Wet carcass syndrome (WCS) is a defect that occurs in sheep and is characterised by a wet, translucent appearance of the carcass, resulting in condemnation and industry losses. This defect is undetectable until the carcass has been chilled after slaughter, and genetic improvement has thus been proposed as a potential mitigation strategy. This study estimated the single nucleotide polymorphism-based heritability of WCS using a case-control population of South African Dorper, merino-type, and cross-bred sheep genotyped using the Illumina OvineSNP50 BeadChip. After quality control, 32 077 single nucleotide polymorphisms and 540 animals (164 cases, 376 controls) were retained. A genomic relationship matrix was constructed, and heritability was estimated using genomic-relatedness-based restricted maximum likelihood on the observed and liability scales. The liability-scale heritability was 0.30 ± 0.03, demonstrating a substantial additive genetic component underlying WCS susceptibility. These results provide foundational evidence that susceptibility to WCS has a genetic component and support future genome-wide association studies and genomic selection aimed at reducing the prevalence of this economically important condition. (Submitted 24 November 2025; Accepted 03 June 2026; Published 04 August 2026)
This study aimed to investigate the effects of varying levels of bacteriocin (nisin) supplementation on the growth performance, nutrient digestibility, small intestinal histomorphology, and caecal microbiota of broiler chickens. A total of 100 one-day-old male chicks were divided into four groups: a control group and three treatment groups receiving 150 mg, 300 mg, or 500 mg of nisin per kilogram of feed. Over the 35-day trial, all chicks had ad libitum access to feed and water. The results demonstrated that nisin supplementation significantly improved the birds' growth performance (body weight gain and feed intake), nutrient digestion, and intestinal histomorphology, and positively modulated their caecal microbiota compared to the control group. While both 300 mg and 500 mg of nisin per kilogram yielded the most significant improvements in growth performance, intestinal histomorphology, and microbial balance, 300 mg/kg was determined to be the optimal and adequate supplementation level. In conclusion, this study suggests that nisin can safely replace traditional antibiotics as a growth promoter without compromising animal health. (Submitted 24 February 2026; Accepted 17 June 2026; Published 26 June 2026)
This experiment investigated the potential of white light-emitting diodes (LEDs) as an indoor artificial light source for Brown Tsaiya ducks. A total of 144 birds (16 weeks old, average body weight: 1270 g) were randomly allocated to three light-source treatment groups, all providing 16 hours of light per day: white fluorescent tubes with sunlight, white LEDs with sunlight, and white LEDs only. The birds were moved into individual cages at 16 weeks of age, and a two-week adaptation period was provided. Eggs were then collected for three consecutive days every two weeks to determine egg quality. Duck behaviour was observed at 27, 31, and 35 weeks of age. Blood samples were collected at 18, 26, 34, and 42 weeks of age and the oestradiol and progesterone concentrations were determined. Although significant differences in egg-laying performance were observed during some periods of the trial, there was no substantial difference between the treatment groups in the average laying performance across the entire experimental period. Regarding egg quality, significant differences between the treatment groups were only observed at a few isolated time points. The three light treatments had no significant effects on duck behaviour or blood hormone concentrations. Based on the results of this trial, white LEDs have no significant negative effects on egg quality and egg-laying performance. Furthermore, LEDs were more efficient and resulted in a decrease in the total cost. White LEDs could thus serve as a beneficial alternative artificial illumination choice for laying duck houses. (Submitted 16 May 2025; Accepted 27 May 2026; Published 10 June 2026)
The global livestock sector is undergoing substantial transformation, driven by the need to improve production efficiency, environmental sustainability, and animal welfare in response to growing demand for animal-derived protein. Precision livestock farming (PLF) has emerged as a paradigm shift from conventional herd-level management to data-driven systems that enable continuous monitoring and management of individual animals. This review synthesises current knowledge and emerging applications of PLF technologies worldwide, with a focus on the South African beef industry, which exhibits a dual production structure comprising both emerging and commercial farming systems. The integration of sensor technologies, automated systems, and advanced data analytics facilitates real-time monitoring of physiological, behavioural, and environmental parameters. Key applications, including radio frequency identification for animal identification and traceability, global positioning system technologies and accelerometers for spatial and behavioural monitoring, and automated feeding systems, are discussed in relation to intensive feedlot operations and extensive rangeland systems. The contribution of these technologies to improving traceability, supporting quality assurance, and enhancing biosecurity within the beef value chain is also highlighted. Strategies addressing the challenges of commercial rangeland systems and emerging smallholder farms are reviewed, highlighting current limitations. Despite challenges associated with implementation costs, data integration, and rural connectivity, PLF offers opportunities to enhance productivity, resource-use efficiency, and sustainability. Adoption of these technologies is critical for the South African beef industry to meet national production goals, strengthen competitiveness, and respond to global market and sustainability demands. The benefits of PLF technology can be made available to the smallholder and emerging sectors through tailor-made financing and technical support. (Submitted 15 January 2026; Accepted 9 April 2026; Published 03 June 2026)
The estimation of genetic parameters allows for the accurate prediction of estimated breeding values (EBVs), which play a crucial role in developing selection indices used to generate genetic progress for economically important traits. This study aimed to estimate genetic parameters and EBVs for the South African Merino sheep breed. A population of 864 754 South African Merino sheep were included in this study. Pedigree information included animals born between 1919 and 2022, of which 457 757 (52.94%) were females and 406 996 (47.06%) were males. Variance components were estimated for all sheep born after 2009, consisting of 62 460 sheep. A multi-trait animal model was used to estimate the variance components, using VCE6 statistical software. Heritability values and standard errors were estimated for seven traits: direct weaning weight (0.25 ± 0.01), maternal weaning weight (0.20 ± 0.00), body weight at wool test (0.26 ± 0.01), clean fleece weight (0.33 ± 0.01), staple length (0.33 ± 0.00), fibre diameter (0.63 ± 0.00), and coefficient of variation of fibre diameter (0.43 ± 0.00). Using the same genetic models as used for variance component estimation, EBVs were predicted using PEST2. Genetic trends were determined by averaging the EBVs of the measured animals per year of birth per trait, and these were compared to the national trends provided by SA Stud Book. This study updates the variance components and EBVs of the South African Merino sheep breed, enabling the accurate genetic selection of animals and facilitating faster genetic progress. (Submitted 3 November 2025; Accepted 24 March 2026; Published 19 May 2026)
A growing concern in South African feedlot systems is the increased prevalence of non-adapting weaner lambs. This study aimed to identify on-farm risk factors associated with poor adaptation using retrospective production data and a structured questionnaire administered to 80 lamb-rearing farms across South Africa. Risk factors were estimated using Poisson regression to calculate risk ratios and 95% confidence intervals. Of the farmers interviewed, 56% (45/80) did not supply creep feed to their pre-weaned lambs in any form, whereas 75% (60/80) supplied additional feed to their ewes. A lack of creep feed supplementation, extensive lamb rearing, and lambs being born in seasons other than summer were significant risk factors for non-adapting lambs. Spatial clustering of high-death locations was also observed. Creep feeding offers critical benefits, including improved rumen development, increased weight gain, earlier weaning, and improved feedlot adaptability. Lamb-producing areas in South Africa occur in semi-arid regions with low carrying capacities, favouring extensive management systems. Creep feed is often infrequently offered or omitted in extensive rearing systems, owing to logistical challenges. The weaner lamb price, typically determined by feedlots, is rarely influenced by on-farm managerial practices such as creep feed supplementation. As a result, producers may view creep feeding as an unnecessary expense, because of the lack of financial incentives. Promoting awareness of the production and economic benefits of creep feeding, improving communication between feedlots and lamb producers, and encouraging the implementation of good agricultural practices would encourage farmers to adopt specified production and management practices to improve lamb adaptability in South African feedlots. (Submitted 20 September 2025; Accepted 04 May 2026; Published 12 May 2026)
The use of antibiotic growth promoters (AGPs) in poultry production has raised concerns for human, animal, and environmental health owing to the development and spread of antimicrobial resistance. These concerns have triggered global efforts to decrease AGP use and have intensified calls for sustainable, antibiotic-free production. Antibiotic-free production aims to safeguard food security and safety while mitigating environmental risks; however, it faces challenges, including reduced productivity, increased disease susceptibility, and economic constraints. This systematic review assesses the current knowledge of AGPs and their alternatives in poultry production and identifies key research gaps. It examines the mechanisms through which AGPs promote growth and antimicrobial resistance, and the challenges and opportunities associated with antibiotic-free poultry systems, including regulatory and sustainability considerations. A total of 149 peer-reviewed articles published between 2005 and 2025 were identified following preferred reporting items for systematic reviews and meta-analyses guidelines. Evidence suggests that no single additive can consistently replace AGPs; rather, successful antibiotic-free production depends on integrated strategies targeting gut integrity, microbial ecology, and host immunity. Key inconsistencies in the literature include variable responses caused by diet composition, environmental conditions, and bird genetics, emphasising the need for mechanistic, systems-level approaches to optimise outcomes. Robust, scalable antibiotic-free systems will require coordinated advances in nutrition, management, and microbial modulation, supported by validation under commercial conditions. The transition from AGPs to sustainable, antibiotic-free poultry production requires coordinated action by researchers, policymakers, industry stakeholders, farmers, and consumers to establish resilient systems that deliver safe, high-quality products while promoting public health, food security, and environmental stewardship. (Submitted 05 February 2026; Accepted 27 March 2026; Published 04 May 2026)
This study investigated the impact of increased vitamin E and nutrient intake during early gestation on reproductive performance in sows. Thirty first-parity sows (Landrace × Yorkshire × Duroc) with an average initial body weight of 163 kg were used. Sows were randomly allocated to three dietary treatments in early gestation and fed one of three diets for 30 days: 1) 1.5 kg of a standard feed per day, 2) 1.5 kg of a feed containing 1.7× the vitamin and mineral content of the standard feed and a total vitamin E content of 150 IU per day, or 3) 2.5 kg of the standard feed per day. Water was provided ad libitum, and ten individually housed sows were assigned to each treatment. Data on body weight, backfat thickness, body condition score, and wean-to-oestrus interval were collected. Piglet data collected included the litter size, number of stillbirths, piglet birthweight, number of piglets weaned, and piglet weaning weight. Sows in treatment 3 had the highest body weight, backfat thickness, and body condition score on day 30 of gestation. Sows in treatment 2 had the lowest body weight, backfat thickness, and body condition score at weaning, but had the highest litter size and number of weaned piglets. Treatment 1 sows produced piglets with the highest average birth and weaning weights. It was concluded that a low intake of a feed containing 1.7× the vitamin and mineral content during early gestation can improve sow reproductive performance, particularly litter size, thereby enhancing profitability in pig production. (Submitted 26 September 2025; Accepted 5 April 2026; Published 04 May 2026)
This study examined the rumen microbiota of Brown Hanwoo, Jeju Black, and Brown Hanwoo × Jeju Black cross-bred steers reared under the same dietary and environmental conditions. Nine steers were included in the study, with three animals per genetic type, and all animals were fed the same total mixed ration. Rumen samples were collected using the stomach-tubing method, and total community DNA was extracted using the repeated bead-beating plus column method. The V3–V4 hypervariable region of the 16S rRNA gene was amplified and sequenced on the Illumina MiSeq platform. The composition of the rumen microbiota was analysed using QIIME 2 for sequence processing and MicrobiomeAnalyst for statistical visualisations. Alpha diversity indices revealed no significant differences in microbial richness or evenness between the three groups. In contrast, beta-diversity analysis revealed significantly distinct microbial community structures. Patescibacteria, Monoglobus, Shuttleworthia, and Lachnospiraceae_UCG-004 were more abundant in the Brown Hanwoo steers than in the steers of the other two genetic types. These findings suggest a possible breed effect on the rumen microbiota composition under controlled dietary conditions. (Submitted 9 December 2025; Accepted 31 March 2026; Published 27 April 2026)
This study determined the selected reproductive traits and growth and survival rates from birth to weaning of Awassi sheep raised in the Adıyaman province of Türkiye between 2016 and 2018 within the scope of the National Sheep and Goat Breeding Project of Türkiye. A total of 9356 Awassi sheep were included in the three-year breeding programme, with the birthweights of 12 816 lambs and the weaning weights of 11 452 lambs being analysed. According to the three years’ worth of data, the birthweights, weaning weights, and average daily gain of the lambs were 4.01 ± 0.006 kg, 22.78 ± 0.049 kg, and 208.51 ± 0.529 g, respectively. The effects of the examined environmental factors, including the year of birth, month of birth, dam’s age, birth type, and sex, were determined to be statistically significant. The overall average survival rate of lambs at weaning was 89.36%. The effect of year of birth, month of birth, dam’s age, and birth type on survival rate was significant, whereas lamb sex did not affect the survival rate. In this study, the number of lambs born per ewe and the average twinning rate were found to be 1.113 and 11.3%, respectively. The results of this study show that the environmental factors measured should be taken into account when selecting Awassi breeding sheep in the region. (Submitted 15 July 2024; Accepted 24 March 2026; Published 22 April 2026)
Over 75% of South Africa’s electricity is generated by coal-powered plants that are primarily located near large coal deposits in the north and east of the country. The Transvaal Highveld region is characterised by commercial agricultural enterprises dispersed among coal-powered electricity plants that produce emissions, resulting in dilute acid precipitation on these landscapes. These ecosystem alterations have been implicated in both plant and livestock trace mineral imbalances. This survey evaluated the trace mineral status of forages grown and beef cattle reared on farms classified as impacted or non-impacted by emissions from coal-powered electricity plants near Middelburg, Mpumalanga. Forage samples were collected at the end and beginning of the growing season and analysed for concentrations of minerals of nutritional relevance to cattle. Soil sulphur and potassium concentrations tended to be higher on impacted than non-impacted farms, but there was no effect of location on soil pH. Farm location had no impact on forage sulphur concentrations, but forage concentrations of phosphorus, potassium, zinc, and selenium were higher on impacted than non-impacted farms. The trace mineral status of beef cattle reared in these regions was assessed by analysing liver tissue harvested from cattle at the time of slaughter. Cattle grazing forages grown in impacted areas had lower copper, selenium, and zinc concentrations than cattle reared in non-impacted areas. These data suggest that the spatial location of farms, relative to coal-powered electricity plants, may impact the mineral characteristics of forages grown at these locations and thus the mineral status of cattle consuming these forages. (Submitted 10 September 2025; Accepted 06 March 2026; Published 14 April 2026)
This study investigated the effects of dietary Bacillus subtilis and Bacillus licheniformis supplements on the growth performance, carcass characteristics, dressing percentage, morbidity, and mortality of weaner lambs under commercial South African feedlot conditions. The blinded field trial included 649 Merino lambs, with an average age of four months and an average weight of 30 kg at the start of the trial. These lambs were randomly allocated to either a probiotic-supplemented diet or a control diet. Lambs were weighed, ear-tagged, and stratified by initial body weight before allocation to treatment groups. Lambs were initially allocated at 65 lambs per pen across 10 pens (five pens per treatment group, 325 lambs per treatment); however, one lamb died during transport prior to pen allocation, leaving a total of 649 lambs enrolled in the study. Probiotic supplementation did not significantly affect overall average daily gain, but differences were observed in interval growth rates between days 15 and 28. Lambs receiving probiotics had numerically higher feed intakes, but a descriptively higher feed conversion ratio compared to the controls. The probiotic treatment group also had a lower dressing percentage and higher incidences of low-grade rumen parakeratosis. No significant differences were observed between the groups for overall morbidity and mortality during the feeding period. These findings suggest that probiotic supplementation can improve growth during the first 28 days of the feeding period; however, the negative effects on rumen and lung health (bronchopneumonia and rumen parakeratosis) that developed in the probiotic-supplemented lambs during the feeding period should be noted. (Submitted 22 November 2025; Accepted 23 March 2026; Published 03 April 2026)
The efficacy and safety of beta-adrenergic agonist use in modern swine production are controversial. This study aimed to determine the effect of dietary ractopamine hydrochloride and salbutamol on the performance of 440 male and female finisher pigs (Topigs Norsvin TN70), housed in 40 pens of 11 animals each, with five treatments and four replicates per treatment. The dietary treatments included a negative control, containing 16% crude protein and no feed additives; ractopamine-16 (negative control plus 6 mg ractopamine/kg); ractopamine-13 (13% crude protein and similar essential amino acid concentrations to the negative control, plus 6 mg ractopamine/kg); salbutamol-6 (negative control plus salbutamol 10% at 6 mg/kg); and salbutamol-4 (negative control plus salbutamol 10% at 4 mg/kg). At 6 mg/kg feed, ractopamine had no effect on pigs' growth and carcass indices compared to the negative control, regardless of the dietary crude protein concentration. However, gilt carcasses had lower lean percentages on the ractopamine-13 diet than on the negative control diet. Pigs fed 4 mg and 6 mg salbutamol/kg had higher lean percentages than the negative control group. The crude protein content of a diet containing ractopamine can thus be decreased from 16% to 13% for boars, whereas gilts may still benefit from a higher crude protein concentration. Salbutamol supplementation suppressed feed intake and growth in boars and enhanced feed efficiency and lean percentage in gilts. Hence, salbutamol supplementation at 4 mg/kg may be a viable alternative to ractopamine for finisher pigs, producing a higher lean percentage and return on investment, and reduced production costs, despite not enhancing growth.
To assess the copper nutritional status of southern African free-ranging wild ruminants, liver copper concentrations from more than 1000 animals representing 14 species were evaluated. Hepatic copper concentrations closely reflect copper intake levels in ruminants, and are widely accepted as the most reliable biomarker of copper status in ruminants, including in cases of environmental copper pollution. The liver serves as the primary copper storage organ in ruminants, maintaining copper supply until hepatic reserves are depleted, with plasma levels only declining once liver concentrations fall below approximately 20 mg/kg dry matter (DM). However, diagnostic thresholds for copper status vary among laboratories: some classify liver concentrations of 20-90 mg copper/kg DM as marginally deficient, whereas others consider concentrations of <20 mg/kg DM indicative of marginal to clinical deficiency. The latter criterion was adopted in this study. If the 20-90 mg/kg DM criterion had been applied, about 40% of the animals sampled would have been classified as marginally deficient; however, in this study a range of 20-500 mg copper/kg DM was interpreted as adequate. Most animals fell within this range, with a small proportion below the deficiency threshold, notably among grazers foraging on floodplains as well as in the southern Kruger National Park, and in the eastern Free State and Mpumalanga provinces. Although interspecies comparisons are confounded by dietary differences, mixed feeders (consuming grass and browse) often exhibited higher liver copper concentrations than grazers occupying the same areas, suggesting either species-specific differences in copper metabolism and/or higher copper concentrations in browse than in grass.
This study evaluated the relationships between sow parity, prepartum faecal score, farrowing and umbilical cord traits, and reproductive performance. Data were obtained from sows of different parities on commercial farms with records of litter characteristics, farrowing intervals and duration, prepartum faecal scores, and umbilical cord artery and vein diameters. Fourth- and sixth-parity sows produced more total piglets and live-born healthy piglets than first-parity sows, while piglets born to second- to fourth-parity sows had higher live birthweights. Parity did not influence the number of piglets born weak or perinatal mortality rates. Faecal scores of 3.00–3.99 and >4.00 three days prepartum were associated with increased numbers of healthy piglets and reduced numbers of stillborn piglets. Short farrowing intervals (<10 minutes) were numerically associated with higher numbers of live-born piglets and fewer stillborn piglets per litter, although these differences were not statistically significant, and a tendency towards an increased number of piglets born weak was observed. Prolonged farrowing duration was associated with increased perinatal mortality. A higher umbilical cord vein diameter was associated with increased live birthweights and fewer piglets born weak, whereas umbilical artery diameter showed no clear association with reproductive performance. Stillbirths tended to increase with umbilical cord vein diameters of 3.6–4.0 mm. These results indicate that sow parity, prepartum faecal score, farrowing traits, and umbilical cord vein traits are closely associated with reproductive outcomes and perinatal mortality. Optimising gastrointestinal function during the prepartum period and improving farrowing management may contribute to enhanced piglet viability and birthweight. (Submitted 27 June 2023; Accepted 10 February 2026; Published 23 February 2026)
The experiment evaluated the effects of encapsulated sodium butyrate and arginine on the gut health of broiler chickens from 1 to 22 days of age, with or without exposure to an enteric challenge. The experiment was carried out in the vivarium of the Federal University of Paraná, Brazil. Seven hundred and sixty-eight one-day-old male Cobb 500® broiler chicks were used. The birds were randomly assigned to eight treatment groups with six replicates each (48 experimental units with 16 birds per replicate) in a 4 × 2 factorial design (four diets, with and without enteric challenge). The four diets were: 1) 113% standardised ileal digestibility (SID) arginine:lysine ratio; 2) 113% SID arginine:lysine ratio + encapsulated sodium butyrate; 3) 130% SID arginine:lysine ratio; 4) 130% SID arginine:lysine ratio + encapsulated sodium butyrate. At 15, 16, and 17 days of age, the birds in the challenged groups received 15 mg of amoxicillin per kilogram of live weight, inoculated into the ingluvium. At 19 days of age, the same birds received an inoculum containing Escherichia coli (ATCC® 8739™, 109 colony-forming units/bird). The results show that from 1 to 14 days of age, birds that received combined arginine and encapsulated sodium butyrate had better weight gain. Enteric challenge increased the production of short-chain fatty acids and reduced the depths of the crypts and the absorption area of the ileal mucosa. Arginine and encapsulated sodium butyrate supplementation effectively improved performance in the second week of life, but did not interact with the enteric challenge model. (Submitted 13 September 2025; Accepted 30 January 2026; Published 13 February 2026)
This study assessed the seasonal availability and nutrient profiles of pig feedstuffs present on small-scale farms in the Cape Metropole, South Africa. Eighty-two feedstuffs (54 in winter and 28 in summer) were collected from 50 small-scale urban pig farms in five low-income, high-density suburbs in the Cape Metropole. There was an association between season and feed category, with fruit wastes and bakery wastes (contributing 36% and 19% of total feed samples, respectively) being the most abundant feedstuffs in summer and winter, respectively. Fruit and vegetable wastes had the lowest dry matter (<25%) and highest crude fibre (>10%) concentrations, regardless of the season. Soybean and milk mix, spinach, and Russian sausage waste had the highest crude protein (31%–48%) and amino acid concentrations in summer. In winter, soybean and fish meal mix, dry commercial feed, and ice cream and cheese mix were the predominant sources of crude protein (31%–35%) and amino acids. Irrespective of season, kitchen wastes containing meat and dairy by-products and bakery wastes containing legume seeds had the highest ether extract (16%–34%) and gross energy (20–24 MJ/kg) values. Spinach and wheat by-products were the richest sources of minerals in summer and winter, respectively. Small-scale farmers in the surveyed areas could use legume grains and vegetable, meat, and dairy wastes as sources of protein, amino acids, and minerals, while kitchen wastes containing meat or dairy by-products and bakery wastes containing legume seeds could be used as energy feedstuffs to formulate customised, cost-optimised, and balanced homemade diets for pigs. (Submitted 11 September 2025; Accepted 07 December 2025; Published 05 February 2026)
This study aimed to evaluate the effect of gonadotropin-releasing hormone (GnRH) administration 48 hours after progesterone-impregnated sponge removal on fertility and prolificacy in lactating Assaf ewes. In this study, 71 ewes were synchronised using intravaginal sponges containing 60 mg medroxyprogesterone acetate for six days. On the day of sponge removal, all ewes received 500 IU of equine chorionic gonadotropin and 75 µg of d-cloprostenol. In the control group (n = 35), ewes were injected with 1 mL of physiological saline solution; in the GnRH group (n = 36), ewes were injected with 0.1 mg of GnRH analogue 48 hours after sponge removal. There were no significant differences between the groups in the progesterone concentration, oestrus response, oestrus duration, onset of oestrus, abortion rate, lambing rate, multiple birth rate, and fertility results. However, the pregnancy rate differed between the groups, being significantly lower in the GnRH-injected ewes (69.44%) than in the control ewes (91.42%). The lambing rates were 90.62% and 96.0% in the control and GnRH ewes, respectively. The results of this study suggest that GnRH administration 48 hours after progesterone-containing sponge removal enhances prolificacy in lactating Assaf ewes during the breeding season, and it was concluded that prolificacy rates could be improved with post-synchronisation GnRH administration. However, pregnancy rates would need to be increased using different supportive treatments. (Submitted 11 July 2025; Accepted 06 December 2025; Published 14 January 2026)
This study aimed to develop and characterise a fish burger made from mechanically separated tambaqui (Colossoma macropomum) meat and incorporating soy okara as a functional ingredient. Four fish burger formulations were developed and the physicochemical characteristics (moisture, ash, lipid, protein, carbohydrate, and energy), instrumental colour parameters (L*, a*, b*, chroma, and hue angle), microbiological quality (facultative aerobic mesophiles, psychrophiles, moulds and yeasts, total coliforms, thermotolerant coliforms, Escherichia coli, coagulase-positive staphylococci, and Salmonella species), cooking characteristics, texture profile, and sensory traits of the tambaqui mechanically separated meat (MSM) and okara were analysed. Tambaqui MSM contained 78.18% moisture, 4.92% ash, 2.98% lipids, 12.47% protein, 1.45% carbohydrates, and 412.09 kcal energy/100 g. Okara contained 80.19% moisture, 3.48% ash, 3.90% lipids, 4.32% protein, 8.11% carbohydrates, and 417.00 kcal energy/100 g. The tambaqui MSM contained <10 most probable number (MPN)/g total and thermotolerant coliforms, and no E. coli or coagulase-positive staphylococci. The fresh okara contained 3.3 × 103 colony-forming units (CFU)/g facultative aerobic mesophiles, <10 CFU/g psychrotrophic bacteria when incubated at 7 °C for 7 days, 2.6 × 103 CFU/g moulds and yeasts, <10 MPN/g total and thermotolerant coliforms, and no E. coli. The intention to buy indicated that the tasters would buy the okara-enriched tambaqui fish burgers, and the fish burgers had good sensory acceptability, while the okara added nutritional value to the product. These results provide a promising option for making burgers using functional ingredients from by-products, as well as for adding value to the soy production chain by reducing waste. (Submitted 21 June 2024; Accepted 17 September 2025; Published 30 December 2025)
The aim of this research was to investigate the effects of different feeding regimes on the growth performance, nutrient intake, apparent digestibility, and ruminal metabolic and morphological characteristics of Awassi lambs. A total of 96 lambs (initial age: 10 ± 1 weeks; mean body weight: 23.62 ± 0.01 kg) were divided into four dietary groups in a completely randomised design (eight replicates/diet, three lambs/replicate). The four diets were as follows: control (CON: 50% barley grain, 50% long lucerne/alfalfa hay), diet 1 (D1: 100% complete pelleted feed), diet 2 (D2: 40% concentrate pellets, 60% long lucerne hay), and diet 3 (D3: 60% concentrate pellets, 40% roughage pellets). The lambs were fed the four diets for 84 days, and growth performance indicators were assessed twice (every 42 days) during this period. After 84 days, all target parameters, including morphometry, fermentation indicators, and bacterial activity in the lambs' rumens, were assessed. The primary findings indicated that treatments D2 and D3 led to increased body weights, weight gains, and feed intakes. Lambs fed D2 had a higher dry matter intake and nutrient digestibility, along with increased papilla height, density, and total surface area. Specific fibre-degrading bacteria were more prevalent in D1, D2, and D3 than in the CON lambs. The higher total volatile fatty acid concentrations measured in the rumens of the D1, D2, and D3 lambs signified an improved fermentation profile. In conclusion, these results highlight the potential of complete diets and concentrate pellets with roughage sources to optimise performance, rumen health, and nutrient utilisation in lambs. (Submitted 31 August 2025; Accepted 21 November 2025; Published 03 December 2025)
