Reproductive efficiency of Nellore cows nursing Nellore or crossbred Simmental × Nellore calves

Vargas, Fernando Miranda de; Wechsler, Francisco Stéfano; Oliveira, Marcus Vinícius Morais de; Seno, Leonardo de Oliveira; Fernandes, Alexandre Rodrigo Mendes; Camilo, Fernando Rossi

doi:10.1590/s1516-35982013000700003

Cited by 3 publications

(2 citation statements)

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“…Assim, com a remoção do bezerro, o eixo hipotálamo-hipofisário da vaca é ativado, o que provoca aumento da frequência dos pulsos do LH e da concentração de IGF-I e, consequentemente, diminuição do período de serviço (Kawashima et al, 2008). Vargas Junior et al (2013) também constataram que a maior frequência de mamadas em bezerros Nelore é responsável pelo maior período de anestro nas vacas.…”

Section: Resultsunclassified

Desempenho de vacas de corte Purunã submetidas a diferentes manejos de amamentação

Moura

Kuss

Moletta

et al. 2014

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi avaliar o desempenho ponderal e reprodutivo de vacas de corte submetidas a diferentes manejos de amamentação. Durante a estação de monta, de 85 dias, foram avaliadas 161 vacas de corte da raça Purunã, de acordo com os seguintes manejos de amamentação: desmame precoce, vacas separadas dos seus bezerros aos 75 dias pós-parto; amamentação controlada, vacas separadas de seus bezerros aos 75 dias de idade, mas colocadas para amamentar uma vez ao dia durante a estação de monta; e desmame convencional, vacas mantidas com seus bezerros ao pé até o final da estação de monta, aos 160 dias de idade dos bezerros, em média. As taxas de prenhez não foram significativamente afetadas pelos manejos de amamentação, tendo sido de 97% no desmame precoce, de 96% na amamentação controlada e de 90% no desmame convencional. No entanto, o desmame precoce resultou em menor eficiência reprodutiva (28,26 kg), quando comparado à amamentação controlada (35,09 kg) e ao desmame convencional (35,34 kg). Vacas de corte mantidas em boas condições corporais ao parto e ao início da estação de monta apresentam alta taxa de fertilidade, independentemente do manejo de amamentação dos bezerros.Termos para indexação: amamentação controlada, anestro pós-parto, desmame precoce, eficiência reprodutiva, intervalo entre partos, taxa de fertilidade. Performance of Purunã beef cows subjected to different nursing managementsAbstract -The objective of this work was to evaluate the weight and reproductive performance of beef cows subjected to different nursing managements. During the breeding season of 85 days, 161 beef cows of the Purunã breed were evaluated, according to the following feeding managements: early weaning, cows separated from their calves at 75 days postpartum; controlled nursing, cows separated from their calves at 75 days of age, but taken to nurse once a day during the breeding season; and conventional weaning, cows kept with their calves until the end of the breeding season, at 160 days of age of calves, in average. Fertility rates were not significantly affected by weaning managements, being 97% for early weaning, 96% for controlled nursing, and 90% for conventional weaning. However, early weaning resulted in lower reproductive efficiency (28.26 kg), when compared to controlled nursing (35.09 kg) and conventional weaning (35.34 kg). Beef cows maintained in good body conditions at birth and at the beginning of the breeding season have a high fertility rate, regardless of calf-feeding management.

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Section: Resultsunclassified

Desempenho de vacas de corte Purunã submetidas a diferentes manejos de amamentação

Moura

Kuss

Moletta

et al. 2014

Pesq. agropec. bras.

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“…Although there are nutritional and management strategies for the primary prevention of NEB, but the negative economic impact of NEB in dairy cattle is undeniable (Loor, 2010). However, it is merit to mentioning that the negative economic and welfare impact of NEB on a bovine depends on its intensity and duration (Vargas Junior et al, 2013). Hence, it is possible to have cows with certain degree of NEB and different health and reproductive performance.…”

Section: Introductionmentioning

confidence: 99%

Integrated regulatory network reveals novel candidate regulators in the development of negative energy balance in cattle

Mozduri

Bakhtiarizadeh

Salehi

2018

Animal

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Negative energy balance (NEB) is an altered metabolic state in modern high-yielding dairy cows. This metabolic state occurs in the early postpartum period when energy demands for milk production and maintenance exceed that of energy intake. Negative energy balance or poor adaptation to this metabolic state has important effects on the liver and can lead to metabolic disorders and reduced fertility. The roles of regulatory factors, including transcription factors (TFs) and micro RNAs (miRNAs) have often been separately studied for evaluating of NEB. However, adaptive response to NEB is controlled by complex gene networks and still not fully understood. In this study, we aimed to discover the integrated gene regulatory networks involved in NEB development in liver tissue. We downloaded data sets including mRNA and miRNA expression profiles related to three and four cows with severe and moderate NEB, respectively. Our method integrated two independent types of information: module inference network by TFs, miRNAs and mRNA expression profiles (RNA-seq data) and computational target predictions. In total, 176 modules were predicted by using gene expression data and 64 miRNAs and 63 TFs were assigned to these modules. By using our integrated computational approach, we identified 13 TF-module and 19 miRNA-module interactions. Most of these modules were associated with liver metabolic processes as well as immune and stress responses, which might play crucial roles in NEB development. Literature survey results also showed that several regulators and gene targets have already been characterized as important factors in liver metabolic processes. These results provided novel insights into regulatory mechanisms at the TF and miRNA levels during NEB. In addition, the method described in this study seems to be applicable to construct integrated regulatory networks for different diseases or disorders.

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Reproductive Performance and Reconception of Nellore Cows According to Their Pure‐ or Cross‐Bred Calves

Wechsler

Nogueira

2015

Reprod Domestic Animals

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ContentsThe objective of the present research was to evaluate the effect of a calf's genetic group on the productive and reproductive efficiency of its Nellore dam. Fixed-time artificial insemination was applied to 800 cows using semen extracted from Nellore, Simmental and Angus Red bulls. Four hundred eleven cows calved, producing 119 Nellore, 103 ½Simmental-½Nellore and 189 ½Nellore-½Angus Red calves. The second mating period, which paired Nellore cows with Simmental bulls, was initiated 10 days after parturitions began and lasted for 5 months. Based on the two successive parturitions, the cumulative parturition rate for calving periods of 3, 4 and 5 months was calculated. Although no significant difference was observed for birth weight among the genetic groups, cross-bred calves weighed, on average, 10% more than did pure-bred calves at the age of 205 days. Nellore dams experienced a gestation period that was 7 days longer than did the cross-bred dams, and the former showed a higher parturition rate at 90 and 120 days of the calving season, but not at 150 days (calving rates of 80.6, 76.4 and 76.2% for mothers of Nellore, ½Nellore-½Angus Red and ½Nellore-½Simmental, respectively, p > 0.05). At 90 and 120 days, Nellore dams produced more kg of calf per mated dam. In conclusion, in a short breeding season, Nellore dams nursing pure-bred Nellore calves were found to have a higher biological efficiency compared with Nellore dams nursing cross-bred calves.

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Reproductive efficiency of Nellore cows nursing Nellore or crossbred Simmental × Nellore calves

Cited by 3 publications

References 14 publications

Desempenho de vacas de corte Purunã submetidas a diferentes manejos de amamentação

Desempenho de vacas de corte Purunã submetidas a diferentes manejos de amamentação

Integrated regulatory network reveals novel candidate regulators in the development of negative energy balance in cattle

Reproductive Performance and Reconception of Nellore Cows According to Their Pure‐ or Cross‐Bred Calves

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