Genome-wide interaction study reveals epistatic interactions for beef lipid-related traits in Nellore cattle.

Gene-gene interactions cause hidden genetic variation in natural populations and could be responsible for the lack of replication that is typically observed in complex traits studies. This study aimed to identify gene-gene interactions using the empirical Hilbert-Schmidt Independence Criterion method to test for epistasis in beef fatty acid profile traits of Nellore cattle. The dataset contained records from 963 bulls, genotyped using a 777 962k SNP chip. Meat samples of Longissimus muscle, were taken to measure fatty acid composition, which was quantified by gas chromatography. We chose to work with the sums of saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA), omega-3 (OM3), omega-6 (OM6), SFA:PUFA and OM3:OM6 fatty acid ratios. The SNPs in the interactions where P < 10 - 8 were mapped individually and used to search for candidate genes. Totals of 602, 3, 13, 23, 13, 215 and 169 candidate genes for SFAs, MUFAs, PUFAs, OM3s, OM6s and SFA:PUFA and OM3:OM6 ratios were identified respectively. The candidate genes found were associated with cholesterol, lipid regulation, low-density lipoprotein receptors, feed efficiency and inflammatory response. Enrichment analysis revealed 57 significant GO and 18 KEGG terms ( P < 0.05), most of them related to meat quality and complementary terms. Our results showed substantial genetic interactions associated with lipid profile, meat quality, carcass and feed efficiency traits for the first time in Nellore cattle. The knowledge of these SNP-SNP interactions could improve understanding of the genetic and physiological mechanisms that contribute to lipid-related traits and improve human health by the selection of healthier meat products.

Nitrogen metabolism and protein requirements for maintenance of growing Red Norte bulls.

Dietary protein adjustments can reduce environmental impact and economic losses in production systems. However, we lack information regarding nitrogen (N) metabolism and protein requirements for maintenance of crossbred animals such as Red Norte breed, precluding a precise dietary management. The objective was to evaluate the effect of increasing dietary CP levels (9%, 11%, 13%, 15% and 17%) on intake, digestibility and N balance, as well as to estimate the metabolizable protein requirements for maintenance (MPm) of growing Red Norte bulls. Thirty five animals averaging 280 ± 4.0 kg BW were fed during 45 days in a 60 : 40 forage : concentrate ratio diet in which the last 5 days were used for the digestibility trial. Intakes of CP and non-fibrous carbohydrates (NFCs) and feed efficiency linearly increased (P < 0.05) as CP levels increased, while DM, NDF, nitrogen efficiency use and ether extract were not influenced by CP levels (P > 0.05). Digestibilities of DM, organic matter, ether extract, NFC and CP as well as metabolizable energy intake linearly increased (P < 0.05), and true digestibility of CP was not affected (P > 0.05) by treatments. Urinary N and retained N linearly increased (P < 0.05) with the increase in dietary N. The MPm were estimated as 4.46 g/BW0.75 and the efficiency of use of MPm was 0.673. In conclusion, obtained MPm requirements of growing Red Norte bulls are greater than the values reported in literature for Zebu cattle and dietary CP levels of 15% and 17% exhibited great responses for growing Red Norte cattle. However, a cost-benefit evaluation should be done before its use.

Effects on meat quality and black bone incidence of elevated dietary vitamin levels in broiler diets challenged with aflatoxin.

Vitamins play an essential role in broiler nutrition. They are fundamental for normal metabolic and physiological process, and their requirements for poultry are not fixed and can be affected by multiple factors. In contrast, mycotoxins are a challenging issue because they hinder performance and the immune system. Vitamin supplementation above minimum requirements would permit improvement in productive potential, health, bone and meat quality in a situation of mycotoxin challenge. The objective of this study was to determine the influence of optimum vitamin nutrition in diets contaminated with aflatoxin in broilers from 1 to 44 days of age. A total of 1800 Cobb 500 male chicks were randomized to 15 sets of eight treatment groups, each containing 15 birds using a 2 × 2 × 2 factorial design (commercial vitamin levels and high vitamin levels, two levels of aflatoxin - 0 and 0.5 ppm with binder levels of 0 and 10 000 mg/kg). The mash diets were corn and soybean meal based, formulated according to commercial practices. Feed intake, weight gain and feed conversion were analyzed for birds from 1 to 44 days of age. To determine carcass characteristics (carcass yield, breast yield and leg yield) and black bone syndrome, two birds were slaughtered from each group at 45 days. Other analyses included breast tenderness, water loss by dripping and malonaldehyde concentrations. The results demonstrated that broilers that were fed high levels of vitamins showed better weight gain, feed conversion, carcass yield and breast yield than broilers that were fed diets with commercial vitamin levels (P < 0.05); also, broilers that were fed diets containing 0.5 ppm aflatoxin had lower weight gain, carcass yield and breast yield (P < 0.05). The use of 10 000 mg/kg of binder improved (P < 0.05) feed conversion throughout the rearing period. We conclude that aflatoxin negatively affects performance and carcass yield; however, feeding optimum vitamin nutrition improved these performance traits.

Blood parameters of Nellore steers fed a high concentrate diet in two restricted feeding regimes followed by ad libitum feeding / Parâmetros sanguíneos de novilhos Nelore submetidos à dieta de alto concentrado em dois regimes alimentares sequenciais (fase 1: restrição e fase 2: alimento ad libitum)

Blood parameters of 18 Nellore steers submitted to high concentrate diet in two sequential feeding regimes (phase 1: restriction and phase 2: ad libitum feeding) were evaluated. In the first phase, steers were fed for 56 days three intake levels of dry mat-ter (ad libitum, 75 g dry matter (DM)/kg metabolic body weight (BW0.75) or 60 g DM/kg BW(0.75). In the second phase, from the 57th day on feed, animals fed 60 g DM/kg BW(0.75) and 75 g DM/kg BW(0.75) were fed ad libitum until the 136th day. In the 8th, 27th, 55th (first phase), 71st, 84th, 112th and 132nd (second phase) day of experimental period, blood samples were collected and insulin-like growth factor I (IGF-I), triiodothyronine (T3), thyroxine (T4), glucose, plasma ureic nitrogen (PUN) and total protein (TP) were determined. In the first phase IGF-I, T4, glucose and total protein concentration was not different among treat-ments (P>0.05) and there was no interaction between treatment and time (P>0.05). There was an interaction among treatments and time on T3 and plasma ureic nitrogen (P0.05). For plasma ureic nitrogen concentration there was an interaction among treatments and time (P=0.02). Lower levels of diet intake can be used to improve animal performance in feedlot.

Foram avaliados parâmetros sanguíneos de 18 novilhos Nelore submetidos a dois regimes sequenciais de alimentação (fase 1: restrição e fase 2: alimento ad libitum) com dieta de alto teor de concentrado. Na primeira fase, os animais foram alimentados por 56 dias em três níveis de ingestão de matéria seca (MS) representando os tratamentos: ad libitum, 75 g MS/kg peso corporal metabólico (PV0,75) e 60 g MS/kg PV(0,75). Na segunda fase, a partir do 57º dia de confinamento, os animais alimentados com 60 g MS/kg PV(0,75) e 75 g MS/kg PV(0,75) receberam alimentação ad libitum até o 136º dia. No 8º, 27º, 55º, primeira fase, e 71º, 84º, 112º e 132º dia de confinamento, segunda fase, foram colhidas amostras de sangue para determinação das concentrações de fator de crescimento semelhante à insulina I (IGF-I), triiodotironina (T3), tiroxina (T4), glicose, nitrogênio ureico plasmático e proteína total. No período de restrição alimentar as concentrações plasmáticas de IGF-I, T4, glicose e proteína total não foram diferentes entre os tratamentos (P>0,05) e não houve interação entre tratamento e tempo (P>0,05). Foi observada interação entre tratamento e tempo para a concentração plasmática de T3 e nitrogênio ureico no plasma (P0,05). Para a concentração de nitrogênio ureico no plasma houve interação entre os fatores tratamentos e tempo (P=0,02). Níveis mais baixos de ingestão de dieta podem ser usados para melhorar o desempenho animal em confinamento.

Oilseeds in diets of fattening lambs / Oleaginosas em dietas para cordeiros em engorda

An experiment was conducted to compare different oilseeds in replacement of ground corn in diets of fattening lambs, evaluating performance, apparent diet digestibility, ingestive behavior, and carcass traits. Twenty-four crossbred lambs, three months old and with initial body weight 25.97 ± 0.75 kg, were kept in individual pens. The animals received one of the following diets: ‘control’ (no oilseeds, 3.11% Ether Extract - EE), ‘cottonseed’ (6.14% EE), ‘sunflower’ (6.33% EE), and ‘soybean’ (6.30% EE). All diets contained 23.63% of coast cross hay and 76.37% of concentrate. After 84 days in feedlot, the animals were slaughtered and the carcasses were evaluated. The dry matter intake (DMI) and daily weight gain (DWG) of animals fed with the control diet was higher than sunflower (P≤0.05). Final body weight and carcass weight were higher (P≤0.05) in the control (42.42 kg and 19.27 kg, respectively) than for sunflower diet (34.85 kg and 16.05 kg, respectively). Neutral detergent fiber (NDF) digestibility was reduced (P≤0.05) when the animals received cottonseed diet (50.34%) in comparison to soybean (71.07%), sunflower (67.07%) and control (66.50%). NDF digestibility for soybean, sunflower and control diets did not differ from each other. Lower (P≤0.05) EE digestibility was observed for the control diet (73.67%). There were no differences (P≥0.05) in the ingestive behavior, however, the addition of cottonseed or sunflower negatively affected (P≤0.05) rumination efficiency of NDF. Sunflower should not be included in high concentrate diets for fattening lambs.

Um experimento foi conduzido para comparar diferentes oleaginosas em substituição ao milho moído na dieta de cordeiros em engorda, avaliando o desempenho, a digestibilidade aparente da dieta, o comportamento ingestivo e as características de carcaça. Vinte e quatro cordeiros cruzados, com 3 meses de idade e peso corporal inicial de 25,97 ± 0,75 kg, foram mantidos em baias individuais. Eles receberam uma das seguintes dietas ou tratamentos: ‘controle’ (sem grãos de oleaginosas, 3,11% de Extrato Etéreo - EE), ‘caroço de algodão’ (6,14% EE), ‘girassol’ (6,33% EE) e ‘soja’ (6,30% EE). Todas as dietas continham 23,63% de feno de coast cross e 76,37% de concentrado. Após 84 dias de confinamento, os animais foram abatidos e as carcaças avaliadas. O consumo de matéria seca e ganho de peso diário dos animais alimentados com a dieta controle foi maior daqueles alimentados com girassol (P≤0,05). O peso corporal final e o peso da carcaça foram maiores (P≤0,05) para aqueles alimentados com a dieta controle (42,42 kg e 19,27 kg, respectivamente) que aqueles da dieta com girassol (34,85 kg e 16,05 kg, respectivamente). A digestibilidade da Fibra em Detergente Neutro (FDN) foi reduzida (P≤0,05) quando os animais receberam caroço de algodão (50,34%) comparado à soja (71,07%); para as dietas com girassol (67,07%) e controle (66,50%) não houve diferenças das demais. Menor (P≤0,05) digestibilidade do extrato etéreo foi observada para a dieta controle (73,67%). Não houve diferenças (P≥0,05) no comportamento ingestivo, no entanto, a inclusão de caroço de algodão ou girassol afetou negativamente (P≤0,05) a eficiência de ruminação da FDN. Grãos de girassol não devem ser incluídos em dietas de alto concentrado para cordeiros em engorda.

Composition of weight gain in Nellore steers at different feed intake levels / Composição do ganho de peso de novilhos Nelore em diferentes níveis de ingestão de alimentos

Thirty six Nellore steers, with an average initial age and weight of 20 months and 360 kg, were fed the same diet in three levels of dry matter intake: ad libitum or in two restriction levels 75g DM/kg BW0.75 or 60g DM/kg BW0.75 during 58 days (Phase 1) to evaluate the effects of feed restriction on weight gain, feed efficiency, diet digestibility, and composition of weight gain in restriction and re-alimentation phases. All steers were fed ad libitum for 78 days (Phase 2). Body composition was estimated with the marker deuterium oxide, which allowed repeated measurements of the same animal and studying its response to re-alimentation. Average daily gain in the restriction phase reflected different weight gain rates provided by feed levels of 0.288 kg, 0.656 kg, and 1.169 kg, respectively for 60g DM/ BW0.75, 75g DM/ BW0.75 and ad libitum. Feed efficiency increased according to feed intake level in Phase 1 and no differences between treatments were observed in Phase 2. Dry matter digestibility did not differ between treatments in both Phase 1 and Phase 2; however, it differed between phases for the same treatment with 78.8% in Phase 1, and with 68.7% in Phase 2 for the treatment with 60 g DM/BW0.75, and 77.8% in Phase 1 and 71.3% in Phase 2 for the treatment with 75 g DM/BW0.75. The deposition of empty weight gain, daily water deposition, ether extract, protein, ash, and energy increased with a higher feed intake level in Phase 1. In Phase 2, no difference occurred between the diet intake levels for empty weight gain, chemical components deposition, and retained energy in the gain. Diet digestibility decreased in Nellore steers fed ad libitum after the period of feed restriction, regardless of the previous restriction level to which the animals were submitted.

Trinta e seis novilhos Nelore, com média de peso e idade inicial de 360 kg e 20 meses, foram alimentados com a mesma dieta em três níveis de ingestão de material seca: à vontade ou em dois níveis de restrição alimentar quantitativa 75g MS/kg PV0,75 ou 60g MS/kg PV0,75 durante 58 dias (Fase 1) para avaliar os efeitos da restrição alimentar no ganho de peso, eficiência alimentar, digestibilidade da dieta e na composição do ganho de peso. Todos os novilhos foram alimentados ad libitum por 78 dias (Fase 2). A composição corporal foi estimada com o marcador óxido de deutério, o qual permite repetir a avaliação no mesmo animal e estudar as respostas à realimentação. O ganho médio diário na fase de restrição alimentar refletiu as diferentes taxas de ganho de peso proporcionadas pelos níveis de alimentação, sendo 0,288 kg, 0,656 kg e 1.169 kg, respectivamente para 60g MS/PV0,75, 75g MS/PV0,75 e ad libitum. A eficiência alimentar variou de acordo com o nível de ingestão de alimentos na Fase 1 e não foram observadas diferenças entre tratamentos na Fase 2. A digestibilidade da matéria seca não diferiu entre tratamentos tanto na Fase 1 como na Fase 2, mas foi diferente entre as Fases para o mesmo tratamento com 78,8% na Fase 1 e 68,7% na Fase 2 para o tratamento 60 g MS/PV0,75 e 77,8% na Fase 1 e 71,3% na Fase 2 para o tratamento 75 g MS/PV0,75. A composição do ganho de peso vazio, a deposição diária de água, extrato etéreo, proteína, cinzas e energia aumentaram de acordo com o nível de ingestão de alimentos na Fase1. Na Fase 2, não houve diferença entre os níveis de ingestão da dieta para ganho de peso vazio, deposição dos componentes químicos e energia retida no ganho. Novilhos Nelore alimentados ad libitum após período de restrição alimentar tiveram a digestibilidade da dieta diminuída, independentemente do...

Effects of the Dietary Supplementation with a Microalga Extract on Broiler Performance and Fatty-Acid Meat Profile

The present study was carried out in the poultry sector of UNOESC Xanxerê to evaluate the effect of various inclusion levels of seaweed (Schizotrichium ssp.) in the diet of broiler chickens in terms of performance, carcass yield, organ profiles and fatty acids levels in meat. We studied 480 one-day-old Cobb chicks, distributed in a completely randomized experimental design, with four treatments and six replicates containing 20 birds each, totaling 24 experimental units. At 7, 21 and 35 days of age, the birds were weighed for performance evaluation (live weight, weight gain, feed intake, feed conversion and mortality). At 35 days of age, one chicken per experimental unit was sacrificed for evaluation of carcass yield and its parts, together with isolation of the left thigh for analysis of the fatty acid profile. The inclusion of seaweed in the diet did not alter the characteristics of performance or yield in carcass and organs; however, the supplement changed the profile of fatty acids of the meat, enriching the omega-3 series, primarily DHA. We conclude that marine algae of the genus Schizotrichium can be added to rations without compromising the development of the birds to improve the profile of fatty acids in the meat.

Effects of the Dietary Supplementation with a Microalga Extract on Broiler Performance and Fatty-Acid Meat Profile

The present study was carried out in the poultry sector of UNOESC Xanxerê to evaluate the effect of various inclusion levels of seaweed (Schizotrichium ssp.) in the diet of broiler chickens in terms of performance, carcass yield, organ profiles and fatty acids levels in meat. We studied 480 one-day-old Cobb chicks, distributed in a completely randomized experimental design, with four treatments and six replicates containing 20 birds each, totaling 24 experimental units. At 7, 21 and 35 days of age, the birds were weighed for performance evaluation (live weight, weight gain, feed intake, feed conversion and mortality). At 35 days of age, one chicken per experimental unit was sacrificed for evaluation of carcass yield and its parts, together with isolation of the left thigh for analysis of the fatty acid profile. The inclusion of seaweed in the diet did not alter the characteristics of performance or yield in carcass and organs; however, the supplement changed the profile of fatty acids of the meat, enriching the omega-3 series, primarily DHA. We conclude that marine algae of the genus Schizotrichium can be added to rations without compromising the development of the birds to improve the profile of fatty acids in the meat.(AU)

Oilseeds in diets of fattening lambs / Oleaginosas em dietas para cordeiros em engorda

An experiment was conducted to compare different oilseeds in replacement of ground corn in diets of fattening lambs, evaluating performance, apparent diet digestibility, ingestive behavior, and carcass traits. Twenty-four crossbred lambs, three months old and with initial body weight 25.97 ± 0.75 kg, were kept in individual pens. The animals received one of the following diets: ‘control (no oilseeds, 3.11% Ether Extract - EE), ‘cottonseed (6.14% EE), ‘sunflower (6.33% EE), and ‘soybean (6.30% EE). All diets contained 23.63% of coast cross hay and 76.37% of concentrate. After 84 days in feedlot, the animals were slaughtered and the carcasses were evaluated. The dry matter intake (DMI) and daily weight gain (DWG) of animals fed with the control diet was higher than sunflower (P≤0.05). Final body weight and carcass weight were higher (P≤0.05) in the control (42.42 kg and 19.27 kg, respectively) than for sunflower diet (34.85 kg and 16.05 kg, respectively). Neutral detergent fiber (NDF) digestibility was reduced (P≤0.05) when the animals received cottonseed diet (50.34%) in comparison to soybean (71.07%), sunflower (67.07%) and control (66.50%). NDF digestibility for soybean, sunflower and control diets did not differ from each other. Lower (P≤0.05) EE digestibility was observed for the control diet (73.67%). There were no differences (P≥0.05) in the ingestive behavior, however, the addition of cottonseed or sunflower negatively affected (P≤0.05) rumination efficiency of NDF. Sunflower should not be included in high concentrate diets for fattening lambs.(AU)

Um experimento foi conduzido para comparar diferentes oleaginosas em substituição ao milho moído na dieta de cordeiros em engorda, avaliando o desempenho, a digestibilidade aparente da dieta, o comportamento ingestivo e as características de carcaça. Vinte e quatro cordeiros cruzados, com 3 meses de idade e peso corporal inicial de 25,97 ± 0,75 kg, foram mantidos em baias individuais. Eles receberam uma das seguintes dietas ou tratamentos: ‘controle (sem grãos de oleaginosas, 3,11% de Extrato Etéreo - EE), ‘caroço de algodão (6,14% EE), ‘girassol (6,33% EE) e ‘soja (6,30% EE). Todas as dietas continham 23,63% de feno de coast cross e 76,37% de concentrado. Após 84 dias de confinamento, os animais foram abatidos e as carcaças avaliadas. O consumo de matéria seca e ganho de peso diário dos animais alimentados com a dieta controle foi maior daqueles alimentados com girassol (P≤0,05). O peso corporal final e o peso da carcaça foram maiores (P≤0,05) para aqueles alimentados com a dieta controle (42,42 kg e 19,27 kg, respectivamente) que aqueles da dieta com girassol (34,85 kg e 16,05 kg, respectivamente). A digestibilidade da Fibra em Detergente Neutro (FDN) foi reduzida (P≤0,05) quando os animais receberam caroço de algodão (50,34%) comparado à soja (71,07%); para as dietas com girassol (67,07%) e controle (66,50%) não houve diferenças das demais. Menor (P≤0,05) digestibilidade do extrato etéreo foi observada para a dieta controle (73,67%). Não houve diferenças (P≥0,05) no comportamento ingestivo, no entanto, a inclusão de caroço de algodão ou girassol afetou negativamente (P≤0,05) a eficiência de ruminação da FDN. Grãos de girassol não devem ser incluídos em dietas de alto concentrado para cordeiros em engorda.(AU)

Composition of weight gain in Nellore steers at different feed intake levels / Composição do ganho de peso de novilhos Nelore em diferentes níveis de ingestão de alimentos

Thirty six Nellore steers, with an average initial age and weight of 20 months and 360 kg, were fed the same diet in three levels of dry matter intake: ad libitum or in two restriction levels 75g DM/kg BW0.75 or 60g DM/kg BW0.75 during 58 days (Phase 1) to evaluate the effects of feed restriction on weight gain, feed efficiency, diet digestibility, and composition of weight gain in restriction and re-alimentation phases. All steers were fed ad libitum for 78 days (Phase 2). Body composition was estimated with the marker deuterium oxide, which allowed repeated measurements of the same animal and studying its response to re-alimentation. Average daily gain in the restriction phase reflected different weight gain rates provided by feed levels of 0.288 kg, 0.656 kg, and 1.169 kg, respectively for 60g DM/ BW0.75, 75g DM/ BW0.75 and ad libitum. Feed efficiency increased according to feed intake level in Phase 1 and no differences between treatments were observed in Phase 2. Dry matter digestibility did not differ between treatments in both Phase 1 and Phase 2; however, it differed between phases for the same treatment with 78.8% in Phase 1, and with 68.7% in Phase 2 for the treatment with 60 g DM/BW0.75, and 77.8% in Phase 1 and 71.3% in Phase 2 for the treatment with 75 g DM/BW0.75. The deposition of empty weight gain, daily water deposition, ether extract, protein, ash, and energy increased with a higher feed intake level in Phase 1. In Phase 2, no difference occurred between the diet intake levels for empty weight gain, chemical components deposition, and retained energy in the gain. Diet digestibility decreased in Nellore steers fed ad libitum after the period of feed restriction, regardless of the previous restriction level to which the animals were submitted.(AU)

Trinta e seis novilhos Nelore, com média de peso e idade inicial de 360 kg e 20 meses, foram alimentados com a mesma dieta em três níveis de ingestão de material seca: à vontade ou em dois níveis de restrição alimentar quantitativa 75g MS/kg PV0,75 ou 60g MS/kg PV0,75 durante 58 dias (Fase 1) para avaliar os efeitos da restrição alimentar no ganho de peso, eficiência alimentar, digestibilidade da dieta e na composição do ganho de peso. Todos os novilhos foram alimentados ad libitum por 78 dias (Fase 2). A composição corporal foi estimada com o marcador óxido de deutério, o qual permite repetir a avaliação no mesmo animal e estudar as respostas à realimentação. O ganho médio diário na fase de restrição alimentar refletiu as diferentes taxas de ganho de peso proporcionadas pelos níveis de alimentação, sendo 0,288 kg, 0,656 kg e 1.169 kg, respectivamente para 60g MS/PV0,75, 75g MS/PV0,75 e ad libitum. A eficiência alimentar variou de acordo com o nível de ingestão de alimentos na Fase 1 e não foram observadas diferenças entre tratamentos na Fase 2. A digestibilidade da matéria seca não diferiu entre tratamentos tanto na Fase 1 como na Fase 2, mas foi diferente entre as Fases para o mesmo tratamento com 78,8% na Fase 1 e 68,7% na Fase 2 para o tratamento 60 g MS/PV0,75 e 77,8% na Fase 1 e 71,3% na Fase 2 para o tratamento 75 g MS/PV0,75. A composição do ganho de peso vazio, a deposição diária de água, extrato etéreo, proteína, cinzas e energia aumentaram de acordo com o nível de ingestão de alimentos na Fase1. Na Fase 2, não houve diferença entre os níveis de ingestão da dieta para ganho de peso vazio, deposição dos componentes químicos e energia retida no ganho. Novilhos Nelore alimentados ad libitum após período de restrição alimentar tiveram a digestibilidade da dieta diminuída, independentemente do...(AU)

Blood parameters of Nellore steers fed a high concentrate diet in two restricted feeding regimes followed by ad libitum feeding / Parâmetros sanguíneos de novilhos Nelore submetidos à dieta de alto concentrado em dois regimes alimentares sequenciais (fase 1: restrição e fase 2: alimento ad libitum)

Blood parameters of 18 Nellore steers submitted to high concentrate diet in two sequential feeding regimes (phase 1: restriction and phase 2: ad libitum feeding) were evaluated. In the first phase, steers were fed for 56 days three intake levels of dry mat-ter (ad libitum, 75 g dry matter (DM)/kg metabolic body weight (BW0.75) or 60 g DM/kg BW(0.75). In the second phase, from the 57th day on feed, animals fed 60 g DM/kg BW(0.75) and 75 g DM/kg BW(0.75) were fed ad libitum until the 136th day. In the 8th, 27th, 55th (first phase), 71st, 84th, 112th and 132nd (second phase) day of experimental period, blood samples were collected and insulin-like growth factor I (IGF-I), triiodothyronine (T3), thyroxine (T4), glucose, plasma ureic nitrogen (PUN) and total protein (TP) were determined. In the first phase IGF-I, T4, glucose and total protein concentration was not different among treat-ments (P>0.05) and there was no interaction between treatment and time (P>0.05). There was an interaction among treatments and time on T3 and plasma ureic nitrogen (P<0.01). In the second phase IGF-I, T3, T4, glucose and total protein concentration was not different among treatments and there was no interaction between treatment and time (P>0.05). For plasma ureic nitrogen concentration there was an interaction among treatments and time (P=0.02). Lower levels of diet intake can be used to improve animal performance in feedlot.(AU)

Foram avaliados parâmetros sanguíneos de 18 novilhos Nelore submetidos a dois regimes sequenciais de alimentação (fase 1: restrição e fase 2: alimento ad libitum) com dieta de alto teor de concentrado. Na primeira fase, os animais foram alimentados por 56 dias em três níveis de ingestão de matéria seca (MS) representando os tratamentos: ad libitum, 75 g MS/kg peso corporal metabólico (PV0,75) e 60 g MS/kg PV(0,75). Na segunda fase, a partir do 57º dia de confinamento, os animais alimentados com 60 g MS/kg PV(0,75) e 75 g MS/kg PV(0,75) receberam alimentação ad libitum até o 136º dia. No 8º, 27º, 55º, primeira fase, e 71º, 84º, 112º e 132º dia de confinamento, segunda fase, foram colhidas amostras de sangue para determinação das concentrações de fator de crescimento semelhante à insulina I (IGF-I), triiodotironina (T3), tiroxina (T4), glicose, nitrogênio ureico plasmático e proteína total. No período de restrição alimentar as concentrações plasmáticas de IGF-I, T4, glicose e proteína total não foram diferentes entre os tratamentos (P>0,05) e não houve interação entre tratamento e tempo (P>0,05). Foi observada interação entre tratamento e tempo para a concentração plasmática de T3 e nitrogênio ureico no plasma (P<0,01). No período de alimento ad libitum as concentrações de IGF-I, T3, T4, glicose e proteína total não foram diferentes entre os tratamentos e não houve interação entre tratamento e tempo (P>0,05). Para a concentração de nitrogênio ureico no plasma houve interação entre os fatores tratamentos e tempo (P=0,02). Níveis mais baixos de ingestão de dieta podem ser usados para melhorar o desempenho animal em confinamento.(AU)

Growth, meat and feed efficiency traits of lambs born to ewes submitted to energy restriction during mid-gestation.

The objective of this study was to evaluate the effects of the energy restriction of gestation of adult ewes from day 45 to day 115 on lamb live performance parameters, carcass and meat traits. In experiment I, dietary energy was restricted at 70% of the metabolizable energy (ME) requirements, after which ewes were re-fed ad libitum until lambing. In experiment II, dietary energy was restricted at 60% of the ME requirements, and ewes were re-fed to ME requirements until lambing. All ewes grazed together from the end of the restriction periods to weaning. Lambs were weaned and lot fed until slaughter. Feed intake, weight gain and feed efficiency were recorded, and body fat thickness and ribeye area (REA) were measured in the longissimus thoracis muscle. After slaughter, carcass weight and yield, fat depth, carcass and leg length, and frenched rack and leg weights and yields were determined. Muscle fiber type composition, Warner-Bratzler shear force, pH and color were determined in the longissimus lumborum muscle. In experiment I, energy restriction followed by ad libitum feeding affected lamb birth weight (P0.05) were observed on later BW, REA, BF or carcass traits. Lambs born to non-restricted-fed ewes had higher (P<0.05) weight and yield of the frenched rack cut and their meat tended (P=0.11) to be tender compared with that of lambs from restricted ewes. The percentage of oxidative muscle fibers was lower for lambs born to non-restricted ewes (P<0.05); however, no effects of ewe treatment were observed on other muscle fiber types. For experiment II, energy restriction followed by ME requirements feeding, affected (P<0.01) pre-weaning live weight gain, weaning and final weights. Lambs from restricted ewes had higher (P<0.05) feed intake as % of leg weight and a trend to be less efficient (P=0.16) than lambs from unrestricted dams. Ribeye area and BF were not influenced by treatment. Treatment significantly affected slaughter weight, but had no effects on carcass yield and traits or on meat traits. The results obtained in both experiments indicate submitting ewes to energy restriction during gestation affects the performance of their progeny but the final outcome would depend on the ewe's re-feeding level during late gestation and the capacity of the offspring to compensate the in utero restriction after birth.

Genetic correlations between visual slaughter conformation scores and growth and reproductive traits in Canchim cattle.

We obtained heritability and (co)variance component estimates for slaughter conformation scores at 420 days of age (SCS420), age at calving (first, AFC; second, ASC), calving occurrence until 38 months of age (CP38), weight at 420 days of age (W420), and scrotal circumference at 420 days (SC420) in Canchim (5/8 Charolais + 3/8 Zebu) cattle. A total of 23,168 records of Canchim animals, including 12,493 females and 10,675 males, were analyzed. SCS420 indicated carcass structure, muscle development, and subcutaneous fat deposition. The slaughter conformation score of each animal was relative to the whole contemporary group; 1 corresponded to the lowest expression of the trait and 6 to the highest. Heritabilities, and genetic and residual correlation estimates between SCS420 and reproductive and weight traits, were estimated by multitrait analyses using an animal model with Bayesian inference, employing a linear model for AFC, ASC, SC420, and W420 and a threshold model for CP38 and SCS420. Heritability estimates for SCS420, AFC, ASC, CP38, W420, and SC420 were 0.11, 0.15, 0.15, 0.15, 0.30, and 0.30, respectively. Genetic correlation estimates between SCS420 and the other traits were 0.08 (AFC), 0.58 (ASC), 0.08 (CP38), 0.43 (W420), and 0.17 (SC420). Visual slaughter conformation scores respond to individual selection and can be used as selection criteria in Canchim cattle. Selection to improve sexual precocity would not be effective in improving carcass conformation and composition, and selection for animals with high breeding values for yearling weight may improve slaughter conformation at the yearling stage.

Effects of the Addition of Glucose, Sodium Bicarbonate, and Vitamin E to the Drinking Water of Pre-Slaughter Broiler Chickens on Carcass Yield, Gastric Emptying and Meat Quality

An experiment was conducted of the poultry facilities of La Salle Agricultural College in Xanxerê, SC, Brazil, to evaluate the effect of the administration of sodium bicarbonate, glucose and vitamin E to the drinking water during pre-slaughter feed withdrawal on carcass yield, organ relative weights (heart, liver, proventriculus, and gizzard), gizzard emptying, and meat quality of broiler chickens. The applied treatments were: water as control; 50g/L of glucose; 50g/L de glucose + 200mg/L of vitamin E; 75g/L of glucose; 75g/L + 200mg/L of vitamin E; 0.45% of sodium bicarbonate; 0.45% of sodium bicarbonate + 200mg/L of vitamin E; 0.55% of sodium bicarbonate; 0.55% of sodium bicarbonate + 200mg/L of vitamin E; 200mg/L de vitamin E. On the last day before slaughter, during the water diet period,500 birds were distributed in a completely randomized experimental design with ten treatments and ten replicates of five birds each. No difference in broiler carcass yield and organ relative weights was found. There were no significant changes in gizzard contents, in ultimate meat, cooking loss, shear force value, or in the meat color parameters L* (lightness), a* (redness) and b* (yellowness). It was concluded is that the addition of glucose, sodium bicarbonate, and vitamin E to the drinking water during pre-slaughter feed withdrawal period has no influence on carcass yield or on relative organ weight, neither on the emptying of the gizzard contents and the meat quality of broiler chickens.(AU)

Desempenho e características da carcaça de cordeiros alimentados com dietas contendo grãos de diferentes cereais / Performance and carcass traits of lambs fed diets containing different cereal grains

Objetivou-se avaliar desempenho, digestibilidade aparente, características da carcaça e da carne de cordeiros alimentados com dietas de alta proporção de concentrado (92,65%) contendo grãos de diferentes cereais (grão moído de milho; grão inteiro de milho; grão inteiro de sorgo; ou substituição de 40% do grão inteiro do milho por grão inteiro de milheto). Foram utilizados vinte e quatro machos inteiros, sem raça definida, com peso corporal de 22,35 ± 3,71 kg, confinados em baias individuais por 56 dias, alocados em delineamento inteiramente casualizado. O consumo de matéria seca em porcentagem do peso corporal foi maior (P=0,0046) para as dietas com sorgo e grão moído de milho, 3,73% e 3,39%, que para milheto e grão inteiro de milho, 3,23% e 3,13%. A eficiência alimentar foi maior (P=0,0140) para grão inteiro de milho e milheto, 0,293 e 0,269, e menor para grão moído de milho e sorgo, 0,247 e 0,226. A digestibilidade aparente da matéria orgânica, matéria seca e proteína bruta foram menores (P=0,0003) para a dieta com sorgo. As características de carcaça e dos cortes cárneos não foram influenciadas pelas dietas fornecidas aos animais, bem como a maciez objetiva do músculo Longissimus. Os parâmetros de cor e luminosidade da carne foram melhores (P<0,0001; P=0,0063) com a inclusão dos grãos inteiros. Recomenda-se a utilização de grãos inteiros de milho e de milheto na alimentação de cordeiros em confinamento, considerando os benefícios nutricionais, eficiência alimentar e a melhoria nas características da carcaça e atributos de qualidade da carne...

The objective of this study was to evaluate the performance, apparent digestibility, and carcass and meat traits of lambs fed high-concentrate diets (92.65%) containing different cereal grains (ground corn, whole grain corn, whole grain sorghum, or replacement of 40% whole grain corn with whole grain millet). Twenty-four feedlot intact lambs of undefined breed, with a body weight of 22.35 ± 3,.71 kg, kept in individual pens for 56 days were allocated in a completely randomized design. Dry matter intake expressed as a percentage of body weight was higher (P=0.0046) for the diets containing sorghum and ground corn (3.73% and 3.39%, respectively) compared to the diets containing millet and whole grain corn (3.23% and 3.13%, respectively). Feed efficiency was higher (P=0.014) for whole grain corn and millet (0.293 and 0.269, respectively) and lower for ground corn and sorghum (0.247 and 0.226, respectively). The apparent digestibility of organic matter, dry matter and crude protein was lower for the sorghum diet (P=0.0003). The carcass traits, meat cuts traits or objective longissimus muscle tenderness were not influenced by the diets offered to the animals. Meat color (P<0.0001) and luminosity (P=0.0063) were improved with inclusion of whole grains. The use of whole corn and millet grains is recommended for the feeding of feedlot lambs considering their nutritional benefits, feed efficiency, and improved carcass traits and meat quality attributes...

Effects of the Addition of Glucose, Sodium Bicarbonate, and Vitamin E to the Drinking Water of Pre-Slaughter Broiler Chickens on Carcass Yield, Gastric Emptying and Meat Quality

An experiment was conducted of the poultry facilities of La Salle Agricultural College in Xanxerê, SC, Brazil, to evaluate the effect of the administration of sodium bicarbonate, glucose and vitamin E to the drinking water during pre-slaughter feed withdrawal on carcass yield, organ relative weights (heart, liver, proventriculus, and gizzard), gizzard emptying, and meat quality of broiler chickens. The applied treatments were: water as control; 50g/L of glucose; 50g/L de glucose + 200mg/L of vitamin E; 75g/L of glucose; 75g/L + 200mg/L of vitamin E; 0.45% of sodium bicarbonate; 0.45% of sodium bicarbonate + 200mg/L of vitamin E; 0.55% of sodium bicarbonate; 0.55% of sodium bicarbonate + 200mg/L of vitamin E; 200mg/L de vitamin E. On the last day before slaughter, during the water diet period,500 birds were distributed in a completely randomized experimental design with ten treatments and ten replicates of five birds each. No difference in broiler carcass yield and organ relative weights was found. There were no significant changes in gizzard contents, in ultimate meat, cooking loss, shear force value, or in the meat color parameters L* (lightness), a* (redness) and b* (yellowness). It was concluded is that the addition of glucose, sodium bicarbonate, and vitamin E to the drinking water during pre-slaughter feed withdrawal period has no influence on carcass yield or on relative organ weight, neither on the emptying of the gizzard contents and the meat quality of broiler chickens.

Desempenho e características da carcaça de cordeiros alimentados com dietas contendo grãos de diferentes cereais / Performance and carcass traits of lambs fed diets containing different cereal grains

Objetivou-se avaliar desempenho, digestibilidade aparente, características da carcaça e da carne de cordeiros alimentados com dietas de alta proporção de concentrado (92,65%) contendo grãos de diferentes cereais (grão moído de milho; grão inteiro de milho; grão inteiro de sorgo; ou substituição de 40% do grão inteiro do milho por grão inteiro de milheto). Foram utilizados vinte e quatro machos inteiros, sem raça definida, com peso corporal de 22,35 ± 3,71 kg, confinados em baias individuais por 56 dias, alocados em delineamento inteiramente casualizado. O consumo de matéria seca em porcentagem do peso corporal foi maior (P=0,0046) para as dietas com sorgo e grão moído de milho, 3,73% e 3,39%, que para milheto e grão inteiro de milho, 3,23% e 3,13%. A eficiência alimentar foi maior (P=0,0140) para grão inteiro de milho e milheto, 0,293 e 0,269, e menor para grão moído de milho e sorgo, 0,247 e 0,226. A digestibilidade aparente da matéria orgânica, matéria seca e proteína bruta foram menores (P=0,0003) para a dieta com sorgo. As características de carcaça e dos cortes cárneos não foram influenciadas pelas dietas fornecidas aos animais, bem como a maciez objetiva do músculo Longissimus. Os parâmetros de cor e luminosidade da carne foram melhores (P<0,0001; P=0,0063) com a inclusão dos grãos inteiros. Recomenda-se a utilização de grãos inteiros de milho e de milheto na alimentação de cordeiros em confinamento, considerando os benefícios nutricionais, eficiência alimentar e a melhoria nas características da carcaça e atributos de qualidade da carne...(AU)

The objective of this study was to evaluate the performance, apparent digestibility, and carcass and meat traits of lambs fed high-concentrate diets (92.65%) containing different cereal grains (ground corn, whole grain corn, whole grain sorghum, or replacement of 40% whole grain corn with whole grain millet). Twenty-four feedlot intact lambs of undefined breed, with a body weight of 22.35 ± 3,.71 kg, kept in individual pens for 56 days were allocated in a completely randomized design. Dry matter intake expressed as a percentage of body weight was higher (P=0.0046) for the diets containing sorghum and ground corn (3.73% and 3.39%, respectively) compared to the diets containing millet and whole grain corn (3.23% and 3.13%, respectively). Feed efficiency was higher (P=0.014) for whole grain corn and millet (0.293 and 0.269, respectively) and lower for ground corn and sorghum (0.247 and 0.226, respectively). The apparent digestibility of organic matter, dry matter and crude protein was lower for the sorghum diet (P=0.0003). The carcass traits, meat cuts traits or objective longissimus muscle tenderness were not influenced by the diets offered to the animals. Meat color (P<0.0001) and luminosity (P=0.0063) were improved with inclusion of whole grains. The use of whole corn and millet grains is recommended for the feeding of feedlot lambs considering their nutritional benefits, feed efficiency, and improved carcass traits and meat quality attributes...(AU)

High levels of whole raw soybean in diets for Nellore bulls in feedlot: effect on growth performance, carcass traits and meat quality.

The objective of this study was to evaluate the effect of whole raw soybean (WRS) in the finishing diet of Nellore cattle on productive performance, carcass traits, meat quality, fatty acid profile of meat, and blood parameters. In a completely randomized design, 52 Nellore bulls (mean body weight ± SD: 380 ± 34 kg) were allotted for 84 days. The animals received the following diets with a forage: concentrate ratio of 40/60: (i) WRS0: control diet without soybean grains; (ii) WRS8: diet containing 8% WRS in dry matter basis; (iii) WRS16: diet containing 16% WRS, and (iv) WRS24: diet containing 24% WRS. At intervals of 28 days, the animals were weighed, muscle and adipose tissue was analysed by ultrasound, and blood samples were collected. The animals were slaughtered on day 85 and liver weight and hot carcass weight were measured during slaughter. The pH and carcass dressing were calculated at 24 h after slaughter. Longissimus dorsi muscle samples were collected for the determination of fatty acid profile of meat, ether extract, tenderness and sensory analysis of meat aged for 14 days. Blood cholesterol content increased linearly with increasing proportion of whole raw soybean grains. The diet did not affect performance or carcass attributes. The WRS8 had the highest shear force values. In fatty acid profile, C14:0 decreased (p = 0.05), whereas 16:1, 20:0 and 20:1 fatty acids increased linearly with increasing proportion of WRS (p < 0.05). However, concentration of conjugated linoleic acid cis 9, trans 11 and 17:0 increased with WRS24 and WRS16. In the sensory analysis, WRS24 was more tender with respect to the other treatments (p < 0.05). Finally, the inclusion of WRS in the finishing diet of feedlot Nellore bulls only evidenced little changes in fatty acid profile and tenderness, in animals fed diets containing 16 or 24% soybean.