Ingestive behavior and temperament of Nellore cattle classified for residual feed intake / Comportamento ingestivo e temperamento de bovinos Nelore classificados por consumo alimentar residual

The objective of this study was to evaluate the relationship between ingestive behavior, temperament and residual feed intake (RFI) in Nellore cattle. Sixty-two bulls and 56 heifers after weaning, housed in individual pens, were evaluated in individual performance tests. Animals were classified as low RFI (<-0.128 kg day <->1; less than mean minus 0.5 standard deviation), medium RFI (-0.128 to 0.135 kg day <->1; ±0.5 standard deviation), and high RFI ( > 0.135 kg day <->1; greater than mean plus 0.5 standard deviation). Ingestive behavior was evaluated for 24 h by direct observation, every 24 days in bulls or every 10 days in heifers. Temperament was assessed by flight speed, reactivity in mobile confinement, composite score, and serum cortisol measurement. The most efficient animals (low RFI, 5.6 kg DM day <->1) consumed 7% less feed than animals with medium efficiency (mean RFI, 6.0 kg DM day <->1) and 13% less than the least efficient animals (high RFI, 6.34 kg DM day <->1). More feed efficient animals spent a longer time feeding and ruminating per kg of DM consumed. Similarly, more efficient animals consumed less DM per hour and ruminated less DM per hour, but made the same number of visits to the feed bunk. High-efficiency animals were 13% and 35% faster to walk 1.77 m after release from the scale than medium- and low-efficiency animals, respectively, suggesting a more reactive temperament without differences in reactivity, composite score, or serum cortisol. Feed efficiency is associated with ingestive behavior and temperament in Nellore cattle. More efficient animals consume and ruminate less feed over the same period of time than animals with medium and low feed efficiency. In addition, more efficient animals exhibit a faster flight speed and are more reactive than less efficient animals.(AU)

O objetivo deste trabalho foi avaliar a relação entre comportamento ingestivo, temperamento e consumo alimentar residual (CAR) em bovinos Nelore. Foram avaliados em teste de desempenho individual 62 machos (idade e peso inicial, 261 dias e 261±26,8 kg) e 56 fêmeas (idade e peso inicial, 293 dias e 207±19,2 kg), alojados em baias individuais. Os animais foram classificados como baixo CAR ( <-0,128 kg/dia; 0,5 desvio padrão abaixo da média; 19 fêmeas e 21 machos), médio CAR (-0,128 a 0,135 kg/dia; ±0,5 desvio padrão; 21 fêmeas e 21 machos), e alto CAR ( > 0,135 kg/dia; 0,5 desvio padrão acima da média; 16 fêmeas e 20 machos). O comportamento ingestivo foi avaliado a cada 24 dias (machos) ou a cada 10 dias (fêmeas), durante 24h, por meio de observações diretas. O temperamento foi avaliado pela velocidade de saída, reatividade em ambiente de contenção móvel, escore composto, e dosagem de cortisol sérico. Animais mais eficientes consumiram (baixo CAR; 5,60 kg MS/dia), em média, 7% menos alimento que os animais de média eficiência (médio CAR; 6,00 kg MS/dia) e 13% menos alimento que os animais menos eficientes (alto CAR; 6,34 kg MS/dia). Animais mais eficientes apresentaram maior tempo de alimentação por kg de matéria seca ingerida (P=0,03), assim como maior tempo de ruminação por kg de matéria seca ingerida (P<0,01). Da mesma forma, animais mais eficientes consumiram menor quantidade de matéria seca por hora (P=0,03) e ruminaram menor quantidade de matéria seca por hora (P<0,01), mas com mesma frequência de visitas ao cocho (P=0,18). Animais classificados como mais eficientes foram, em média, 13% e 35% mais rápidos (P=0,02) para percorrer 1,77 m logo após sair da balança, do que os animais de média e baixa eficiência alimentar, sugerindo temperamento mais reativo, sem diferenças nas variáveis reatividade em ambiente de contenção móvel, escore composto, e dosagem de cortisol sérico. A eficiência alimentar tem relação com comportamento ingestivo e com o...(AU)

Development and evaluation of prediction equations for methane emission from Nellore cattle

Dry matter intake (DMI), nutrient intake and enteric CH4 emission were evaluated in 48 Nellore cattle (392 ± 27 days of age). Equations were generated from intake data and evaluated using root mean square prediction error (RMSPE), and validated by cross-validation. Equations that included DMI and hemicellulose intake (HEMI) [ CH4(MJd−1)=4.08(±1.65)+11.6(±2.34)DMI(kgd−1)−33.4(±7.21)HEMI(kgd−1)] ; DMI and total carbohydrate intake (TCHI) [CH4(MJd−1)=5.26(±1.69)−6.3(±1.47)DMI(kgd−1)+8.8(±1.81)TCI(kgd−1)]; metabolizable energy intake (MEI) and cellulose intake (CELI) [CH4(MJd−1)=5.16(±1.72)−0.13(±0.048)MEI(MJd−1)+7.37(±1.53)CELI(kgd−1)] , and non-fiber carbohydrate intake (NFCI) [CH4(MJd−1)=3.14(±1.48)+3.65(±1.05)NFCI(kgd−1)] resulted in the lowest RMSPE (14.3, 14.1, 14.3 and 14.7%, respectively). When literature equations were evaluated using our database, the most accurate predictions were obtained with equations that included DMI and lignin intake (RMSPE = 15.27%) and MEI, acid detergent fiber intake and lignin intake (RMSPE = 15.7%). The mean error of predicting enteric CH4 emission with the equations developed in this study based on DMI and nutrient intake is 17% and the most accurate predictions are obtained with equations including DMI, carbohydrate intake and MEI.(AU)  

Development and evaluation of prediction equations for methane emission from Nellore cattle

Dry matter intake (DMI), nutrient intake and enteric CH4 emission were evaluated in 48 Nellore cattle (392 ± 27 days of age). Equations were generated from intake data and evaluated using root mean square prediction error (RMSPE), and validated by cross-validation. Equations that included DMI and hemicellulose intake (HEMI) [ CH4(MJd−1)=4.08(±1.65)+11.6(±2.34)DMI(kgd−1)−33.4(±7.21)HEMI(kgd−1)] ; DMI and total carbohydrate intake (TCHI) [CH4(MJd−1)=5.26(±1.69)−6.3(±1.47)DMI(kgd−1)+8.8(±1.81)TCI(kgd−1)]; metabolizable energy intake (MEI) and cellulose intake (CELI) [CH4(MJd−1)=5.16(±1.72)−0.13(±0.048)MEI(MJd−1)+7.37(±1.53)CELI(kgd−1)] , and non-fiber carbohydrate intake (NFCI) [CH4(MJd−1)=3.14(±1.48)+3.65(±1.05)NFCI(kgd−1)] resulted in the lowest RMSPE (14.3, 14.1, 14.3 and 14.7%, respectively). When literature equations were evaluated using our database, the most accurate predictions were obtained with equations that included DMI and lignin intake (RMSPE = 15.27%) and MEI, acid detergent fiber intake and lignin intake (RMSPE = 15.7%). The mean error of predicting enteric CH4 emission with the equations developed in this study based on DMI and nutrient intake is 17% and the most accurate predictions are obtained with equations including DMI, carbohydrate intake and MEI.

Average daily gain and reactivity in Caracu young bulls / Ganho médio diário e reatividade em novilhos da raça Caracu

Studies have shown associations between temperament traits and productivity on cattle industry, some results indicate that animals which adapt easily are less agitated, therefore there will be fewer losses in carcass due to the low incidence of hematomas and higher weight gain. The objective of this study was to associate the average daily gain in Caracu animals, subject to performance test (PT), with reactivity measured by flight speed test. The average daily gain was divided in three classes, considering 0.5 standard deviation below and above the average. The average gain classes 1, 2 and 3 was 1158.55 ± 89.48, 957.14 ± 54.77, 620.88 ± 127.41 g/day, respectively. The flight speed test (FS) measures how long the animal takes to cover a known distance after the release of the squeeze chute. Faster animals were considered more reactive. The study was performed at Centro APTA Bovinos de Corte from Instituto de Zootecnia-Sertãozinho, SP, in which were used 109 flight speed records, of 56 animals, obtained in the beginning and at the end of PT. Data were analyzed using the PROC MIXED (SAS 9.3). The model of analyses included the fixed effects of average daily gain classes (1, 2 and 3) and measures (1 and 2), besides the random-effects of animal and residue. The interaction classes measures, even as age as covariate, were excluded from the initial model, because they didnt show sig

ês.

Immunological parameters and residual feed intake of Nellore heifers / Parâmetros imunológicos e consumo alimentar residual de novilhas Nelore

The residual feed intake (RFI) is a parameter used in the identification of animals with respect to more efficient feed utilization. However, physiological basis are still unknown, however, the interrelationships between nutrition an immunity of the animal can contribute to the investigation of biological phenomena relevant to the RFI, since the defense system to oxidative effects caused by free radicals, is formed by acid polyunsaturated fatty acids, water soluble substances and enzymes, which derive mainly from the use of nutrients in the diet. The objective of this study was to evaluate the immunological parameters of Nellore heifers classified according to RFI. It were evaluated 176 heifers (born between 2008 and 2010), Traditional Nellore herd from Instituto de Zootecnia - Sertãozinho/SP, forming three groups of evaluation, submitted to test post weaning feed efficiency and classified into high (> mean + 0.5 SD, n= 55), medium (± 0.5 SD, n= 65) and low RFI ( mean 0.5 SD, n= 56). The diet was formulated based on Brachiaria decumbens hay, corn, cottonseed meal and mineral mixture (45:55, forage: concentrate). The weight of the animals were performed in fasting blood samples collected by venipuncture vein, using tubes of 10 ml type vacuntainer with EDTA anticoagulant. In the clinical laboratory, we measured the values of leukocytes (LEU); Targeted (SEG) and lymphocyt

O artigo não apresenta resumo em português.

Relationship between residual feed intake and daily methane emission in young Nellore bulls / Relação entre consumo alimentar residual e emissão diária de metano em novilhos Nelore

The cattle production is a sector of agricultural activity that has impact on global warming due to enteric fermentation from digestive process that releases methane (CH4), with energy loss of food and consequent inefficiency of system. Residual feed intake (RFI) is a feed efficiency trait defined as the difference between actual feed intake and the one predicted on the basis of requirements for body weight production and maintenance. There are evidences that more efficient cattle (low RFI) have lower methane daily emissions than less efficient cattle (high RFI). This study aimed to evaluate the pattern of CH4 daily emission and its relationship with RFI obtained during the CH4 collection in Nelore previously evaluated for this trait. A sample of 23 from 62 young bulls, previously classified into low RFI72 and high RFI72 in the 72-days performance test (RFI72), were evaluated. After the 72-days test, the individual feed intake was recorded for a further 45 days. Another RFI was obtained from the last 32 days (RFI32), and the animals were classified into two RFI32 classes: below zero (low RFI32) and above zero (high RFI32). CH4 daily emissions of each animal were collected during the last 7 days of this period, being preceded by 7 days for adaptation of animals to the collection apparatus. The sulfur hexafluoride (SF6) tracer technique was used for estimating enteric methane emi

O artigo não apresenta resumo em português.

Influence of reactivity in residual feed intake classification in beef catlle / Influência da reatividade na classificação do consumo alimentar residual em bovinos de corte

The reactivity is an important behavioral trait that is directly linked to the economic characteristics of beef. Less reactive animals have better performance and efficiency, thus, this study aimed to evaluate the influence of reactivity in the animals´ classification for residual feed intake (RFI). The study was conducted at Centro APTA Bovinos de Corte Instituto de Zootecnia -Sertãozinho/SP. Sixty males belonging to the Traditional Nelore herd were classified into high (> mean + 0.5 SD, n = 21), medium (±0.5 SD from mean, n = 20) and low RFI ( mean - 0.5 SD, n = 19) . The animals had, on average, 256 kg and 264 days, respectively, for weight and age. They were housed in individual pens for 112 days, being 28 for adaptation to facilities and diet and 84 days for data collection. The diet was composed by Brachiaria hay, corn, cottonseed meal and mineral supplement and was offered to the animals twice a day, with ad libitum access to diet and water. The RFI was calculated as the difference between observed and predicted intake by a multiple regression equation, which considers the average daily gain and metabolic body weight. To measure the temperament, blood samples were collected from the animals´ jugular vein and analyzed to quantify serum levels of cortisol. The composite score (CS) was done by a trained observer, giving scores from 1 to 5 for the general movement of

O artigo não apresenta resumo em português.

Immunological parameters and residual feed intake of Nellore heifers / Parâmetros imunológicos e consumo alimentar residual de novilhas Nelore

The residual feed intake (RFI) is a parameter used in the identification of animals with respect to more efficient feed utilization. However, physiological basis are still unknown, however, the interrelationships between nutrition an immunity of the animal can contribute to the investigation of biological phenomena relevant to the RFI, since the defense system to oxidative effects caused by free radicals, is formed by acid polyunsaturated fatty acids, water soluble substances and enzymes, which derive mainly from the use of nutrients in the diet. The objective of this study was to evaluate the immunological parameters of Nellore heifers classified according to RFI. It were evaluated 176 heifers (born between 2008 and 2010), Traditional Nellore herd from Instituto de Zootecnia - Sertãozinho/SP, forming three groups of evaluation, submitted to test post weaning feed efficiency and classified into high (> mean + 0.5 SD, n= 55), medium (± 0.5 SD, n= 65) and low RFI ( mean 0.5 SD, n= 56). The diet was formulated based on Brachiaria decumbens hay, corn, cottonseed meal and mineral mixture (45:55, forage: concentrate). The weight of the animals were performed in fasting blood samples collected by venipuncture vein, using tubes of 10 ml type vacuntainer with EDTA anticoagulant. In the clinical laboratory, we measured the values of leukocytes (LEU); Targeted (SEG) and lymphocyt

O artigo não apresenta resumo em português.

Ingestive behavior and temperament of Nellore cattle classified for residual feed intake / Comportamento ingestivo e temperamento de bovinos Nelore classificados por consumo alimentar residual

The objective of this study was to evaluate the relationship between ingestive behavior, temperament and residual feed intake (RFI) in Nellore cattle. Sixty-two bulls and 56 heifers after weaning, housed in individual pens, were evaluated in individual performance tests. Animals were classified as low RFI ( 0.135 kg day

O objetivo deste trabalho foi avaliar a relação entre comportamento ingestivo, temperamento e consumo alimentar residual (CAR) em bovinos Nelore. Foram avaliados em teste de desempenho individual 62 machos (idade e peso inicial, 261 dias e 261±26,8 kg) e 56 fêmeas (idade e peso inicial, 293 dias e 207±19,2 kg), alojados em baias individuais. Os animais foram classificados como baixo CAR ( 0,135 kg/dia; 0,5 desvio padrão acima da média; 16 fêmeas e 20 machos). O comportamento ingestivo foi avaliado a cada 24 dias (machos) ou a cada 10 dias (fêmeas), durante 24h, por meio de observações diretas. O temperamento foi avaliado pela velocidade de saída, reatividade em ambiente de contenção móvel, escore composto, e dosagem de cortisol sérico. Animais mais eficientes consumiram (baixo CAR; 5,60 kg MS/dia), em média, 7% menos alimento que os animais de média eficiência (médio CAR; 6,00 kg MS/dia) e 13% menos alimento que os animais menos eficientes (alto CAR; 6,34 kg MS/dia). Animais mais eficientes apresentaram maior tempo de alimentação por kg de matéria seca ingerida (P=0,03), assim como maior tempo de ruminação por kg de matéria seca ingerida (P<0,01). Da mesma forma, animais mais eficientes consumiram menor quantidade de matéria seca por hora (P=0,03) e ruminaram menor quantidade de matéria seca por hora (P<0,01), mas com mesma frequência de visitas ao cocho (P=0,18). Animais classificados como mais eficientes foram, em média, 13% e 35% mais rápidos (P=0,02) para percorrer 1,77 m logo após sair da balança, do que os animais de média e baixa eficiência alimentar, sugerindo temperamento mais reativo, sem diferenças nas variáveis reatividade em ambiente de contenção móvel, escore composto, e dosagem de cortisol sérico. A eficiência alimentar tem relação com comportamento ingestivo e com o...

Average daily gain and reactivity in Caracu young bulls / Ganho médio diário e reatividade em novilhos da raça Caracu

Studies have shown associations between temperament traits and productivity on cattle industry, some results indicate that animals which adapt easily are less agitated, therefore there will be fewer losses in carcass due to the low incidence of hematomas and higher weight gain. The objective of this study was to associate the average daily gain in Caracu animals, subject to performance test (PT), with reactivity measured by flight speed test. The average daily gain was divided in three classes, considering 0.5 standard deviation below and above the average. The average gain classes 1, 2 and 3 was 1158.55 ± 89.48, 957.14 ± 54.77, 620.88 ± 127.41 g/day, respectively. The flight speed test (FS) measures how long the animal takes to cover a known distance after the release of the squeeze chute. Faster animals were considered more reactive. The study was performed at Centro APTA Bovinos de Corte from Instituto de Zootecnia-Sertãozinho, SP, in which were used 109 flight speed records, of 56 animals, obtained in the beginning and at the end of PT. Data were analyzed using the PROC MIXED (SAS 9.3). The model of analyses included the fixed effects of average daily gain classes (1, 2 and 3) and measures (1 and 2), besides the random-effects of animal and residue. The interaction classes measures, even as age as covariate, were excluded from the initial model, because they didnt show sig

ês.

Relationship among residual feed intake, digestibility and ingestive behavior in Nellore heifers / Relações entre consumo alimentar residual, comportamento ingestivo e digestibilidade em novilhas Nelore

The aim of this study was to evaluate digestibility and feeding behavior of Nellore heifers belonging to different classes of residual feed intake (RFI). Thirty-two heifers ranked high in RFI (0.491± 0.51 kg/d; n=15) and RFI low (- 0.447 ± 0.51 kg/d; n=17) with a mean age of 502 ± 23.61 days and average weight 364 ± 27.96 kg were kept in confinement for 48 days, with formulated diet based on Tifton 85 hay, corn, cottonseed meal and urea, and ratio of forage: concentrate ratio of 45:55%. The parameters analyzed were digestibility, ingestive behavior and their correlation. Animals low RFI showed higher digestibility of dry matter (DMD), neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose that high RFI animals (49.14% versus 45.38%, 56.65% versus 49.88%, 49.96% versus 45.08%, 61.61% versus 56.40% for DMD, NDFD, ADFD, CELD, respectively). These results indicate that more efficient animals have better food utilization. No differences were found in the variables of ingestive behavior among classes of RFI. Changes in the RFI can be partly explained by the digestibility of nutrients, which is related to ingestive behavior of animals.

Avaliou-se a digestibilidade e comportamento ingestivo em novilhas Nelore pertencentes a duas classes de consumo alimentar residual (CAR) a fim de elucidar as fontes de variação envolvidas nas diferenças de eficiência alimentar observadas entre os animais. Trinta e duas novilhas classificadas em alto CAR (0,491± 0,51 kg de matéria seca/dia; n=15) e baixo CAR (- 0,447 ± 0,51 kg de matéria seca/dia; n=17), com idade média de 502 ± 23,61 dias e peso vivo médio 364 ± 27,96 kg foram mantidas em confinamento por 42 dias, com dieta formulada à base de feno de Tifton 85, milho moído, farelo de algodão e uréia, com relação volumoso:concentrado de 45:55%. Foram avaliados a digestibilidade aparente dos nutrientes e o comportamento ingestivo dos animais. Animais baixo CAR apresentaram maior digestibilidade aparente de matéria seca (DMS), fibra em detergente neutro (DFDN), fibra em detergente ácido (DFDA) e celulose (DCEL) que animais alto CAR (49,14% versus 45,38%; 56,65% versus 49,88%; 49,96% versus 45,08%; 61,61% versus 56,40% para DMS, DFDN, DFDA, DCEL, respectivamente). Esses resultados indicaram que animais mais eficientes têm melhor aproveitamento dos alimentos. Não foram detectadas diferenças nas variáveis de comportamento ingestivo entre as classes de CAR. As variações entre os animais mais e menos eficientes podem ser, em parte, explicadas pela capacidade de digestibilidade dos nu

Influence of reactivity in residual feed intake classification in beef catlle / Influência da reatividade na classificação do consumo alimentar residual em bovinos de corte

The reactivity is an important behavioral trait that is directly linked to the economic characteristics of beef. Less reactive animals have better performance and efficiency, thus, this study aimed to evaluate the influence of reactivity in the animals´ classification for residual feed intake (RFI). The study was conducted at Centro APTA Bovinos de Corte Instituto de Zootecnia -Sertãozinho/SP. Sixty males belonging to the Traditional Nelore herd were classified into high (> mean + 0.5 SD, n = 21), medium (±0.5 SD from mean, n = 20) and low RFI ( mean - 0.5 SD, n = 19) . The animals had, on average, 256 kg and 264 days, respectively, for weight and age. They were housed in individual pens for 112 days, being 28 for adaptation to facilities and diet and 84 days for data collection. The diet was composed by Brachiaria hay, corn, cottonseed meal and mineral supplement and was offered to the animals twice a day, with ad libitum access to diet and water. The RFI was calculated as the difference between observed and predicted intake by a multiple regression equation, which considers the average daily gain and metabolic body weight. To measure the temperament, blood samples were collected from the animals´ jugular vein and analyzed to quantify serum levels of cortisol. The composite score (CS) was done by a trained observer, giving scores from 1 to 5 for the general movement of

O artigo não apresenta resumo em português.

Relationship between residual feed intake and daily methane emission in young Nellore bulls / Relação entre consumo alimentar residual e emissão diária de metano em novilhos Nelore

The cattle production is a sector of agricultural activity that has impact on global warming due to enteric fermentation from digestive process that releases methane (CH4), with energy loss of food and consequent inefficiency of system. Residual feed intake (RFI) is a feed efficiency trait defined as the difference between actual feed intake and the one predicted on the basis of requirements for body weight production and maintenance. There are evidences that more efficient cattle (low RFI) have lower methane daily emissions than less efficient cattle (high RFI). This study aimed to evaluate the pattern of CH4 daily emission and its relationship with RFI obtained during the CH4 collection in Nelore previously evaluated for this trait. A sample of 23 from 62 young bulls, previously classified into low RFI72 and high RFI72 in the 72-days performance test (RFI72), were evaluated. After the 72-days test, the individual feed intake was recorded for a further 45 days. Another RFI was obtained from the last 32 days (RFI32), and the animals were classified into two RFI32 classes: below zero (low RFI32) and above zero (high RFI32). CH4 daily emissions of each animal were collected during the last 7 days of this period, being preceded by 7 days for adaptation of animals to the collection apparatus. The sulfur hexafluoride (SF6) tracer technique was used for estimating enteric methane emi

O artigo não apresenta resumo em português.