Relationship of post-weaning growth and age at puberty in crossbred beef heifers

Abstract

-This study was intended to evaluate body size structure and growth parameters of crossbred heifers fed at four nutritional levels to achieve puberty earlier. Animals were classified depending on their level of crossing between Nelore and Hereford and subjected to four nutritional levels (kg day -1 ) as follows: 0.5 (light; n = 32), 0.75 (medium; n = 32), 1.00 (high; n = 29), and 1.25 (very high; n = 27). Heifers at puberty and at weaning were individually classified for growth parameters. The fat thickness and longissimus muscle area throughout the experimental period were determined by ultrasonography. The height, heart girth, frame, and weight:height ratio were variables used to evaluate body traits. Univariate analysis of variance using the GLIM MIXED procedure os SPSS was performed and the significance level was set at 0.05. Age and body weight at puberty were 388±1.9 days and 331.4±1.3 kg, respectively. Body condition score demonstrated an interaction between nutritional level and crossbred degree. Heifers with the highest degree of Nelore had higher fat thickness and lower weight:height ratio compared with other racial groups at puberty. Pearson correlation coefficient showed a negative association for body condition score (-0.34) and fat thickness (-0.58) compared with age at puberty. The increased fat thickness at younger ages at puberty was observed in all racial groups. The increased weight:height ratio at younger ages at puberty was observed in all racial groups. We observed higher values for a frame in animals at the higher level of supplementation. There is a greater correlation between live weight gain and phenotypic traits during weaning to achieve puberty at an earlier age in crossbred heifers.

Heritability estimation and genetic correlations for mature weight, visual scores, and growth traits in Nellore cattle

“…Moreover, pre-weaning nutrition and average daily gain (ADG) are strategies to improve the economic and biological efficiency of cow-calf production systems, allowing anticipation of age at first breeding to determine puberty in heifers. There is a positive correlation between BW of dams and of their respective daughters, which can influence selection goals for replacement heifers, thereby achieving a significant improvement in growth efficiency of heifers (Barcellos et al, 2014;Walker et al, 2015;Pereira et al, 2017).…”

Novel Encapsulated Calcium Butyrate Supplement Enhances On-Farm Dairy Calf Growth Performance and Body Conformation in a Pasture-Based Dairy Production System

“…The practical implication of this improved performance is on the lifetime performance of the calf. Accelerated growth can lead to early attainment of puberty and age at first calving, both of which have been shown to have a significant and positive impact on lifetime lactation of cows [ 3 , 34 ]. There is also the reproductive benefit when calves can achieve accelerated growth in the pre-weaning period so that they reach puberty and first calving at an early age [ 35 , 36 ].…”

“…The early attainment of weaning weight and age at first calving via faster growth and body conformation has major economic implications on heifer rearing costs because a healthy and well-developed heifer is likely to become a profitable and improved lifetime performing cow [ 2 ]. It is well established that puberty is triggered by body weight; hence, age at first calving could be affected by the body weight of a heifer calf [ 3 ]. Studies have also shown that there is a positive correlation between body weight at calving and milk yield of dairy cows [ 4 ], suggesting that there could be a positive relationship between rearing weight or growth rate of heifers and their subsequent milk production [ 5 ].…”

Estrus and pregnancy rate of Simmental-Ongole Crossbred and Ongole Grade heifer after being synchronized and inseminated

“…Therefore, heifer should be carefully selected. Reproductive performance of heifers is strongly influenced by genetic, conditions of weaning time, and the growth starting from weaning to puberty (Pereira et al, 2017). Genetic factors and poor growth can lead to organ abnormalities and physiology disorders of reproduction.…”