Tropical animal health and production最新文献

{"title":"Management factors affecting milk yield, composition, and quality on smallholder dairy farms.","authors":"Marie Anne Mukasafari, Jean Pierre Mpatswenumugabo, Jean Baptiste Ndahetuye, Ewa Wredle, Renée Båge","doi":"10.1007/s11250-025-04294-x","DOIUrl":"https://doi.org/10.1007/s11250-025-04294-x","url":null,"abstract":"<p><p>A cross-sectional study on 156 smallholder dairy farms in Rwanda was carried out to assess the association between farm management practices and milk yield and quality. A pre-tested questionnaire was used to collect data on cow characteristics and farm management practices. Milk yield was recorded at household level, milk composition was monitored using a Lactoscan device (Milk Analyzer). Somatic cell count (SCC) was determined using a DeLaval cell counter (DCC). A Delvotest SP-NT kit was used to determine antibiotic residues in raw milk. Most dairy cows were kept in zero-grazing system (84.6%) and most farmers had less experience of dairy production (78.2%). Mean daily milk yield was 3.9 L/cow and was associated with type of breed, milking frequency, stage of lactation, and parity. Mean milk content of protein, fat, lactose and solid non-fat, and density were normal and showed no association with different management practices. Based on SCC analyses, 65.8% of the milk samples with less than 300,000 cells/mL were graded as acceptable for delivery to a milk collection centre (MCC) and 12.9% of the samples tested positive for antibiotic residues. These findings suggest low milk yields on smallholder farms in Rwanda that are attributable to type of breed and prevalent high level mastitis, among other factors. The results also indicate possible non-compliance with withdrawal periods, resulting in antibiotic residues in milk, which has public health implications for consumers. Routine testing at MCC for both SCC and antibiotic residues is important for quality control.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"41"},"PeriodicalIF":1.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seroprevalence and risk factors of Bluetongue virus in camels in Northern Oman: a cross-sectional study.","authors":"Wafa Al-Mamari, Elshafie Ibrahim Elshafie, Aliya Al Ansari, Bahja Al Riyami","doi":"10.1007/s11250-025-04288-9","DOIUrl":"https://doi.org/10.1007/s11250-025-04288-9","url":null,"abstract":"<p><p>Bluetongue virus (BTV) has emerged as a significant concern in Oman, affecting various animal species, including camels. This cross-sectional study aimed to assess the seroprevalence of BTV in camels and explore the associated risk factors within the northern region of Oman. Between October 2016 and March 2017, 439 serum samples and 100 blood samples were collected from camels in five governorates. Competitive enzyme-linked immunosorbent assay (c-ELISA) was employed to screen the serum for BTV antibodies, and real-time reverse transcription-polymerase chain reaction (RT-qPCR) was used to detect BTV genomic RNA in blood. The findings revealed an overall seroprevalence of BTV of 56.04% (246 out of 439), with a 95% confidence interval ranging from 51.3% to 60.7%. BTV seropositivity was significantly associated with various factors, including geographical location, camel age, sex, participation in events, and a history of previous outbreaks. However, no significant correlation was found with tick infestations on farms or a history of abortion. These results underscore the enzootic and widespread nature of BTV in northern Oman, with camels appearing to manifest BTV infection as an asymptomatic or subclinical condition. To gain a more comprehensive understanding, further investigations are essential to identify the specific BTV serotypes currently in circulation within the Sultanate of Oman. The implications of these findings extend to the development of targeted interventions to manage and control the spread of BTV in this region.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"40"},"PeriodicalIF":1.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143060825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feeding broilers with the addition of an Ilex paraguariensis coproduct affects zootechnical performance and meat quality responses.","authors":"Laura de Vasconcelos Costa, Bruna Trindade Paim, Yasmin Völz Bezerra Massaut, Cassio Antonio Ficagna, Paulo Vinícius de Oliveira, Daisa Bonemann, Fernanda de Candido de Oliveira, Cesar Valmor Rombaldi, Anderson Schwingel Ribeiro, Roger Wagner, Marcel Manente Boiago, Aleksandro Schafer da Silva, Elessandra Zavareze, Adriana Dillenburg Meinhart","doi":"10.1007/s11250-025-04291-0","DOIUrl":"10.1007/s11250-025-04291-0","url":null,"abstract":"<p><p>During the harvest of Ilex paraguariensis, approximately 2-5 tons per hectare of thick stems are left on the soil surface. The outer portion of these stems, referred to as the coproduct, constitutes 30% of the total residue mass. Although this coproduct has been partially characterized in terms of its phytochemical profile, its technological applications remain unexplored. The objective of this research is to evaluate whether broilers fed with feed incorporating I. paraguariensis harvest prunings will exhibit improved zootechnical performance as well as enhanced biochemical and impacts on meat quality. One-day-old Cobb 500 broilers (n = 300) were raised for 42 days in the broiler shed at the experimental farm in housed in 2.0 m² pens with a 10 cm layer of poultry litter and equipped with tubular feeders and nipple drinkers. They were arranged in a completely randomized design, comprising four treatments with five replicates of 15 birds each. The treatments consisted of the following diets: a basal diet (0%; the control), feed with 1% coproduct (1% treatment), feed with 2% coproduct (2% treatment), and feed with 3% coproduct (3% treatment). Broilers were assessed for zootechnical performance, intestinal morphometry, and serum biochemical properties. Additionally, meat quality was evaluated, including centesimal composition, chlorogenic acid content, antioxidant activity, metal concentration, and fatty acid profile. Chlorogenic acid was not detected in the meat of broiler chickens. The inclusion of the coproduct impacted both zootechnical performance and meat quality, with a linear effect proportional to the concentration of the additive used in the diet; that is, the worst performance was seen in chickens that consumed 3% of the co-product. It reduced feed consumption and weight gain, lowered cholesterol and triglyceride levels in broiler blood, but increased polyunsaturated fatty acids in the meat, one effect verified for the two largest inclusions (2 and 3% of the co-product). In the intestine, greater villus height and levels of reactive oxygen species were observed in the highest dose of the additive, a group of birds in which greater activity of the enzymes creatine kinase and pyruvate kinase was also observed. In general, none of the doses tested proved to be effective in enhancing productive performance; in addition, it did not increase the concentration of chlorogenic acid in the meat, which would be our hypothesis of having a nutraceutical food.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"39"},"PeriodicalIF":1.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143053573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of weighted genomic BLUP and Bayesian methods for Hanwoo carcass traits.","authors":"Md Azizul Haque, Eun-Bi Jang, Han-Deul Lee, Dae-Hyun Shin, Ji-Hee Jang, Jong-Joo Kim","doi":"10.1007/s11250-025-04293-y","DOIUrl":"10.1007/s11250-025-04293-y","url":null,"abstract":"<p><p>To improve the quality and yield of the Korean beef industry, selection criteria often focus on estimated breeding values for carcass weight (CWT), eye muscle area (EMA), backfat thickness (BF), and marbling score (MS). This study estimated genetic parameters and assessed the accuracy of genomic estimated breeding values (GEBVs) using SNP weighting methods. We compared the accuracy of these methods with the genomic best linear unbiased prediction (GBLUP) and various Bayesian approaches (BayesA, BayesB, BayesC, and BayesCPi) for the specified traits. The study used single-trait animal models, including GBLUP, weighted GBLUP (WGBLUP), and the Bayesian methods to predict genomic breeding values in a population of Hanwoo steers. A total of 19154 phenotypes were collected with all animals genotyped using the Illumina Bovine 50 K SNP chip. The average heritability for the carcass traits was 0.33 (GBLUP) and 0.35 (Bayesian), with Bayesian methods yielding heritability estimates that were on average 0.02 points (6.1%) higher than GBLUP. The accuracy of genomic predictions ranged from 0.7-0.83 (GBLUP), 0.83-0.87 (WGBLUP), and 0.81-0.87 across the Bayesian methods. WGBLUP accuracies for the carcass traits were, on average 8.97% higher than the GBLUP accuracies and 1.80% higher than the Bayesian alphabets. The Bayesian alphabet's accuracy is also, on average 6.00% higher than the GBLUP accuracy. According to these findings, the weighting GBLUP approach provides higher prediction accuracy for Hanwoo carcass traits than the Bayesian alphabet. Therefore, WGBLUP can be used for genomic selection in the Hanwoo evaluation program.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"38"},"PeriodicalIF":1.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143053589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic analysis of growth traits in Salem Black goats under farm conditions.","authors":"Akshata Patil, D Cauveri, P Devendran, J Muralidharan, P Senthilkumar","doi":"10.1007/s11250-025-04286-x","DOIUrl":"10.1007/s11250-025-04286-x","url":null,"abstract":"<p><p>In this study, data on pedigree, production traits for 19 years (2002-2022) of Salem Black goat from the Mecheri Sheep Research Station, Tamil Nadu, India was used. Various growth traits viz., birth weight (BW), weaning weight (WW), 6-month weight (6W), 9-month weight (9W), 12-month weight (YW), pre- and post-weaning average daily gain (ADG) (3-6, 6-9, 9-12 and 3-12 months) were analyzed. Univariate analysis was carried out after correcting for significant non-genetic factors. (Co)variance components for different production and functional traits were estimated by Restriction Maximum Likelihood method (REML) using WOMBAT. Heritability estimates for most of the growth traits were medium providing better scope for selection. Direct heritability estimates for BW, WW, 6W, 9W and YW, pre- and post-weaning ADG (3-12) were 0.177 ± 0.066, 0.094 ± 0.055, 0.111 ± 0.068, 0.123 ± 0.082, 0.181 ± 0.122, 0.118 ± 0.060 and 0.188 ± 0.126 respectively. Through bivariate analysis genetic and phenotypic correlations between growth traits were obtained. Positive, medium to high genetic correlation was observed in post-weaning body weight traits which would support multistage selection. Similar positive and medium to high genetic correlation between pre- and post-weaning ADG (3-6 and 3-12 months) with post- weaning body weight traits would facilitate indirect selection. Breeding values (EBV) for BW, WW, 6W, 9W, YW, pre- and post-weaning ADG (3-12 months) were estimated. High genetic variability was observed in weaning and post- weaning body weight traits. The findings of this study could further aid in the improvement of the breeding programme.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"37"},"PeriodicalIF":1.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143053575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential Myf5 and Myf6 expression and muscle fiber traits in Angora, Hair, Honamlı, and Kilis goats.","authors":"Büşra Bayrak, Uğur Şen, Dilek Gökçek, Emre Şirin","doi":"10.1007/s11250-025-04277-y","DOIUrl":"10.1007/s11250-025-04277-y","url":null,"abstract":"<p><p>The present study was conducted on specific skeletal muscles of six weaned male kids from each of the Angora, Hair, Honamlı, and Kilis goat breeds. The relationships between the expression of myogenic factor 5 (Myf5) and myogenic factor 6 (Myf6) genes and muscle fibre characteristics were analysed. Muscle samples from the longissimus dorsi (LD) and semitendinosus (ST) were collected from six 90-day-old weaned male kids of each breed. Muscle fiber characteristics were assessed through histochemical staining, while expression levels of Myf5 and Myf6 genes were quantified using real-time PCR. Total RNA content in the LD and ST muscles was significantly higher (p < 0.05) in Honamlı kids compared to those of the other breeds. Similarly, the expression of Myf5 gene in Honamlı kids was significantly higher (p < 0.05) than that observed in kids from the other breeds in LD muscle. Conversely, in the ST muscle, Hair kids exhibited a significantly lower expression of Myf5 (p < 0.05) when compared to both Honamlı and Kilis kids Additionally, Kilis kids demonstrated a significant reduced expression of Myf6 gene (p < 0.05) relative to the other breeds. The highest expression levels of the Myf6 gene (p < 0.05) were detected in the ST muscle of Honamlı and Angora kids, significantly surpassing those observed in Hair and Kilis kids. Moreover, significant correlations (p < 0.05) were observed among Myf5 and Myf6 gene expression levels and various muscle fiber characteristics differing across breeds. The results of this study underscore the pivotal role of these myogenic regulatory factors in muscle development, offering insights into the molecular mechanism driving breed-specific muscle growth. This association between gene expression and muscle phenotype could have profound implications for targeted breeding programs aimed at optimizing muscle traits in livestock species.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"36"},"PeriodicalIF":1.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different environmental enrichment tools to improve behavior, welfare, and growth performance of broiler chickens.","authors":"Abdul Ghani, Shahid Mehmood, Faisal Hussnain, Saima","doi":"10.1007/s11250-025-04292-z","DOIUrl":"https://doi.org/10.1007/s11250-025-04292-z","url":null,"abstract":"<p><p>This study was performed to evaluate the effect of various environmental enrichment (EE) tools on broiler growth, welfare, behavior, carcass, and meat quality. A total of 300 commercial broilers were randomly divided into 05 treatments. The treatments include various EE tools such as perches, balls, hanging bottles, and laser lights placed for birds and a control group. The birds kept with perches and hanging bottles had the lowest feed intake, while the birds in the control group showed the poor feed conversion ratio compared to all EE treatments. Broilers raised under different EE were more active and exhibited frequent maintenance behavior (i.e., walking, jumping, running, wing flapping and aggressiveness) than the control group which spent more time in feeding and drinking. Moreover, the birds with EE had reduced incidence of toe injuries and footpad dermatitis than those in the control group. Birds reared with perches had higher meat lightness, whereas meat from the birds in the control group had lower cooking loss and shear force. It can be concluded that the use of various EE tools improved the welfare and behavior of the birds without affecting bodyweight of the birds. Furthermore, the use of hanging bottles and placing perches reduced feed intake and improved feed conversion ratio.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"33"},"PeriodicalIF":1.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of Eimeria spp. parasite load on productivity parameters in lambs fed with babassu byproduct.","authors":"Sara Silva Reis, Henrique Nunes Parente, Anderson de Moura Zanine, Gisele Thamires Araújo da Silveira, Edegleicia Alves de Sousa, Arlan Araújo Rodrigues, Thalia Caldas da Silva, José Gracione do Nascimento Souza Filho, Janaina Marques do Nascimento, Thiago Vinicius Costa Nascimento, Michelle de Oliveira Maia Parente, Carlos Rodrigo Hermosilla, Ivo Alexandre Leme da Cunha","doi":"10.1007/s11250-025-04279-w","DOIUrl":"https://doi.org/10.1007/s11250-025-04279-w","url":null,"abstract":"<p><p>This study investigated the modulation of Eimeria spp. parasite load and its impact on productivity parameters in lambs fed varying levels of babassu by-product (BBP). Twenty-four Dorper × Santa Inês lambs naturally infected with Eimeria spp. were divided into four groups and assigned to dietary treatments with increasing levels of BBP inclusion: Control group (0% BBP; n = 6), G1 (5% BBP; n = 6), G2 (10% BBP; n = 6), and G3 (15% BBP; n = 6). Fecal oocyst counts, dry matter intake (DMI), average daily gain (ADG), and apparent digestibility coefficients were monitored throughout the experiment. Results revealed that 9.5% BBP inclusion was associated with the lowest mean oocyst count per gram of feces, without compromising ADG. Nine Eimeria species were identified, with E. crandallis, E. parva and E. ovinoidalis being the most prevalent. Principal component analysis revealed a negative correlation between Eimeria spp. infection intensity and lamb performance, with higher BBP inclusion levels being associated with improved DMI, ADG, and digestibility. These findings suggest that dietary BBP at 9.5% inclusion effectively modulates Eimeria spp. parasite load in lambs while maintaining productivity. Although the exact mechanisms require further investigation, these results highlight BBP as a promising natural alternative for coccidiosis management in sheep production. This natural, sustainable approach offers a promising strategy for coccidiosis management in sheep, particularly in tropical and subtropical production systems.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"34"},"PeriodicalIF":1.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of lipoic acid on production performance, meat quality, serum biochemistry and antioxidant function in heat-stressed broilers.","authors":"Xueqi Zhang, Kai Song, Jiajun Miao, Shiang Sun, Yongjie Xiong, Shaojun He","doi":"10.1007/s11250-025-04280-3","DOIUrl":"https://doi.org/10.1007/s11250-025-04280-3","url":null,"abstract":"<p><p>This study was aim to investigate the effects of lipoic acid (ALA) on performance, meat quality, serum biochemistry and antioxidant function of broilers under heat stress (HS). Two hundred1-day-old Cobb broilers were randomly divided into four treatment groups and each treatment consisted of 4 replicates of 10 broilers each. The treatment group adopts a 2 × 2 two-factor setting, which is divided into two diets (basic diet or 250 mg/kg ALA diet) and two temperatures (24 ± 1℃ or 33 ± 1℃). Starting from the 28th day of age, broilers are kept at room temperature (24 ± 1℃) or exposed to cyclic HS (33 ± 1℃ from 8:00 am to 18:00, 24 ± 1℃ from 18:00 to 8:00 am). HS significantly decreased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), direct bilirubin (D-BIL), total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD). However, HS increased breast meat pH, serum uric acid (UA), total cholesterol (TC) and malondialdehyde (MDA). Dietary ALA significantly decreased leg meat shear force and water loss rate, serum total bilirubin(T-BIL), UA, triglyceride (TG) and MDA of broilers. However, it increased daily gain (ADG), serum D-BIL and T-SOD. There is a significant interaction between temperature and additives. HS can destroy the balance of the oxidation-antioxidant system, and lead to damage to liver and kidney function and confusion energy metabolism. Dietary ALA improves the antioxidant capacity of broilers, reduces the level of blood lipids and liver and kidney metabolism, and increases the daily gain of heat-stressed broilers.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"35"},"PeriodicalIF":1.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of monensin, virginiamycin, trace minerals, and yeast combination on animal performance, carcass and meat characteristics of finishing feedlot bulls fed high grain diet.","authors":"Vanessa Duarte, Fabio Garcia Ribeiro, Aylle Medeiros Matos, Rodolpho Martin do Prado, Luiz Fernando Costa E Silva, Venício Macedo Carvalho, Vicente Alfonso Díaz Ávila, Melina Aparecida Plastina Cardoso, Ivanor Nunes do Prado","doi":"10.1007/s11250-025-04289-8","DOIUrl":"https://doi.org/10.1007/s11250-025-04289-8","url":null,"abstract":"<p><p>This study was realized to evaluate the influence of monensin, virginiamycin,trace minerals and yeast combination on animal performance, feed efficiency, in situ digestibility, feeding behavior, and carcass and meat characteristics from bulls finished in feedlot fed high-grain diet. A total of 36 (European vs. Nellore) bulls at 24 ± 3.2 months of age and with a body weight (BW) of 385.5 ± 3.84 kg were used in a completely randomized design. The four experimental diets were: CONT - without additives; MONE - inclusion of 30 mg of monensin/kg of DM; MOVI - inclusion of 30 mg of monensin + 30 mg of virginiamycin/kg of DM; MOMY - inclusion of 30 mg of monensin/kg of DM + 0.3 g/kg of BW of trace minerals and yeast. Final body weight was higher (P < 0.05) for the bulls fed MOVI (558.7 kg) and MOMY (554.6 kg) diets, intermediate for bulls fed MONE (529.3 kg) diet, and lower for bulls fed CONT (514.6 kg) diet. Likewise, the average daily gain was higher (P < 0.01) for bulls fed MOVI and MOMY (2.02 kg/d), intermediate for bulls fed MONE (1.72 kg/d), diet and lower for bulls fed CONT (1.57 kg/d) diets. Dry matter intake and other nutrients were similar (P > 0.05) among treatments. However, feed conversion improved (P < 0.05) for bulls fed MOVI and MOMY diets. Animals fed MOVI and MOMY spent more time ruminating compared to animals fed CONT and MONE (P = 0.034) diets. The carcass weights, carcass dressing and backfat thickness were greater (P < 0.05) for the bulls fed MOVI and MOMY diets. In conclusion, the inclusion of monensin or a combination of monensin + virginiamycin or monensin + trace minerals and yeast resulted in higher animal performance and improved feed efficiency.</p>","PeriodicalId":23329,"journal":{"name":"Tropical animal health and production","volume":"57 2","pages":"32"},"PeriodicalIF":1.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143029777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}