Research Article

Effect of Early Weaning on Performance Traits and Health Parameters of Bonsmara Bull Calves in a Backgrounding Program

Kgotso Patrick Matli1, Thobela Louis Tyasi2, Pieter Fourie1*

1Department of Agriculture, Central University of Technology, Free State, Private Bag X20539, Bloemfontein, 9300, South Africa; 2Department of Agricultural Economics and Animal Production, University of Limpopo, Private Bag X1106, Sovenga 0727, Limpopo, South Africa.

Received | October 15, 2024; Accepted | March 11, 2025; Published | October 07, 2025

*Correspondence | Pieter Fourie, Department of Agriculture, Central University of Technology, Free State, Private Bag X20539, Bloemfontein, 9300, South Africa; Email: [email protected]

Citation | Matli KP, Tyasi TL, Fourie P (2025). Effect of early weaning on performance traits and health parameters of bonsmara bull calves in a backgrounding program. Adv. Anim. Vet. Sci. 13(10): 2179-2187.

DOI | https://dx.doi.org/10.17582/journal.aavs/2025/13.10.2179.2187

ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331

Copyright: 2025 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

INTRODUCTION

During the period of drought when the forage quantity and quality declines, the cow-calf producers commonly use early weaning strategy to reduce grazing pressure on pasture, reducing nutrient requirements and restoring body condition of the cows for the next breeding season (Rasby, 2007). The earlier the weaning occurs, the higher the possibilities of the cows to becoming pregnant within the first weeks of the breeding season (Alforma et al., 2023). Early weaning is defined as a separation of calves from their dams at less than 180 days of age and it can be performed with calves as young as 45 days (Rasby, 2007). However, this practice may result in lower calf value at weaning compared to calves weaned conventionally (Story et al., 2000). A backgrounding program is an intermediate post-weaning growing program that links cow-calf and feedlot sectors and provide additional weight and value to calves (Peel, 2006). According to Pethick et al. (2004) this management practice is aiming to add muscle and frame to smaller calves prior to finishing, in order to achieve optimal slaughter weights. A major determining factor of feeder cattle is a calf size (small, medium and heavy weight) upon weaning and finishes at different beef standard rates (Dolezal et al., 1993). According to Fourie and Matli (2014) it was evident that backgrounding beef calves involves growing of weaned calves ranging from 160 to 190 kg and indicated that most of the backgrounding farmers (60%) prefer marketing their calves at 240 to 260 kg. However, based on the authors’ knowledge there are no conclusive studies on influence of early weaning on performance traits and health parameters of Bonsmara Bull Calves in a backgrounding program. The objectives of this study were to 1) Determine the effect of early weaning of Bonsmara bull calves on the performance traits including the initial body weight, end body weight, dry matter intake, average daily gain, feed conversion ratio and 2) Determine the effect of early weaning on the health parameters which includes morbidity, mortality and case fatality rates of Bonsmara bull calves.

MATERIALS AND METHODS

Description of the Study Area

A cattle backgrounding trial was conducted from Mid-October to Late-November in 2023 at Sparta Clocolan farms situated 15 km West of Clocolan, Free State province of South Africa, on 28°53ʼ 45.29600ˮ S latitude, 27°28ʼ49.85815ˮ E longitude. The area is situated at an elevation of 1573.6 m above sea level with an annual rainfall of 387mm. The average summer temperature ranges from 14.8 to 25.4 0C and the average winter temperature ranges from 2.8 to 14.8 0C (Weather Atlas, 2024). The town is on the eastern part of the Free State in the Thabo Mofutsanyane District under Setsoto local municipality. Alma and Ascot are the Sparta farms where calves are backgrounded and are also used as a feedlot satellite when there is water shortage at Sparta Feedlot.

Experimental Animals and Sample Size

Two-hundred and eighty-six (n = 286) Bonsmara bull calves were purchased in the normal course of the business, being sourced from different reputable stud breeders. These calves were used as sample size. The sample size for the current study (n = 286) was decided based on the study of Jaeger et al. (2022) and Hodder et al. (2023) who used n = 239 and n = 250, respectively. These bull calves were divided into two weaning strategies such as early and traditionally weaned calves. The early weaned calves (EWC) (n = 136) ranged from 144 to 219 kg with an average weight of 196 ±18.0 kg (early weaned calves - EWC), while traditionally weaned calves (TWC) (n = 150) ranged from 221 to 295 kg with an average weight of 248 ±18.9 kg.

Animal Management

The receiving protocols used upon the day of arrival on the farm were in line with that of Hodder et al. (2023). Briefly, calves were allowed 24-hour relaxation before they were processed and the processing of calves included weighing and sorting, vaccination, taking rectal temperature, ear tagging, growth-promoting implant, dehorning and branding were followed. Additionally, ear tags were placed on both ears for identification and management purposes (Figure 1).

 

Table 1: Nutritive VALUE of the Eragrostis Teff grass used in the backgrounding program.

Parameters	Percentages (%)
Moisture	5.54
Protein dry basis	11.2
Fat dry basis	0.98
Fiber dry basis	32.62
Ash dry basis	4.99
ADF dry basis	41.65
NDF dry basis	71.07
Phosphorus as is basis	0.07

 

Feeding Management

Calves were allocated into two different camps of Eragrostis teff and were backgrounded for a period of thirty-seven (37) days. Table 1 is presenting the nutrient content of Eragrostis teff. The analysis revealed that the pasture contained 71.07% NDF, 41.64% ADF, 32.62% fibre, 11.20% protein, 5.54% moisture, 4.99% ash and smaller amounts of fat and phosphorus at 0.98% and 0.07%, respectively. Calves were introduced to a starter ration (Table 2) ad libitum for a period of ten (10) days and spent the remaining days on grower ration (Table 3). The diet was formulated based on NRC (1996) to achieve 1.44 Mcal NEm/kg, 13% CP and minimum recommended levels of minerals and vitamins.

 

Table 2: The composition and nutritive value of the starter ration fed in backgrounding program.

Ingredients	Grams/head	Percentages (%)
Molasses	150	3
Hominy chop	2010	40.20
Sunflower oilcake	350	7
Corn silage	1300	26
Bran	350	7
Teff grass (milled)	380	7.60
Background HPC	460	9.20
Total	5000	100
Background HPC contents
Premix chop	85.25	18.53
Salt	180	39.13
Lime	120	26.09
Urea	70	15.22
SM44 – Compound	1.85	0.40
Grower Premix	3	0.65
Total	460	100

 

Moisture: 12.47%; Crude Protein = 11.83%; ADF = 14.15%; NDF = 33.35%; ADL = 3.95%. The Energy content expressed in Mcal/MJ/kg: TDN = 52.46 DM%; ME = 7.92 MJ/kg; NEM = 1.27 Mcal/MJ/kg; NEg = 0.0.85 Mcal/MJ/kg. Protein = 10.7%; Fat = 5%; Fiber = 11.73%; Ash = 6.28%; Calcium = 0.74%; Phosphorus = 0.35%.

 

Collection of Performance Traits

The animals were individually weighed using a Silencer hydraulic chute with scale calibrated at 280 kg of certified weights before use (Smock et al., 2021). Body weight (BW) of each animal was recorded during processing of new arrivals at the beginning and end of the backgrounding phase using the inspected, permanent weighing and handling facilities (Smith et al., 2015). Initial body weight (IBW) and ending body weight (EBW) of each group were measured at the beginning and conclusion of the backgrounding program. Dry matter of feed samples was used to compute the average daily DMI from the average daily feed intake (ADFI) data (Abitante et al., 2024). Average daily gain (ADG) for individual steers was calculated as coefficient of a linear regression of body weight against time of the data points (Abitante et al., 2024). Feed conversion ratio (FCR) was determined as gain: feed ratio.

Collection of Health Parameters Data

The number of morbidities and mortalities were recorded on daily basis along with their identification tags, diagnoses, quantity of and medication used. Table 4 represents how the morbidity, mortality and case fatality rates were determined. The diagnosis was based on the visual detection of clinical signs such as nasal discharges, dry or wet muzzle, depression, fever and poor condition of the calf as explained by McMullen et al. (2019). The dead calves were weighed and examined, with an assessment of the internal organs conducted.

 

Table 3: The composition and nutritive value of grower ration fed in backgrounding program.

Ingredients	Grams/head	Percentages (%)
Hominy chop	2200	33.85
Sunflower oilcake	500	7.69
Corn silage	2700	41.54
Bran	450	6.92
Molasses	190	2.92
Background HPC	460	7.08
Total	6500	100
Background HPC content
Premix chop	85.25	18.53
Salt	180	39.13
Lime	120	26.09
Urea	70	15.22
SM44 – Compound	1.85	0.40
Grower Premix	3	0.65
Total	460	100

 

Moisture: 21.53%; Crude Protein = 11.83%; ADF = 4.56%; NDF = 18.37%; ADL = 1.05. The Energy content expressed in Mcal/MJ/kg: TDN = 48.40 DM%; ME 7.28 MJ/kg; NEM = 1.18 Mcal/MJ/kg; NEg = 0.80 Mcal/MJ/kg. Protein = 9.38%; Fat = 3.39%; Fibre = 6.37%; Ash = 3.61%; Calcium = 0.74%; Phosphorus = 0.32%.

 

Statistical Analysis

The statistical analysis software (SAS, 2023) version 9.4 was used for analysis. All the collected data was tested for normality using Shapiro–Wilk’s test before analysis (Shapiro and Wilk, 1965). The student T-Test was used for analysis of variance between two weaning strategies in performance traits and health parameters. The significance levels were observed at p < 0.05.

RESULTS AND DISCUSSION

The backgrounding and feedlot farmers are struggling to recognize the benefits of EWC or lighter calves, especially in the cattle feeding operations, this is evident through conflicting reports of effects in finishing on average daily feed intake and the feed efficiency potentially due to the confounding effects of body size and growth potential (Myers et al., 1999b; Barker-Neef et al., 2001; Arthington et al., 2005; Scheffler et al., 2014). It is important to unfold on the results of EWC vs TWC on their performance traits and health parameters thereby determining productive benefits.

 

Table 4: The presentations of the formulas in determining the production traits and health parameters.

Parameters	Formula
Production traits
Average IBW	Total IBW/ number of animals in the group (n)
Average EBW	Total EBW / number of animals in the group (n)
ADG	(EBW – IBW) / Total number of days in program
ADFI (AS IS)	Total fed/ quantity of animals in group
DMI	ADFI - Moisture%
FCR	DMI / ADG
Health parameters
Processing Morbidity %	Quantity treated/Quantity in group ×100
Backgrounding treatments %	Quantity treated in backgrounding/Quantity in group ×100
Respiratory morbidity %	Quantity treated for respiratory infections/Quantity in group ×100
Digestive treatments %	Quantity treated for digestives/Quantity in group ×100
Backgrounding relapse %	Quantity relapsed/Total treatments ×100
Overall morbidity %	Total treatments/Quantity in group ×100
Mortality %	Quantity of deaths/Quantity in group ×100
Case fatality rate %	Quantity of death/ Quantity of treatments ×100

 

The means of the treatments, initial and end BW (IBW and EBW), dry matter intake (DMI), average daily gain (ADG) and feed conversion (FCR) are presented in Table 5. The IBW and EBW for EWC were significantly lighter (P < 0.05) than that of the TWC (196 vs. 248 kg and 254 vs. 308 kg), respectively. The EBW of EWC and TWC increased by 29.59% and 24.19%, respectively. The EWC were 52 kg (26.53%) and 54 kg (21.26%) lighter than traditionally weaned calves (TWC) at beginning and the end of the backgrounding program, respectively. The percentage difference of 5.40% between EBW and IBW, shows the potential effect of EWC to convert feed more efficiently and effectively. This could be evidence of compensatory gain, given the expectation that calves experiencing a period of slow growth due to nutritional stress induced at early stages of life may regain BW once nutritional conditions are restored (Arthington et al., 2005). It was hypothesized that early weaned calves will need longer standing days to achieve the desired feedlot entry weight of 200-260 kg and this will result in increased costs of feeding, high morbidity and mortality in backgrounding program.

 

Table 5: The means, standard deviations (±) and the P-values of the production traits.

Performance traits	EWC	TWC	P values
Initial BW (kg)	196a ±18.0	248b ±18.9	<0.0001
Ending BW (kg)	254a ±28.4	308b ±23.5	<0.0001
DMI (kg)	4.17a ±3.60	4.22a ±3.98	0.952
ADG (kg)	1.59a ±0.49	1.66a ±0.41	0.205
FCR DM (kg)	2.62a ±2.26	2.54a ±2.39	0.885

 

a, b Means with different letters within the same row differ significantly at P < 0.05.

 

These results are consistent with those reported by Arthington et al. (2005) that EWC were lighter (P = 0.03) at normal weaning than normal weaned calves (221 vs.269 kg; 21.72%) and they tended to be lighter (P = 0.12) at 28-day period (242 vs. 282 kg; 16.53%). Wolcott et al. (2010) also reported that EWC were significantly lighter (P < 0.001) than their conventionally weaned contemporaries through backgrounding and finishing. The results of this study are similar to those of Abitante et al. (2024) who found that early weaners (EW) were approximately 44 kg lighter than conventional weaners (CW) and that weight difference had no influence on the ADG, DMI and FE in finishing phase. The findings are also supported by Wolcott et al. (2010) who reported that the weaning treatment did not affect feed efficiency whether measured as RFI (P = 0.64) or feed conversion ratio (FCR) (P = 0.27). The BW difference which persisted throughout backgrounding program may be the results of an additional milk intake period by TWC group which may represent an advantage in terms of BW during this interval. The results of this study are in contrast with those of Smith et al. (2015) and other researchers (Lusby et al., 1990; Barker-Neef et al., 2001; Schoonmaker et al., 2001; Schoonmaker et al., 2004; Meyer et al., 2005; Waterman et al., 2012; Scheffler et al., 2014) who reported that EW steers were consistently heavier upon completion of ad libitum access of early concentrate feeding period than CW steers which remained un-supplemented with their dams.

In keeping with the consistent effect of weaning treatment on the live weights, there were no significant effects of weaning treatment on the DMI (P = 0.95), ADG (P = 0.21) and the FCR (P = 0.89) between the groups (Table 5). Both EWC and TWC calves had ad libitum access to the same diet and period in backgrounding phase. The DMI of EWC was 1.20% (4.17 vs. 4.22) lower than that of TWC and these results are similar to those of Terblanche et al. (2020) who found no differences between the percentage feed intake of Bonsmara heifers (2.46%) and bulls (2.40%). NRC’s (2000) intake values were 2.50 to 2.70% for cattle between 250 and 360 kg. Even though TWC had a slightly higher DMI than their counterparts in this study, their improvement in ADG resulted in improved FCR.

The current study indicated that there were no significant differences (P = 0.89) in feed conversion ratios (FCR) between the groups, but the FCR of TWC was 3.15% (2.54 vs. 2.62 kg) slightly better than that of EWC. Based on the targeted supplementation intake of 6 kg (3%), EWC had relatively lower residual feed intake (0.69 kg) than TWC with the residual feed intake of 2.02 kg. EWC were expected to consume 5.88 kg, but they consumed 5.19 while TWC were expected to consume 7.44 kg, but they only consumed 5.44 kg during backgrounding. Our study indicated that EWC consumed 0.25 kg (4.82%) less feed than TWC. These results are similar to those found by Wolcott et al. (2010) that early weaned animals tended to eat less feed than their conventionally weaned contemporaries.

According to Ball et al. (2015) and Beck et al. (2016), most of the backgrounding operations have a goal of achieving ADG of 0.68 kg per day or greater. However, both groups exceeded the expected ADG target of 0.60 kg, by 2.65 and 2.77 times more for EWC and TWC, respectively. The average daily gain (ADG) in this study was 1.59 and 1.66 kg for EWC and TWC, respectively and they did not differ significantly, but ADG for TWC was 4.40%; slightly higher than that of EWC. Smith et al. (2015) supported the results of this study that ADG in backgrounding for EWC was consistently lower than that of CW steers within the treatment by season and treatment by year interaction. Landblom et al. (2006) also reported that the weaning weights for normally weaned steers were heavier than early weaned calves at the end of backgrounding phase (P<0.01) and had greater ADG and ADFI than EWC, but EWC were more efficient than TWC. The results in this study support the statement by Bergh et al. (2010) that the large gene pool of this indigenous breed (Bonsmara) allows for sufficient variation and performs equally well on grazing and in feedlots.

Defiantly, Fluharty et al. (2000) reported that EW steers gained 0.46 kg per day more than TW weaned steers during the time period leading up to traditional weaning when were compared at two different weaning ages (EW, 103 d; TW, 203 d). The results from this study varied from that of Blanco et al. (2009) who reported that ADG of EWC was 42% higher than that of TWC and they were 22 kg heavier at 150 days.

The lighter body weight observed in the EWC group indicate that they require more days in the backgrounding program to reach the desired feedlot entry body weight. However, this statement supports the hypothesis that early weaned calves require longer days to achieve the desired feedlot entry weight of 200-260 kg. Surprisingly, the results showed that statistically, there was no significant difference in terms of DMI, ADG and FCR although there was a slight difference in favour of the TWC group. Therefore, this study demonstrates that following the immediate weaning weight (196 and 248 kg), EWC can perform comparably well compared to their counterparts throughout the backgrounding phase. This outcome could be attributed to reduction of stress from abrupt weaning, facilitated by the adoption of feeding strategies such as introduction of starter and grower rations, and the creep-feeding (Myers et al.,1999b; Lardy and Maddock, 2007). The results are consistent with the hypothesis that the TWC group will show higher feed intake and better feed conversion ratio, resulting in better average daily gain than early weaned calves.

 

Animal Health Parameters

Table 6 is presenting the health parameters of both groups from processing and during backgrounding program. During processing of new calves, processing treatments were regarded as respiratory related symptoms and EWC were 2.38 times (19 vs. 8; 13.97 vs. 5.33%) higher than that of their counterpart. High processing morbidity of EWC may be an indication of distress which is arousing from the nature of early weaning – shorter suckling period, exposure to stressful management practice (vaccination) and most importantly shipping stress while their lighter and weaker. Similarly, Smith et al. (2003) reported that steers that were EW at four months of age displayed more distress associated with weaning than their contemporaries that were CW at seven months of age. Earlier on this study, it was hypothesized that because of weaning and post-weaning stress, early weaned calves will show high rate of respiratory morbidities and mortalities.

The backgrounding morbidity for EWC and TWC was 4.41% and 0.67%, respectively and only 10% of EWC were relapsed from the processing treatments. The results in this study indicated that the overall respiratory related morbidity reported in backgrounding phase for EWC was 16.18% and TWC had 6%. According to Nickell and White (2010) the estimated incidence rate of bovine respiratory disease (BRD) must be at least 25% fometaphylaxis program to be cost effective. The overall rate of digestive treatments in the backgrounding program was 2.20% which was for EWC and this observed percentage of digestives in EWC could be attributed to the adaptation of the calves’ gastrointestinal tract to the new diet. In their study, Myers et al. (1999a) reported a small incidence of digestive morbidity (7%) that did not differ between calves weaned at 90 or 215 days of age.

The overall morbidity percentage of EWC and TWC was 18.38 and 6, respectively, and the former being 3.06 times higher than the latter group. The results in this study indicated that EWC calves were 2.57 and 3.06 times more likely to be diagnosed with respiratory related symptoms and the overall morbidity in backgrounding program, respectively. Similar results were further supported by Gummow and Mapham (2000) and Step et al. (2008) who reported that calves weighing less than the mean BW were 1.4 times more likely to be diagnosed with BRD than those that weighed more than the mean BW of the group. The results in this study indicates that EWC falls under high risk category and this was supported by (Bateman et al., 1990; Taylor et al., 1999; Gummow and Mapham, 2000; Sanderson et al., 2008) that light-weight calves were at greater risk than heavier ones.

Sanderson et al. (2008) reported similar results that calves that are heavier at arrival were associated with a decreased morbidity. They found that calves weighing more than 318 kg less likely to be diagnosed with BRD than calves weighing less than 250 kg (RR = 0.18, P < 0.00). Pinchak et al. (2004), evaluated several groups of stocker calves and found that there was an association between BW and BRD, with lighter calves having a greater incidence of BRD. The lighter calves at arrival could have been younger than their heavier counterparts. It can therefore, be speculated that lighter calves could have been exposed to potential pathogens and given an opportunity to build up immunity to those pathogens.

The mortality percentage of TWC was 0.67% and the case fatality rate was 11.11% which was 1.11% higher than the 10% norm (Table 6). However, there was no mortality reported in EWC even though they possess a high morbidity percentage. These results are supported by the conclusion made by Smith et al. (2015) that EWC are better equipped to handle the stressors incurred throughout the various proceeding management phases, potentially due to an enhanced immune system. On the early days (4th) of backgrounding, one calf from TWC group died due to respiratory disease and it was not treated. The results of untreated dead calf in TWC, may be due to lacking of respiratory clinical symptoms and the good looking body condition of the calf. Due to a high morbidity rates observed in EWC group, less attention was given to TWC group. Another factor that aggravated lower mortality in EWC group is the good weather conditions of the season during which the trial was conducted. A warmer and rainy weather conditions which results to the good grass quality and quantity. However, the mortality of EWC group could have been worse if the study was conducted during winter season.

According to Enriquez et al. (2011) and Taylor et al. (2019) weaning of beef calves from their dams is widely recognized as a stressful event. Weaning has entailed abrupt separation of calves from their dam, often with immediate shipment and sale. Combining weaning with other stressors is considered as a contributing factor to development of bovine respiratory disease (BRD) (Taylor et al., 2010). The source of weaning stress is likely multifactorial and includes the loss of nutritional support through milk, disruption of social bonding with the dam, increased social stress as calves seek to establish dominance in a population lacking adults and impacts of introducing to a novel environment (Enriquez et al., 2011). However, in early weaned beef calves, these multifactorial stressors may be more detrimental and contribute to or worsen the health outcomes in the subsequent segment.

The younger they are weaned, the more difficult it is for them to cope with the physiological, nutritional, physical (Lynch et al., 2019), and immunological challenges (Teixeira et al., 2021b). According to Enriquez et al. (2011) one of the greatest challenges is dietary transition. If the process of ruminal development does not occur properly, early weaning can impair the development of calves (Steele et al., 2016), resulting in poorer performance compared to calves weaned at a conventional age (Rasby, 2007).

Another factor that may contribute to reduction in ADG after weaning is their behaviour in consequence to weaning stress (Teixeira et al., 2021a). Calves weaned at an early age (30 and 75 days) were found to be more active than those weaned conventionally. This increased activity was characterized by more time spent walking and vocalizing, as well as reduced feeding time (Teixeira et al., 2021a), which reduces feed intake and could help explain the variation in body weight. These behavioral patterns are indicators of stress and can influence feed intake and weight gain (Price et al., 2003).

High-frequency tags contain important data such as calf origin, vaccination and treatments data, the initial and current body weight, and ADG. Some tags are missing and need to be replaced with other tags, with which if there is a discrepancy, can affect the quality of the data and quantity of animals per group. Removal of wet feed during rainy weather can affect the overall quantity of feed fed even when weighed at the time of removal. However, early weaned calves have the potential to experience higher morbidity and mortality than their counterparts due to multifactorial stressors which may show a biasness in this study.

The sample size was supposed to be 150 animals per group, but due to lack of lighter Bonsmara calves, only 136 calves were available and came from the same sources.

Conclusions and recommendations

The study assessed the effects of early weaning of Bonsmara bull calves on performance and health parameters in a backgrounding program. The study suggests that early weaning practice affects the body weight of calves. The study also suggests that the calves’ health should be of a greater concern even though no mortality was recorded. It is advisable that farmers should consider backgrounding conventionally weaned calves due to their heavy body weight and lower morbidity incidences. This study was limited to Bonsmara bull calves grazing Eragrostis teff pastures. Further research can be extended to Bonsmara steers, other breeds and seasons of the year.

ACKNOWLEDGEMENTS

This research study is funded by Central University of Technology, Free State (CUT, FS) under Research Development and Postgraduate Studies. The author would like to thank Sparta Baby Beef feedlot for their enormous contribution and making this research trial viable. Disclaimer: Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author (s) and do not necessarily reflect the view of the organization.

NOVELTY STATEMENTS

This is the first study to report that the weaning treatment had no effect on the DMI, ADG and FCR, and that the EWC group were more susceptible to diseases than TWC group.

AUTHOR’S CONTRIBUTIONS

Fourie Pieter: Conceptualization, Methodology, Validation, Writing - original draft, Writing – review and editing, Visualization, Supervision, Project administration, Funding acquisition.

Tyasi Thobela Louis: Conceptualization, Methodology, Validation, Formal Analysis, Data curation, Writing – review and editing, Visualization, Supervision.

Matli Kgotso Patrick: Conceptualization, Methodology, Investigation, Resources, Data curation, Visualization, Project Administration.

All authors reviewed and approved the final manuscript.

Conflict of Interest

The authors have declared no conflict of interest.

REFERENCES

Abitante G, Leme PR, De Paula Carlis MS, Ramirez-zamudio GD, Gomes BIP, De Andrade LB, Goulart RS, Pugliesi G, Saran Netto A, Dahlen CR, Silva SL (2024). Effects of Early Weaning on Performance and Carcass Quality of Nellbore Young Bulls. Animals, 12: 779. https://doi.org/10.3390/ani14050779

Alforma AMP, Periera GR, Rocha MK, Teixeira OS, Oliveira MCM, Lima JA, Cumbe TA, Barcellos JOJ (2023). Influence of weaning management at 30, 75 and 180 days of age on non-esterified fatty acids and reproductive performance in beef cows. J. Anim. Physiol. Anim. Nutr., 107: 407 – 417. https://doi.org/10.1111/jpn.13736

Arthington JD, Spears JW, Miller DC (2005). The effect of early weaning on feedlot performance and measures of stress in beef calves. J. Anim. Sci., 83 (4): 933 – 939. https://doi.org/10.2527/2005.834933x

Ball DM, Hoveland CS, Lacefield GD (2015). Southern Forages: Modern Concepts for Forage Crop Management. Fifth Edition. International Plant Nutrition Institute.

Barker-Neef JM, Buskirk DD, Black JR, Doumit ME, Rust SR (2001). Biological and economic performance of early-weaned angus steers. J. Anim. Sci., 79: 2762 – 2769. https://doi.org/10.2527/2001.79112762x

Bateman KG, Martin SW, Shewen PE, Menzies PI (1990). An evaluation of antimicrobial therapy for undifferentiated bovine respiratory disease. Can. Vet. J., 31: 689 – 696.

Beck PA, Stewart CB, Sims MB, Gadberry MS, Jennings JA (2016). Effect of stocking rate, forage management, and grazing management on performance and economics of cow-calf production in Southwest Arkansas. J. Anim. Sci., 94: 3996 – 4005. https://doi.org/10.2527/jas.2016-0634

Bergh L, Gerhard R, Scholtz MM, MAMABOLO MJ (2010). Introduction to the information on beef and dual purpose breeds in South Africa. Part two in: Beef Breeding in South Africa. 2nd ed. Ed. Scholtz, M. M. Agric. Res. Counc., 150 – 291.

Blanco M, Villalba D, Ripoll G, Sauerwein H, Casasus I (2009). Effect of early weaning and breed on calf performance and carcass and meat quality in autumn-born bull calves. Liv. Sci., 120: 103 – 115. https://doi.org/10.1016/j.livsci.2008.05.003

Dolezal HG, Tatum JD, Williams FL (1993). Effect of feeder cattle frame size, muscle thickness, age class on days fed, weight, and carcass composition. J. Anim. Sci., 71: 2975 – 2985. https://doi.org/10.2527/1993.71112975x

Enriquez D, Hotzel MJ, Ungerfeld R (2011). Minimizing the stress of weaning of beef calves: a review. Acta Vet. Scand., 53: 28. https://doi.org/10.1186/1751-0147-53-28

Fluharty F L, Loerch SC, Tuner TB, Moeller SJ, Lowe GD (2000). Effects of weaning age and diet on growth and carcass characteristics in steers. J. Anim. Sci., 78: 1759 – 1767. https://doi.org/10.2527/2000.7871759x

Fourie PJ, Matli KP (2014). Promoting profitability and sustainability in the backgrounding of beef calves: The role of Agricultural Extension. S. Afr. J. Agric. Ext., 42 (2): 115 – 126.

Gummow B, Mapham PH (2000). A stochastic partial-budget analysis of an experimental Pasteurella haemolytica feedlot vaccine trial. Prev. Vet. Med., 43: 29 – 42. https://doi.org/10.1016/S0167-5877(99)00071-9

Hodder A, Pajor E, van der Meer F, Louden J, Thompson S, Orsel K (2023). Feeding behaviour and activity of beef calves during the first week at the feedlot: Impact of calf source and commingling ratios. Appl. Anim. Behav. Sci., 258. https://doi.org/10.1016/j.applanim.2022.105810

Jaeger JR, Preedy GW, Waggoner JW, Harmoney KR, Olson KC (2022). Effect of weaning method on postweaning performance by early weaned beef calves. Transl. Anim. Sci., 6: 1 – 7. https://doi.org/10.1093/tas/txac030

Landblom DG, Paisley S, Johnson P, Gates R, Fausti SW, Patterson HH (2006). Effects of weaning date and retained ownership on cattle performance and forage disappearance in Spring calving beef systems. Proceedings, Western Section. Am. Soc. Anim. Sci., 57: 2006.

Lardy GP, Maddock TD (2007). Creep feeding nursing beef calves. Vet. Clin. N. Am. Pract., 23: 21 – 28. https://doi.org/10.1016/j.cvfa.2006.11.002

Lusby KS, Gill DR, Anderson DM, Gardner TL, Dolezal, HG (1990). Limit feeding vs full feeding high concentrate diets to early weaned calves – Effects on performance to slaughter. Okla. Agric. Exp. Station Res. Rep., MP – 129, Stillwater.

Lynch E, McGee M, Early B (2019). Weaning management of beef calves with implications for animal health and welfare. J. Appl. Anim. Res., 47: 167 – 175. https://doi.org/10.1080/09712119.2019.1594825

Mapham PH (2018). Sparta Baby Beef: Monthly animal health meeting notes – Personal communication: 9 October 2018.

McMullen C, Orsel K, Alexander TW, van der Meer F, Plastow G, Timsit E (2019). Comparison of the nasopharyngeal bacterial microbial of beef calves raised without the use of antimicrobials between healthy calves and those diagnosed with bovine respiratory disease. Vet. Microbiol., 231: 56 – 62. https://doi.org/10.1016/j.vetmic.2019.02.030

Meyer DL, Kerley MS, Walker EL, Keisler DH, Pierce VL, Schmidt TB, Stahl CA, Linville ML, Berg EP (2005). Growth rate, body composition, and meat tenderness in early vs. traditionally weaned beef calves. J. Anim. Sci., 83: 2752 – 2761. https://doi.org/10.2527/2005.83122752x

Myers SE, Faulkner DB, Ireland FA, Berger LL, Parrett DF (1999a). Production systems comparing early weaning to normal weaning with or without creep feeding for beef steers. J. Anim. Sci., 77: 330 – 310. https://doi.org/10.2527/1999.772300x

Myers SE, Faulkner DB, Ireland FA, Parrett DF (1999b). Comparison of three weaning ages on cow-calf performance and steer carcass traits. J. Anim. Sci., 77: 323 – 329. https://doi.org/10.2527/1999.772323x

National Research Council (NRC) (1996). Nutrient Requirements of Beef Cattle. National Academy Press. Washington, DC.

National Research Council (NRC) (2000). Nutrient requirement of beef cattle. National Academy Press, Washington DC.

Nickell JS, White BJ (2010). Metaphylactic antimicrobial therapy for bovine respiratory disease in stocker and feedlot cattle. Vet. Clin. Food. Anim., 26: 285 – 301. https://doi.org/10.1016/j.cvfa.2010.04.006

Peel DS (2006). Economics of Stocker Production. Vet. Clin. Food Anim. Pract., 22: 271 – 296. https://doi.org/10.1016/j.cvfa.2006.03.007

Pethick DW, Harper GS, Oddy VH (2004). Growth, development and nutritional manipulation of marbling in cattle: A review. Aus. J. Exp. Agric., 44: 705 – 715. https://doi.org/10.1071/EA02165

Pinchak WE, Tolleson DR, Mccloy M, Hunt LJ, Gill RJ, Ansley RJ, Bevers SJ (2004). Morbidity Effects on Productivity and Profitability of Stocker Cattle Grazing in the Southern Plains. J. Anim. Sci., 82: 2773 – 2779. https://doi.org/10.2527/2004.8292773x

Price EO, Harris JE, Borgwardt RE, Sween ML, Connor JM (2003). Fence-line contact of beef calves with their dams at weaning reduces the negative effects of separation on behaviour and growth rate. J. Anim. Sci., 81: 116 – 121. https://doi.org/10.2527/2003.811116x

Rasby R (2007). Early weaning beef calves. Vet. Clin. Food. Anim., 23: 29 – 40. https://doi.org/10.1016/j.cvfa.2007.01.002

Sanderson MW, Dargatz DA, Wagner BA (2008). Risk factors for initial respiratory disease in United States’ feedlots based on producer-collected daily morbidity counts. Can. Vet. J., 49: 373 – 378.

SAS, Institute Inc (2023). SAS/STAT R15.3 User’s Guide. NC: SAS Institute Inc.

Scheffler JM, Mccann MA, Greiner SP, Jiang H, Hanigan MD, Bridges GA, Lake SK, Gerrard DE (2014). Early metabolic imprinting events increase marbling scores in fed cattle. J. Anim. Sci., 92: 320 – 324. https://doi.org/10.2527/jas.2012-6209

Schoonmaker JP, Fluharty FL, Loerch SC, Turner TB, Moeller SJ, Wulf DM (2001). Effect of weaning status and implant regimen on growth, performance and carcass characteristics of steers. J. Anim. Sci., 79: 1074 – 1084. https://doi.org/10.2527/2001.7951074x

Schoonmaker JP, Cecava MJ, Fluhary FL, Zerby HN, Loerch SC (2004). Effect of source and amount of energy and rate of growth in the growing phase on performance and carcass characteristics of early- and normal-weaned steers. J. Anim. Sci., 82: 273 – 282. https://doi.org/10.2527/2004.821273x

Shapiro SS, Wilk MB (1965). An Analysis of Variance Test for Normality (complete Samples). Biometrika, 52: 591 – 611. https://doi.org/10.1093/biomet/52.3-4.591

Smith DL, Wiggers DL, Wilson LL, Comerford JW, Harpster HW, Cash EH (2003). Postweaning behaviour and growth performance of early and conventionally weaned beef calves. Prof. Anim. Sci., 19: 23 – 29. x https://doi.org/10.15232/S1080-7446(15)31370-X

Smith JK, Chair MAM, Greiner SP, Hanigan MD, Johnson SE, El-Kadi SW (2015). The effect of early weaning on finishing feed efficiency, marbling development and retail product quality of beef steers. PhD. Virginia Polytechnic Institute and State University.

Smock TM, Woerner DR, Petry AL, Manahan JL, Helmuth CL, Coppin CM, Hales KE (2021). Effects of feedlot bunk management and bulk density of steam-flaked corn on growth performance, carcass characteristics, and liver score of finishing beef steers fed high-concentrate diets without by-products or tylosin phosphate. Appl. Anim. Sci., 37: 722 – 732. https://doi.org/10.15232/aas.2021-02206

Steele MA, Penner GB, Chaucheyras-Durand F, Guan LL (2016). Development and physiology of the rumen and the lower gut: Targets for improving gut health. J. Dairy Sci., 99: 4955 – 4966. https://doi.org/10.3168/jds.2015-10351

Step DL, Krehbiel CR, Depra HA, Cranston JJ, Fulton RW, Kirkpatrick JG, Gill DR, Payton ME, Montelongo MA, Confer AW (2008). Effects of commingling beef calves from different sources and weaning protocols during a forty-day receiving period on performance and bovine respiratory disease. J. Anim. Sci., 86: 3146 – 3158. https://doi.org/10.2527/jas.2008-0883

Story C E, Rasby RJ, Clark RT, Milton CT (2000). Age of calf at weaning of spring-calving beef cows and effect on cow and calf performance and production economics. J. Anim. Sci., 78: 1403 – 1413. https://doi.org/10.2527/2000.7861403x

Taylor LF, Booker CW, Jim GK, Guichon PT (1999). Sickness, mortality and the buller steer syndrome in a western Canadian feedlot. Bovine Practitioner. 33: 80 – 84. https://doi.org/10.21423/bovine-vol33no1p80-84

Taylor JD, Fulton RW, Lehenbauer TW, Step DL, Confer AW (2010). The epidemiology of bovine respiratory disease: what is the evidence for preventative measures? Can. Vet. J., 51: 1351 – 1359.

Taylor JD, Gilliam JN, Mourer G, Stansberry C (2019). Comparison of effects of four weaning methods on health and performance of beef calves. Animal, 14 (1): 161 – 170. https://doi.org/10.1017/S1751731119001228

Teixeira OS, Rocha MK, Alforma AMP, Fernandes VS, Feijó, JO, Correa MN, Canozzi MEA, Mcmanus C, Barcellos JOJ (2021a). Behavioural and physiological responses of male and female beef cattle to weaning at 30, 75 or 180 days of age. Appl. Anim. Behav. Sci., 240: 105339. https://doi.org/10.1016/j.applanim.2021.105339

Terblanche I, Jordaan JW, Brand TS, Van Der Merwe D (2020). A study on certain factors that may affect the economic viability of backgrounding beef weaner calves on pastures in the Southern Cape area of South Africa. Page 31. M.Tech dissertation, Nelson Mandela University, George Campus, South Africa.

Waterman RC, Geary TW, Paterson JA, Lipsey RJ, Shafer WR, Berger LL, Faulkner DB, Homm JW (2012). Early weaning in Northern Great Plains beef cattle production systems: III. Steer weaning, finishing and carcass characteristics. Livestock Sci., 148: 282 – 290. https://doi.org/10.1016/j.livsci.2012.06.024

Weather-Atlas (2024). Average Rainfall days Clocolan, South Africa. Available at: www.weather-atlas.com. (Accessed on the 27th June 2024).

Wolcott ML, Graser HU, Johnston DJ (2010). Effect of early weaning on growth, feed efficiency and carcass traits in Shorthorn cattle. Anim. Prod. Sci., 50 (4) 315 – 321. https://doi.org/10.1071/AN09153