Assessing dual-energy X-ray absorptiometry prediction of intramuscular fat content in beef longissimus steaks.

This study assessed the capability of dual-energy X-ray absorptiometry (DEXA) to predict intramuscular fat (IMF) content of beef longissimus steaks against chemical IMF as the gold standard. DEXA performance of fat% prediction was assessed using a leave-one-out cross validation method among Angus and Nellore steaks, which generated a chemical fat% range of 14.05-36.82% and 2.46-7.84%, respectively, and using pooled data. There was a significant positive association between DEXA predicted fat and chemical fat content. However, higher precision was found for pooled data (R2 = 0.95, RMSECV = 1.95) and Angus (R2 = 0.75, RMSECV = 2.39) than Nellore (R2 = 0.15, RMSECV = 1.22) group. Accuracy also had the same response with average slope values close to 1 for pooled data and Angus and a lower value (0.42) for Nellore group. DEXA precisely predicts IMF content across a wide range of fat content. However, its precision and accuracy of prediction within low-fat content samples are lower than in high-fat content.

Broiler responses to copper levels and sources: growth, tissue mineral content, antioxidant status and mRNA expression of genes involved in lipid and protein metabolism.

BACKGROUND: Five hundred 8-d old male broilers Cobb500 were randomly allotted into 10 treatments in factorial arrangement with 5 Cu levels (0, 4, 8, 12, and 16 mg/kg), and 2 sources (Cu proteinate, CuPro and Cu sulphate, CuSO4.5H2O) for a 10-d-experiment. RESULTS: Feed conversion ratio (FCR) was better (P < 0.05) in CuPro fed chicks compared with CuSO4.5H2O group. Average daily feed intake (ADFI) decreased linearly (P < 0.05) as dietary Cu increased. A quadratic response (P < 0.05) to Cu levels was found for FCR, being optimized at 9.87 and 8.84 mg Cu/kg in CuPro and CuSO4.5H2O diets, respectively. Copper supplementation linearly increased liver Cu content (P < 0.05) and tended to linearly increase (P = 0.07) phosphorus (P) and copper in tibia. Manganese and zinc were higher (P < 0.05) in tibia of CuPro fed birds. Broilers fed CuPro exhibited lower liver iron (P < 0.05) content, lower activities of Cu, Zn superoxide dismutase (CuZnSOD) in breast muscle and liver, and glutathione peroxidase in liver. Glutathione peroxidase reduced linearly (P < 0.05) with CuPro levels and increased linearly (P < 0.05) with CuSO4.5H2O levels and were lower (P < 0.05) in all CuPro levels in breast muscle. Breast muscle malondialdehyde concentration tended to be higher (P = 0.08) in broilers fed CuSO4.5H2O. Copper levels linearly increased (P < 0.05) metallothionein (MT) and malate dehydrogenase (MDH) expression in liver, and six-transmembrane epithelial antigen of the prostate-1 (STEAP-1) in the intestine. Copper elicited a quadratic response (P < 0.050) in AKT-1 and mammalian target of rapamycin (mTOR) in breast muscle, CuZnSOD in liver and antioxidant 1 copper chaperone (ATOX 1) in intestine. Broilers fed CuPro exhibited higher mRNA expression of mTOR in muscle breast and lower CuZnSOD in liver and ATOX 1 in intestine. Interaction (P < 0.05) between levels and sources was found in mRNA expression for GSK-3ß, MT, and CuZnSOD in breast muscle, FAS and LPL in liver and MT and CTR1 in intestine. CONCLUSIONS: CuPro showed beneficial effects on feed conversion and bone mineralization. Organic and inorganic Cu requirements are 9.87 and 8.84 mg Cu/kg, respectively.

Assessment of digestible lysine requirements in lipopolysaccharide-challenged pigs.

To evaluate the effect of an Escherichia coli lipopolysaccharide (LPS) challenge on the digestible lysine (Lys) requirement for growing pigs, a nitrogen (N) balance assay was performed. Seventy-two castrated male pigs (19 ± 1.49 kg body weight [BW]) were allocated in a 2 × 6 factorial design composed of two immune activation states (control and LPS-challenged) and six dietary treatments with N levels of 0.94, 1.69, 2.09, 3.04, 3.23, and 3.97% N, as fed, where Lys was limiting, with six replicates and one pig per unit. The challenge consisted of an initial LPS dose of 30 µg/kg BW via intramuscular (IM) injection and a subsequent dose of 33.6 µg/kg BW after 48 h. The experimental period lasted 11 d and was composed of a 7-d adaptation and a subsequent 4-d sampling period in which N intake (NI), N excretion (NEX), and N deposition (ND) were evaluated. Inflammatory mediators and rectal temperature were assessed during the 4-d collection period. A three-way interaction (N levels × LPS challenge × time, P < 0.05) for IgG was observed. Additionally, two-way interactions (challenge × time, P < 0.05) were verified for IgA, ceruloplasmin, transferrin, haptoglobin, α-1-acid glycoprotein, total protein, and rectal temperature; and (N levels × time, P < 0.05) for transferrin, albumin, haptoglobin, total protein, and rectal temperature. LPS-challenged pigs showed lower (P < 0.05) feed intake. A two-way interaction (N levels × LPS challenge, P < 0.05) was observed for NI, NEX, and ND, with a clear dose-response (P < 0.05). LPS-challenged pigs showed lower NI and ND at 2.09% N and 1.69 to 3.97% N (P < 0.05), respectively, and higher NEX at 3.23% N (P < 0.05). The parameters obtained by a nonlinear model (N maintenance requirement, NMR and theoretical maximum N deposition, NDmaxT) were 152.9 and 197.1 mg/BWkg0.75/d for NMR, and 3,524.7 and 2,077.8 mg/BWkg0.75/d for NDmaxT, for control and LPS-challenged pigs, respectively. The estimated digestible Lys requirements were 1,994.83 and 949.16 mg/BWkg0.75/d for control and LPS-challenged pigs, respectively. The daily digestible Lys intakes required to achieve 0.68 and 0.54 times the NRmaxT value were 18.12 and 8.62 g/d, respectively, and the optimal dietary digestible Lys concentration may change depending on the feed intake levels. Based on the derived model parameters obtained in the N balance trial with lower cost and time, it was possible to differentiate the digestible Lys requirement for swine under challenging conditions.

In-feed organic and inorganic manganese supplementation on broiler performance and physiological responses.

OBJECTIVE: A trial was conducted to investigate the effects of supplemental levels of Mn provided by organic and inorganic trace mineral supplements on growth, tissue mineralization, mineral balance, and antioxidant status of growing broiler chicks. METHODS: A total of 500 male chicks (8-d-old) were used in 10-day feeding trial, with 10 treatments and 10 replicates of 5 chicks per treatment. A 2×5 factorial design was used where supplemental Mn levels (0, 25, 50, 75, and 100 mg Mn/kg diet) were provided as MnSO4∙H2O or MnPro. When Mn was supplied as MnPro, supplements of zinc, copper, iron, and selenium were supplied as organic minerals, whereas in MnSO4∙H2O supplemented diets, inorganic salts were used as sources of other trace minerals. Performance data were fitted to a linearbroken line regression model to estimate the optimal supplemental Mn levels. RESULTS: Manganese supplementation improved body weight, average daily gain (ADG) and feed conversion ratio (FCR) compared with chicks fed diets not supplemented with Mn. Manganese in liver, breast muscle, and tibia were greatest at 50, 75, and 100 mg supplemental Mn/kg diet, respectively. Higher activities of glutathione peroxidase and superoxide dismutase (total-SOD) were found in both liver and breast muscle of chicks fed diets supplemented with inorganic minerals. In chicks fed MnSO4∙H2O, ADG, FCR, Mn balance, and concentration in liver were optimized at 59.8, 74.3, 20.6, and 43.1 mg supplemental Mn/kg diet, respectively. In MnPro fed chicks, ADG, FCR, Mn balance, and concentration in liver and breast were optimized at 20.6, 38.0, 16.6, 33.5, and 62.3 mg supplemental Mn/kg, respectively. CONCLUSION: Lower levels of organic Mn were required by growing chicks for performance optimization compared to inorganic Mn. Based on the FCR, the ideal supplemental levels of organic and inorganic Mn in chick feeds were 38.0 and 74.3 mg Mn/kg diet, respectively.

Selenium source and level on performance, selenium retention and biochemical responses of young broiler chicks.

BACKGROUND: Selenium (Se) has been recognized as an essential micronutrient for nearly all forms of life. In recent decades, broiler responses to dietary Se supplemental levels and sources have received considerable attention. On environmental grounds, organic trace mineral utilization in practical broiler feeds has been defended due to its higher bioavailability. In such feeds, trace minerals are provided simultaneously in the same supplement as inorganic salts or organic chelates, a fact commonly ignored in assays conducted to validate organic trace mineral sources. The current assay aimed to investigate growth and biochemical responses, as well as Se retention of growing chicks fed diets supplemented with organic and inorganic Se levels and where the trace minerals (zinc, copper, manganese, and iron) were provided as organic chelates or inorganic salts according to Se source assessed. In so doing, a 2 × 5 factorial arrangement was used to investigate the effects of sodium selenite (SS) and selenium-yeast (SY) supplemented in feeds to provide the levels of 0, 0.08, 0.16, 0.24, and 0.32 mg Se/kg. RESULTS: Chicks fed selenium-yeast diets had body weight (BW), and average daily gain (ADG) maximized at 0.133 and 0.130 mg Se/kg, respectively. Both Se sources linearly increased (P < 0.05) the glutathione peroxidase (GSH-Px) activity in chick blood but higher values were observed in sodium selenite fed chicks (P < 0.05). Both Se sources influenced thyroid hormone serum concentrations (P < 0.05). Chicks fed SY exhibited greater retention of Se in the feathers (P < 0.05). Relative bioavailability of selenium yeast compared with SS for the Se content in carcass, feathers, total and Se retention were, 126, 116, 125 and 125%, respectively. SY supplementation resulted in lower liver Se concentration as Se supplementation increased (P < 0.05). CONCLUSIONS: Based on performance traits, the supplemental level of organic Se as SY in organic trace minerals supplement to support the maximal growth of broiler chicks is 0.133 mg Se/kg.

Metabolizable energy levels for meat quails from 15 to 35 days of age / Níveis de energia metabolizável para codornas de corte de 15 a 35 dias de idade

ABSTRACT: This trial was carried out to evaluate the effects of dietetic metabolizable energy levels on performance and carcass traits of meat quails from 15 to 35 days old. Five hundred sixty, 15-d old, meat quails were randomly assigned to five treatments (2.850; 2.950; 3.050; 3.150 e 3.250kcal of ME kg-1 of diet), with eight replicates and fourteen birds per experimental unit. Feed intake, protein and lysine intake and feed conversion decreased linearly as the metabolizable energy content of diets increased (P<0.01), whereas metabolizable energy intake, body weight, weight gain and viability were not affected (P>0.05) by the treatments. Diets did not influence (P>0.05) carcass traits as dry matter, moisture and protein content in carcass. However a quadratic effect (P<0.04) were observed on carcass fat content. Based on these results, the adequate metabolizable energy level to ensure better meat quails' growth is 3.250kcal of ME kg-1 diet, that corresponds to a metabolizable energy: crude protein ratio of 139,24.

RESUMO: Com o objetivo de avaliar o efeito dos níveis de energia metabolizável (EM) sobre o desempenho de codornas de corte de 15 a 35 dias de idade, foi conduzido um experimento com 560 aves aos 15 dias de idade, distribuídas em delineamento inteiramente casualizado com cinco tratamentos (2.850; 2.950; 3.050; 3.150 e 3.250kcal de EM kg-1 de ração), oito repetições com 14 aves por unidade experimental. Verificou-se redução linear (P<0,01) no consumo de ração, de proteína, de lisina e na conversão alimentar, com o aumento dos níveis de EM da ração. O consumo de energia metabolizável, o peso corporal, o ganho de peso, viabilidade das aves não foram influenciados (P>0,05) pelos níveis de EM utilizados. Os níveis de EM das dietas não influenciaram (P>0,05) a matéria seca, o teor de umidade e a proteína nas carcaças. Foi observado efeito quadrático (P<0,04) dos níveis de EM sobre o teor de gordura nas carcaças. Conclui-se que o nível de EM de 3.250kcal kg-1 de ração, correspondendo à relação de energia metabolizável:proteína bruta de 139,24, possibilita melhor desempenho das codornas de corte.

Sunflower meal and supplementation of an enzyme complex in diets for growing and finishing pigs / Farelo de girassol e suplementação de complexo enzimático em dietas para suínos em crescimento e terminação

This study aimed to evaluate the inclusion of sunflower meal and an enzyme complex supplement on the performance and carcass parameters in swine from 30 to 100 kg live weight. A total of 96 pigs with average live weight of 32.19 ± 3.27 kg were distributed in a randomized blocks design with a 4 × 2 factorial arrangement of treatments (four levels of sunflower meal-SM: 0, 8, 16 and 24%, with or without inclusion of an enzyme complex-EC), factorial arrangement with six replicates and two animals per experimental unit. The analyzed variables were feed intake (kg), weight gain (kg), feed conversion (kg/kg), backfat thickness (mm), carcass muscularity (kg), hot carcass weight (%), lean meat carcass percentage (%), and lean meat carcass weight (kg). There was no interaction between factors for any of the studied variables. Feed conversion of animals from 30 to 70 kg live weight was improved by the inclusion of EC. This enzyme complex inclusion did not affect carcass characteristics. Increasing levels of SM in the test subject feed diet rations presented a quadratic effect on weight gain and on backfat thickness that reached maximum values in parameters of 7.26% and 8.16%, respectively.

Este estudo teve como objetivo avaliar a inclusão de farelo de girassol e a suplementação de complexo enzimático sobre os parâmetros de desempenho e características de carcaça de suínos, dos 30 aos 100 kg de peso vivo. Foram utilizados 96 suínos com peso vivo médio de 32,19 ± 3,27 kg distribuídos em um delineamento experimental de blocos casualiza- dos, em esquema fatorial 4 x 2 (quatro níveis de farelo de girassol-FG: 0, 8, 16 e 24% com ou sem inclusão do complexo enzimático-CE), com seis repetições e dois animais por unidade experimental. As variáveis analisadas foram: o consumo de ração (kg), o gancho de peso (kg), a conversão alimentar (kg/kg), a espessura de toucinhos (mm), a musculosidade (kg), o peso da carcaça quente (%), a porcentagem de carne magra na carcaça (%), a quantidade de carne magra na carcaça (kg). Na houve interação entre os fatores para nenhuma de variáveis estudadas. A conversão alimentar dos animais dos 30 aos 70 kg de peso foi diminuida pela inclusão do CE, porém não afetou os parâmetros de carcaça. Níveis crescentes de FG na ração apresentaram efeito quadrático sobre o ganho de peso dos animais e sobre a espessura de toucinho, com valores máximos destas variáveis em 7,26% e 8,16% de inclusão do FG, respectivamente

Agentes tróficos na dieta de leitões desmamados sobre a atividade das enzimas digestivas e o desempenho / Trofic agents in the diet of weaned pigs on the activity of the digestive enzymes and the performance

Foi avaliado o efeito da adição de glutamina, ácidos graxos poliinsaturados ou parede celular de levedura à dieta de leitões desmamados sobre a atividade das enzimas pancreáticas (lipase, amilase e tripsina) e da mucosa intestinal (dipeptidase, sacarase e maltase) e sobre o desempenho. Foram utilizados 45 leitões desmamados e distribuídos em delineamento em blocos casualizados, em esquema fatorial, com quatro dietas (T1 - dieta basal (DB); T2 - DB + 1% de glutamina; T3 - DB + 0,2% de parede celular de levedura; T4 - DB + 5% de óleo de peixe) e duas idades de abate (sete e 14 dias pós-desmame). O desempenho foi medido nas duas primeiras semanas pós-desmame. A adição de 1% de glutamina na dieta dos leitões aumentou a atividade específica e total da amilase, e atividade total da tripsina na segunda semana pós-desmame. Os demais aditivos não alteraram a atividade das enzimas digestivas nos leitões. Também foi observado aumento na atividade total da lipase, e atividade específica da tripsina e maltase em função da idade pós desmame. De modo geral, as atividades das enzimas digestivas estiveram correlacionadas positivamente, com exceção da dipeptidase que não se correlacionou com nenhuma outra enzima. Foi observada correlação positiva entre ganho de peso e atividades da lipase e da amilase. Os aditivos incluídos na dieta não influenciam o desempenho dos leitões no pós-desmame.

It was evaluated the effect of the addition of glutamine, polyunsaturated fatty acids or cellular wall of yeast to the diet of weaned pigs on the activity of the pancreatic enzymes (lipase, amylase and trypsin) and the intestinal mucous membrane (dipeptidase, sucrase and maltase) and on the performance. Forty-five weaned pigs were used and distributed in a randomized block design, in factorial outline, with four diets (T1 - basal diet (BD); T2 - BR + 1% glutamine; T3 - BD + 0,2% cellular wall of yeast; T4 - BD + 5% fish oil) and two slaughter ages (seven and 14 days post weaning). The performance was measured in the first two weeks post-weaning. The addition of 1% glutamine in the diet of pigs increased the specific and total activity of the amylase, and total activity of the trypsin in the second week post weaning. The others supplements not change the activity of the digestive enzymes in the pigs. Also an increase was observed in the total activity of the lipase, and specific activity of the trypsin and maltase in function of the age post-weaning. In general, the activities of the digestive enzymes were correlated positively, except for the dipeptidase that was not correlated with any other enzyme. Positive correlation was observed between weight gain and activity of the lipase and of the amylase. The supplements included in the diet not influence the performance of weaned pigs.

Diferentes níveis de betaína sobre incidência de diarreia, desempenho, características de carcaça e parâmetros sanguíneos de suínos / Different levels of betaine on diarrhea incidence, performance, carcass characteristics and blood parameters of pigs

Foram utilizados 36 leitões desmamados aos 19 dias de idade, distribuídos em um delineamento experimental em blocos ao acaso, aonde foram avaliados os efeitos da adição de níveis crescentes de betaína (0,0%, 0,1%, 0,2% e 0,3%) na dieta sobre o desempenho na fase inicial, crescimento e terminação. Foram monitorados os índices de incidência de diarreia nos primeiros 14 dias da fase inicial e os parâmetros sanguíneos aos 20, 75 e 150 dias de idade, como também características de carcaça ao final do experimento. Não foi observado (P > 0,05) efeito da betaína sobre a incidência de diarreia. Foram verificadas diferenças significativas (P < 0,05) entre os tratamentos na fase de terminação, para ganho diário de peso e conversão alimentar. Foram observadas diferenças (P < 0,0001) entre os dias para os parâmetros sanguíneos analisados. Para espessura de toucinho (ET), foi verificada diferença significativa (P < 0,05) entre os tratamentos

Thirty six piglets weaned at 19 days of age were useddistributed in a randomized block design, were used to evaluate the effects of the addition of crescent levels of betaine (0,0%, 0,1%, 0,2% e 0,3%) in the diets on the performance in initial, growing and finishing phases. The indexes of diarrhea incidence were monitored in the first 14 days post–weaning; and the blood parameters at 20, 75, and 150 days of age, as well as the carcass characteristics at the end of the experiment. It was not observed (P > 0,05) effect of the betaine on the diarrhea incidence. Significative differences (P < 0.05) were verified among treatments in the finishing phase for daily weight gain and feed conversion. Differences (P < 0.0001) among the days to the blood parameters analysed were also observed. In regard to the backfat thickness, it was verified significative difference (P < 0.05) among the treatments.

Plasma suíno e ovo inteiro em rações de leitões sobre desempenho na fase inicial e efeito residual até a terminação / Swine plasma and whole egg in ration for weaner pigs in performance in initial phase and residual effect until finishing phase

Foram utilizados 64 leitões distribuídos em oito tratamentos: ração com leite em pó (LP), três rações com níveis crescentes de plasma suíno (PS), três rações com níveis crescentes de ovo inteiro (OI) e ração com alto nível de farelo de soja (FS). Avaliou-se o ganho diário de peso (GDP), o consumo diário de ração (CDR) e a conversão alimentar (CA). Os animais que consumiram ração FS apresentaram média de GDP superior aos demais tratamentos, dos 35 aos 48 dias de idade. O aumento dos níveis de PS proporcionou redução linear do GDP, dos 21 aos 35 e dos 35 aos 48 dias de idade e do CDR dos 48 aos 138 dias de idade e piora linear da CA, dos 21 aos 35 dias de idade. Considerando o período da desmama até à terminação as rações inicias podem conter PS e OI, substituindo parcialmente à PB do leite em pó em 25 e 45%, respectivamente.

Were used 64 weaned pigs, distributed in eight treatments: ration with skim milk (SM), three rations with crescent levels of swine plasma (SP), three rations with whole egg (WE) and a ration with high inclusion of soybean meal (SB). Daily weight gain (DWG), daily feed intake (DFI) and feed conversion (FC) were evaluated. The animals that consumed ration SB have the mean of DWG higher that other treatments, and inferior FC, from 35 to 48 days of age. The crescent levels of SP promoted linear reduction in DWG, from 21 to 35, and from 35 to 48 days of age, in DFI from 48 to 138 days of age and linear increased in FC from 21 to 35 of age. Considering the weaned phase until finishing, initial rations can be formulated with SP and WE substituted partially the CP of skim milk in 25 and 45%, respectively.

Diferentes fontes proteicas em rações de leitões sobre atividade da tripsina e parâmetros sangüíneos / Different protein sources in rations of piglets on activity of trypsin and blood parameters

Foram utilizados 64 leitões, submetidos a oito tratamentos: ração com leite em pó (LP), três rações com níveis crescentes de plasma suíno (PS), três rações com níveis crescentes de ovo inteiro (OI) eração com alto nível de farelo de soja (FS). Foi coletado sangue dos animais aos 27 e 34 dias de idade para avaliação dos parâmetros sangüíneos, e aos 28 e 35 dias de idade quatro animais por tratamento foram abatidos para coleta do pâncreas e posterior determinação do peso absoluto (PA) e peso relativo (PR) do pâncreas e da atividade datripsina (AT). Os tratamentos não influenciaram significativamente o PA e a AT. Verificou-se efeito significativo dos níveis crescentes de PS,com redução linear dos leucócitos e aumento do volume globular,aos 27 dias; enquanto aos 34 dias, observou-se aumento linear das hemácias. Aos 27 dias, os animais arraçoados com níveis de PS apresentaram menor percentagem de eosinófilos do que aqueles arraçoados com níveis de OI. A utilização de plasma suíno promoveu menor estímulo à resposta imune, enquanto que a utilização de ovo inteiro promoveu maior resposta humoral dos leitões

Were used 64 piglets submitted eight treatments: ration with skim milk (SM), three rations with crescent levels of swine plasma (SP),three rations with whole egg (WE) and a ration with high inclusion of soybean meal (SB). Were monitored the blood parameters (BP) in pigs at 27 and at 34 days of age. The piglets were slaugther at 28 and at 35 days of age, for collections pancreas and posterior mensurements of absolut (AW) and relative weigth (RW) of pancreas and trypsinactivity (TA). Treatments not influencied AW and TA. Significant effect of the crescent levels was verified of SP, with lineal reduction ofthe leukocytes and increase of the globular volume, to the 27 days;while to the 34 days, lineal increase of the hematias was observed. At27 days, animals feds rations with crescent levels of SP have inferior percentage of e osinophils than others that consumed crescent levelsof WE. The utilization of SP promoted smaller stimulus to the immune reply, while the use of WE promoted larger humoral replyof the piglets