Selectivity and feeding behavior of Saanen goats subjected to three nutritional levels

This study was conducted to investigate the effect of selective feeding habits on the quality of the ingested diet and the effect of feed restriction on the selectivity and behavior of goats in feedlots. Differences were found only in the amount of feed given to the animals, with a difference in the amount of feed rejected as a function of the nutritional level. Higher levels of orts were measured for those animals that received the ad libitum diet. For the composition of orts, differences were measured only in the ether extract fraction. Animals fed the ad libitum diet increased their intake of ether extract and energy, crude fiber, neutral detergent fiber, and acid detergent fiber. Thus, they had a preference for consuming the fibrous and energetic portions of the diet to the detriment of the mineral matter. The granulometry influenced the leftovers for the male and female treatments only in the diet that contained the 2.00- and 0.063-mm sized particles, with larger leftovers for the females. There were statistical differences as a function of feeding level for time spent in rumination, with stereotypical behavior, and in time spent standing up or lying down. As a function of sex, the differences were the same variables, including the time spent with agonistic behavior. Animals that received the ad libitum diet had a greater gain and final weight, whereas the animals that received the 60% restricted diet had the lowest performance, as did the females. Feed restriction changed the natural feeding behavior of goats, with smaller feed particles preferred. The feed restriction and sex also influenced the time spent on nonproductive activities, and the animals became more restless, with females having a higher social behavior than males.(AU)

Main driving factors influencing passage kinetics in ruminants / Principais fatores que influenciam a taxa de passagem em ruminantes

Mean retention time (MRT) is a key stepin feed evaluation. Passage rate (kp) and MRT can be affected by several factors. In general, they can be classified as animal or diet-dependent factors. Furthermore, the markers and methods are central aspects of discrepancy regarding the procedures used to estimate kp and MRT in ruminants. Therefore, the primary objective of this paper was to review the main factors and the current knowledge regarding markers and the direct method used to determine kp and MRT in ruminants.

Tempo médio de retenção (TMR) é um ponto chave na avaliação de alimentos. Taxa de passagem (kp) e TMR pode ser afetada por diversos fatores. Em geral, pode ser classificada como fatores dependente do animal ou da dieta. Além disso, marcadores e métodos são aspectos centrais de divergência com relação ao procedimento para estimar kp e TMR em ruminantes. Portanto, o objetivo desse artigo foi revisar os principais fatores e o conhecimento atual relacionado aos marcadores e ao método direto usado para determinar kp e MRT em ruminantes.

Main driving factors influencing passage kinetics in ruminants / Principais fatores que influenciam a taxa de passagem em ruminantes

Mean retention time (MRT) is a key stepin feed evaluation. Passage rate (kp) and MRT can be affected by several factors. In general, they can be classified as animal or diet-dependent factors. Furthermore, the markers and methods are central aspects of discrepancy regarding the procedures used to estimate kp and MRT in ruminants. Therefore, the primary objective of this paper was to review the main factors and the current knowledge regarding markers and the direct method used to determine kp and MRT in ruminants.(AU)

Tempo médio de retenção (TMR) é um ponto chave na avaliação de alimentos. Taxa de passagem (kp) e TMR pode ser afetada por diversos fatores. Em geral, pode ser classificada como fatores dependente do animal ou da dieta. Além disso, marcadores e métodos são aspectos centrais de divergência com relação ao procedimento para estimar kp e TMR em ruminantes. Portanto, o objetivo desse artigo foi revisar os principais fatores e o conhecimento atual relacionado aos marcadores e ao método direto usado para determinar kp e MRT em ruminantes.(AU)

Energy and protein requirements during the growing phase of indigenous goats / Exigências de proteína e energia durante a fase de crescimento de caprinos sem padrão racial definido

The objective of this study was to investigate both energy and protein requirements for the maintenance and growth of indigenous goats, based on data from two separate studies. Goats were weaned at 79 ± 4.4 days of age, with milk and solid diet intake recorded daily. To determine energy maintenance requirements, 32 kids of 4.90 ± 0.302 kg initial body weight (BW) were used. Ten kids were slaughtered at 5.40 ± 0.484 kg BW to estimate initial body composition, with the remaining kids randomly assigned to one of two DM intake levels: ad libitum and restricted-fed (1.2-times maintenance level). Heat production (HP) was calculated as the difference between ingested metabolizable energy (MEI) and retained energy. Net energy requirement for maintenance (NEm) was estimated as the ?0 parameter of the relationship between HP and MEI [HP = ?0 × exp (?1 × MEI)]. Metabolizable energy required for maintenance (MEm) was calculated iteratively, as HP = MEI. Efficiency of energy utilization for maintenance (km) was calculated as NEm/MEm. The intercept of the linear regression of retained CP on CP intake was used to calculate net protein requirements for maintenance (NPm). Net energy and protein requirement for gain (NEg and NPg, respectively) were obtained using 26 kids fed ad libitum and randomly slaughtered at 5.40 ± 0.484 kg BW (n = 10), 15.8 ± 0.655 kg BW (n = 10), and 26.3 ± 1.27 kg BW...

Objetivou-se com o presente estudo, investigar as exigências de proteína e energia para mantença e ganho de caprinos sem padrão racial definido. Para tal, foram utilizados dados individuais de caprinos de 2 estudos. Os caprinos foram desmamados com 79 ± 4,4 dias de idade. Ingestão de leite e dieta sólida foi tomada diariamente. Utilizou-se 32 cabritos de 4,90 ± 0,302 kg de peso corporal (PC) inicial. Nesse momento, 10 cabritos foram abatidos para estimativa de composição corporal inicial. Os cabritos remanescentes foram distribuídos aleatoriamente em dois níveis de ingestão: ad libitum ou com ingestão de 20% acima do nível de mantença. A produção de calor (C) foi calculada pela diferença da energia metabolizável (IEM) ingerida e energia retida. A energia líquida para manteça (ELm) foi estimada pelo parâmetro ?0 da relação entre C e IEM [C = ?0 × exp (?1 × IEM)]. A exigência de energia metabolizável para mantença (EMm) foi calculada quando C = IEM. A eficiência de utilização de energia para mantença (km) foi calculada por ELm/EMm. Utilizou-se o intercepto da regressão linear da proteína retida pela proteína bruta (PB) ingerida para estimativa da proteína líquida exigida para mantença (PLm). A exigência líquida de proteína e energia para ganho (ELg e PLg, respectivamente) foram obtidas utilizando-se 26 cabritos alimentados à vontade e abatidos aos 5,40 ± 0,484 kg PC (n = 10), 15...

Energy and protein requirements during the growing phase of indigenous goats / Exigências de proteína e energia durante a fase de crescimento de caprinos sem padrão racial definido

The objective of this study was to investigate both energy and protein requirements for the maintenance and growth of indigenous goats, based on data from two separate studies. Goats were weaned at 79 ± 4.4 days of age, with milk and solid diet intake recorded daily. To determine energy maintenance requirements, 32 kids of 4.90 ± 0.302 kg initial body weight (BW) were used. Ten kids were slaughtered at 5.40 ± 0.484 kg BW to estimate initial body composition, with the remaining kids randomly assigned to one of two DM intake levels: ad libitum and restricted-fed (1.2-times maintenance level). Heat production (HP) was calculated as the difference between ingested metabolizable energy (MEI) and retained energy. Net energy requirement for maintenance (NEm) was estimated as the ?0 parameter of the relationship between HP and MEI [HP = ?0 × exp (?1 × MEI)]. Metabolizable energy required for maintenance (MEm) was calculated iteratively, as HP = MEI. Efficiency of energy utilization for maintenance (km) was calculated as NEm/MEm. The intercept of the linear regression of retained CP on CP intake was used to calculate net protein requirements for maintenance (NPm). Net energy and protein requirement for gain (NEg and NPg, respectively) were obtained using 26 kids fed ad libitum and randomly slaughtered at 5.40 ± 0.484 kg BW (n = 10), 15.8 ± 0.655 kg BW (n = 10), and 26.3 ± 1.27 kg BW...(AU)

Objetivou-se com o presente estudo, investigar as exigências de proteína e energia para mantença e ganho de caprinos sem padrão racial definido. Para tal, foram utilizados dados individuais de caprinos de 2 estudos. Os caprinos foram desmamados com 79 ± 4,4 dias de idade. Ingestão de leite e dieta sólida foi tomada diariamente. Utilizou-se 32 cabritos de 4,90 ± 0,302 kg de peso corporal (PC) inicial. Nesse momento, 10 cabritos foram abatidos para estimativa de composição corporal inicial. Os cabritos remanescentes foram distribuídos aleatoriamente em dois níveis de ingestão: ad libitum ou com ingestão de 20% acima do nível de mantença. A produção de calor (C) foi calculada pela diferença da energia metabolizável (IEM) ingerida e energia retida. A energia líquida para manteça (ELm) foi estimada pelo parâmetro ?0 da relação entre C e IEM [C = ?0 × exp (?1 × IEM)]. A exigência de energia metabolizável para mantença (EMm) foi calculada quando C = IEM. A eficiência de utilização de energia para mantença (km) foi calculada por ELm/EMm. Utilizou-se o intercepto da regressão linear da proteína retida pela proteína bruta (PB) ingerida para estimativa da proteína líquida exigida para mantença (PLm). A exigência líquida de proteína e energia para ganho (ELg e PLg, respectivamente) foram obtidas utilizando-se 26 cabritos alimentados à vontade e abatidos aos 5,40 ± 0,484 kg PC (n = 10), 15...(AU)

Methods of body composition estimative of growing goats / Métodos de estimativa da composição corporal de caprinos em crescimento

The objective of this study was to compare methods for estimative of body composition of goats based on tritiated water space technique (TOH), specific gravity (SG) of carcass and 9-11th ribs. Ten Toggenburg x Alpine intact male goat kids, from 5.3±0.4 to 25.9±1.3 kg of body weight (BW), were used to estimate body composition by: 1) direct method, 2) TOH method, 3) SG of the carcass and 4) SG of the 9-11th whole ribs. In addition, update linear equations for predicting body composition were developed using data from direct method. The TOH space overestimated water body composition on average 31%. The SG of the carcass and 9-11th ribs underestimated water empty body composition (%) on average 21 and 12%, respectively. In spite of its overestimate, the determination of TOH space can be used as a reliable field technique to study relative changes in body composition of growing goats. Specific gravity is practicable in most circumstances and does not require expensive equipment. However, the SG of the carcass and 9-11th ribs has not a valid equation to predict body composition of growing goats.(AU)

O objetivo deste estudo foi comparar métodos para estimar a composição corporal de caprinos, baseando-se em água tritiada (AT) e gravidade específica (GE) da carcaça e da 9 à 11ª costela. Dez cabritos Toggenburg x Alpine machos não castrados, de 5,3 ± 0,4 para 25,9 ± 1,3 kg de peso corporal (PC), foram utilizados para estimar a composição corporal por: 1) método direto; 2) espaço de AT; 3) GE da carcaça e 4) GE da 9 à 11ª costela. Além disso, equações lineares para predizer a composição corporal foram desenvolvidas, usando dados do método direto. O espaço AT superestimou a composição corporal em água em 31%, em média. A GE da carcaça e a da 9 à 11ª costela subestimaram a composição corporal percentual de água (%), em média, em 21 e 12%, respectivamente. Apesar da sua superestimativa, a determinação do espaço AT pode ser usado como uma técnica de campo viável para estudar alterações relativas na composição corporal de caprinos em crescimento. O uso da GE é possível na maioria das circunstâncias e não requer equipamentos caros. No entanto, a GE da carcaça e a da 9 à 11ª costela ainda não possuem uma equação de predição válida para estimar adequadamente a composição corporal de caprinos em crescimento.(AU)

Methods of body composition estimative of growing goats / Métodos de estimativa da composição corporal de caprinos em crescimento

The objective of this study was to compare methods for estimative of body composition of goats based on tritiated water space technique (TOH), specific gravity (SG) of carcass and 9-11th ribs. Ten Toggenburg x Alpine intact male goat kids, from 5.3±0.4 to 25.9±1.3 kg of body weight (BW), were used to estimate body composition by: 1) direct method, 2) TOH method, 3) SG of the carcass and 4) SG of the 9-11th whole ribs. In addition, update linear equations for predicting body composition were developed using data from direct method. The TOH space overestimated water body composition on average 31%. The SG of the carcass and 9-11th ribs underestimated water empty body composition (%) on average 21 and 12%, respectively. In spite of its overestimate, the determination of TOH space can be used as a reliable field technique to study relative changes in body composition of growing goats. Specific gravity is practicable in most circumstances and does not require expensive equipment. However, the SG of the carcass and 9-11th ribs has not a valid equation to predict body composition of growing goats.

O objetivo deste estudo foi comparar métodos para estimar a composição corporal de caprinos, baseando-se em água tritiada (AT) e gravidade específica (GE) da carcaça e da 9 à 11ª costela. Dez cabritos Toggenburg x Alpine machos não castrados, de 5,3 ± 0,4 para 25,9 ± 1,3 kg de peso corporal (PC), foram utilizados para estimar a composição corporal por: 1) método direto; 2) espaço de AT; 3) GE da carcaça e 4) GE da 9 à 11ª costela. Além disso, equações lineares para predizer a composição corporal foram desenvolvidas, usando dados do método direto. O espaço AT superestimou a composição corporal em água em 31%, em média. A GE da carcaça e a da 9 à 11ª costela subestimaram a composição corporal percentual de água (%), em média, em 21 e 12%, respectivamente. Apesar da sua superestimativa, a determinação do espaço AT pode ser usado como uma técnica de campo viável para estudar alterações relativas na composição corporal de caprinos em crescimento. O uso da GE é possível na maioria das circunstâncias e não requer equipamentos caros. No entanto, a GE da carcaça e a da 9 à 11ª costela ainda não possuem uma equação de predição válida para estimar adequadamente a composição corporal de caprinos em crescimento.

Kinetic and in vitro ruminal fermentation characteristics of copra meal diets with different fat levels

This study aimed at evaluating the chemical composition and in vitro ruminal characteristics of diets using copra meal with different fat contents. Three levels of copra meal inclusion (10, 20 and 30%) and two levels of fat (high-fat copra meal HFCM and low-fat copra meal LFCM) were used in replacement of soybean meal. The addition of copra meal increased EE and reduced CP and NFC of diets, especially when HFCM was included. Treatments with the inclusion of 30% copra meal had a higher colonization time (L), independently of fat content. The maximum gas production was reduced from 59.06 to 39.21 mL/g DM with the addition of HFCM, but was not affected when diets contained LFCM. Digestibility was also reduced with the addition of copra meal, the highest reduction being with the addition of 30% copra meal. Copra meal inclusion has reduced the ammonia concentration from 29.75 mg/100 mL (control diet) to 17.05 mg/100 mL (30% copra meal) but did not affect significantly methane production. Copra meal impacts the chemical composition and ruminal fermentation characteristics of diets, especially when containing high oil content.

Kinetic and in vitro ruminal fermentation characteristics of copra meal diets with different fat levels

This study aimed at evaluating the chemical composition and in vitro ruminal characteristics of diets using copra meal with different fat contents. Three levels of copra meal inclusion (10, 20 and 30%) and two levels of fat (high-fat copra meal HFCM and low-fat copra meal LFCM) were used in replacement of soybean meal. The addition of copra meal increased EE and reduced CP and NFC of diets, especially when HFCM was included. Treatments with the inclusion of 30% copra meal had a higher colonization time (L), independently of fat content. The maximum gas production was reduced from 59.06 to 39.21 mL/g DM with the addition of HFCM, but was not affected when diets contained LFCM. Digestibility was also reduced with the addition of copra meal, the highest reduction being with the addition of 30% copra meal. Copra meal inclusion has reduced the ammonia concentration from 29.75 mg/100 mL (control diet) to 17.05 mg/100 mL (30% copra meal) but did not affect significantly methane production. Copra meal impacts the chemical composition and ruminal fermentation characteristics of diets, especially when containing high oil content.(AU)

Desempenho de bovinos em pastejo submetidos a duas frequências de suplementação no período da seca / Steers performances in grazing submitted by two supplementation intervals during dry season

Com o objetivo de avaliar diferentes frequências de suplementação no período da seca foram utilizados 48 bovinos da raça Nelore com peso médio inicial de 320 kg, em pastagem de Brachiaria brizantha cv. Marandu, submetidos aos tratamentos: suplementação diária e suplementação três vezes por semana, a fim de avaliar o ganho médio diário de peso corporal dos animais nesse período. Os animais de ambos os tratamentos receberam, semanalmente 7,0 kg de suplemento animal-1 e foram pesados em intervalos de 28 dias. Os dados foram analisados pelo procedimento MIXED do SAS (2004) com medidas repetidas no tempo. Observou-se oferta de forragem média de 4,2 toneladas de MS ha-1, com teores médios de 3,5% de PB, 82,24% de FDN e 64,97% de FDA na forragem. Não foi observada diferença (p > 0,01) nos ganhos de peso médio diário entre os animais que receberam o suplemento diariamente (0,23 kg dia-1) e aqueles que receberam três vezes por semana (0,13 kg dia-1). Portanto, as frequências de suplementação não influenciaram no ganho diário de peso corporal dos animais no período da seca.(AU)

This work was carried out to evaluate different frequencies of supplementation during the dry season. Forty-eight Nellore steers with 320 kg of initial live weight were fed with Brachiaria brizantha cv. Marandu pasture on a continuous stocking rate. The animals were submitted to following treatments: daily supplementation and supplementation three times a week. The animals in both treatments received 7 kg of supplementation animal-1 weekly, and were weighted at 28-day intervals. The data were analyzed by the MIXED procedure in SAS (2004), with measurements repeated over time. The study observed average forage allowance of 4.2 tons of DM ha-1, with 3.5% CP, 82.24% NDF and 64.97% ADF. There was no difference (p < 0.01) among daily weight gains of animals who received daily supplementation and those received supplementation three times a week (0.23 and 0.13 kg day-1, respectively). Therefore, the supplementation intervals did not influence steer performance during the dry season.(AU)

Desempenho de bovinos em pastejo submetidos a duas frequências de suplementação no período da seca / Steers performances in grazing submitted by two supplementation intervals during dry season

Com o objetivo de avaliar diferentes frequências de suplementação no período da seca foram utilizados 48 bovinos da raça Nelore com peso médio inicial de 320 kg, em pastagem de Brachiaria brizantha cv. Marandu, submetidos aos tratamentos: suplementação diária e suplementação três vezes por semana, a fim de avaliar o ganho médio diário de peso corporal dos animais nesse período. Os animais de ambos os tratamentos receberam, semanalmente 7,0 kg de suplemento animal-1 e foram pesados em intervalos de 28 dias. Os dados foram analisados pelo procedimento MIXED do SAS (2004) com medidas repetidas no tempo. Observou-se oferta de forragem média de 4,2 toneladas de MS ha-1, com teores médios de 3,5% de PB, 82,24% de FDN e 64,97% de FDA na forragem. Não foi observada diferença (p > 0,01) nos ganhos de peso médio diário entre os animais que receberam o suplemento diariamente (0,23 kg dia-1) e aqueles que receberam três vezes por semana (0,13 kg dia-1). Portanto, as frequências de suplementação não influenciaram no ganho diário de peso corporal dos animais no período da seca.

This work was carried out to evaluate different frequencies of supplementation during the dry season. Forty-eight Nellore steers with 320 kg of initial live weight were fed with Brachiaria brizantha cv. Marandu pasture on a continuous stocking rate. The animals were submitted to following treatments: daily supplementation and supplementation three times a week. The animals in both treatments received 7 kg of supplementation animal-1 weekly, and were weighted at 28-day intervals. The data were analyzed by the MIXED procedure in SAS (2004), with measurements repeated over time. The study observed average forage allowance of 4.2 tons of DM ha-1, with 3.5% CP, 82.24% NDF and 64.97% ADF. There was no difference (p < 0.01) among daily weight gains of animals who received daily supplementation and those received supplementation three times a week (0.23 and 0.13 kg day-1, respectively). Therefore, the supplementation intervals did not influence steer performance during the dry season.

Métodos de estimativa de composição corporal e exigências nutricionais de cabritos F1 Boer x Saanen

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