Number of Calving and Its Relationship with Productive Indicators in Nelore Cows  

作　　者：Atsuko Ikeda Fernando Guzman Vaca Juan Antonio Pereira Pablo Roberto Marini 

机构地区：[1]Faculty of Veterinary Sciences,National University of Rosario,S2170HG,Argentina [2]Faculty of Veterinary and Zootectist,Autonomy University of Gariel,Rene Moreno,Ave.26 de Febrero,Santa Cruz,Bolivia

出　　处：《Journal of Agricultural Science and Technology(A)》2020年第3期151-158,共8页农业科学与技术（A）

摘　　要：The objective of this study was to evaluate the relationship of the calving number with productive indicators in Nelore cows in a grazing system in the Bolivian tropics.Retrospective data,corresponding to the period between 1991 and 2019 referred to 1,566 primiparous and multiparous Nelore breed cows were used.A decrease in the total number of animals was observed from the first to the fifth calving,it was also observed that the age of the first calving was similar in all cows without significant differences,showing that longevity is not associated with the age at the first calving.Live weight presented significant differences(p≤0.05),according to the number of calvings;the fourth and fifth calving cows are the heaviest.Weight of calf at birth did not show a relationship with the number of calvings either.However,it does so in the weight of calf at weaning,which increases from the first to the fifth calving with significant differences(p≤0.05).There were significant differences(p≤0.05)for the interval between calvings,decreasing as the calvings progressed.It is concluded that there is a relationship between the number of calving with productive indicators in Nelore cows in a grazing system in the Bolivian tropics,fundamentally those efficiency variables where longevity is important.

关 键 词：Zootechnic efficiency interval between calvings CALF weight at WEANING ACCUMULATIVE production grazing system 

分 类 号：S82[农业科学—畜牧学]