RESUMO
This study aimed to evaluate the ingestive behavior of F1 Holstein × Zebu cows grazing on deferred pasture receiving different supplementation strategies. The experimental design was completely randomized, in a 3×4 factorial, with three supplementation strategies and four evaluation periods. The ingestive behavior of 24 cows divided into three groups of supplementation provided at milking was observed, and two of these groups received protein in the pasture. Ingestive behavior was monitored every 10 minutes for 24 hours and analyzed in the form of periods (morning, afternoon, night, and dawn) and total time. The animals remained longer grazing during the afternoon when the BGHI presented values of 83.8. Protein consumption did not influence grazing time but interfered with forage consumption. For the total grazing time, the animals in group 2 spent less time grazing. The groups of animals presented no difference concerning the time spent on rumination and idleness. During night and dawn, when the climate was characterized as thermal comfort, the animals spent more time ruminating. The climatic conditions did not influence the ingestive behavior, as the grazing peak was observed at times of higher BGHI. However, supplementation of the animals in group 2 modified the ingestive behavior of F1 H × Z cows.
Assuntos
Animais , Bovinos , Comportamento Animal , Bovinos/fisiologia , Suplementos Nutricionais , Ingestão de AlimentosRESUMO
The aim of this study was to evaluate different levels of feed restriction in the diet for F1 Holstein x Zebu cows during the winter on performance and economic viability. Data from Zootechnical book keeping, and from experiments conducted in the Experimental Field of Felixlândia, belonging to EPAMIG, were used. Total lactation of sixty F1 Holstein x Zebu cows receiving different diets was analyzed, by 2.00%, 2.25%, 2.50%, 2.75% body weight (BW), and a control group (3.4%; no feed restriction), allowing 5% leftovers in relation to the dry matter supplied, distributed in a completely randomized design. Data on milk production and feed cost were collected, evaluating the different periods that characterize the lactation of an animal. The highest milk production was found in the diet levels 3.4 %, and 2.75% BW, 3,636.00, and 3,271.50 kg, respectively. Lower milk production was observed at levels of 2.50%; 2.25%; 2.00% BW, respectively. The highest feed cost was verified without feed restriction followed by the levels of 2.75%, 2.50%, 2.25%, and 2.00% BW. The supply of the no feed restriction diet resulted in a performance superior to levels 2.75; 2.50; 2.25; 2.00% BW. The items profit, profitability were similar between all treatments, indicating that, when there is occasional feed shortage, a restriction in the diet supply of up to 2% BW provides economic security to the rural producer.
Objetivou-se por meio deste estudo avaliar diferentes níveis de restrição alimentar da dieta de vacas F1 Holandês x Zebu durante o inverno sobre o desempenho e viabilidade econômica. Foram utilizados dados da escrituração zootécnica e de experimentos realizados no Campo Experimental de Felixlândia, pertencente à EPAMIG. Foi analisada a lactação total de sessenta vacas F1 Holandês x Zebu submetidas a diferentes ofertas de dieta, em 2,00%, 2,25%, 2,50%, 2,75% do peso corporal (PC) e um grupo controle com alimentação à vontade (3,4%), permitindo 5% de sobras em relação à matéria seca fornecida, distribuídos em delineamento inteiramente casualizado. Os dados de produção de leite e custo alimentar foram coletados, avaliando os diferentes períodos que caracterizam a lactação de um animal. A maior produção de leite foi verificada nos níveis de dieta 3.4% e 2,75% PC, sendo 3.636,00 e 3.271,50 kg, respectivamente. Produção de leite inferiores foram verificadas nos níveis de 2,50%; 2,25%; 2,00% do PC. O maior custo com alimentação foi verificado no nível de alimentação à vontade seguido dos níveis de 2,75%; 2,50%, 2,25% e 2,00% do PC. A oferta da dieta sem restrição teve um rendimento superior aos respectivos 2,75 níveis; 2,50; 2,25; 2,00% do PC, respectivamente. Os itens lucro, lucratividade e rentabilidade foram semelhantes entre todos os tratamentos, demonstrando que, quando há escassez eventual de alimento, a restrição no fornecimento da dieta de até 2% do PC oferece segurança econômica ao produtor rural que utiliza vacas em seu sistema F1 Holandês x Zebu.
Assuntos
Animais , Bovinos , Custos e Análise de Custo , Leite , Dieta/veterinária , Dietoterapia/veterináriaRESUMO
The objective of this study was to evaluate the effects of different concentrate supplementation strategies to lactating F1 Holstein x Zebu cows managed on deferred signal grass pasture on milk yield, composition and body weight gain. Thirty-six F1 Holstein x Zebu cows with average days in milk of 102 ± 10 and body weight of 501 ± 19 kg were allotted to a 4 x 5 completely randomized factorial design, with four feeding strategies and five weeks of evaluation. The treatments consisted of four nutritional strategies: deferred pasture as a source of roughage + 700 grams of protein supplement (PDPI); deferred pasture as a source of roughage + 1,200 grams of protein supplement (PDPII); deferred pasture + 15 kilograms of corn silage (natural basis) + 1,200 grams of protein supplement (PDSP) and corn silage (ad libitum) + 700 grams of protein supplement (CSS). There was no interaction (P = 0.99) between supplementation strategies and test days on milk yield and chemical composition. The mean milk yield of cows managed on PDPI, PDPII and PDSP was 11.50 kg/day (P > 0.05), which was 14.30% lower than that of cows managed on CSS. Fat content (P < 0.01), protein (P < 0.01), lactose (P < 0.01), defatted dry extract (DDE) (P< 0 .01), total solids (P < 0.01) and milk casein (P < 0.01) were affected by different supplementation strategies. F1 Holstein x Zebu cows on deferred Urochloa decumbens cv. Basilisk pasture and supplemented with concentrate maintains milk production at 11.50 kg with normal composition, maintaining satisfactory body weight and condition score.(AU)
O objetivo deste estudo foi avaliar os efeitos de diferentes estratégias de suplementação com concentrado para vacas F1 Holandês x Zebu em lactação manejadas em pastagem de capim-braquiária diferida sobre a produção, composição e ganho de peso corporal do leite. Trinta e seis vacas F1 Holandês x Zebu com média de dias em leite de 102 ± 10 e peso corporal de 501 ± 19 kg foram distribuídas em um planejamento fatorial 4 x 5 inteiramente casualizado, com quatro estratégias de alimentação e cinco semanas de avaliação. Os tratamentos consistiram em quatro estratégias nutricionais: pasto diferido como fonte de volumoso + 700 gramas de suplemento protéico (PDPI); pastagem diferida como fonte de volumoso + 1.200 gramas de suplemento protéico (PDPII); pastagem diferida + 15 quilos de silagem de milho (base natural) + 1.200 gramas de suplemento protéico (PDSP) e silagem de milho (ad libitum) + 700 gramas de suplemento protéico (CSS). Não houve interação (P = 0,99) entre as estratégias de suplementação e os dias de teste na produção e composição química do leite. A produção média de leite das vacas manejadas com PDPI, PDPII e PDSP foi de 11,50 kg / dia (P > 0,05), que foi 14,30% menor que a das vacas manejadas com CSS. O teor de gordura (P < 0,01), proteína (P < 0,01), lactose (P < 0,01), extrato seco desengordurado (DDE) (P < 0,01), sólidos totais (P < 0,01) e caseína do leite (P < 0,01) foram afetados por diferentes estratégias de suplementação. Vacas F1 Holandês x Zebu em Urochloa decumbens diferida cv. O pasto de Basilisk e suplementada com concentrado mantém a produção de leite em 11,50 kg com composição normal, mantendo peso corporal e escore de condição satisfatórios.(AU)
Assuntos
Animais , Feminino , Bovinos , Peso Corporal , Lactação , Aumento de Peso , Caseínas , Pastagens , PoaceaeRESUMO
This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.(AU)
Assuntos
Animais , Feminino , Bovinos , Paspalum/química , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Bovinos , Comportamento Animal/fisiologia , Termografia/veterináriaRESUMO
This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.
Assuntos
Feminino , Animais , Bovinos , Bovinos , Comportamento Animal/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Paspalum/química , Ração Animal/análise , Termografia/veterináriaRESUMO
This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.(AU)
Assuntos
Animais , Feminino , Bovinos , Paspalum/química , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Bovinos , Comportamento Animal/fisiologia , Termografia/veterináriaRESUMO
The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P < 0.05) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (P>0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).
Assuntos
Ração Animal/análise , Dieta/veterinária , Metano/análise , Animais , Composição Corporal , Peso Corporal , Bovinos , Ingestão de Energia , Metabolismo Energético , Feminino , Idade Gestacional , Hibridização Genética , GravidezRESUMO
Records of 234 lactations from F1 Holstein x Gyr daughters of proven bulls were used in this study for the evaluation of productive and reproductive characteristics of cows. Data were collected from a private farm located in the municipality of Santo Antônio do Monte, MG, Brazil. The objective of this study was to evaluate the effects of Holstein bull's PTA milk (predicted transmitting ability) calving year, season, and parity on the productive and reproductive characteristics of F! cows. The productive characteristics analyzed were total milk production (TMP), average daily production (ADP), days in milk (DIM), and milk yield per day of calving interval (MYDCI). The studied reproductive characteristics were service interval (SI), calving interval (CI), and gestation length (GL). The results were subjected to statistical analysis and means for significant effects were compared using Duncan's test at a significance level of 5%. F1 animals efficiently expressed their genetic potential for milk production with an average total milk production of 7842.61 kg and average daily production of 24.53 kg. Means for days in milk, milk yield per day of calving interval, service interval, calving interval, and gestation length were 322.52 days, 20.73 kg, 106.0 days, 383.23 days, and 276.18 days, respectively. Properly managed F1 Holstein x Gyr daughters of proven bulls fed a balanced diet efficiently expressed their genetic potential for milk production without adverse effects on reproduction. Moreover, Holstein x Gyr cows should be selected based on parents' PTA for milk traits and other factors such as environmental conditions and management.
Assuntos
Bovinos/fisiologia , Lactação , Paridade , Reprodução , Animais , Brasil , Feminino , Masculino , Leite/metabolismo , Estações do AnoRESUMO
A maioria dos estudos sobre o uso da somatotropina bovina recombinante (rbST) foram conduzidos em países de clima temperado utilizando animais de genética Bos taurus e todo o protocolo de utilização foi pautado para tais animais e extrapolados aos mestiços (Bos taurus x Bos indicus) em ambientes tropicais. No entanto, existem características diferenciadas da curva de produção de leite e alguns aspectos fisiológicos que diferem os mestiços dos taurinos, sendo assim, estabelecer padrões específicos para uso do rbST para vacas mestiças podem melhorar a eficiência, reduzir custos e expandir o uso da tecnologia para os sistemas brasileiros. Estabelecer ajuste da dosagem, o intervalo, o melhor tempo para início e término da aplicação, avaliar o melhor retorno financeiro do uso para o sistema produtivo assim como as respostas produtivas e reprodutivas das vacas pode trazer adequação do uso da tecnologia no sistema de produção de gado mestiço leiteiro. O objetivo da revisão é identificar critérios a serem considerados para uso do rbST em vacas mestiças a fim de potencializar a estratégia do uso do mesmo. O rbST promove notório aumento da produção de leite e mais detalhes do protocolo de uso do hormônio para vacas mestiças necessita ser avaliado já que algumas características da curva de leite e capacidade produtiva são diferentes para animais cruzados.(AU)
Most studies on the use of recombinant bovine somatotropin (rbST) were conducted in countries with temperate climates using Bos taurus animals and the entire use protocol was based on such animals and extrapolated to crossbred animals (Bos taurus x Bos indicus) in tropical environments. However, there are different characteristics in the milk production curve and some physiological aspects that differentiate the crossbred from those cattle. Therefore, the establishment of specific standards for the use of rbST for crossbred cattle can improve efficiency, reduce costs, and expand the use of technology to Brazilian systems. Establishing dosage adjustment, the interval, the best time to start and end the application, evaluating the best financial return from use on the productive system, as well as the productive and reproductive responses of the cows can help foster the adequacy of the use of technology in the production system of crossbred dairy cattle. The purpose of this review is to identify criteria to be considered for the use of rbST in crossbred cows in order to enhance the strategy of using it. The use of rbST promotes a noticeable increase in milk production; however, further details of the hormone use protocol for crossbred cows need to be evaluated since some characteristics of the milk curve are different for crossbred animals.(AU)
La mayoría de los estudios sobre el uso de somatotropina bovina recombinante (rbST) se han realizado en países de clima templado utilizando animales de genética Bos taurus y todo el protocolo de utilización se ha pautado para tales animales y extrapolados a los mestizos (Bos taurus x Bos indicus) en ambientes tropicales. Sin embargo, existen diferentes características de la curva de producción de leche y algunos aspectos fisiológicos que diferencian al mestizo de los toros, por lo tanto, establecer estándares específicos para el uso de rbST para vacas mestizas puede mejorar la eficiencia, reducir costos y expandir el uso de tecnología para Sistemas brasileños. Establecer el ajuste de dosis, el intervalo, el mejor momento para iniciar y finalizar la aplicación, evaluar el mejor retorno económico del uso para el sistema productivo, así como las respuestas productivas y reproductivas de las vacas pueden propiciar la adecuación del uso de la tecnología en el sistema de producción de ganado mestizo lechero. El propósito de la revisión es identificar los criterios que se deben considerar para el uso de rbST en vacas mestizas con el fin de mejorar la estrategia de uso. El rbST promueve un aumento notable en la producción de leche y es necesario evaluar más detalles del protocolo de uso de hormonas para vacas cruzadas, ya que algunas características de la curva de la leche son diferentes para los animales cruzados.(AU)
Assuntos
Animais , Feminino , Bovinos , Bovinos/fisiologia , Bovinos/genética , Hormônio do Crescimento , Hormônio do Crescimento/genética , Leite , EficiênciaRESUMO
A maioria dos estudos sobre o uso da somatotropina bovina recombinante (rbST) foram conduzidos em países de clima temperado utilizando animais de genética Bos taurus e todo o protocolo de utilização foi pautado para tais animais e extrapolados aos mestiços (Bos taurus x Bos indicus) em ambientes tropicais. No entanto, existem características diferenciadas da curva de produção de leite e alguns aspectos fisiológicos que diferem os mestiços dos taurinos, sendo assim, estabelecer padrões específicos para uso do rbST para vacas mestiças podem melhorar a eficiência, reduzir custos e expandir o uso da tecnologia para os sistemas brasileiros. Estabelecer ajuste da dosagem, o intervalo, o melhor tempo para início e término da aplicação, avaliar o melhor retorno financeiro do uso para o sistema produtivo assim como as respostas produtivas e reprodutivas das vacas pode trazer adequação do uso da tecnologia no sistema de produção de gado mestiço leiteiro. O objetivo da revisão é identificar critérios a serem considerados para uso do rbST em vacas mestiças a fim de potencializar a estratégia do uso do mesmo. O rbST promove notório aumento da produção de leite e mais detalhes do protocolo de uso do hormônio para vacas mestiças necessita ser avaliado já que algumas características da curva de leite e capacidade produtiva são diferentes para animais cruzados.(AU)
Most studies on the use of recombinant bovine somatotropin (rbST) were conducted in countries with temperate climates using Bos taurus animals and the entire use protocol was based on such animals and extrapolated to crossbred animals (Bos taurus x Bos indicus) in tropical environments. However, there are different characteristics in the milk production curve and some physiological aspects that differentiate the crossbred from those cattle. Therefore, the establishment of specific standards for the use of rbST for crossbred cattle can improve efficiency, reduce costs, and expand the use of technology to Brazilian systems. Establishing dosage adjustment, the interval, the best time to start and end the application, evaluating the best financial return from use on the productive system, as well as the productive and reproductive responses of the cows can help foster the adequacy of the use of technology in the production system of crossbred dairy cattle. The purpose of this review is to identify criteria to be considered for the use of rbST in crossbred cows in order to enhance the strategy of using it. The use of rbST promotes a noticeable increase in milk production; however, further details of the hormone use protocol for crossbred cows need to be evaluated since some characteristics of the milk curve are different for crossbred animals.(AU)
La mayoría de los estudios sobre el uso de somatotropina bovina recombinante (rbST) se han realizado en países de clima templado utilizando animales de genética Bos taurus y todo el protocolo de utilización se ha pautado para tales animales y extrapolados a los mestizos (Bos taurus x Bos indicus) en ambientes tropicales. Sin embargo, existen diferentes características de la curva de producción de leche y algunos aspectos fisiológicos que diferencian al mestizo de los toros, por lo tanto, establecer estándares específicos para el uso de rbST para vacas mestizas puede mejorar la eficiencia, reducir costos y expandir el uso de tecnología para Sistemas brasileños. Establecer el ajuste de dosis, el intervalo, el mejor momento para iniciar y finalizar la aplicación, evaluar el mejor retorno económico del uso para el sistema productivo, así como las respuestas productivas y reproductivas de las vacas pueden propiciar la adecuación del uso de la tecnología en el sistema de producción de ganado mestizo lechero. El propósito de la revisión es identificar los criterios que se deben considerar para el uso de rbST en vacas mestizas con el fin de mejorar la estrategia de uso. El rbST promueve un aumento notable en la producción de leche y es necesario evaluar más detalles del protocolo de uso de hormonas para vacas cruzadas, ya que algunas características de la curva de la leche son diferentes para los animales cruzados.(AU)