Effects of feeding B. subtilis and B. licheniformis on the growth and carcass characteristics of feedlot lambs
DOI:
https://doi.org/10.17159/sajas.v56i04.01Keywords:
average daily gain, organ pathology, probiotics, sheep, South African Mutton MerinoAbstract
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)
References
Aarestrup, F.M., Wegener, H.C., & Collignon, P., 2008. Resistance in bacteria in the food chain: epidemiology and control strategies. Expert Review of Anti-infective Therapy, 6:733–750. DOI: https://doi.org/10.1586/14787210.6.5.733
Ahasan, A.S.M.L., Agazzi, A., Invernizzi, G., Bontempo, V., & Savoini, G., 2015. The beneficial role of probiotics in monogastric animal nutrition and health. Journal of Dairy Veterinary and Animal Research, 2:116–132. DOI: https://doi.org/10.15406/jdvar.2015.02.00041
Antunović, Z., Šperanda, M., Liker, B., Šerić, V., Senčić, Đ., Domaćinović, M., & Šperandat, T., 2005. Influence of feeding the probiotic Pioneer PDFM® to growing lambs on performances and blood composition. Acta Veterinaria, 55:287–300. DOI: https://doi.org/10.2298/AVB0504287A
Ashraf, R. & Shah, N.P., 2014. Immune system stimulation by probiotic microorganisms. Critical Reviews in Food Science and Nutrition, 54:938–956. DOI: https://doi.org/10.1080/10408398.2011.619671
Baldwin, R.L., 1999. The proliferative actions of insulin, insulin-like growth factor I, epidermal growth factor, butyrate and propionate on ruminal epithelial cells in vitro. Small Ruminant Research, 32:261–268. DOI: https://doi.org/10.1016/S0921-4488(98)00188-6
Bernardeau, M., Lehtinen, M.J., Forssten, S.D., & Nurminen, P., 2017. Importance of the gastrointestinal life cycle of Bacillus for probiotic functionality. Journal of Food Science and Technology, 54:2570–2584. DOI: https://doi.org/10.1007/s13197-017-2688-3
Bowling, R.A., Riggs, J.K., Smith, G.C., Carpenter, Z.L., Reddish, R.L., & Butler, O.D., 1978. Production, carcass and palatability characteristics of steers produced by different management systems. Journal of Animal Science, 46:333–340. DOI: https://doi.org/10.2527/jas1978.462333x
Bull, L.S., Bush, L.J., Friend, J.D., Harris, J.R., & Jones, E.W., 1965. Incidence of ruminal parakeratosis in calves fed different rations and its relation to volatile fatty acid absorption. Journal of Dairy Science, 48:1459–1466. DOI: https://doi.org/10.3168/jds.S0022-0302(65)88499-5
Campos, F.S., Carvalho, G.G.P., Santos, E.M., Araújo, G.G.L., Gois, G.C., Rebouças, R.A., Magalhães, A.L.R., Oliveira, J.S., Voltolini, T.V., Carvalho, B.M.A., & Perazzo, A.F., 2019. Characteristics of carcass and non-carcass components of lambs fed diets containing silages of forages adapted to the semi-arid environment. South African Journal of Animal Science, 49:119–130. DOI: https://doi.org/10.4314/sajas.v49i1.14
Capelloza., B.I., Segura, A., Milora, N., Galschioet, C., Schjelde, M., & Copani, G., 2023. Stability of Bacillus and Enterococcus faecium 669 probiotic strains when added to different feed matrices used in dairy production. Animals, 13:2350. DOI: https://doi.org/10.3390/ani13142350
Clauss, M., Stewart, M., Price, E., Peilon, A., Savage, T., Van Ekris, I., & Munn, A., 2016. The effect of feed intake on digesta passage, digestive organ fill and mass, and digesta dry matter content in sheep (Ovis aries): Flexibility in digestion but not in water reabsorption. Small Ruminant Research, 138:12–19. DOI: https://doi.org/10.1016/j.smallrumres.2016.03.029
Copani, G.C., Queiroz, O.C.M., & Boll, E.J., 2020. Lactobacillus animalis LA51 and Bacillus sp. probiotics confer protection from the damaging effects of pathogenic Clostridium perfringens and Escherichia coli on the intestinal barrier. Journal of Dairy Science, 103:103.
Cordeiro, M.W.S., Cappellozza, B.I., de Melo, N.N., & Bernardes, T.F., 2024. Effects of a Bacillus based direct-fed microbial on performance, blood parameters, fecal characteristics, rumen morphometrics, and intestinal gene expression in finishing beef bulls. Journal of Animal Science, 102:skae259. DOI: https://doi.org/10.1093/jas/skae259
Cull, C., Singu, V.K., Cull, B.J., Lechtenberg, K.F., Amachawadi, R.G., Schutz, J.S., & Bryan, K.A., 2022a. Efficacy of Lactobacillus animalis and Propionibacterium freudenreichii-based feed additives in reducing Salmonella-associated health and performance effects in commercial beef calves. Antibiotics, 11:1328. DOI: https://doi.org/10.3390/antibiotics11101328
Cull, C., Singu, V.K., Cull, B.J., Lechtenberg, K.F., Amachawadi, R.G., Schutz, J.S., & Bryan, K.A., 2022b. Efficacy of two probiotic products fed daily to reduce Clostridium perfringens-based adverse health and performance effects in dairy calves. Antibiotics, 11:1513. DOI: https://doi.org/10.3390/antibiotics11111513
Deng, K.D., Xiao, Y., Ma, T., Tu, Y., Diao, Q.Y., Chen, Y.H., & Jiang, J.J., 2018. Ruminal fermentation, nutrient metabolism, and methane emissions of sheep in response to dietary supplementation with Bacillus licheniformis. Animal Feed Science and Technology, 241:38–44. DOI: https://doi.org/10.1016/j.anifeedsci.2018.04.014
Dias, B.G.C., Santos, F.A.P., Meschiatti, M., Brixner, B.M., Almeida, A.A., & Queiroz, O., 2022. Effects of feeding different probiotic types on metabolic, performance, and carcass responses of Bos indicus feedlot cattle offered a high concentrate diet. Journal of Animal Science, 100:skac289. DOI: https://doi.org/10.1093/jas/skac289
Do Vale, A., Cabanes, D., & Sousa, S., 2016. Bacterial toxins as pathogen weapons against phagocytes. Frontiers in Microbiology, 7:42. DOI: https://doi.org/10.3389/fmicb.2016.00042
Dubreuil, J.D., 2017. Enterotoxigenic Escherichia coli and probiotics in swine: What the bleep do we know? Biosciences of Microbiota Food and Health, 36:75–90. DOI: https://doi.org/10.12938/bmfh.16-030
El Jeni, R., Villot, C., Koyun, O.Y., Osario-Doblado, A., Baloyi, J.J., Lourenco, J.M., Steele, M., & Callaway, T.R., 2024. Invited review: “Probiotic” approaches to improving dairy production: reassessing “magic foo-foo dust”. Journal of Dairy Science, 107:1832–1856. DOI: https://doi.org/10.3168/jds.2023-23831
Elshaghabee, F.M.F., Rokana, N., Gulhane, R.D., Sharma, C., & Panwar, H., 2017. Bacillus as potential probiotics: status, concerns and future perspectives. Frontiers in Microbiology, 8:1490. DOI: https://doi.org/10.3389/fmicb.2017.01490
Fuerniss, L.K., Kreikemeier, K.K., Reed, L.D., Cravey, M.D., & Johnson, B.J., 2022. Cecal microbiota of feedlot cattle fed a four-species Bacillus supplement. Journal of Animal Science, 100:skac258. DOI: https://doi.org/10.1093/jas/skac258
Galyean, M.L., Duff, G.C., & Rivera, J.D., 2022. Galyean appreciation club review: revisiting nutrition and health of newly received cattle – what have we learned in the past 15 years? Journal of Animal Science, 100:skac067. DOI: https://doi.org/10.1093/jas/skac067
Gao, Y., Wei, W., Tian, D., Li, J., Wang, Y., & Qi, J., 2023. Corn straw total mix dietary supplementation of Bacillus subtilis-enhanced growth performance of lambs by favourably modulating rumen bacterial microbiome. Fermentation, 9:32. DOI: https://doi.org/10.3390/fermentation9010032
Green, D.H., Wakeley, P.R., Page, A., Barnes, A., Baccigalupi, L., Ricca, E., & Cutting, S.M., 1999. Characterization of two Bacillus probiotics. Applied and Environmental Microbiology, 65:4288–4291. DOI: https://doi.org/10.1128/AEM.65.9.4288-4291.1999
Gresse, R., Cappellozza, B.I., Macheboeuf, D., Torrent, A., Danon, J., Capern, L., Sandvang, D., Niderkorn, V., Copani, G., & Forano, E., 2025. In vitro investigation of the effects of Bacillus subtilis-810B and Bacillus licheniformis-809A on the rumen fermentation and microbiota. Animals, 15:476. DOI: https://doi.org/10.3390/ani15040476
Guillot, J.F., 1998. Les probiotiques en alimentation animale. Cahiers Agricultures. 7:49–54.
Guimaraes, O., Preedy, G., Trent Fox, J., Cappellozza, B.I., Davis, T.C., Schutz, J.S., & Theurer, M.E., 2024. A novel direct-fed microbial impacts growth performance and supports overall health of feedlot cattle. Ruminants, 4:267–279. DOI: https://doi.org/10.3390/ruminants4020019
Hansen, L.H.B., Lauridsen, C., Nielsen, B., Jorgensen, L., & Canibe, N., 2022. Impact of early inoculation of probiotics to suckling piglets on post weaning diarrhoea – A challenge study with enterotoxigenic E. coli F18. Animal, 16:100667. DOI: https://doi.org/10.1016j.animal.2022.100667
Harvill, E.T., Cotter, P.A., Yuk, M.H., & Miller, J.F., 1999. Probing the function of Bordetella bronchiseptica adenylate cyclase toxin by manipulating host immunity. Infection and Immunity, 67:1493–1500. DOI: https://doi.org/10.1128/IAI.67.3.1493-1500.1999
Hernandez, J., Benedito, J.L., Abuelo, A., & Castillo, C., 2014. Ruminal acidosis in feedlot: From aetiology to prevention. The Scientific World Journal, 2014:702572. DOI: https://doi.org/10.1155/2014/702572
Hinders, R.G. & Owen, F.G., 1965. Relation of ruminal parakeratosis development to volatile fatty acid absorption. Journal of Dairy Science, 48:1069–1073. DOI: https://doi.org/10.3168/jds.S0022-0302(65)88393-X
Hong, H.A., Le, H.D., & Cutting, S.M., 2005. The use of bacterial spore formers as probiotics. FEMS Microbiology Reviews, 29:813–835. DOI: https://doi.org/10.1016/j.femsre.2004.12.001
Izuddin, W.I., Loh, T.C., Foo, H.L., Samsudin, A.A., & Humam, A.M., 2019. Postbiotic L. plantarum RG14 improves rumen epithelium growth, immune status and upregulates the intestinal barrier function in post-weaning lambs. Scientific Reports, 9:9938. DOI: https://doi.org/10/.1038/s41598-019-46076-0
Jones, S.D.M., Rompala, R.E., & Jeremiah, L.E., 1985. Growth and composition of the empty body in steers of different maturity types fed concentrate or forage diets. Journal of Animal Science, 60:427–433. DOI: https://doi.org/10.2527/jas1985.602427x
Khafipour, E., Krause, D.O., & Plaizier, J.C., 2009. A grain-based subacute ruminal acidosis challenge causes translocation of lipopolysaccharide and triggers inflammation. Journal of Dairy Science, 92:1060–1070. DOI: https://doi.org/10.3168/jds.2008-1389
Kleen, J.L., Hooijer, G.A., Rehage, J., & Noordhuizen, J.P.T.M., 2003. Subacute ruminal acidosis (SARA): a review. Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine, 50:406–414. DOI: https://doi.org/10.1046/j.1439-0442.2003.00569.x
Kochewad, S.A., Chahande, J.M., Kanduri, A.B., Deshmukh, D.S., Ali, S.A., & Patil, V.M., 2009. Effect of probiotic supplementation on growth parameters of Osmanabadi kids. Veterinary World, 2:29.
Kotarski, S.F., Waniska, R.D., & Thurn, K.K., 1992. Starch hydrolysis by the rumen microflora. The Journal of Nutrition, 122:178–190. DOI: https://doi.org/10.1093/jn/122.1.178
Lopez, A.M., Sarturi, J.O., Johnson, B.J., Woerner, D.R., Henry, D.D., Ciriaco, F.M., Silva, K.G.S., & Rush, C.J., 2024. Effects of bacterial direct-fed microbial combinations on beef cattle growth performance, feeding behaviour, nutrient digestibility, ruminal morphology and carcass characteristics. Journal of Animal Science, 102:skae004. DOI: https://doi.org/10.1093/jas/skae004
Lovett, D., Lovell, S., Callan, J., Finlay, M., Connoly, J., & O’Mara, F.P., 2003. Effect of forage/concentrate ratio and dietary coconut oil level on methane output and performance of finishing beef heifers. Livestock Production Science, 84:135–146. DOI: https://doi.org/10.1016/j.liveprodsci.2003.09.010
Luise, D., Bosi, P., Raff, L., Amatucci, L., Virdis, S., & Trevisi, P., 2022. Bacillus spp. probiotic strains as a potential tool for limiting the use of antibiotics and improving the growth and health of pigs and chickens. Frontiers in Microbiology, 13:801827. DOI: https://doi.org/10.3389/fmicb.2022.801827
Markowiak, P. & Slizewska, K., 2018. The role of probiotics, prebiotics and synbiotics in animal nutrition. Gut Pathogens, 10:21. DOI: https://doi.org/10.1186/s13099-018-0250-0
Minchin, W., Buckley, F., Kenny, D.A., Monahan, F.J., Shalloo, L., & O’ Donovan, M., 2009. Effect of grass silage and concentrate based finishing strategies on cull dairy cow performance, carcass and meat quality characteristics. Meat Science, 81:93–101. DOI: https://doi.org/10.1016/j.meatsci.2008.07.001
Muela, E., Sanudo, C., Campo, M.M., Medel, I., & Beltran, A., 2010. Effects of cooling temperature and hot carcass weight on the quality of lamb. Meat Science, 84:101–107. DOI: https://doi.org/10.1016/j.meatsci.2009.08.020
Nagaraja, T.G. & Titgemeyer, E.C., 2007. Ruminal acidosis in beef cattle. The current microbiological and nutritional outlook. Journal of Dairy Science, 90:17–38. DOI: https://doi.org/10.3168/jds.2006-478
Nithya, V. & Halami, P.M., 2013. Evaluation of the probiotic characteristics of Bacillus species isolated from different food sources. Annals of Microbiology, 63:129–137. DOI: https://doi.org/10.1007/s13213-012-0453-4
Nocek, J.E., 1997. Bovine acidosis: implications on laminitis. Journal of Dairy Science, 80:1005–1028. DOI: https://doi.org/10.3168/jds.S0022-0302(97)76026-0
Pahumunto, N., Dahlen, G., & Teanpaisan, R., 2021. Evaluation of potential probiotic properties of Lactobacillus and Bacillus strains derived from various sources for their potential use in swine feeding. Probiotics and Antimicrobial Proteins, 15:479–490. DOI: https://doi.org/10.1007/s12602-021-09861-w.
Peng X., Ed-Dra, A., Song, Y., Elbediwi, M., Nambiar, R.B., Zhou, X., & Yue, M., 2022. Lacticaseibacillus rhamnosus alleviates intestinal inflammation and promotes microbiota-mediated protection against Salmonella fatal infections. Frontiers in Immunology, 13:973224. DOI: https://doi.org/10.3389/fimmu.2022.973224
Pesonen, M., Honkavaara, M., & Huuskonen, A.K., 2012. Effect of breed on production, carcass traits and meat quality in Aberdeen angus, limousine and Aberdeen angus × limousine bulls offered a grass silage-grain-based diet. Agricultural and Food Science, 21:361–369. DOI: https://doi.org/10.23986/afsci.6520SU
Petrovic, M.Z., Dokovic, R., Cincovic, M., Ilic, Z., Petrovic, M.D., Cobanovic, N., & Karabasil, N., 2012. Effect of age of young Simmental bulls on dressing percentage. Acta Agriculturae Serbica. 22:11–21. DOI: https://doi.org/10.5937/AASer1743011P
Plaizier, J.C., Khafipour, E., Li, S., Gozho, G.N., & Krause, D.O., 2012. Subacute ruminal acidosis (SARA), endotoxins, and health consequences. Animal Feed Science and Technology, 172:9–21. DOI: https://doi.org/10.1016/j.anifeedsci.2011.12.004
Poole, T. & Sheffield, C., 2013. Use and misuse of antimicrobial drugs in poultry and livestock: mechanisms of antimicrobial resistance. Pakistan Veterinary Journal, 33:266–271.
Rabelo, C.H.S., Lara, E.C., Basso, F.C., Härter, C.J., & Reis, R.A., 2018. Growth performance of finishing feedlot lambs fed maize silage inoculated with Bacillus subtilis and lactic acid bacteria. The Journal of Agricultural Science, 156:839–847. DOI: https://doi.org/10.1017/S0021859618000679
Rhayat, L., Maresca, M., Nicoletti, C., Perrier, J., Brinch, K.S., Christian, S., & Devillard, E., 2019. Effect of Bacillus subtilis strains on intestinal barrier function and inflammatory response. Frontiers in Immunology, 10:564. DOI: https://doi.org/10.3389/fimmu.2019.00564
Ríos-Utrera, A., Cundiff, L.V., Gregory, K.E., Koch, R.M., Dikeman, M.E., Koohmaraie, M., & Van Vleck, L.D., 2005. Genetic analysis of carcass traits of steers adjusted to age, weight, or fat thickness slaughter end points. Journal of Animal Science, 83:764–776. DOI: https://doi.org/10.2527/2005.834764x
Rojas, M., Woods, C.R., Mora, A.L., Xu, J., & Brigham, K.L., 2005. Endotoxin-induced lung injury in mice: Structural, functional, and biochemical responses. American Journal of Physiology, 288:333–341. DOI: https://doi.org/10.1152/ajplung.00334.2004
Saleem, A.M., Zanouny, A.I., & Singer, A.M., 2016. Growth performance, nutrients digestibility, and blood metabolites of lambs fed diets supplemented with probiotics during pre- and post-weaning period. Asian- Australasian Journal of Animal Sciences, 30:523–530. DOI: https://doi.org/10.5713/ajas.16.0691
Santano, N.B., Boll, E.J., Capern, L.C., Cieplak, T.M., Keleszade, E., Letek, M., & Costabile, A., 2020. Comparative evaluation of the antimicrobial and mucus induction properties of selected Bacillus strains against enterotoxigenic Escherichia coli. Antibiotics, 9:849. DOI: https://doi.org/10.3390/antibiotics9120849
Shin, D., Chang, S.Y., Bogere, P., Won, K., Choi, J.Y., Choi, Y,J., Lee, H.K., Hur, J., Park, B.Y., & Kim, Y., 2019. Beneficial roles of probiotics on the modulation of gut microbiota and immune response in pigs. PloS One, 14:e0220843. DOI: https://doi.org/10.1371/journal.pone.0220843
Silva, K.G.S., Sarturi, J.O., Johnson, B.J., Woerner, D.R., Lopez, A.M., Rodrigues, B.M., Nardi, K.T., & Rush, C.J., 2024. Effects of bacterial direct-fed microbial mixtures offered to beef cattle consuming finishing diets on intake, nutrient digestibility, feeding behaviour, and ruminal kinetics/fermentation profile. Journal of Animal Science, 102:skae003. DOI: https://doi.org/10.1093/jas/skae003
Steele, M.A., Alzahal, O., Hook, S.E., Croom, J., & McBride, B.W., 2009. Ruminal acidosis and the rapid onset of ruminal parakeratosis in a mature dairy cow: a case report. Acta Veterinaria Scandinavica, 51:39. DOI: https://doi.org/10.1186/1751-0147-51-39
Su, Y., Liu, C., Fang, H., & Zhang, D., 2020. Bacillus subtilis: A universal cell factory for industry, agriculture, biomaterials and medicine. Microbial Cell Factories, 19:173. DOI: https://doi.org/10.1186/s12934-020-01436-8
Thompson, P.N., Stone, A., & Schultheiss, W.A., 2006. Use of treatment records and lung lesion scoring to estimate the effect of respiratory disease on growth during the early and late finishing periods in South African feedlot cattle. Journal of Animal Science, 84:488–498. DOI: https://doi.org/10.2527/2006.842488x
Tomczyk, G., Niczyporuk, J.S., Kozdrun, W., Sawicka-Durkalec, A., Bocian, L., Barabasz, M., & Michalski, M., 2024. Probiotic supplementation as an alternative to antibiotics in broiler chickens. Journal of Veterinary Research, 68:147–154. DOI: https://doi.org/10.2478/jvetres-2024-0009
Van, T.T.H., Yidana, Z., Smooker, P.M., & Coloe, P.J., 2020. Antibiotic use in food animals worldwide, with a focus on Africa: Pluses and minuses. Journal of Global Antimicrobial Resistance, 20:170–177. DOI: https://doi.org/10.1016/j.jgar.2019.07.031
Walsh, K., O’Kiely, P., Moloney, A.P., & Boland, T.M., 2008. Intake, performance and carcass characteristics of beef cattle offered diets based on whole-crop wheat or forage maize relative to grass silage or ad libitum concentrates. Livestock Science, 116:223–236. DOI: https://doi.org/10.1016/j.livsci.2007.10.010
Wang, K., Cao, G., Zhang, H., Li, Q., & Yang, C., 2019. Effects of Clostridium butyricum and Enterococcus faecalis on growth performance, immune function, intestinal morphology, volatile fatty acids, and intestinal flora in a piglet model. Food and Function. 10:7844–7854. DOI: https://doi.org/10.1039/c9fo01650c
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