ESTRUTURA POPULACIONAL DO REBANHO NELORE CRIADO NO SEMIÁRIDO DO NORDESTE BRASILEIRO

Objetivou-se avaliar a estrutura populacional de 91.579 animais da raça Nelore criados no Semiárido Nordestino, nascidos entre 1965 e 2011. Analisaram-se o pedigree e a estimação dos parâmetros populacionais baseados na probabilidade de origem do gene. Nos primeiros anos, registraram-se nascimentos superiores de fêmeas, tendendo ao equilíbrio entre os sexos com o passar dos anos. Os números de efetivo de animais fundadores (fe) e ancestrais (fa) indicaram a utilização reduzida de animais na formação genética do rebanho. Dentre 24.676 ancestrais, 450 foram responsáveis por 50% da variabilidade genética da população. Dos 10 fundadores de maior importância, 8 se apresentam dentre os 10 ancestrais; o indivíduo com maior expressão apresentou coeficiente de relação médio (CR) de 1,31%, explicando 1,81% da variabilidade. 72% dos animais têm pais e mães identificados, observando-se perda de informação entre as gerações. 100% dos rebanhos utilizam touros externos e 61% deles vendem touros, não havendo classificação núcleo ou isolado. Endogamia variou de 0,14% na segunda geração a 0,73% na oitava, enquanto que o CR oscilou de 0,8% a 0,35% entre a primeira e a quarta geração, decrescendo a partir da quinta. Observou-se um intervalo médio de gerações de 8,3 anos. O rebanho possui número reduzido de animais na formação genética e pequena integralidade do pedigree, dificultando a estimativa de alguns parâmetros populacionais. Palavras-chave: endogamia; intervalo de gerações; variabilidade genética; zebuínos

Behavior of Murrah buffaloes under influence of strangers in the milk parlor during milk control

ABSTRACT Objective. The study was carried out in two farms, located in São Sebastião do Passé, Bahia, Brazil, during the three first months of lactation of 81 female buffaloes, to observe if stranger people at milk parlor could affect the milk production. Materials and methods. Four strangers were at the milking parlor during the milking time to observe the following parameters: Duration of Stay in the Milking Parlor; Milking Period; Rumination; Defecation; Urination Reactivity; Stress Level; Side Preference in the Milking Parlor ; Milk Yield, and Post Control Milk Yield. The females were categorized as 1=primiparous, 2=pluriparous, and 3=when information about calving number was not available. The data were analyzed using SAS Statistical Package. Results. During the presence of four strangers at the milking parlor, it was observed that the mean value for Duration of Stay in the Milking Parlor was 23 minutes (varying from 12 to 38 minutes). Average Milking Period was 8 minutes (varying from 4 to 13 minutes). Average Milk Yield during observation days (MY) varied from 2.30 kg to 14.70 kg, with an average value of 7.70±2.60 kg, while Mean Milk Yield after the observation days was 8.600±2.70 kg. Conclusions. As far as Post Control Milk Yield, since the animals presented increased milk yield in both farms on the days following the observations, it is possible to assert that the presence of strangers in the milk parlor during milk control reduced milk yield only during the day of observation, with no adverse effects on subsequent milk production

POPULATION STRUCTURE OF THE NELLORE HERD REARED IN THE BRAZILIAN NORTHEAST SEMI-ARID

The objective of this study was to evaluate the population structure of 91,579 Nellore cattle reared in the Northeast semi-arid, born between 1965 and 2011. We analyzed the pedigree and the estimation of population parameters based on the probability of gene origin. In the early years, a higher number of female births occured, tending to gender balance over the years. The number of founder animals (fe) and ancestors (fa) indicated the reduced use of animals in the genetic formation of the herd. Among 2,4676 ancestors, 450 were responsible for 50% of the genetic variability of the population. Of the 10 most important founders, 8 were among the 10 ancestors. The individual with the highest expression presented a mean coefficient of relationship (CR) of 1.31%, explaining 1.81% of the variability.72% of animals have identified fathers and mothers, revealing loss of information between generations. 100% of the herds use external bulls and 61% of them sell bulls, with no core classification or isolate. Inbreeding ranged from 0.14% in the second generation to 0.73% in the eighth, while the CR ranged from 0.8% to 0.35% between the first and fourth generations, decreasing from the fifth on. The average generation interval observed was of 8.3 years. The herd has a small number of animals in the genetic make-up, and small completeness of pedigree, making it difficult to estimate some population parameters. Keywords: generation interval; genetic variability; inbreeding; Zebu

Maternal-calf relationships and their influence on calves up to 120 days

Objectives. To research parental behavior and measure the weight of Nelore and Guzerat calves up to 120 days of age, collecting data from birth up to the first lactation. Materials and methods. Seven different corporal positions were considered to obtain specific data for each of the following categories: time to stand (TP), time to intend to feed after standing (TPTM), weight at birth (PN), weight at 120 days (P120), and time in contact with the calf (TCC). Additionally, independent variables were also evaluated, organized by class: weight at birth (CPN), number of calvings (CNP), order of calving in relation with the herd (CLPR), time of calving (CHP), and finally, hindering to feed (CTAT). Results. There was a significant result in favor of the Nelore race over the Guzerat race. The statistical averages for Nelore and Guzerat were: Time to stand averaged 71 and 153 minutes; time to intend to feed after standing, 39 minutes for Nelore and of 114 minutes for Guzerat. For variable weight at 120 days, Nelore reached an average of 122 kg, and Guzerat 109 kg. For the time in contact with the calf variable there was no significant variance between races. Conclusions. Results showed the superiority of the Nelore race, considering it better adapted to local environmental conditions.   Key words: Behavior, calves, suckling, well being (Source: CAB)

Maternal-calf relationships and their influence on calves up to 120 days

Objectives. To research parental behavior and measure the weight of Nelore and Guzerat calves up to 120 days of age, collecting data from birth up to the first lactation. Materials and methods. Seven different corporal positions were considered to obtain specific data for each of the following categories: time to stand (TP), time to intend to feed after standing (TPTM), weight at birth (PN), weight at 120 days (P120), and time in contact with the calf (TCC). Additionally, independent variables were also evaluated, organized by class: weight at birth (CPN), number of calvings (CNP), order of calving in relation with the herd (CLPR), time of calving (CHP), and finally, hindering to feed (CTAT). Results. There was a significant result in favor of the Nelore race over the Guzerat race. The statistical averages for Nelore and Guzerat were: Time to stand averaged 71 and 153 minutes; time to intend to feed after standing, 39 minutes for Nelore and of 114 minutes for Guzerat. For variable weight at 120 days, Nelore reached an average of 122 kg, and Guzerat 109 kg. For the time in contact with the calf variable there was no significant variance between races. Conclusions. Results showed the superiority of the Nelore race, considering it better adapted to local environmental conditions. Key words: Behavior, calves, suckling, well being (Source: CAB)

Maternal-calf relationships and their influence on calves up to 120 days

Objectives. To research parental behavior and measure the weight of Nelore and Guzerat calves up to 120 days of age, collecting data from birth up to the first lactation. Materials and methods. Seven different corporal positions were considered to obtain specific data for each of the following categories: time to stand (TP), time to intend to feed after standing (TPTM), weight at birth (PN), weight at 120 days (P120), and time in contact with the calf (TCC). Additionally, independent variables were also evaluated, organized by class: weight at birth (CPN), number of calvings (CNP), order of calving in relation with the herd (CLPR), time of calving (CHP), and finally, hindering to feed (CTAT). Results. There was a significant result in favor of the Nelore race over the Guzerat race. The statistical averages for Nelore and Guzerat were: Time to stand averaged 71 and 153 minutes; time to intend to feed after standing, 39 minutes for Nelore and of 114 minutes for Guzerat. For variable weight at 120 days, Nelore reached an average of 122 kg, and Guzerat 109 kg. For the time in contact with the calf variable there was no significant variance between races. Conclusions. Results showed the superiority of the Nelore race, considering it better adapted to local environmental conditions.Objetivo. Investigar el comportamiento materno y observar su influencia en el peso de los terneros de las razas Nelore y Guzerat hasta los 120 días de edad, evaluándolos desde su nacimiento hasta el primer amamantamient. Materiales y métodos. Se consideraron siete posturas corporales diferentes, las cuales fueron usadas para obtener las observaciones específicas en cada una de las siguientes categorías: Tiempo para ponerse de pie (TP), Tiempo para intentar lactar después de ponerse de pie (TPTM), peso al nacer (PN), peso a los 120 días (P120) y tiempo de contacto con la cría (TCC). Se evaluaron las variables independientes, organizadas en clases: peso al nacer (CPN); número de partos (CNP); orden del parto en relación al rebaño (CLPR); hora del parto (CHP) y obstaculización de mamada (CTAT). Resultados. Se obtuvo un mejor resultado en los terneros de la raza Nelore en relación a los de la raza Guzerat. Los promedios estadísticos para Nelore y Guzerat fueron los siguientes: TP con media de 71 y 153 minutos; TPTM de 39 y 114 minutos; P120 con 122 kg para terneros Nelore y 109 kg para los de la raza Guzerat. La variable TCC no obtuvo una diferencia significativa entre las razas. Conclusiones. Los resultados demuestran una superioridad para animales de la raza Nelore, lo que permite inferir que poseen una mejor adaptación a las condiciones ambientales locales

Maternal-calf relationships and their influence on calves up to 120 days

Objectives. To research parental behavior and measure the weight of Nelore and Guzerat calves up to 120 days of age, collecting data from birth up to the first lactation. Materials and methods. Seven different corporal positions were considered to obtain specific data for each of the following categories: time to stand (TP), time to intend to feed after standing (TPTM), weight at birth (PN), weight at 120 days (P120), and time in contact with the calf (TCC). Additionally, independent variables were also evaluated, organized by class: weight at birth (CPN), number of calvings (CNP), order of calving in relation with the herd (CLPR), time of calving (CHP), and finally, hindering to feed (CTAT). Results. There was a significant result in favor of the Nelore race over the Guzerat race. The statistical averages for Nelore and Guzerat were: Time to stand averaged 71 and 153 minutes; time to intend to feed after standing, 39 minutes for Nelore and of 114 minutes for Guzerat. For variable weight at 120 days, Nelore reached an average of 122 kg, and Guzerat 109 kg. For the time in contact with the calf variable there was no significant variance between races. Conclusions. Results showed the superiority of the Nelore race, considering it better adapted to local environmental conditions.Objetivo. Investigar el comportamiento materno y observar su influencia en el peso de los terneros de las razas Nelore y Guzerat hasta los 120 días de edad, evaluándolos desde su nacimiento hasta el primer amamantamient. Materiales y métodos. Se consideraron siete posturas corporales diferentes, las cuales fueron usadas para obtener las observaciones específicas en cada una de las siguientes categorías: Tiempo para ponerse de pie (TP), Tiempo para intentar lactar después de ponerse de pie (TPTM), peso al nacer (PN), peso a los 120 días (P120) y tiempo de contacto con la cría (TCC). Se evaluaron las variables independientes, organizadas en clases: peso al nacer (CPN); número de partos (CNP); orden del parto en relación al rebaño (CLPR); hora del parto (CHP) y obstaculización de mamada (CTAT). Resultados. Se obtuvo un mejor resultado en los terneros de la raza Nelore en relación a los de la raza Guzerat. Los promedios estadísticos para Nelore y Guzerat fueron los siguientes: TP con media de 71 y 153 minutos; TPTM de 39 y 114 minutos; P120 con 122 kg para terneros Nelore y 109 kg para los de la raza Guzerat. La variable TCC no obtuvo una diferencia significativa entre las razas. Conclusiones. Los resultados demuestran una superioridad para animales de la raza Nelore, lo que permite inferir que poseen una mejor adaptación a las condiciones ambientales locales