differ from CO diet. No significant differences of treatments on daily weight gain and feed efficiency were observed. Blood urea nitrogen was greater (P=0,01) for CA treatment than AG treatment. Carcass dressing, rib eye area, fat thickness, kidney and pelvic fat, liver weight, pH and temperature did not show significant difference. No difference on water loss during cooking and tenderness measured by shear force at different aging times was detected. Diets with 5% calcium salt of fatty acids or 21% whole cottonseed can be used for feedlot with no change on animal performance or carcass characteristics.

Utilização do Bagaço de Cana-de-Açúcar em Dietas com Elevada Proporção de Concentrados para Novilhos Nelore em Confinamento

The objective of this work was to evaluate the performance and carcass characteristics of cattle fed high concentrate diets containing 15, 21 or 27% of sugarcane bagasse in the dry matter. Twenty-four Nellore steers with 279 kg of shrunk body weight and 24 months of age, two per pen, were fed for 98 days. No significant effects were observed for average daily gain (mean =1.461 kg) and feed efficiency among the treatments. It was observed a linear effect between dry matter intake and levels of bagasse, with greater intake in treatments with lower proportion of bagasse. Consistent with intake, the liver weight presented linear association with bagasse levels, with higher weight in treatments with more concentrate. The hot carcass weight, kidney, pelvic, heart and inguinal fat, ribeye area and fat thickness were no different between treatments. However, it was observed a linear association between dressing percentage and bagasse levels, with higher percentage in treatments with more concentrate, consistent with the energy level of the diet. The results showed the viability of the use of 15 or 21% of sugarcane bagasse as the only roughage in high concentrate diets with corn, citrus pulp and soybean meal for Nellore steers in feedlot.

Características da Carcaça e Qualidade da Carne de Tourinhos Alimentados com Dietas de Alta Energia

Thirty six 3⁄4 European 1⁄4 Zebu bulls were fed diets containing 9, 15 and 21% of the dry matter as sugar cane bagasse in natura (BIN). The animals, with initial body weight of 257 kg, were slaughtered with 435 kg, after 138 days on feed. Measurements in the carcass and the 9-10-11th rib cut physical composition were taken. Samples of Longissimus dorsi and Supraspinatus muscles, aged 0, 7 and 14 days, were analyzed for texture and color. Renal, pelvic and inguinal fat was higher for treatments with 9 and 15% of BIN. There was a tendency for greater backfat thickness in the treatments with 9 and 15% of BIN. BIN level in the diets had no effect on physical composition or carcass characteristics. However, greater fat deposition in the inguinal and pelvic region was observed in treatments with greater energy. The objective texture (WB) was different with ageing in the two muscles, with greater tenderness after 14 days than after 7, or 0 day. No significant differences in meat color were observed due to the BIN levels, but affected this characteristic. The aged steaks (0 and 14 days) were more tender and brilliant and their colors enhanced. Results suggest aging has great benefits on tenderness in young intact males with carcasses of 230 kg and 4 mm of fat thickness.Thirty six ¾ European ¼ Zebu bulls were fed diets containing 9, 15 and 21% of the dry matter as sugar cane bagasse in natura (BIN). The animals, with initial body weight of 257 kg, were slaughtered with 435 kg, after 138 days on feed. Measurements in the carcass and the 9-10-11th rib cut physical composition were taken. Samples of Longissimus dorsi and Supraspinatus muscles, aged 0, 7 and 14 days, were analyzed for texture and color. Renal, pelvic and inguinal fat was higher for treatments with 9 and 15% of BIN. There was a tendency for greater backfat thickness in the treatments with 9 and 15% of BIN. BIN level in the diets had no effect on physical composition or carcass characteristics. However, greater fat deposition in the inguinal and pelvic region was observed in treatments with greater energy. The objective texture (WB) was different with ageing in the two muscles, with greater tenderness after 14 days than after 7, or 0 day. No significant differences in meat color were observed due to the BIN levels, but affected this characteristic. The aged steaks (0 and 14 days) were more tender and brilliant and their colors enhanced. Results suggest aging has great benefits on tenderness in young intact males with carcasses of 230 kg and 4 mm of fat thickness.

Gene expression profile of intramuscular muscle in Nellore cattle with extreme values of fatty acid

BackgroundFatty acid type in beef can be detrimental to human health and has received considerable attention in recent years. The aim of this study was to identify differentially expressed genes in longissimus thoracis muscle of 48 Nellore young bulls with extreme phenotypes for fatty acid composition of intramuscular fat by RNA-seq technique.ResultsDifferential expression analyses between animals with extreme phenotype for fatty acid composition showed a total of 13 differentially expressed genes for myristic (C14:0), 35 for palmitic (C16:0), 187 for stearic (C18:0), 371 for oleic (C18:1, cis-9), 24 for conjugated linoleic (C18:2 cis-9, trans11, CLA), 89 for linoleic (C18:2 cis-9,12 n6), and 110 genes for α-linolenic (C18:3 n3) fatty acids. For the respective sums of the individual fatty acids, 51 differentially expressed genes for saturated fatty acids (SFA), 336 for monounsaturated (MUFA), 131 for polyunsaturated (PUFA), 92 for PUFA/SFA ratio, 55 for ω3, 627 for ω6, and 22 for ω6/ω3 ratio were identified. Functional annotation analyses identified several genes associated with fatty acid metabolism, such as those involved in intra and extra-cellular transport of fatty acid synthesis precursors in intramuscular fat of longissimus thoracis muscle. Some of them must be highlighted, such as: ACSM3 and ACSS1 genes, which work as a precursor in fatty acid synthesis; DGAT2 gene that acts in the deposition of saturated fat in the adipose tissue; GPP and LPL genes that support the synthesis of insulin, stimulating both the glucose synthesis and the amino acids entry into the cells; and the BDH1 gene, which is responsible for the synthesis and degradation of ketone bodies used in the synthesis of ATP.ConclusionSeveral genes related to lipid metabolism and fatty acid composition were identified. These findings must contribute to the elucidation of the genetic basis to improve Nellore meat quality traits, with emphasis on human health. Additionally, it can also contribute to improve the knowledge of fatty acid biosynthesis and the selection of animals with better nutritional quality.

Growth performance, and carcass and meat quality traits in progeny of Poll Nellore, Angus and Brahman sires under tropical conditions

This study aimed to characterise progeny of sires representing major families in the Poll Nellore breed. Fourteen Poll Nellore sires, two Angus sires and one Brahman sire were mated by AI to ~400 multiparous Poll Nellore dams. Calves were raised and stocked on pasture in central Brazil until reaching ~18 months of age, then fed a sugarcane bagasse-based diet on an ad libitum basis until reaching market weight and finish (average 23 months). There were 236 Poll Nellore (N), 38 Angus × Poll Nellore (AN) and 31 Brahman × Poll Nellore (BN) calves born in total. The weaning and 423-day weight weights, and growth rates and pre- and post-weaning were greater (P 0.05) by sex or by sire within N, but was lowest (P 0.05). Heifers reached the end of the study with lower bodyweight (BW) and dressing percentage than steers, resulting in lower carcass weights, smaller longissimus muscle areas (LMA), but greater 12th to 13th rib backfat (BF) and similar marbling score and mean shear force. However, the proportion of carcasses grading Choice or Prime was numerically greater in heifers than in steers (23.6% vs 9.8%). AN cattle reached greater harvest weights than BN, and those were heavier than N cattle (P < 0.001). However, dressing percentages were lowest in AN animals, so that there was no significant difference in carcass weight between AN and BN cattle. AN carcasses also had greater LMA, BF and marbling scores than the N carcasses. The proportion of carcasses grading Choice or Prime was numerically greater in AN cattle than in the BN and N groups (25.9%, 11.8% and 15.9%, respectively). Steaks from AN calves were more tender than N steaks, with the BN steaks being intermediate. There was significant variation among N sires for final BW, dressing percentage, carcass weight, LMA and marbling score, but not for BF or mean shear force. The percentages of carcasses of N cattle grading Choice or Prime ranged from 0% to 61.5%. Three N sires produced progeny with greater than 40% of carcasses grading Choice or above (Berilio OB, Furador OB, and Litoral OB). Likewise, three N sires (Blitz OB, Furador OB and Sossego OB) had progeny with 67%, 62% and 75%, respectively, of steaks classified as tender. This study confirmed that Zebu cattle have inferior carcass and meat quality relative to AN crossbreds under tropical conditions, however there is substantial variation within the N breed for these traits, and several sires have a proportion of their progeny comparable in terms of meat tenderness to those of Angus sires.

Lipid and selenium sources on fatty acid composition of intramuscular fat and muscle selenium concentration of Nellore steers

The objective of this study was to evaluate the effect of lipid and selenium sources in diets for finishing Nellore steers on the fatty acid composition and selenium concentration of the longissimus muscle. Fifty Nellore steers (body weight = 458±39 kg) were assigned to one of six dietary treatments: 1) diet containing sunflower seed and inorganic selenium; 2) sunflower seed and organic selenium; 3) whole cottonseed and inorganic selenium; 4) whole cottonseed and organic selenium; 5) soybeans and inorganic selenium; and 6) soybeans and organic selenium. Diets were formulated with the same amount of nitrogen and calories and supplied once daily to steers in collective pens, with three animals per pen, for 120 d. At the end of the trial, steers were slaughtered and samples of the longissimus muscle were collected for fatty acid and selenium analysis. Effect of selenium sources was detected for selenium concentration in the longissimus muscle. Organic selenium had higher concentrations in the meat compared with inorganic selenium. The total saturated, monounsaturated and polyunsaturated fatty acids did not differ between the sources of lipids and selenium. For selenium sources, no differences were observed between the concentrations of polyunsaturated fat. Also, no differences in C18:2 cis-9 trans-11 concentrations were noted; however, steers fed sunflower seed presented greater proportions of this fatty acid in the meat. The results indicated that the use of sunflower seed, cottonseed or soybeans and organic or inorganic selenium in feedlot diets to Nellore cattle does not alter the great part of the fatty acid profile of the longissimus muscle. However, the inclusion of sunflower seed in the diet increases the meat CLA cis-9, trans-11, which is desirable and beneficial for the health of consumers.

Days on feed and sex effects on live weight and carcass traits measured by ultrasound

Existem poucos dados na literatura sobre as alteracoes na composicao corporal de bovinos Nelore e seus cruzamentos, especialmente em relacao a novilhas (NOV) e machos inteiros (MI). A ultra-sonografia e uma ferramenta util para obter essa informacao de forma facil, com minimo disturbio ao animal e a baixo custo. Efeitos do sexo e dias de confinamento sobre o peso vivo (PV) e a area do musculo Longissimus dorsi (AOLU) e a espessura de gordura subcutânea (EGSU) medidas por ultra-som, foram avaliadas em 27 novilhas e 27 machos inteiros, F1 Piemontes ´ Nelore. NOV e MI com PV inicial de 256 ± 5,6 e 265 ± 5,6 kg, respectivamente, foram confinados com uma dieta contendo 77% de NDT, durante 131 dias. O PV, a AOLU e a EGSU foram avaliadas a cada 28 dias aproximadamente. Foi observada uma interacao entre sexo e dias de confinamento para todas as caracteristicas avaliadas. O PV aumentou linearmente com os dias de confinamento e MI apresentaram maior PV que as NOV desde o inicio do experimento. A AOLU media inicial foi 55,8 e 55,5 cm2 nas NOV e MI, respectivamente, aumentando linearmente ate o final do confinamento (78,7 e 82,8 cm2, respectivamente). Em relacao ao efeito do sexo, MI tiveram maior AOLU que NOV somente na ultima medida. A EGSU inicial foi 0,04 e 0,4 mm para MI e NOV, respectivamente e aumentaram linearmente durante e periodo de confinamento (2,4 e 4,3 mm, respectivamente). NOV tiveram maior EGSU desde o inicio ate o final do periodo experimental. MI tiveram maiores taxas de crescimento do PV e AOLU que NOV, no entanto, estas tiveram maior taxa de crescimento da EGSU.

Genetic parameters for fatty acids in intramuscular fat from feedlot-finished Nelore carcasses

The aim of the present study was to estimate covariance components and genetic parameters for beef fatty acid (FA) composition of intramuscular fat in the longissimus thoracis muscle in Nelore bulls finished in feedlot. Twenty-two FAs were selected. The heritability estimates for individual FAs ranged from 0.01 to 0.35. The heritability estimates for myristic (0.25 ± 0.09), palmitic (0.18 ± 0.07), oleic (0.28 ± 0.09), linoleic (0.16 ± 0.06) and α-linolenic (0.35 ± 0.10) FAs were moderate. Stearic, elaidic, palmitoleic, vaccenic, conjugated linoleic acid, docosahexanoic, eicosatrienoic and arachidonic FAs had heritability estimates below 0.15. The genetic-correlation estimates between the individual saturated FAs (SFAs) were low and negative between myristic and stearic FAs (–0.22 ± 0.84), moderate between palmitic and myristic FAs (0.58 ± 0.56) and negative between palmitic and stearic FAs (–0.69 ± 0.45). The genetic correlations between the individual long-chain polyunsaturated FAs (PUFAs) were positive and moderate (>0.30). However, the genetic-correlation estimates between long-chain PUFAs and α-linolenic acid were low (<0.30), except for the correlation between arachidonic and α-linolenic acids. The genetic correlation estimates of the sums of SFAs with monounsaturated fatty acids and omega 6 FAs were low (0.25 ± 0.59 and –0.02 ± 0.51 respectively), high with PUFAs and omega 9 FAs (–0.85 ± 0.15 and 0.86 ± 0.17 respectively) and moderate with omega 3FAs (–0.67 ± 0.26). The present study demonstrated the existence of genetic variation and, hence, the possibility to increase the proportion of healthy and favourable beef FAs through selection. The results obtained in the study have provided knowledge to elucidate the additive genetic influence on FA composition of intramuscular fat. In addition, genetic-relationship estimates of intramuscular FA profile help seek strategies for genetic selection or genetic-based diet management to enhance the FA profile in Zebu cattle.

Fatty acid composition of the longissimus dorsi muscle in crossbred steers fed different sources of fatty acids

The objective of this study was to evaluate the fatty acid composition of the longissimus dorsi muscle in carcasses of ¾ Bos taurus taurus ¼ Bos taurus indicus steers fed different sources of fatty acids. Thirty-six steers aged 14 months, with a mean live weight of 320 kg, were fed the following diets for 96 days: 1) control diet, containing no supplemental fat source; 2) CaSFA, diet containing 50 g calcium salts of fatty acids per kg total dry matter; 3) CS diet, containing 210 g cottonseed per kg total dry matter. The fatty acid composition of the longissimus dorsi muscle was determined by gas chromatography. No difference in slaughter weight, carcass weight, backfat thickness, or longissimus dorsi muscle area was observed between animals receiving the diets CaSFA and CS. Animals consuming the two fat-supplemented diets presented higher concentrations of oleic (C18:1), palmitic (C16:0) and stearic (C18:0) acids, corresponding to an average 80.76% of total fatty acids, and higher concentrations of vaccenic acid (C18:1 t11) in the muscle when compared with the control group. Supplementation of the diet of feedlot crossbred steers with CaSFA or cottonseed did not promote significant alterations in the lipid composition of the longissimus dorsi muscle.

Propionato de cálcio no amaciamento do músculo Longissimus dorsi de bovinos de corte

A maciez da carne e influenciada pela atuacao do sistema proteolitico das calpainas, durante o processo de maturacao pos-morte. O propionato de calcio fornece calcio suficiente para aumentar a concentracao de calcio plasmatico e, assim, ativar essas proteases dependentes de calcio, melhorando a maciez da carne. Os objetivos desta pesquisa foram avaliar o efeito do fornecimento via oral de propionato de calcio nas caracteristicas quali-quantitativas da carcaca de bovinos de corte. Neste estudo, 24 machos castrados (3/4 Simental+1/4 Nelore) receberam, por via oral, os tratamentos 0 ou 630 g de propionato de calcio, 12 horas antes do abate. Apos o abate, foram estudados o amaciamento e as perdas por cozimento apos 1, 8 e 15 dias de maturacao, a analise sensorial, o pH da carne, a area do olho do lombo, a espessura de gordura, os rendimentos da carcaca e a concentracao de calcio no plasma e no musculo Longissimus dorsi. Os resultados mostraram que o tratamento com propionato de calcio nao teve efeito sobre as caracteristicas de carcaca, a concentracao de calcio no musculo Longissimus dorsi, a forca de cisalhamento, as perdas por cozimento e a maciez, o sabor e avaliacao geral na analise sensorial. O tratamento com propionato de calcio aumentou a concentracao de calcio plasmatico e melhorou a suculencia sensorial.