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Animal nutrition needs simple methodologies to be applied under field conditions, providing valid estimates of consumption and digestibility that can be used by both farmers and animal input industry. Thus, the search for new substances, provided in a practical way, quantified by simple and low-cost analytical methodologies, replacing external indicators (chromic oxide used as reference) would be well accepted by the scientific community. In this context, the aim of this study was to assess the supply of chorionic oxide by esophageal route or mixed in the diet and the use of kaolin as an indicator, under the same forms of administration, to estimate fecal production and digestibility using four castrated male Holstein cattle. The experimental design was a 4 × 4 Latin square design, with four experimental periods of 12 days and six-day intervals between periods. Treatments consisted of supplying chromic oxide by esophageal route (COer), kaolin by esophageal route (Kaoer), chromic oxide mixed to the diet (COdiet), and kaolin mixed to the diet (Kaodiet). The treatment Kaodiet allowed obtaining estimates of fecal production similar to the treatment COer. The treatment COdiet did not differ from the treatment COer (p > 0.05) considering all the assessed parameters, evidencing that the indicator chromic oxide can be supplied mixed directly in the diet without damaging the estimates of fecal production and digestibility. Under the studied conditions, kaolin was not an effective indicator to obtain accurate estimates of fecal production and further studies are needed to adjust the analytical techniques of aluminum extraction as well as to resolve some doubts regarding its digestion process.

Objetivou-se avaliar o crescimento dos componentes corporais de borregas mestiças alimentadas com níveis crescentes de concentrado na dieta e estabelecer o nível adequado de suplementação para produção de fêmeas para abate. Foram utilizadas 30 borregas lanadas, oriundas de cruzamentos com ovinos da raça Texel, alimentadas com feno de capim-Tifton 85 (Cynodon spp.) e quatro níveis de concentrado na dieta (20, 40, 60 e 80%). No início do experimento foi realizado abate para determinação da composição corporal de seis borregas. Os demais foram abatidos com aproximadamente 48 kg. Para o estudo do crescimento dos componentes em relação ao crescimento corporal dos animais foi utilizado o modelo CC = a x PCJb, onde CC = peso do componente corporal; a e b parâmetros das equações de crescimento e PCJ = peso corporal em jejum. A carcaça, músculos, ossos e trato gastrintestinal foram classificados como componentes de crescimento precoce (b < 1; P < 0,01). Foi observado efeito linear positivo dos níveis de concentrado sobre o crescimento da carcaça e gordura da carcaça (P < 0,05). A quantidade total de gordura aumentou com os níveis crescentes de inclusão de concentrado na dieta (P < 0,05). Recomenda-se a inclusão de 60% de concentrado na dieta de borregas em crescimento para produção de carcaças com precocidade para deposição de músculo e gordura. A inclusão de 20% de concentrado na dieta de borregas é o suficiente para produção de carcaças com máxima deposição de músculos e sem excesso de gordura.

Objetivou-se avaliar dietas com níveis crescentes de concentrado para borregas confinadas e estabelecer a proporção de concentrado ideal para maximizar a utilização dos nutrientes e o desempenho durante as fases de recria e terminação. Foram confinadas 24 borregas alimentadas com feno de capim-Tifton e níveis crescentes de concentrado na dieta (20, 40, 60 e 80%) para avaliação individual do consumo de matéria seca (CMS), digestibilidade dos nutrientes das dietas, ganho médio diário (GMD) e eficiência alimentar (EA). As borregas foram abatidas com 47 kg. Na fase de recria, o CMS não foi alterado (P>0,05) pela inclusão de concentrado nas dietas (1176 g/dia). Foi observado efeito quadrático dos níveis de concentrado (P0,05). O CDMS e o valor de NDT apresentaram comportamento quadrático (P0,05). Recomenda-se a inclusão de 71,50% de concentrado na dieta de borregas para maximizar o aproveitamento dos nutrientes e o desempenho na fase de recria e 72,3% de concentrado para fase de terminação.

Objetivou-se ajustar e avaliar modelos Pará predição das proporções de Ossos, Músculos e Gordura da Carcaça de Borregas A Partir de Medidas obtidas in vivo, na Seção HH e 12ª costela. Como 30 Borregas lanadas, oriundas de Cruzamentos com ovinos da Raça Texel, foram confinadas, alimentadas com níveis crescentes de Concentrado. (20; 40; 60 e 80%) e abatidas com 37,70 ± 10,23 kg Pará Estimativa da proporção de Gordura (GC%) e músculo (MC%) na Carcaça foram ajustados modelos com SO percentuais de Gordura e músculo da 9ª a 11ª costela (Seção HH) UO da 12ª costela, acompanhados OU NÃO da espessura de Gordura (EGS mm) UO da área de olho de lombo da Carcaça (AOL cm2), respectivamente. a proporção de Ossos da Carcaça (OC%) foi Predito Cabelo percentual de Ossos na Seção HH UO da 12ª costela. Para predição in vivo, foram ajustadas Equações com peso corporal em jejum (PCJ), altura de cernelha (AC), EGS e AOL Medidas POR ultrassom. A GC% PODE Ser Estimada Pela EGS obtida na Carcaça EO Teor de Gordura na 12ª costela. O MC% PODE Ser Predito de forma acurada Mais considerando o Teor de músculo na Seção HH ea AOL da Carcaça. A Seção HH foi o modelo Mais acurado Paragrafo predição da OC%. Para Obtenção da GC% e MC% in vivo OS modelos devem Incluir PCJ e AC. O OC% in vivo PODE Ser Estimado a Partir do PCJ. Recomenda-se a utilização da Composição Física da 12ª costela Paragrafo Estimativa acurada da proporção de Gordura na Carcaça EO USO da Seção HH Paragrafo predição das proporções de músculo e Ossos na Carcaça. Para predição acurada das proporções de Gordura, músculo e Ossos de Borregas in vivo, o modelo DEVE apresentar peso corporal em jejum e Medidas de altura de cernelha.

Three experiments were conducted with the objective of evaluating the effects of supplementation (concentrate or mineral supplementation), supplementation strategy (continuous or strategic supplementation) and gender class on the ingestive and diurnal behaviour of grazing beef cattle. To evaluate the effect of the supplementation (Experiment 1) and the gender class (Experiment 3) on their diurnal behaviour, behaviour visualisations were performed by two people at observation stations outside the picket area with the aid of binoculars. The animal behaviour was classified as: supplement intake, grazing, water intake, standing ruminating, standing idle, lying ruminating, lying idle and walking. To evaluate the effect of the supplementation strategy on the ingestive behaviour of the supplement (Experiment 2), refusals of the supplement were weighed for six consecutive days at different times (20, 40, 60, 90, 120, 180, 240, 480 and 1,440 minutes) after the concentrate was supplied. The intake of concentrate per animal, at each observation time, was calculated by subtracting the weight of the scraps at that time from the total weight of the batch of supplement provided on the day, and dividing the result by the number of animals in each batch. Finally, a logistic model was adjusted for each treatment. A 10% significance level was adopted for all statistical procedures. Concentrate supplementation reduced the time that the animals spent grazing. The continuous supplementation strategy affected the uniformity of the supplement intake speed, without affecting the average speed or the total supplement intake. The gender class of the animals also influenced their diurnal behaviour, castrated males spent more time lying, compared to females. The specificities of cattle behaviour should be considered when delineating the supplementation of grazing cattle, since the type of supplement, previous supplementation and gender class interfere with their behaviour.

Consumers are more interested in having healthier and better quality products. The diet offered to animals can strongly affect the composition of meat. Thus, this study aimed to evaluate the effect of different levels of concentrate on lipid profile ( in natura meat) and cholesterol content ( in natura and cooked meat) of ewe lambs’ meat cuts. Therefore, twenty-four lambs with a mean weight of 23.1 ± 2.1 kg were confined and fed different levels of a concentrate (20, 40, 60 and 80%) for 120 days. The diets consisted of tifton hay and concentrate based on corn and soybean meal. The muscles triceps brachii (shoulder ), longissimus dorsi (loin) and semimembranosus (leg) represented the respective cuts that were analyzed. Increased levels of concentrate decreased only C18:3 (5.82 to 0.20 mg/100 g) in meat and without affecting saturated fatty acids (SFA), unsaturated (UFA), monounsaturated (MUFA), polyunsaturated (PUFA), both desirable and total levels. Levels of concentrate had no effect on UFA/SFA (1.01), MUFA/SFA (0.97), PUFA/SFA (0.04) ratios, or the atherogenic (AI) and thrombogenic index (TI), nor on the content cholesterol in natura and cooked meat. The meat cuts had different lipid profiles, IA, IT and cholesterol content. Concentrate levels slightly alter the lipid profile and do not alter the cholesterol content, while meat cuts are different for these components.

This study aimed at evaluating carcass traits and meat quality of Nellore steers on pasture submitted to different dietary supplementation strategies. The 32 Nellore animals tested (8 ± 0.6 months) were raised under rotational grazing on Brachiaria brizantha cv. Piatã (syn. Urochloa brizantha cv. Piatã) pasture and distributed in four treatments: supply of mineral salt ad libitum in the growth and finishing phases (MSGF); concentrate supplementation only during the growth phase (CG); concentrate supplementation only during the finishing phase (CF) and concentrate supplementation the growth and finishing phases (CGF). The concentrated supplement was supplied at 0.5% of body weight and mineral ad libitum. The steers were slaughtered when more than 50% of the lot of each treatment reached 450 kg body weight. The mean the hot and cold carcass weight and subcutaneous fat thickness did not differ between treatments (P > 0.05). The calves the treatment CF and CGF showed a larger rib-eye area and higher ether extract levels in the Longissimus dorsi muscle than in MSGF and CG (P < 0.05). Mean shearing force was similar between treatments (P > 0.05). The use of feeding strategies on pasture with concentrate supplementation in the growth and finishing phases of Nellore cattle anticipates slaughter in 92 days and produces carcasses and meat with satisfactory traits.

This study aimed to evaluate the adequacy of seven non-linear models (France, Orskov and McDonald, Gompertz, exponential, logistic, two-pool exponential and two-pool logistic) in the adjustment of the curve and in the generation of parameters of cumulative gas production from five tropical feedstuffs (rice hulls, sugarcane, cassava chips, turnip by-product, and peach-palm by-product) used in ruminant nutrition. To this end, the feedstuffs were incubated in vitro in graduated glass syringes together with a buffer inoculum solution, in triplicate. Gas production was read at 0, 2, 4, 6, 8, 10, 12, 24, 26, 28, 30, 32, 36, 48, 52, 54, 56, 60 and 72 h of incubation. The data were used to generate the parameters of each model using the SAS statistical package. After the parameters were generated, the gas volume values were obtained at the aforementioned times, for each model, and these were compared with the values observed at incubation by using Model Evaluation System (MES) software. For the comparison, regression parameters were tested using Mayer’s test, in addition to the evaluation of the mean bias (MS), concordance correlation coefficient (CCC), and mean squared prediction error (MSPE). The France, Logistic, and Gompertz models, for rice hulls, and the Orskov and McDonald model, for cassava chips, were significant (P < 0.1) according to Mayer’s test, indicating lack of fit of the model. Besides presenting the lowest MSPE, the models that showed fit according to Mayer’s test were the two-pool logistic for rice hulls and cassava chips, and the two-pool exponential for sugarcane, turnip, and peach palm. Thus, the non-linear two-pool models are the most efficient in adjusting to the curve and in the generation of parameters of cumulative production of gases from the tested feedstuffs. Objetivou-se avaliar a adequação de sete modelos não lineares (France, Orskov & McDonald, Gompertz, exponenciais simples e bicompartimental e logísticos simples e bicompartimental) no ajuste da curva e na geração de parâmetros de produção cumulativa de gases de cinco alimentos tropicais (casca de arroz, cana-de-açucar, raspa de mandioca, resíduo de nabo e resíduo da pupunha) utilizados na nutrição de ruminantes. Para tal, realizou-se a incubação in vitro, em triplicata, dos alimentos em seringas de vidro graduadas junto com solução tamponada de inoculante. A leitura da produção de gás foi realizada nos tempos 0, 2, 4, 6, 8, 10, 12, 24, 26, 28, 30, 32, 36, 48, 52, 54, 56, 60 e 72 horas. Os dados gerados foram utilizados para geração dos parâmetros de cada modelo testado com auxílio do pacote estatístico SAS. Após a geração dos parâmetros foram obtidos valores de volume de gás nos tempos supracitados, para cada modelo, e estes foram comparados aos valores observados na incubação através do programa Model Evaluation System (MES). Para comparação, testou-se os parâmetros de regressão pelo teste de Mayer, além da avaliação dos valores de viés médio (VM), coeficiente de concordância da correlação (CCC) e quadrado médio do erro de predição (QMEP). Os modelos de France, Logístico e Gompertz, para casca de arroz, além do modelo de Orskov & McDonald, para raspa de mandioca, foram significativos (P < 0,1) ao teste de Mayer, indicando falta de ajuste do modelo. Os modelos que apresentaram ajuste segundo o teste de Mayer, além de apresentarem os menores QMEP, foram o Logístico Bicompartimental para a casca de arroz e raspa de mandioca e o Exponencial Bicompartimental para cana-de-açucar, nabo e pupunha. Sendo assim, os modelos não lineares bicompartimentais são os mais eficientes no ajuste da curva e na geração de parâmetros de produção cumulativa de gases dos alimentos testados.

A nutricao animal necessita de metodologias simples que possam ser aplicadas em condicoes de campo, que sejam capazes de fornecer estimativas validas de consumo e digestibilidade e que possam ser utilizadas tanto pelos produtores rurais quanto pela industria produtora de insumos para animais. Assim a busca por novas substâncias, fornecidas de forma pratica, quantificadas por metodologias analiticas simples e de baixo custo em substituicao aos indicadores externos (oxido cromico usado como referencia) seriam bem aceitas pela comunidade cientifica. Neste contexto objetivou-se avaliar o fornecimento do oxido cromico via esofagica ou misturado na racao, e o uso do caulim como indicador, sob as mesmas formas de fornecimento, para estimar a producao fecal e digestibilidade, utilizando quatro bovinos machos castrados da raca Holandesa. Foram testados quatro tratamentos, distribuidos aos animais segundo um delineamento quadrado latino 4x4, sendo o primeiro aquele em que os animais foram submetidos ao fornecimento de oxido cromico fornecido via esofagica (OCesof), no segundo tratamento os animais receberam o caulim via esofagica (Caulesof), no terceiro o fornecimento do oxido cromico aos animais foi misturado a racao (OCrac) e no quarto tratamento o caulim foi administrado misturado a racao (Caulrac), em quatro periodos experimentais de 12 dias, com intervalos de seis dias entre os periodos. O tratamento Caulrac permitiu obter estimativas de producao fecal semelhante ao tratamento OCesof. O tratamento OCrac nao diferiu do tratamento OCesof (p > 0,05) em nenhum dos parâmetros avaliados, evidenciando que o indicador oxido cromico pode ser fornecido misturado diretamente na racao sem prejudicar as estimativas de producao fecal e digestibilidade.

This study aimed to assess the performance, carcass traits, and non-carcass components of feedlot finished Texel crossbred lambs from different residual feed intake classes (RFI). Forty-seven uncastrated male Texel crossbred lambs (¾ Texel + ¼ Pantaneira) tested here were 4-month-old with an initial weight of 29.9 ± 5.5 kg. The lambs were confined for 70 days for individual dry matter intake (DMI) and average daily gain (ADG) assessment. The diet containing corn silage was provided as roughage, while the concentrate consisted of corn grain, soybean meal, urea, and mineral mixture with a 40:60 roughage to concentrate ratio and 76.34% total digestible nutrients (TDN). After confinement for 70 days, the lambs were slaughtered to assess carcass traits and non-carcass components. Based on the RFI, lambs were divided into three classes according to the standard deviation (sd): Positive RFI (inefficient, 0.5 above the mean), Negative RFI (efficient, 0.5 below the mean), and Medium RFI (intermediate). Classes with Negative (efficient) and Positive RFI (inefficient) showed no differences in ADG (0.321 vs 0.306 kg; P > 0.05). Dry matter intake (g d-1), and percentage of body weight (BW) differed significantly between the RFI classes (P < 0.05). Compared to lambs in the inefficient class, those in the efficient class (Negative RFI) showed a 9% reduction in DMI and had the same ADG. The lambs in either Positive or Negative RFI classes showed no weight differences between non-carcass components (P > 0.05). The RFI classes showed no differences in shrunk body weight, hot carcass weight, hot dressing, and weight of commercial cuts (P > 0.05). They showed no differences in neck, shoulder + shank, loin, rack, flank steak, rack cap off, and leg weights (P > 0.05). Our results indicate that improvement in feed efficiency, as a function of the RFI index, does not compromise performance and carcass traits of Texel crossbred lambs.

This study aimed to evaluate the growth of body components in crossbred ewe lambs fed increasing levels of dietary concentrate and to determine the optimum level of supplementation for finishing ewe production. Thirty crossbred (½ Pantaneira × ½ Texel) wool ewe lambs fed Tifton 85 hay (Cynodon spp.) and different dietary concentrate levels (20, 40, 60, and 80% DM basis) were selected for study. At the beginning of the study, six animals were slaughtered for determination of initial body composition. The remaining animals were slaughtered at approximately 48 kg live weight. The growth of body components in relation to body growth was estimated from the allometric model BC = a × (FBW)b, where BC is body component weight, a and b are growth equation parameters, and FBW is fasted body weight. Carcass, muscle, bone, and gastrointestinal tract were late maturing (b < 1, P < 0.01). Carcass and carcass fat growth was positively affected (linear, P < 0.05) by concentrate level. Total fat weight increased with increasing concentrate level (P < 0.05). The addition of up to 60% concentrate in growing ewe lamb diets is recommended for production of carcasses with early deposition of muscle and fat. The addition of 20% concentrate in ewe lab diets is sufficient for production of carcasses with maximum deposition of muscle and no excess fat. Objetivou-se avaliar o crescimento dos componentes corporais de borregas mestiças alimentadas com níveis crescentes de concentrado na dieta e estabelecer o nível adequado de suplementação para produção de fêmeas para abate. Foram utilizadas 30 borregas lanadas, oriundas de cruzamentos com ovinos da raça Texel, alimentadas com feno de capim-Tifton 85 (Cynodon spp.) e quatro níveis de concentrado na dieta (20, 40, 60 e 80%). No início do experimento foi realizado abate para determinação da composição corporal de seis borregas. Os demais foram abatidos com aproximadamente 48 kg. Para o estudo do crescimento dos componentes em relação ao crescimento corporal dos animais foi utilizado o modelo CC = a x PCJb, onde CC = peso do componente corporal; a e b parâmetros das equações de crescimento e PCJ = peso corporal em jejum. A carcaça, músculos, ossos e trato gastrintestinal foram classificados como componentes de crescimento precoce (b < 1; P < 0,01). Foi observado efeito linear positivo dos níveis de concentrado sobre o crescimento da carcaça e gordura da carcaça (P < 0,05). A quantidade total de gordura aumentou com os níveis crescentes de inclusão de concentrado na dieta (P < 0,05). Recomenda-se a inclusão de 60% de concentrado na dieta de borregas em crescimento para produção de carcaças com precocidade para deposição de músculo e gordura. A inclusão de 20% de concentrado na dieta de borregas é o suficiente para produção de carcaças com máxima deposição de músculos e sem excesso de gordura.

To maximize economic gain in sheep production systems it is critical to adjust feedlot diets to maximize performance while minimizing feed, and especially concentrate, waste. Little information is available on ideal diets for crossbred ewe lambs. Therefore, this study aimed to evaluate the performance of feedlot crossbred ewe lambs, and the digestibility of diets, with increasing levels of concentrate during the growing and finishing phases. Twenty-four crossbred Texel × Pantaneira Texel ewe lambs were confined and fed Tifton hay with increasing levels of concentrate in the diet (20, 40, 60 and 80%) for individual evaluation of dry matter intake (DMI), digestibility of diets, average daily gain (ADG) and feed efficiency (FE). Animals were slaughtered at 47 kg. In the growing phase, the inclusion of concentrate in the diets (1176 g.kg-1) did not change DMI (p > 0.05). Concentrate levels had a quadratic effect (p < 0.05) on the dry matter digestibility coefficient (DMDC) and on total digestible nutrients (TDN) during the growing phase. In the finishing phase, there was a negative linear effect of concentrate levels on DMI (p < 0.05), but TDN intake was similar among the experimental diets (p > 0.05). DMDC and TDN values displayed a quadratic behavior (p < 0.05), plateauing at 60% concentrate. ADG and FE increased as concentrate was added to the diet in the growing phase (p < 0.05). During the finishing phase, lamb performance was similar (p > 0.05) for different diets. Thus, the use of 60% concentrate in the confined crossbred ewe lamb diet during growing and 20% concentrate during finishing is recommended.

The present work aimed at evaluating models that predict the proportion of bone, muscle, and fat in ewe lamb carcasses using in vivo data obtained from the 9th to 11th rib section and from the 12th rib. A study population of 30 wooled ewe lambs, derived from Texel breed crosses, were fed with different concentrate levels (0%, 20%, 40%, 60%, and 80%) and slaughtered at a weight of 37.70 ± 10.23 kg. Carcass fat content (FC%) and muscle content (MC%) were estimated from models using the proportion of muscle and fat in the 9th to 11th rib section or in the 12th rib, with or without additional data regarding subcutaneous fat thickness (SFT mm) or carcass ribeye area (RA cm2). Carcass bone content (BC%) was predicted based on the proportion of bones in the 9th to 11th rib section or in the 12th rib. Modeling with in vivo data included fasting body weight (FBW), withers height (WH), and ultrasound measurements of SFT and RA. The FC% could be estimated from the carcass SFT and fat content in the 12th rib. The MC% was more accurately predicted from the proportion of muscles in the 9th to 11th rib section and from carcass RA. The 9th to 11th rib section provided the most accurate data for the prediction of BC%. To determine FC% and MC% from in vivo inputs, the model must include FBW and WH. In vivo FBW measurements alone allow for the estimation of BC%. We recommend the use of 12th rib composition for the accurate estimation of carcass fat content, and the use of the 9th and 11th rib section for the prediction of carcass muscle and bone content. Models using in vivo data for the prediction of fat, muscle, and bone in ewe lambs should incorporate FBW and WH.