Genetic parameters, genetic trends and correlated responses of growth traits considering maternal ability in Nelore cattle.

The growth of Nelore cattle was analysed considering the following performance parameters; the effect of the calving order of cows on the phenotypic expression of birth weight (BW), average daily gain from birth to weaning (BWG), and weaning weight (WW), the estimated genetic parameters for the traits, including the covariance components between direct and maternal genetic effects. Genetic trends and correlated responses were also obtained for the studied traits. The calving order of cows, as well as other fixed effects used to obtain the adjusted phenotypic means, were statistically significant (p < 0.001) for studied traits. Direct heritability was estimated at 0.24 ± 0.01 (BW), 0.15 ± 0.01 (BWG), and 0.18 ± 0.01 (WW), while maternal heritability was 0.06 ± 0.01 (BW), 0.12 ± 0.01 (BWG), and 0.11 ± 0.01 (WW). The correlations between direct and maternal effects within the same trait were negligible. Moderate to higher direct genetic correlations (ranging from 0.54 ± 0.04 to 0.98 ± 0.01) and maternal genetic correlations (ranging from 0.34 ± 0.09 to 0.99 ± 0.002) were estimated between the studied traits. Unlike direct genetic effects, there was no significant change in maternal genetic effects over time (p > 0.05). These results indicated the need for revising selection indexes for enhancing maternal ability. Correlated responses were generally lower compared to direct responses, except for BWG. The selection for BWG, considering the maternal genetic effect, would be more efficient to improve maternal ability of the cows for pre-weaning growth in relation to selection for WW. Our results found that direct genetic merit improves pre-weaning weight and this trait can be incorporated into the breeding goal as reflected in the WW.

Estado nutricional al inicio del embarazo, ganancias ponderales y retención de peso al año de paridas / Nutritional Condition at the Beginning of Pregnancy, Weight Gains and Weight Retention One Year after Delivery

Introducción: El embarazo es una etapa de riesgo de obesidad persistente después del parto, entre otras causas, es secundario al estado nutricional al inicio del embarazo y a las ganancias de peso por encima de lo recomendado. Objetivo: Describir las ganancias de peso gestacionales por categorías nutricionales y su asociación con la retención de peso al año del parto. Métodos: Se realizó un estudio observacional de corte transversal en 100 mujeres al año del parto, pertenecientes a tres áreas de salud del municipio Santa Clara, en el periodo comprendido de julio 2016 a julio 2017. Se revisaron los tarjetones de las embarazadas para recoger el peso en kg a la captación, su evaluación nutricional según el índice de masa corporal en la primera consulta y el peso al final de la gestación. Las mismas fueron visitadas en su domicilio al año de paridas; se recogieron datos generales, se midió la talla de pie, el peso corporal y la circunferencia de la cintura. Se calcularon los índices de masa corporal y cintura/talla. Resultados: Predominó la condición de peso adecuado a la captación (67,08 por ciento). El 82,87 por ciento de las mujeres retuvo peso al año de paridas; con mayor frecuencia en las obesas (90,0 por ciento) y sobrepeso (83,01 por ciento) según su estado nutricional a la captación. Todas las mujeres tuvieron índice cintura/talla por encima de 0,50 al año de paridas. Conclusiones: Las mujeres con mayores ganancias por encima de lo recomendado, tienen menor capacidad de recuperación del peso corporal al año de paridas(AU)

Introduction: Pregnancy is a period of persistent obesity risk after delivery. Among other causes, it is secondary to the nutritional status at the beginning of pregnancy and to gaining weight above the recommended. Objective: To describe gestational weight gains by nutritional categories and their association with weight retention one year after delivery. Methods: An observational and cross-sectional study was conducted with 100 women one year after delivery and from three health areas of Santa Clara Municipality, in the period from July 2016 to July 2017. Their pregnancy identification cards were reviewed to collect their weight in kilograms at the time pregnancy was identified, nutritional evaluation based on the body mass index at the first office visit, and the weight at the end of pregnancy. They were paid home visits one year after delivery. General data were collected, foot size, body weight, and waist circumference were measured. Body mass and waist/height indexes were calculated. Results: The weight condition adequate to the time pregnancy was identified (67.08 percent). 82.87 percent of women retained weight one year after delivery, more frequently in obese (90.0 percent) and overweight (83.01 percent) women according to their nutritional status at the time pregnancy was identified. All women had waist/height index above 0.50 one year after delivery. Conclusions: Women with weight gains higher than recommended have less capacity to recover their body weight one year after delivery(AU)

Estimação do valor energético da pastagem e simulação de parâmetros do desempenho produtivo de novilhas em pasto / Estimation of pasture energy value and simulation of productive performance of heifers under grazing

Estimaram-se o valor energético das forrageiras e o consumo de matéria seca por novilhas, em função do ganho de peso, criadas em pastagens de capim-elefante (Pennisetum purpureum Schum. cv. Napier) e capim-mombaça (Panicum maximum, cv. Mombaça), manejadas sob sistema rotacionado, mediante amostras tomadas via extrusa esofágica. As amostras relativas ao terceiro, segundo e primeiro dias de ocupação foram utilizadas para determinar os teores matéria seca, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, lignina e cinzas para calcular os nutrientes digestíveis totais (NDT). Os valores do NDT preditos pelo sistema americano (NRC) e os estimados a partir do ganho de peso foram comparados com ajustamento de modelo de regressão linear simples. Os ganhos médios de peso diário foram de 0,649kg e de 0,590kg, respectivamente, para o capim-elefante e para o capim-mombaça, o que resultou na rejeição da hipótese de nulidade, ou seja, resultou em ausência de equivalência entre os valores preditos pelo sistema e os observados. A incorporação do fator empírico de correção (0,85) em substituição ao valor (0,667) proposto pelo NRC minimizou a ocorrência deste comportamento viesado.(AU)

Elephantgrass (Pennisetum purpureum, Schum. cv. Napier) and mombaçagrass (Panicum maximum, cv. Mombaça) pastures were evaluated under rotational grazing with samplings taken by esophageal extrusa. The energy value of grasses and the dry matter intake of heifers as a function of the weight gains were estimated. Samples relating to the third, second, and first days of the occupation period were used to determine the dry matter (DM), crude protein (CP), ether extract (EE), organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) to calculate the total digestible nutrients (TDN). The TDN values predicted by the American System (NRC) and those estimated from heifers weight gains were compared with adjustment of simple linear regression. The average weight gains were 0.649 and 0.590kg, respectively, for elephantgrass and mombaçagrass, that resulted in the rejection of nullity hypothesis, which means, it resulted in absence of similarity among values predicted by the system and those observed. The incorporation of the empirical factor (0.85) replacing the value (0.667) proposed by NRC resulted in better estimation.(AU)

Estimação do valor energético da pastagem e simulação de parâmetros do desempenho produtivo de novilhas em pasto / Estimation of pasture energy value and simulation of productive performance of heifers under grazing

Estimaram-se o valor energético das forrageiras e o consumo de matéria seca por novilhas, em função do ganho de peso, criadas em pastagens de capim-elefante (Pennisetum purpureum Schum. cv. Napier) e capim-mombaça (Panicum maximum, cv. Mombaça), manejadas sob sistema rotacionado, mediante amostras tomadas via extrusa esofágica. As amostras relativas ao terceiro, segundo e primeiro dias de ocupação foram utilizadas para determinar os teores matéria seca, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, lignina e cinzas para calcular os nutrientes digestíveis totais (NDT). Os valores do NDT preditos pelo sistema americano (NRC) e os estimados a partir do ganho de peso foram comparados com ajustamento de modelo de regressão linear simples. Os ganhos médios de peso diário foram de 0,649kg e de 0,590kg, respectivamente, para o capim-elefante e para o capim-mombaça, o que resultou na rejeição da hipótese de nulidade, ou seja, resultou em ausência de equivalência entre os valores preditos pelo sistema e os observados. A incorporação do fator empírico de correção (0,85) em substituição ao valor (0,667) proposto pelo NRC minimizou a ocorrência deste comportamento viesado.

Elephantgrass (Pennisetum purpureum, Schum. cv. Napier) and mombaçagrass (Panicum maximum, cv. Mombaça) pastures were evaluated under rotational grazing with samplings taken by esophageal extrusa. The energy value of grasses and the dry matter intake of heifers as a function of the weight gains were estimated. Samples relating to the third, second, and first days of the occupation period were used to determine the dry matter (DM), crude protein (CP), ether extract (EE), organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) to calculate the total digestible nutrients (TDN). The TDN values predicted by the American System (NRC) and those estimated from heifers weight gains were compared with adjustment of simple linear regression. The average weight gains were 0.649 and 0.590kg, respectively, for elephantgrass and mombaçagrass, that resulted in the rejection of nullity hypothesis, which means, it resulted in absence of similarity among values predicted by the system and those observed. The incorporation of the empirical factor (0.85) replacing the value (0.667) proposed by NRC resulted in better estimation.

Evaluation o f the influence o f antihelminthic treatments on weight gains, hemoglobin rates and helminth infestations in Guzerá yearlings, in the region of Sertãozinho, São Paulo, Brazil. / Avaliação da influência de tratamentos antihelmínticos no ganho de peso, no nível de hemoglobina e na infestação parasitária de novilhas Guzerá na região de Sertãozinho, S.Paulo, Brasil

Anthihelminthic treatment did not result in significant differences in the averages of weight gains or of bloody levels of hemoglobin when 15 treated Guzerá heifers were compared with an equal number of non-treated ones. The observations were conducted for one year-and the criterion for treatment of the treated groups was its reaching an average count of 200 eggs per gram of faeces. The no significant results were attributed to the low level of infection of the animals employed in which low egg counts prevailed during most of the time: only twice during the one year of observation did the average egg count raise above of 200 in the treated groups. Coprocultures showed a predominance of larvae belonging to the genuses Cooperia, Haemonchus and Oesophagostomum.

A aplicação de anti-helmínticos num lote de 15 bezerras desmamadas, raça Guzerá, não determinou diferenças significativas nas médias de ganho de peso finais nem nas médias dos níveis de hemoglobina sanguínea obtidas nos animais deste lote em relação às verificadas num lote de 15 animais controle. Os animais foram observados pelo prazo de um ano, sendo que os não pertencentes ao lote testemunho eram sempre dosificados quando a média de ovos tipo Strongyloidea (OPG) atingia o nível de 200. Os resultados obtidos foram atribuídos à baixa infestação helmíntica dos animais. As contagens de ovos de nematóides por grama de fezes foram sempre reduzidas, sendo que somente em duas ocasiões as médias mensais de o.p.g. foram superiores a 200 no lote de animais tratados. As coproculturas evidenciaram predominância de larvas infestantes pertencentes aos gêneros Cooperia, Haemonchus e Oesophagos tomum.

Evaluation o f the influence o f antihelminthic treatments on weight gains, hemoglobin rates and helminth infestations in Guzerá yearlings, in the region of Sertãozinho, São Paulo, Brazil / Avaliação da influência de tratamentos antihelmínticos no ganho de peso, no nível de hemoglobina e na infestação parasitária de novilhas Guzerá na região de Sertãozinho, S.Paulo, Brasil

Anthihelminthic treatment did not result in significant differences in the averages of weight gains or of bloody levels of hemoglobin when 15 treated Guzerá heifers were compared with an equal number of non-treated ones. The observations were conducted for one year-and the criterion for treatment of the treated groups was its reaching an average count of 200 eggs per gram of faeces. The no significant results were attributed to the low level of infection of the animals employed in which low egg counts prevailed during most of the time: only twice during the one year of observation did the average egg count raise above of 200 in the treated groups. Coprocultures showed a predominance of larvae belonging to the genuses Cooperia, Haemonchus and Oesophagostomum.

A aplicação de anti-helmínticos num lote de 15 bezerras desmamadas, raça Guzerá, não determinou diferenças significativas nas médias de ganho de peso finais nem nas médias dos níveis de hemoglobina sanguínea obtidas nos animais deste lote em relação às verificadas num lote de 15 animais controle. Os animais foram observados pelo prazo de um ano, sendo que os não pertencentes ao lote testemunho eram sempre dosificados quando a média de ovos tipo Strongyloidea (OPG) atingia o nível de 200. Os resultados obtidos foram atribuídos à baixa infestação helmíntica dos animais. As contagens de ovos de nematóides por grama de fezes foram sempre reduzidas, sendo que somente em duas ocasiões as médias mensais de o.p.g. foram superiores a 200 no lote de animais tratados. As coproculturas evidenciaram predominância de larvas infestantes pertencentes aos gêneros Cooperia, Haemonchus e Oesophagos tomum.

Dried citrus pulp for fattening cattle / Polpa cítrica peletizada para bovinos em confinamento

During 140 experimental days, ground pelleted citrus pulp replaced ground corn ears in rations for fattening cattle. Ration A, contained no citrus pulp and 30% ground corn ears; rations B, contained 15% from each of them and ration C, contained 30% citrus pulp and no ground corn ears. Average daily gains were-. A = .792 kg; B = .957 kg and C = .992 kg. Feed conversions were: A = 12.590 : 1; B = 11.626 : 1 and C = 111.232 : 1. Weight gains data underwent statistical analysis followed by Duncans procedure which declared treatments B and C greater than treatment A. but equal between themselves. These results suggest that dried, citrus pulp is a good replacer for ground corn ears in rations for fattening cattle.

A polpa cítrica peletizada substituiu parcial e totalmente as espigas de milho desintegradas num experimento de blocos ao acaso, com três tratamentos e seis repetições, totalizando 18 bovinos mestiços holandeses, todos machos inteiros e com idade inicial aproximada de 17 meses. Após 140 dias experimentais, os animais apresentaram, em média, os seguintes ganhos em peso, diários: A = 0,792 kg; B = 0,957 kg e C = 0,992 kg. Os pesos médios dos animais, inicial e final, foram respectivamente: A = 244,0 e 383,0 kg; B 21/6,0 e 380,0 kg; C = 244,0 e 383,0 kg. Houve diferença estatística significativa ao nível de 5% de probabilidade e pelo teste de DUNCAN , o s tratamentos B e C foram superiores ao tratamento A, porém iguais entre si.

Dried citrus pulp for fattening cattle / Polpa cítrica peletizada para bovinos em confinamento

During 140 experimental days, ground pelleted citrus pulp replaced ground corn ears in rations for fattening cattle. Ration A, contained no citrus pulp and 30% ground corn ears; rations B, contained 15% from each of them and ration C, contained 30% citrus pulp and no ground corn ears. Average daily gains were-. A = .792 kg; B = .957 kg and C = .992 kg. Feed conversions were: A = 12.590 : 1; B = 11.626 : 1 and C = 111.232 : 1. Weight gains data underwent statistical analysis followed by Duncans procedure which declared treatments B and C greater than treatment A. but equal between themselves. These results suggest that dried, citrus pulp is a good replacer for ground corn ears in rations for fattening cattle.

A polpa cítrica peletizada substituiu parcial e totalmente as espigas de milho desintegradas num experimento de blocos ao acaso, com três tratamentos e seis repetições, totalizando 18 bovinos mestiços holandeses, todos machos inteiros e com idade inicial aproximada de 17 meses. Após 140 dias experimentais, os animais apresentaram, em média, os seguintes ganhos em peso, diários: A = 0,792 kg; B = 0,957 kg e C = 0,992 kg. Os pesos médios dos animais, inicial e final, foram respectivamente: A = 244,0 e 383,0 kg; B 21/6,0 e 380,0 kg; C = 244,0 e 383,0 kg. Houve diferença estatística significativa ao nível de 5% de probabilidade e pelo teste de DUNCAN , o s tratamentos B e C foram superiores ao tratamento A, porém iguais entre si.