South African Journal of Animal Science
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The effects of red and white LED lighting on laying performance in hens over 72 weeks of age
Get PDFArtificial lighting has enabled improvements in egg production, and different types of light and wavelengths have been tested to achieve better production results in the past. It has been established that red light positively affects the laying performance of hens when such a lighting programme is applied prior to sexual maturation. However, few studies have investigated the effects of light colour on the performance of laying hens during the final stages of production. This study examined the effects of supplementing natural light with white or red lighting during the autumn–winter season on the laying performance, feed intake, average egg weight, egg mass, and feed conversion per egg of laying hens, and the albumen height, yolk colour, and Haugh units of their eggs. The effects on shell thickness, shell strength, body mass, ovary weight, and oviduct weight were also assessed. A total of 7680 70-week-old Lohmann LSL laying hens housed in four California-type sheds were used in the study. Hens exposed to the white light treatment had significantly heavier ovaries; however, no significant differences between red and white lighting were found among the other evaluated variables.
(Submitted 11 May 2025; Accepted 30 September 2025; Published 14 October 2025
Phenotypic characterisation of four naked neck chicken ecotypes indigenous to Pakistan
Get PDFThis study characterised four naked neck chicken phenotypes (black, white-and-black, light brown, and dark brown) at 20 weeks of age, based on both qualitative and quantitative traits. A total of 320 birds were evaluated, with 40 males and 40 females per phenotype. Qualitative traits assessed included head shape, comb type, wattle size, plumage pattern, shank colour, spur presence, and number of toes. Quantitative traits measured included neck length, keel length, wingspan, shank length, shank circumference, drumstick length, drumstick circumference, and body length. Both sexes of all phenotypes exhibited a plain head and a single comb. Wattle size varied by sex, being medium-sized in females and highly developed in males. Feathers in the breast, wing bow, wing bar, wing bay, saddle, and tail areas most commonly had a plain pattern, followed by stippled, pencilled, and laced patterns. Shank colouration differed between the sexes, with males most commonly having yellow shanks, followed by grey, off-white, and green shanks. In contrast, females predominantly had grey shanks, followed by yellow, green, and off-white shanks. Among the phenotypes, white-and-black, light brown, and dark brown chickens exhibited the highest frequency of yellow shanks, while grey shanks were most commonly found in black birds. Males were significantly larger than females for most morphometric traits. Additionally, the light brown and dark brown phenotypes exhibited higher values for quantitative traits than the black and white-and-black phenotypes. All birds of the naked neck phenotype, regardless of sex, had four toes, normal spurs, and tufted feathers on the ventral neck region above the crop.
Submitted 23 September 2021; Accepted 8 April 2025; Published April 2025
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Significance of research to South African science
The article by Shafiq et al. (2025) provides valuable insights for South African poultry science and sustainable livestock development in similar agroecological zones. Although based in Nigeria, the study evaluates key phenotypic traits - such as body weight, growth rate, and heat tolerance - of naked neck chickens under heat-stress conditions, which are increasingly relevant due to climate change. For South Africa, where smallholder and rural poultry systems remain important for food security and livelihoods, the findings support breed selection strategies that prioritise adaptability, resilience, and productivity in hot climates. This research contributes to regional efforts in promoting climate-smart animal agriculture and preserving indigenous genetic resources
The effect of ecotype and year on the production and reproductive performance of Nguni cows in the Limpopo Province of South Africa
Get PDFThis study investigated the effects of Nguni cattle ecotype and year on the production and reproductive performance of cows in the Limpopo Province of South Africa. Production data for 471 calvings (142 Venda, 65 Shangaan, and 264 Pedi ecotype Nguni cows) at Mara Research Station were analysed to determine the differences between years and ecotypes in birthweight, weaning weight, days-to-reconception, inter-calving period, weight of cow at breeding and at weaning, and weaning efficiency. The effects of ecotype and year on the production and reproduction parameters were analysed using the SAS® mixed models procedure. Cows of the Shangaan ecotype were the smallest in size, while the Venda ecotype was both heavy and short, and gave birth to calves with lower birthweights and higher weaning weights. Ecotype did not affect the inter-calving period and days-to-reconception, but influenced weaning efficiency and weight-related reproduction traits. Year influenced the birth and weaning weights, with years with high precipitation also having high production efficiencies. The smaller-framed Shangaan ecotype had a better weaning efficiency, days-to-reconception, and inter-calving period than the Pedi and Venda ecotypes in the year with the lowest precipitation (2011). No year effects were observed for days-to-reconception, but the inter-calving period, weaning efficiency, and weight-related reproductive traits were affected by year. Ecotype and year thus both influenced the production and reproduction traits of Nguni cattle.
Submitted 19 September 2024; Accepted 20 December 2024; Published February 2025
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Significance of research to South African science
This research enhances scientific understanding of how different Nguni cattle ecotypes - Venda, Pedi, and Shangaan - perform under varying environmental conditions over time. It provides empirical evidence that both genetic variation (ecotype) and year-to-year environmental factors (especially precipitation) significantly influence production traits (like birthweight and weaning weight) and reproductive performance (like weaning efficiency and inter-calving periods). Given South Africa’s vulnerability to climate variability, especially in arid regions like Limpopo, the findings offer practical guidance for breeding, herd management, and climate adaptation strategies in indigenous livestock systems. Furthermore, the study contributes to the preservation of indigenous cattle genetics and supports efforts toward sustainable livestock production aligned with food security goals in the region
Erratum to ‘Effects of rumen undegradable protein source on feed intake and milk yield of Holstein dairy cows’
Get PDFThe article ‘Effects of rumen undegradable protein source on feed intake and milk yield of Holstein dairy cows’ (SAJAS volume 53, issue 5, DOI: 10.4314/sajas.v53i5.15) was initially published with an incorrect author list.
The correct author list is as follows:M. Savari, M.S.S. Firouzabadi, F. Mohammadi, R. Abigaba, A.R. Rayshan, A. Gharagozloo, F. Abdollahzadeh, & E. Ghasem
Predicting body weight in Ross 308 broiler chickens using a data mining algorithm approach
Get PDFRoss 308 broiler chickens are raised specifically for meat production, as they are fast growing and can be slaughtered at six weeks of age. This study aimed to use multivariate adaptive regression splines (MARS) and classification and regression tree (CART) data mining algorithms to predict the live body weights of Ross 308 male and female chickens from their morphological traits, and to compare the predictive performances of these two approaches. One hundred and twenty birds (60 males and 60 females) were used. The flock was reared under intensive conditions, and the entire flock was kept in the same house. Body weight and morphological traits such as wing length, beak length, shank length, body girth, body length, and shank circumference were measured for every Ross 308 chicken. Two data mining algorithms, MARS and CART, were used for body weight prediction, and goodness-of-fit criteria were used to select the best model. The CART data mining algorithm was found to be the best model, as it had greater predictive accuracy, and higher Pearson’s correlation coefficient, coefficient of determination, and adjusted coefficient of determination test results, when predicting body weight in both male and female Ross 308 chickens. These results suggest that the CART data mining algorithm could be used to help farmers recognise the morphological traits that are most influential in determining body weight.
Submitted 8 September 2024; Accepted 18 January 2025; Published 30 June 2025
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Significance of research to South African science
The article “Predicting body weight in Ross 308 broiler chickens using morphometric traits” by Bila (2025) contributes meaningfully to South African poultry science by offering practical and low-cost methods for estimating broiler performance. By establishing strong correlations between body weight and easily measurable traits such as shank length and chest circumference, the study provides a valuable tool for smallholder and commercial farmers to monitor growth and optimise selection without relying on expensive weighing equipment. These insights support more efficient poultry management, particularly in rural and resource-constrained environments, and align with South Africa’s broader goals of improving food security, animal productivity, and data-driven livestock production
Wildlife substitution equivalents based on metabolisable energy for calculating stocking densities on Southern African wildlife ranches
Get PDFThis study aims to bridge the gap between the large stock unit method and the grazer and browser unit methods for estimating the stocking densities of wild herbivore ungulates on wildlife ranches and reserves using both extensive and intensive production methods. Animal substitution equivalents based on metabolisable energy are calculated to estimate stocking densities; however an annual up-to-date vegetation evaluation is required to estimate the carrying capacity of the habitat to support wild herbivore ungulates without it being degraded over time. This study provides an applied approach to how refined large stock, wild herbivore, grazer, and browser unit equivalents can be used effectively. The two production methods described differ in their intensity of animal management. In the extensive wild herbivore ungulate production method, the mean animal mass is used to calculate the large stock, wild herbivore, grazer, and browser substitution equivalent units, while in the intensive wild herbivore ungulate production method, the mean mass per physiological state, with varying percentages of suckling offspring, is used to do so. These methods are extrapolated from mean linear transformations of the different physiological states and sexes of the different types of herbivores. The extensive wild herbivore ungulate production method is preferred when evaluating wildlife ranches focused on hunting and tourism, as wildlife census data do not incorporate the numbers of males, females, and offspring, whereas the intensive wild herbivore ungulate production method is preferred for intensive breeding systems in which the numbers of males, females, and offspring are known.
Submitted 11 November 2023; Accepted 30 March 2025; Published 23 July 2025
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Significance of research to South African science
The article “Wildlife substitution equivalents for assessing grazing capacity in South African protected areas” by Shepstone et al. (2025) makes a critical contribution to ecological management and conservation science in South Africa. By developing updated substitution ratios for various wildlife species in relation to grazing capacity assessments, the study provides scientifically grounded tools for managing herbivore populations in protected areas. This is especially important for balancing biodiversity conservation with sustainable land use in national parks and reserves. The research supports informed decision-making by conservation authorities, enhances ecological monitoring frameworks, and contributes to the adaptive management of South Africa’s rich but pressured wildlife ecosystems.
 
Effects of in ovo injection of naringin into fertile broiler chicken eggs on hatchability and hatchling weight and length
Get PDFNaringin is an important flavonoid found in the fruit or peels of fruit from species of the Rutaceae family, such as grapefruit. The aim of this study was to investigate the effects of in ovo naringin injection on hatchability, hatchling weight, and hatchling length. A total of 180 fertilised Ross 308 broiler eggs were purchased from broiler flocks and randomly assigned to control (no in ovo injection), negative control (injection of 0.1 mL deionised water), and naringin (injection of 15 mg naringin in 0.1 mL deionised water) treatment groups. The eggs were incubated at 37.5 °C and 56% relative humidity and in ovo injections were made on the 18th day of incubation. Data were analysed using SPSS version 13.0, with the chi-square test used to determine the effects on hatchability, and hatchling weight and length compared using analysis of variance. The hatchability rates of the eggs in the control, negative control, and naringin treatment groups were 83.3%, 80%, and 88.3%, respectively, indicating that 15 mg naringin provided a 6% increase in hatchability. Hatchling weights were 46.26 g, 46.83 g, and 46.56 g, and hatchling lengths were 16.95 cm, 17.17 cm, and 17.28 cm, in the control, negative control, and naringin groups, respectively. In ovo injection with naringin insignificantly decreased hatchling weight, while significantly increasing hatchling length and insignificantly increasing hatchability compared to the control group. Additional research is needed to determine the most effective naringin level to obtain optimum results from in ovo injection during the incubation process.
Submitted 9 July 2024; Accepted 14 July 2025; Published 25 July 2025
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Significance of research to South African science
The article “Effects of in ovo injection of naringin on hatchability, antioxidant status, intestinal morphology, and growth performance in broiler chicks” by Peşmen (2025) provides valuable insights for South African poultry science, particularly in the search for natural, growth-promoting alternatives to antibiotics. Naringin, a flavonoid derived from citrus, was found to enhance chick development, intestinal health, and antioxidant capacity when administered before hatching. This research is relevant for South African producers seeking sustainable strategies to improve poultry health and productivity while complying with evolving regulations on antibiotic use. It supports innovation in hatchery management and contributes to safer, more efficient poultry production aligned with both national food security goals and global consumer trends
The identification of low-producing hens in egg production systems using objective methods
Get PDFIn commercial egg production, hen productivity declines over time, leading to flock disposal for economic reasons at 72–80 weeks of age. Identifying and removing low-producing hens can enhance economic sustainability by maximising the performance of high-performing hens and conserving feed resources. Additionally, more space per productive hen can improve overall welfare. Current methods for identifying low-producing hens are subjective and challenging, particularly in large operations. Thus, objective culling techniques are needed. This study evaluated hen productivity by examining physiological and thermal changes. We correlated body colour and temperature with productivity criteria such as egg production and the feed conversion ratio (FCR). Twelve white Lohmann LSL and 12 Lohmann Brown hens of 83–100 weeks of age were included in the trial, which was conducted over an 18-week period. Hens with an egg production rate below 60% or FCR above 3 were deemed low-producing. Weekly thermal imaging captured head and foot temperatures, while spectrophotometry and digital imaging recorded the colour of the feet, combs, and beaks. A significant correlation between productivity and RGB values was found in both hybrid lines. These findings suggest the potential practical application of these techniques in poultry houses, especially as the available technological advances.
Submitted 31 October 2024; Accepted 17 February 2025; Published March 2025
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Significance of research to South African science
This article contributes to South African science by advancing sustainable poultry farming through innovative, data-driven approaches. Although authored by researchers from Türkiye, its publication in a South African journal aligns with the country’s agricultural research priorities, especially regarding food security and animal welfare. The study introduces non-invasive, objective techniques - using digital imaging, spectrophotometry, and thermal cameras - to identify low-producing hens based on physiological indicators like foot colour and body temperature. These methods offer practical applications for improving efficiency, reducing resource use, and enhancing hen welfare in commercial egg production systems, including within South Africa’s own poultry sector
Effects of grapefruit juice supplementation on the performance, egg quality, and blood biochemistry of late-phase laying hens
Get PDFThis study investigated the effects of grapefruit juice supplementation on the performance, egg quality, and blood biochemistry of late-phase laying hens. A total of 144 Babcock White laying hens, aged 62 weeks and weighing 1603.05 ± 14.33 g, were divided into six groups. Each group was further divided into four replicates containing six hens each. Grapefruit juice was added to the hens’ drinking water at concentrations of 0% (control), 0.25%, 0.50%, 1.0%, 2.5%, and 5.0% for four weeks. Grapefruit juice supplementation positively affected hen-day egg production and egg mass, but did not affect body weight, feed consumption, feed conversion ratio, or egg weight. The water consumption of the 5.0% group was higher than that of the other groups. Although grapefruit juice supplementation increased the Haugh unit, albumen index, and yolk index values, it decreased the eggshell thickness and egg yolk colour values. Serum glucose levels were lower in the 1.0% and 2.5% groups (134.83 mg/dL and 148.16 mg/dL, respectively) than in the control group (186 mg/dL), and serum immunoglobulin G levels were higher in the 1.0% and 2.5% groups than in the other groups. While the grapefruit juice supplementation increased the total antioxidant capacity of the hens, it reduced their gamma-glutamyl transferase values. No differences were observed between the groups in terms of high-density lipoprotein, low-density lipoprotein, cholesterol, alanine aminotransferase, alkaline phosphatase, or total oxidant status values. The results indicate that providing grapefruit juice to laying hens improves their performance, egg quality, and metabolism, depending on dose
The impact of increased vitamin and mineral intake during early gestation on the reproductive performance of sows
Get PDFThis study investigated the effects of supplementing vitamins and minerals to sows during early gestation. A total of 36 primiparous sows were randomly assigned one day before mating to four dietary treatments that were applied from mating to day 30 of gestation. Treatment 1: low feed intake (1.5 kg/day) with standard vitamin and mineral provision (0.10% as fed); treatment 2: low feed intake (1.5 kg/day) with double the standard provision of vitamins and minerals (0.20% as fed); treatment 3: medium feed intake (2.0 kg/day) with standard vitamin and mineral provision (0.10% as fed); and treatment 4: high feed intake (3.0 kg/day) with standard vitamin and mineral provision (0.10% as fed). Results showed that sows in treatment 4 had the highest body weights at days 30 (179.17 kg) and 80 (211.97 kg) of gestation. Sows in treatments 2 and 4 also had numerically larger litters (12.50 and 12.74 piglets, respectively) than sows in treatments 1 and 3 (9.88 and 10.71 piglets, respectively), although this difference was not statistically significant. Additionally, treatment 2 and 4 sows tended to wean more piglets (11.00 and 11.20 piglets, respectively) than treatment 1 and 3 sows. Overall, both a high level of vitamin and mineral supplementation with a low feed intake (treatment 2), and a high feed intake with standard vitamin and mineral supplementation (treatment 4) during early gestation seemed to have the potential to increase litter size to a similar extent, although a high feed intake may be associated with non-significantly reduced piglet growth.
(Submitted 26 March 2025; Accepted 31 October 2025; Published 13 November 2025