Small Ruminant Research最新文献

{"title":"Dose-response of Asparagopsis extract and diet quality effects enteric methane emissions for sheep fed high-forage diets","authors":"Charlotte Adam ,&nbsp;Frances C. Cowley ,&nbsp;Daniel Korir Sitienei ,&nbsp;Nigel Tomkins ,&nbsp;Lewis Kahn ,&nbsp;James Preston ,&nbsp;Emma Doyle","doi":"10.1016/j.smallrumres.2025.107487","DOIUrl":"10.1016/j.smallrumres.2025.107487","url":null,"abstract":"<div><div><em>Asparagopsis spp</em>. (Asparagopsis) receives considerable attention, due to the antimethanogenic properties it exhibits when included in diets of ruminant livestock. However, only one previous study has investigated the use of Asparagopsis in sheep <em>in vivo,</em> offered as part of a modified total mixed ration, reporting up to 80 % enteric methane (CH₄) abatement at an inclusion of 3 % (organic-matter basis). The objective of this study was to investigate the interaction of bromoform (CHBr₃) dose and basal diet quality on CH₄ abatement in sheep, when fed a high forage basal diet with supplementary pellets containing CHBr₃ extracted from <em>Asparagopsis armata</em> in oil (Asp-oil). Sixty merino wethers were used in a split plot design of five supplementary pellet treatments (100 g/d) of increasing CHBr₃ concentrations (A0, 0 mg CHBr₃/kg DM; A1, 36 mg CHBr₃/kg DM; A2, 72 mg CHBr₃/kg DM; A3, 108 mg CHBr₃/kg DM; and A4, 144 mg CHBr₃/kg DM) and fed either a high-quality (neutral detergent fibre (NDF) 40 %) or low-quality (NDF 55 %) forage basal diet. Wethers were housed in individual pens for 117 days to allow for measurements of feed intake and production parameters. Five measurements of CH₄ production (MP, g CH₄/d), 14 days apart, were conducted with open circuit respiration chambers. Wool growth (g/d), intake of basal diet and supplementary pellets (kg DMI/d), and average daily gain (kg/d) were production parameters. There was no significant interaction between diet × Asp-oil level on CH₄ yield (MY, g CH₄/kg DMI), but independently each had a significant effect. In comparison to their respective control (A0), A4 resulted in a 12 % and 19 % MY abatement for high-quality and low-quality diets, respectively. Average daily gain was significantly affected by diet (P &lt; 0.001) but not Asp-oil inclusion. Wool growth rate was affected by diet (P = 0.05) only. This study has demonstrated that feeding sheep Asp-oil can reduced MP, regardless of diet quality. However, basal diet continues to influence MY. Future grazing trials are necessary to validate the results of this animal house experiment.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107487"},"PeriodicalIF":1.6,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and risk factors of Haemonchus contortus in small ruminants in China: A systematic review and meta-analysis","authors":"Wei Wei ,&nbsp;Zhuo Lan ,&nbsp;Zhengyi Li ,&nbsp;Rui Wang","doi":"10.1016/j.smallrumres.2025.107486","DOIUrl":"10.1016/j.smallrumres.2025.107486","url":null,"abstract":"<div><div>Haemonchosis, caused by <em>Haemonchus contortus</em>, is a major parasitic disease impacting ruminants, with serious consequences for animal health and ruminant production. Despite numerous studies on its prevalence, a comprehensive understanding of the disease in China is still lacking. To address this gap, we conducted a meta-analysis of studies examining <em>H. contortus</em> infection in sheep and goats across 17 provinces in China. A total of 52 studies were included, revealing an overall pooled prevalence of 72 %. The highest infection rate was observed in central China (71.31 %), with Henan and Liaoning provinces showing particularly high rates of 87.22 % and 85.57 %, respectively. Region, season, and climatic factors significantly influenced infection rates (P &lt; 0.05), with free-ranging small ruminants and over 6 months of age being more susceptible. Additionally, the study emphasized that goats are more susceptible to infection than sheep, with infection rates rising after 2015. These findings highlight the widespread distribution of <em>H. contortus</em> in China and the urgent need for targeted control measures. Efforts should focus on improving management practices during the autumn season, implementing rotational grazing, using anthelmintics judiciously, and ensuring adequate nutritional support to reduce infection risks and minimize small ruminants production losses, all of which are crucial for advancing the small ruminants industry and fostering broader socioeconomic development.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107486"},"PeriodicalIF":1.6,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681985","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":"Ultrasonographic analyses of fetal gastrointestinal characteristics and correlations with gestational age and maturity in sheep","authors":"Jenna E. Bayne ,&nbsp;Edzard van Santen ,&nbsp;Robert C. Cole","doi":"10.1016/j.smallrumres.2025.107485","DOIUrl":"10.1016/j.smallrumres.2025.107485","url":null,"abstract":"<div><div>This observational study aimed to describe the ultrasonographic development of the fetal gastrointestinal (GI) tract in late-gestation ewes and to determine the statistical probabilities of detecting the onset and progressive changes to the GI parameters with advancing gestational age. A grading scale based on studies in other species was applied, specifically for the onset and progressive changes in intestinal wall definition, luminal content characteristics, peristalsis, and segmental dilation. Based on these characteristics, a GI score was assigned to each fetus during serial ultrasonographic examinations until term (median 148 days). With advancing gestational age, progressive maturation and increasing GI scores were observed, with probabilities greater than 90 % for detecting GI scores of 3 and 4 at term. Intestinal wall definition was well-defined with 50 % and greater than 90 % detection probabilities at days 130 and 132 of gestation, respectively. The onset of detectable motility was similar for the forestomach, abomasum, and intestines between 126 and 130 days of gestation. A greater than 90 % probability of detecting motility of the forestomach, abomasum, and intestine were present at 148-, 148-, and 138-days gestation, respectively. As gestational age advanced, intestinal luminal content changed from mixed echogenic to anechoic, and the onset of purposeful segmental dilation progressed from occasional to rhythmic in frequency. At term, there was approximately 90 % or greater probability of observing anechoic luminal content and rhythmic segmental dilation, respectively. Future studies are needed in high-risk pregnancies to determine the predictiveness of fetal GI characteristics as a measure of readiness for birth and potential correlates with neonatal morbidity and mortality in the peripartum period.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107485"},"PeriodicalIF":1.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642217","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":"Runs of homozygosity and selection signature in Santa Inês sheep: A genomic analysis","authors":"Tamires de Sousa Silva ,&nbsp;Fábio Barros Britto ,&nbsp;José Lindenberg Rocha Sarmento ,&nbsp;Ana Paula Soares e Silva ,&nbsp;Dayane Pereira de Castro ,&nbsp;Fabiana Cristina Belchior de Sousa ,&nbsp;Gislayne Souza do Nascimento ,&nbsp;Gleyson Vieira dos Santos ,&nbsp;Natanael Pereira da Silva Santos","doi":"10.1016/j.smallrumres.2025.107478","DOIUrl":"10.1016/j.smallrumres.2025.107478","url":null,"abstract":"<div><div>Runs of homozygosity (ROH) and selection signatures are the results of selection processes in livestock species that have been shown to affect several traits in farm animals. The objective of this study was to investigate runs of homozygosity, identify selection signatures and the genes involved, in Santa Ines sheep. The genotype file contained 390 animals and 52,744 SNP markers. The ROH and selection signature analyses were conducted using the detectRUNS tool and PLINK software. The ROH analyses identified a selection signature for the five genetic groups on chromosome 16. When the level of similarity (90 %) within the genetic groups was increased, 8 selection signature regions were found on chromosomes 2, 3, 6, 7, 12, 16, and 18. The genes found in regions with selection signatures are related to several functions of great productive and adaptive interest, such as immunity (MYD88, NFKB1), growth (IGFBP2, IGFBP5, SKP2) and meat and milk quality (IL7R, RANBP3L). Chromosome 16 stands out because it concentrates genes associated with milk, meat and fat production, evidencing its importance for economic traits in the Santa Inês breed. On the other hand, the absence of genes annotated in specific regions, such as chromosome 12, suggests the need for additional studies to identify biological processes that have not yet been characterized. These results reinforce the relevance of exploring selection signatures and associated genes in genetic improvement programs, aiming to optimize the productivity and adaptability of Santa Inês sheep.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107478"},"PeriodicalIF":1.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601361","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 soybean molasses on ruminal fermentation pattern, performance and meat quality of feedlot sheep","authors":"Sérgio A.G. Pereira-Junior ,&nbsp;Juliana A. Torrecilhas ,&nbsp;Rayanne V. Costa ,&nbsp;Edivilson S. Castro Filho ,&nbsp;Maria Carolina G. Arruda ,&nbsp;João Pedro A. Bertoco ,&nbsp;Andresa L. Feliciano ,&nbsp;Julia L. Rodrigues ,&nbsp;Rosemary L. Galati ,&nbsp;Angélica C. dos Santos ,&nbsp;Marcos R. Chiaratti ,&nbsp;Ricardo P. Nociti ,&nbsp;Flavio V. Meirelles ,&nbsp;José Bento S. Ferraz ,&nbsp;Márcia H.M.R. Fernandes ,&nbsp;Eric H.C.B. van Cleef ,&nbsp;Marco Túlio C. Almeida ,&nbsp;Jane M.B. Ezequiel","doi":"10.1016/j.smallrumres.2025.107477","DOIUrl":"10.1016/j.smallrumres.2025.107477","url":null,"abstract":"<div><div>This study sought to assess the impact of substituting cracked corn grain with soybean molasses (SM) on ruminal degradation patterns in sheep (Exp 1), as well as the performance and meat quality of feedlot-finished male lambs (Exp 2). In Exp 1, nine rumen-cannulated crossbred (Santa Inês × Dorper) male sheep (18 months old; 73.3 ± 2.5 kg BW) were assigned to a triple 3 × 3 Latin square design to assess rumen parameters (pH, ammonia N and SCFA) and <em>in situ</em> degradability of diets containing different levels of SM: CON (0 g kg⁻¹ SM) SM15 (150 g kg⁻¹ SM) and SM30 (300 g kg⁻¹ SM), with a roughage concentrate ratio of 40:60. In Exp 2, twenty male lambs (Santa Inês × Dorper, 98 days old; 21.13 ± 0.92 kg BW) were assigned to randomized block design with two experimental diets: CON (0 g kg⁻¹ SM) and SM20 (200 g kg⁻¹ SM), consisting of 16 % roughage and 84 % concentrate. The animals were evaluated for carcass traits, meat quality (physical and chemical analysis), and muscle transcriptome profile. The inclusion of SM in the diet decreased (<em>P</em> &lt; 0.01) ruminal ammonia concentration and increased (<em>P</em> &lt; 0.01) ruminal pH, while enhancing DM and CP solubility (<em>P</em> &lt; 0.01). No differences were observed in performance, carcass, or meat parameters, but elevated expression was observed in the transcripts involved in fructose metabolism (GO-0006000; <em>P</em> = 4.56 × 10⁻⁴) and insulin signaling pathway (hsa04910; <em>P</em> = 0.003), supported by higher triglycerides in blood plasma (<em>P</em> = 0.04) and subcutaneous adipocyte diameter (<em>P</em> = 0.01). Replacing corn with SM in sheep’s diets improved the rumen environment and modulated muscle energy metabolism, making it a promising feed alternative for small ruminants.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107477"},"PeriodicalIF":1.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549397","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":"Determinants of motives for keeping small ruminants: Evidence from the Northern Ghana","authors":"Emmanuel Zumanye ,&nbsp;Nicholas Opong Mensah ,&nbsp;Thomas Bilaliib Udimal ,&nbsp;Tekuni Nakuja ,&nbsp;Samuel Afotey Anang ,&nbsp;Nanii Yenibehit","doi":"10.1016/j.smallrumres.2025.107476","DOIUrl":"10.1016/j.smallrumres.2025.107476","url":null,"abstract":"<div><div>This study aims to identify the motives for keeping small ruminants and factors that influence farmers’ motives for keeping small ruminants in Northern Ghana. A sample of four hundred small ruminant holders were randomly selected for the study. Multinomial logistic model was used for empirical analysis. The results show that small ruminant farmers mainly keep the small ruminants for food, security/insurance, source of income, and pension. The results further show that credit has a negative effect on pension motive for keeping small ruminants relative to food motive. The value of animals has a positive effect on the pension motive relative to food motive. Age has a negative influence on saving motive relative to food motive. Animal value has a positive effect on saving motive relative to food motive. Also, monthly income, and other type of businesses have positive influence on income motive relative to food motive. Also, years of education and other type of farming activities have positive influence on security/insurance motives relative to food motive.</div><div>The study brings to light small ruminant farmers’ motive for keeping animals and factors that influence their motives.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107476"},"PeriodicalIF":1.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549514","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":"The role of non-aureus Staphylococcus in small ruminant mastitis: A systemic review on etiological agents, risk factors, virulence determinants, and novel treatments","authors":"Rocío Angélica Ruiz-Romero ,&nbsp;Navid Ghavipanje ,&nbsp;Einar Vargas-Bello-Pérez","doi":"10.1016/j.smallrumres.2025.107475","DOIUrl":"10.1016/j.smallrumres.2025.107475","url":null,"abstract":"<div><div>Clinical mastitis is a primary contributor to physical, chemical, and bacteriological changes in milk leading to significant economic loss and welfare impairment. While mastitis in small ruminants can be rooted in varied infectious agents and physical injuries, bacterial infections stand as the predominant cause. <em>Staphylococci</em>, <em>Streptococci</em>, and <em>coliforms</em> are identified as the primary bacterial pathogens responsible for mastitis. Mastitis-causing <em>staphylococci</em> are typically categorized into <em>Staphylococcus aureus</em> and non-<em>aureus staphylococci</em> (NAS). NAS encompasses mainly coagulase-negative <em>Staphylococcus</em> species (CNS) and selects coagulase-positive and coagulase-variable <em>staphylococci</em>. NAS species exhibit variability in their epidemiology, pathogenicity, virulence, ecological niche, host adaptation, and antimicrobial resistance profiles. Their unique interactions with the udder's microbiome composition may confer protection against other mastitis pathogens. In small ruminants, treatment for NAS mastitis faces challenges such as antibiotic resistance and limited availability of veterinary drugs. Emerging treatments include bacteriophages, probiotics, immunotherapy, phytochemicals, nanotechnology, and peptides. This review will discuss the importance of NAS as a cause of mastitis in small ruminants, the virulence factors of this group, and for greater scientific reach, the species-level interactions within the microbiome and its interplay with host genetics are crucial to elucidate the role of NAS in mastitis and udder health in small ruminants.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"245 ","pages":"Article 107475"},"PeriodicalIF":1.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548029","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":"Evaluation of acute phase proteins, hormonal changes and gene expression of immunological, metabolic and reproductive markers in she camel during the transition period","authors":"Ahmed Adel El-Sayed","doi":"10.1016/j.smallrumres.2025.107467","DOIUrl":"10.1016/j.smallrumres.2025.107467","url":null,"abstract":"<div><div>To explore gene expression and serum profile of acute phase proteins (APPs) and hormones during transition period in dromedary camels, blood samples were collected from twenty apparently healthy pregnant female at−21, 0, and+ 21 days of expected date of delivery. Toll like receptor 4 (TLR4), Beta defensin 5 (BDEF5), Toll like receptor 6 (TLR6), interlukin 2 (IL2), IL6 and IL8 markers showed down-regulation at 0 day, whereas an opposite trend was noted for Estrogen receptor (ESR) and Steroidogenic acute regulatory protein (StaR). A significant up-regulation of progesterone receptor (PR) and aromatase gene was also reported at −21 and + 21, respectively. A significant up-regulation of Iodothyronine Deiodinase 3 (DIO3) genes reported at −21 followed by 0 and + 21 days; however mRNA level of Acetyl CoA Carboxylase Alpha (ACACA) elicited an opposite trend. Our findings revealed a significant (p = 0.001) high values of haptoglobin (Hp) at 0 and + 21 day while the concentration of ceruloplasmin increased significantly (P = 0.001) at −21 day. Serum amyloid A (SAA), fibrinogen, cortisol and estrogen level increased significantly (P = 0.003) at 0 day then decreased at + 21 day. Serum level of progesterone decreased significantly (P = 0.001) at the 0 day, although serum concentration of T3 and T4 increased significantly (P = 0.001) at + 21 days. Significant changes in the levels of APPs, hormones may be a biomarker that aids in female camel health monitoring during the periparturient phase in order to reduce the frequency, severity of illnesses and, as a result, to establish selection-effective management strategy by studying the animal adaptation to harsh conditions through genetic selection which is strengthened by identifying differences in the expression levels of regulatory genes. These genes could be used to create adaptable animals that can reproduce in harsh environments without suffering large losses.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"245 ","pages":"Article 107467"},"PeriodicalIF":1.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509918","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":"Analysis of the effects of climate change on rangeland livestock: The example of the Central Anatolia Region in Türkiye","authors":"Celal Cevher ,&nbsp;Gülbin Feridun ,&nbsp;Meral Ebegil ,&nbsp;Uğur Özkan ,&nbsp;Sule Coskun-Cevher","doi":"10.1016/j.smallrumres.2025.107464","DOIUrl":"10.1016/j.smallrumres.2025.107464","url":null,"abstract":"<div><div>Global climate change affects all production sectors, especially agriculture and livestock production. Adequate perception of global climate change by farmers will contribute to the timely implementation of adaptation strategies and thus to the increase of animal production. In this study, Türkiye's Central Anatolia Region, most sensitive to climate change in terms of agricultural activities and rangeland management was examined. Crop production and Rangeland-based animal husbandry are widely practiced in this selected region. This research aims to analyze the climate change perceptions of rangeland-based livestock farmers, their rangeland perceptions, and the farmers' adaptation strategies in all aspects of the effects of climate change. Data was collected through a face-to-face survey from 385 farmers using the stratified random sampling technique in four provinces in the study region. Binary logistic regression analysis and Likert rating scale were used to analyze the data. Our results showed a statistically significant relationship between farmers' perception of climate change and knowing the characteristics of the Rangeland and their adaptation strategies (p &lt; 0.05). Age, education level, presence of small livestock, different provinces, and land area were the most critical determinants of the perception of climate change. It has been determined that farmers do not perceive the long-term effects of climate change on rangeland animal husbandry sufficiently. We recommend that institutions making decisions on research and adaptation to climate change increase their publication services on the impact of climate change on animal production and rangeland. This study will contribute to creating new policies to accelerate farmers' coping with climate change, reduce the adverse effects of climate change, and increase adaptation strategies.</div></div>","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"245 ","pages":"Article 107464"},"PeriodicalIF":1.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509976","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 dietary supplementation with slow-release urea coated with carnauba wax on intake, ingestive behavior, selectivity, ruminal parameters, performance and carcass traits of lambs","authors":"Tainan da Silva Batista ,&nbsp;Leilson R. Bezerra ,&nbsp;Pedro H.S. Mazza ,&nbsp;Analivia M. Barbosa ,&nbsp;Beatriz S.C. de Castro ,&nbsp;Melissa D. Ferrer ,&nbsp;Ana Carolina Ferreira ,&nbsp;Jasiel S. de Morais ,&nbsp;Edson C. da Silva Filho ,&nbsp;Ronaldo L. Oliveira","doi":"10.1016/j.smallrumres.2025.107468","DOIUrl":"10.1016/j.smallrumres.2025.107468","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study developed slow-release urea microparticles coated by carnauba wax (SRU&lt;sub&gt;WAX&lt;/sub&gt;), and evaluated their effect on intake, ingestive behavior, selectivity, ruminal parameters, performance, and carcass traits of lambs. Firstly, a completely randomized design with three SRU formulations through fusion-emulsification was adopted. Three SRU were produced [SRU&lt;sub&gt;50:50&lt;/sub&gt;, SRU&lt;sub&gt;60:40&lt;/sub&gt; and SRU&lt;sub&gt;70:30&lt;/sub&gt; based on shell (carnauba wax) and core (urea) ratios] and characterized. SRU&lt;sub&gt;70:30&lt;/sub&gt; and SRU&lt;sub&gt;60:40&lt;/sub&gt; showed the highest yields averaging 96 and 94 %, also exhibiting the highest coating efficiencies with values close to 99 %. Among the formulations evaluated, SRU&lt;sub&gt;50:50&lt;/sub&gt; showed the highest urea retention percentage when compared to SRU&lt;sub&gt;60:40&lt;/sub&gt; and SRU&lt;sub&gt;70:30&lt;/sub&gt;. The crude protein (CP) content of SRU&lt;sub&gt;60:40&lt;/sub&gt; was 13 % higher than that of SRU&lt;sub&gt;70:30&lt;/sub&gt;. Microscopic analysis revealed similar characteristics among SRU formulations. Differential Scanning Calorimetry indicated that the melting points were similar. Therefore, the formulation 60:40 presented better traits, and it was used in the lamb’s diet. Fifty male lambs (Santa Ines × Dorper) weighting an average 31.2 ± 4.8 kg, were assigned to a completely randomized design consisting of five treatments with ten replications. The experiment included a control treatment containing 4.0 g of free urea (U&lt;sub&gt;FREE&lt;/sub&gt;), and four SRU&lt;sub&gt;WAX&lt;/sub&gt; inclusion levels: 10, 20, 30, and 40 g/kg of total dry matter (DM). SRU&lt;sub&gt;WAX&lt;/sub&gt; did not affect (P &gt; 0.05) the DM intake and its nutritional fractions. Diet selectivity estimates from the nutrients effectively consumed OM, EE, and &lt;sub&gt;a&lt;/sub&gt;NDF&lt;sub&gt;om&lt;/sub&gt; and dietary particle size were not influenced by the form of urea supply (P &gt; 0.05). However, there was a linear increase on the concentrations of TDN and NFC and a linear reduction in the concentrations of CP effectively consumed due to the inclusion of SRU&lt;sub&gt;WAX&lt;/sub&gt; (P &lt; 0.05). The form of urea supply (U&lt;sub&gt;FREE&lt;/sub&gt; × SRU&lt;sub&gt;WAX&lt;/sub&gt;) did not affect (P &gt; 0.05) the ingestive behavior, performance and carcass traits of the lambs. However, SRU&lt;sub&gt;WAX&lt;/sub&gt; addition linearly increased (P = 0.032) the number of boli chewed/day. There was interaction effect (P &lt; 0.05) between treatment and time after feeding to ruminal pH and N-NH₃. Including SRU&lt;sub&gt;WAX&lt;/sub&gt; at 40 g stabilized ruminal pH closer to neutrality compared to other treatments. U&lt;sub&gt;FREE&lt;/sub&gt; resulted in higher peak NH₃-N concentrations compared to SRU&lt;sub&gt;WAX&lt;/sub&gt;, without difference to SRU&lt;sub&gt;WAX&lt;/sub&gt; levels. SRU&lt;sub&gt;WAX&lt;/sub&gt; inclusion in the diet linearly reduced (P &lt; 0.01) the final weight, average daily gain (ADG), hot carcass weight, and feed efficiency of the lambs. Carnauba wax was confirmed as an excellent shell for urea protection, and the best proportion was 60:40 (shell: core). However, the addition of SRU&lt;sub&gt;WA","PeriodicalId":21758,"journal":{"name":"Small Ruminant Research","volume":"246 ","pages":"Article 107468"},"PeriodicalIF":1.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520674","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}