Meta-Analysis of Early Growth Performance of Cattle in Ethiopia

Fikadu Wodajo Tirfie^*
*Correspondence: Fikadu Wodajo Tirfie, Department of Veterinary Science, Ethiopian Institute of Agricultural Research (EIAR), Holetta Agricultural Research Center, Addis Ababa, Ethiopia, Email:

Keywords

Cattle • Crossbred • Growth traits • Meta data analysis • Growth traits

Introduction

Growth, which involves the development of the reproductive system alongside an increase in body size and weight, is influenced by various factors, including genetics, nutrition, and management [1]. Each animal has a genetically determined mature body size that it strives to reach, with environmental factors either accelerating or slowing the growth process but having minimal impact on the ultimate size [2-3]. Carefully selecting replacement heifers can significantly reduce herd costs, as their production accounts for about 20% of the total expenditures on dairy farms [4]

Growth performance is a crucial metric for evaluating beef and dual-purpose cattle, often assessed through body weight and growth rate [5]. Changes in cattle body weight are influenced by both genetic and environmental factors, with feed availability, which is largely dependent on climatic conditions, being a key environmental determinant. Birth weight, an easily measurable trait, is an essential predictor of subsequent weaning weight and growth rate [6]. While genetic selection for growth traits is less favored due to the low rate of genetic gain, crossbreeding offers an effective alternative for enhancing traits with low heritability [7].

Reliable performance evaluation and data collection can serve as critical resources for developing a national breeding strategy [8]. Performing a meta-analysis of early growth performance in cattle entails systematically reviewing and integrating data from various studies to achieve a holistic understanding of growth patterns, influencing factors, and possible strategies for improvement. Therefore, the purpose of this paper is to summarize data on the growth performance of Ethiopia's cattle breed, which has been studied by various scholars in different parts of the Ethiopia.

Martials and Methods

Source of data and data collection

Data collected from the different secondary source such as PhD Dissertations, MSc Thesis, journals articles, proceedings and review article. Both local and crossbred animals were grouped into their respective genetic groups and performance of a given trait for each genotype was recorded and average value taken.

Data collected from different literature included: Breed/genetic group, site of study, birth weight, weaning weight, yearling weight, preweaning average daily weight gain, and source of data (authors). The total number of records used for analysis was 213 records which collected from different articles (Table 1).

Table 1. Number of records used for analysis.

Trait to be studied

Birth weight, weaning weight, yearling weight, daily body weight gains (between birth and weaning date) of growth trait were used for analysis.

Data analysis

After collecting the necessary data from different source for analyses, preliminary editing was performed to adjust orderly the data entered and coded using Microsoft Excel. The organized data was summarized and analyzed using the descriptive statistics with Statistical Analysis System software (SAS), 2004 version 9.0. Differences between means of a trait for different genetic group were tested using the Duncan multiple range test based on the ANOVA result.

The following statistical models were used:

Y_ijklmn= μ+G_i+e_in

Where,

Yin=BW, WW, YW and PrWADBG (B-W)

Yin=nth record of ith genotype

μ=Overall mean

Gi=Effect of ith genotype (i=HF cross, Jersey cross, Simmental cross, Local)

ein=Random errors associated with each

Results and Discussion

Early growth performance of the cattle

Birth Weight (BW): The overall mean Birth Weight (BW) was 24.31 ±3.61 kg, as presented in Table 2. This result is comparable to the reported value for Sanga and Friesian × Sanga crossbred dairy cattle breeds kept under hot and humid environments in Ghana, which was 22.8 ± 1.4 kg [9]. It is also similar to crossbreds of HF with local breeds, such as 23.5 kg for HF × Fogera at ALRC, 22.13 ± 0.14 kg for HF × Horro at Bako Agricultural Research Center, and 24.58 ± 0.10 kg for 50% HF × Fogera at Metekele Cattle Breeding and Improvement Ranch.

However, the present finding for BW is lower than the reported value of 32.1 ± 4.89 kg in South Africa and 46.54 ± 4.79 kg for Canadian Charolais cattle. The variation in birth weight performance among cattle might be attributed to differences in genetic potential, nutrition, and other environmental factors. Simmental crosses showed better birth weight performance compared to Holstein Friesian (HF) and Jersey crosses. This could be due to the dualpurpose nature (meat and milk) of the Simmental breed, while HF and Jersey are dairy breeds. The results of this study align well with literature from crossbreeding studies conducted in Ethiopia.

The birth weight performance for local breeds (20.80 ± 2.14 kg) in the current study is higher than Horro cattle (17.5 ± 2.25 kg) reported at the Bako Agricultural Research Center and Horro Gudurru Cattle Breeding and Improvement Ranch and Sheko cattle (16.12 ± 0.22 kg) in Bench Maji Zone, Southwestern Ethiopia. It is comparable to Ogaden cattle (21.5± 0.29 kg) at Haramaya University and Fogera cattle (20.7 ± 0.11 kg) at the Metekel Cattle Breeding and Multiplication Ranch [5]. Birth weight of calves depends on the intrauterine environment of the dam, which varies between breeds (especially local versus exotic), as well as the dam's health status and nutrition before birth.

Weaning Weight (WW): The overall mean Weaning Weight (WW) was 90.84 ± 19.97 kg. This result is greater than the weaning weight performance of 62.5% HF × Boran (56.8 ± 0.5 kg), 50% HF × Boran (54.2 ± 1.2 kg), 75% HF × Boran (55 ± 0.8 kg), and 87.5% HF × Boran (56.6 ± 0.8 kg) reported by Haile et al. Habtamu et al. reported lower weaning weight values of 47.5 ± 0.358 kg and 42.9 ± 0.52 kg for HF × Horro and Jersey × Horro, respectively.

Simmental crosses outperformed other genetic groups, but the differences between groups were not statistically significant. This might be due to differences in management practices and the adaptability of local breeds to harsh environments after birth. Local breed’s exhibit better disease resistance and tolerance to environmental stress compared to crossbreds and exotic breeds.

The weaning weight performance of the Horro breed at the Bako Agricultural Research Center was 39.8 ± 0.39 kg, which is lower than the current result of 76.27 ± 23.33 kg. On the other hand, other Ethiopian local breeds, such as Boran (95.2 ± 1.3 kg) and Barka (92 kg) under research station management, showed higher performance than the present study.

Yearling Weight (YW): The overall mean yearling weight (YW) was 134.97 ± 20.50 kg. This result is higher than Boran cattle, with reported values of 130.1 kg and 129.3 kg, and lower than 50% HF × Boran crossbred dairy cattle, which showed 149.6 ± 4.5 kg and 192.16 ± 2.33 kg.

The better performance of Holstein Friesian and Simmental crosses compared to other genetic groups could be due to their genetic predisposition for large body size and faster growth. Ethiopian local breeds consistently showed lower yearling weight performance. This might be due to multiple stressors, including poor nutrition, heat, parasites, disease, and inadequate management systems, which significantly affect growth performance in smallholder systems. Kosgey indicated that improvement in growth traits can be achieved through better management and feeding practices and by selecting genetically superior animals.

Pre-Weaning Average Daily Gain (PrWADG): The overall mean Pre-Weaning Average Daily Gain (PrWADG) was 405.29 ± 45.00 g, as presented in Table 2. This result is comparable to the values of 410 g and 420 g for 75% and 87.5% HF × Fogera crosses, respectively, at the Metekel Cattle Breeding and Improvement Ranch. It is higher than the values reported by Habtamu et al., but lower than the performance of 50% HF × Barka (F1) crosses, which showed 492.9 ± 9.6 g.

Ethiopian local calves consistently showed lower PrWADG than crossbreds. This variation is expected due to genotype-environment interactions; as different genotypes respond differently to environmental conditions. The superior growth performance of crossbreds over local calves highlights the positive effects of heterosis achieved through crossing local breeds with Jersey, Friesian, and Simmental breeds (Figure 1).