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Simple Summary: Subacute rumen acidosis (SARA) is a significant clinical issue in high-yield livestock, including dairy sheep, and it is characterized by rumen pH dropping below 5.8 for at least four hours daily. This condition leads to economic losses due to reduced milk production and lower milk fat content. High-concentrate, low-fiber diets increase the risk of SARA by disrupting rumen fermentation. Diagnosing SARA is challenging, with rumen fluid pH measurement being the gold standard. This study investigated the prevalence of SARA and its impact in forty-two Greek dairy sheep flocks, as well as the potential of computerized rumen colorimetry as a diagnostic tool post mortem. Over nine months, rumen pH and milk composition were monitored, and rumen wall samples were analyzed for color and histological changes. The results showed increased epithelium thickness and discoloration in SARA-affected sheep. This study highlights the prevalence of SARA in the modern intensive dairy sheep industry, underscores the need for balanced feeding strategies, and suggests computerized rumen colorimetry as a promising tool for SARA detection and management in dairy sheep farms. Subacute rumen acidosis (SARA) is a current issue in intensive livestock farming, and it is particularly associated with feeding high-concentrate diets. This study investigated the prevalence and impact of SARA in forty-two Greek dairy sheep flocks by recording rumen pH, milk composition, and milk yield over a period of nine months. Moreover, it explored the use of computerized rumen colorimetry as a management and diagnostic tool for SARA in dairy sheep. In culled ewes, computerized rumen mucosal colorimetry was applied, and rumen wall samples taken for histological examination. SARA cases were identified in 19 farms (45%, n = 42). Farms with SARA cases had lower milk fat levels, while milk yield and milk protein levels did not differ based on the SARA status of the farms. In culled ewes, rumen color was significantly associated with the flock's SARA status, and affected ewes showed increased thickness in non-keratinized and total epithelial layers. It was concluded that computerized rumen mucosal colorimetry in aged, culled ewes shows promise as an indicator, post mortem, of SARA present in dairy sheep flocks whose impact can be minimized by making significant changes in dietary management. [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate the phenotypic correlations between udder and teat morphology traits, milk production traits, and somatic cell score in dairy sheep from a flock in New Zealand. A total of 162 lactating ewes were scored for morphology traits during the milk production season of 2021–2022. The 130-d lactation yields of milk, fat, protein, and lactose were obtained with 2–4 test-days from each ewe and modelled using random regression with orthogonal polynomials. Age had a significant effect on all udder and teat traits. Coat-colour (genetic variety within the breed; white or black) was a significant effect for teat angle and udder separation. Udders that were above the hook were associated with lower milk, fat, protein, and lactose yields. Udders with well-defined separation between halves were associated with higher milk, protein, and lactose yields, and with lower somatic cell count. Well-attached udders were associated with lower fat yield and lower somatic cell score. Teats with a backwards angle were associated with lower milk and lactose yields. Further studies are needed to estimate heritability and genetic correlations between these traits to determine whether these traits should be implemented in breeding programs for dairy sheep in New Zealand. [ABSTRACT FROM AUTHOR]

The stems of Cynomorium songaricum are used in traditional Chinese medicine as a tonic and also used locally as a food material and livestock feed. It is known that some of the falvan‐3‐ol monomers and dimers that entered the milk of dairy sheep fed with C. songaricum stems are biotransformation products of the original flavan‐3‐ol polymers in C. songaricum stems. This study was performed to investigate the biotransformation process of the flavan‐3‐ols in dairy sheep and to evaluate the bioactivities. The results showed that procyanidin A2 and epicatechin could be released from the polymeric flavan‐3‐ols of C. songaricum through rumen microbial metabolism. On traumatic and lipopolysaccharide (LPS)‐induced inflammation models of Tg (mpx: EGFP) zebrafish larvae and LPS‐induced liver injury models of Tg (fabp10a: DsRed) zebrafish larvae, the milk from sheep fed with C. songaricum stems showed stronger anti‐inflammatory and hepatoprotective activities compared to blank milk. The absorbed chemical constituents of C. songaricum stems and the metabolites also exhibited anti‐inflammatory and hepatoprotective activities, with the dimeric flavan‐3‐ols being more effective than the monomers. The milk, the absorbed chemical constituents of C. songaricum stems, and the metabolites alleviated the increased level of reactive oxygen species induced by LPS in zebrafish larvae. Practical Application: This study found that C. songaricum stems as livestock feed could produce milk that has a beneficial impact on consumer and livestock health in terms of anti‐inflammation and hepatoprotection. [ABSTRACT FROM AUTHOR]

Simple Summary: Sheep farmers face increasing pressure to produce more in order to meet market demands, while consumers have more interest in animal welfare status and the environment. The aim of this paper was to categorize the on-farm welfare risks using the ClassyFarm protocol and to identify if welfare risk changed according to farm size. The critical issues we found were the low number of stockpersons, the small areas available for the animals, the lack of udder cleaning procedures during milking, and the lack of prevention plans for the most important infectious ovine diseases. As the number of animals within the farm increased, the management of the flock improved; on the other hand, the number of animal inspections decreased and the hygiene of the water worsened. The objective of the present work was to categorize the risks in the on-farm welfare of dairy sheep in semi-extensive systems in order to highlight if risks in welfare vary according to the farm size. To the best of our knowledge, this study constitutes one of the few categorizations of the risks in the welfare of dairy sheep reared semi-extensively. The survey was conducted on 12 semi-extensive dairy sheep farms in Tuscany (Central Italy), which were classified according to flock size: <500, from 500 to 1000, and >1000. The results showed an adequate rating for all the farms included in the study. The most critical issues concerned the ratio between the number of stockpersons and the number of animals within the farms, the small decubitus areas, the lack of udder cleaning procedures during milking operations, and, in terms of biosecurity, the lack of prevention, control, and eradication plans for the most important infectious ovine diseases. The results show that different items in the five areas evaluated, including the assessments of management of the flock, the number of daily inspections, and the hygiene of the water supplies are associated with the farm size. In large farms, the assessment of management of the flock was better, but the number of daily inspections and the hygiene of the water supplies were worse. [ABSTRACT FROM AUTHOR]

Genetic selection for higher productivity increased dairy sheep susceptibility to diseases and environmental stressors, challenging their health and welfare status and production efficiency. Improving resilience to such stressors can enhance their ability to face these challenges without compromising productivity. Our objective was to estimate genomic heritability and perform genome-wide association studies (GWAS) to detect SNPs and candidate genes associated with three proxy traits for resilience (milk somatic cell count—SCC, lactation persistency—LP, body condition score—BCS) of Chios and Frizarta dairy ewes. We used genome-wide genotypes of 317 Chios and 346 Frizarta ewes. Individual records of milk yield and BCS, and milk samples were collected monthly for two consecutive milking periods; samples were analyzed to determine SCC. The LP was calculated as the regression coefficient of daily milk yield on days from lambing. Within breed, variance components analyses and GWAS were performed using genomic relatedness matrices in single-trait animal linear mixed models. Genomic-based heritability estimates were relatively high (BCS: h2 = 0.54 and 0.55, SCC: h2 = 0.25 and 0.38, LP: h2 = 0.43 and 0.45, for Chios and Frizarta ewes, respectively), compared to previous pedigree-based studies. The GWAS revealed 7 novel SNPs associated with the studied traits; one genome-wide and two suggestive significant SNPs for SCC (Frizarta: rs403061409, rs424064526 and rs428540973, on chromosomes 9, 1 and 12, respectively), one suggestive significant SNP for BCS (Chios: rs424834097 on chromosome 4) and three suggestive significant SNPs for LP (Frizarta: rs193632931 and rs412648955 on chromosomes 1 and 6, Chios: rs428128299 on chromosome 3). Nineteen candidate genes were detected: two for BCS (Chios: POT1, TMEM229A), thirteen for SCC (Frizarta: NTAQ1, ZHX1, ZHX2, LOC101109545, HAS2, DERL1, FAM83A, ATAD2, RBP7, FSTL1, CD80, HCLS1, GSK3B) and four for LP (Frizarta: GRID2, FAIM, CEP70—Chios: GRIP1). Present results show that resilience in the studied dairy sheep breeds is heritable and advance existing knowledge on the genomic background of SCC, LP, and BCS. Future research will quantify effects of different alleles of significant SNPs on the studied traits and search for possible correlations among traits to facilitate their effective incorporation in breeding programs aiming to improve resilience. [ABSTRACT FROM AUTHOR]

In sheep farming, gastrointestinal parasites can be responsible for significant reductions in animal health and production. Nitrogen (N) and phosphorus (P) fecal excretions are the main determining factors for N2O emissions from manure management and may pose other environmental problems, such as the acidification and eutrophication of natural habitats. By using the Mini-FLOTAC technique on fecal samples from sheep of different ages and physiological status from 19 dairy sheep farms in Tuscany (central Italy), gastrointestinal parasite infections were evaluated. The animal N and P fecal contents were also assessed, with the aim of evaluating possible relationships between the identified parasites and the environmental sustainability of the examined farms. The obtained results showed that Eimeria spp. (86.36%) and gastrointestinal strongyle (54.55%) infections are prevalent in the examined farms. Moreover, significantly higher (p ≤ 0.05) P and Eimeria oocyst/gram-of-feces (OPG) values were found in fecal samples from animals < 1 year of age, and a significant (p ≤ 0.05) positive correlation resulted between N content and Eimeria OPG in fecal samples from animals in the first month of lactation. The findings from this study suggest for the first time that Eimeria spp. infections may have an impact on the environmental sustainability of sheep farming. [ABSTRACT FROM AUTHOR]

Copyright of Informacion Tecnica Economica Agraria is the property of Asociacion Interprofesional para el Desarrollo Agrario (AIDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Streptococcus (S.) species are important pathogens that cause mastitis in sheep. The study aimed to examine Streptococcus species in sheep milk with subclinical mastitis, assessing their prevalence, antimicrobial resistance, and virulence genes. A total of 200 milk samples were collected from sheep farms in İzmir's five districts. Out of 32 (28.6%) Streptococcus isolates identified by phenotypic methods, 25 were genotypically identified as S. uberis, 5 as S. agalactiae, and 2 as S. dysgalactiae. Disk diffusion was used to determine the antimicrobial resistance of the isolates. PCR was employed to identify antimicrobial resistance and virulence genes in the isolates. The highest resistance was found for cloxacillin (100%), and the highest sensitivity was found for florfenicol (84%). The most common resistance gene combination was tetM+tetS (3/32) for S. uberis in 9.4%. A total of five virulence genes were detected. GapC+sua (56.2%) constituted the most common gene pattern. The highest virulence gene gapC was detected in 78.1% (25/32) of the isolates. The cylE gene was not detected (0%) in the isolates. Streptococcus species may play a role in mastitis in sheep, emphasising the need for meticulous hygienic milking practices. [ABSTRACT FROM AUTHOR]

Brewer's spent yeast (BSY) is a byproduct of the beer industry, rich in proteins and bioactive compounds. The effects of BSY were investigated through a 6-week feeding trial on 30 lactating dairy Blackhead sheep (54.7 ± 5.66 kg, 177.34 days in milk) distributed under a completely randomised design in two groups: a control group (with soybean meal and sunflower meal as protein sources), and a BSY group, where soybean meal was totally replaced by BSY (5.4% inclusion, DM basis). The inclusion of BSY led to a 25% decrease in ruminal propionate and in the acetate/propionate ratio. BSY influenced the milk fatty acid profile by significantly decreasing the omega 6: omega 3 ratio and increasing the contents of caproic, capric, and lauric acids. Also, the inclusion of BSY was associated with an increase in the milk's total polyphenols. Consistently, determinations of the parameters of the milk fat's oxidative stability revealed a decrease in conjugated diene contents. Moreover, the mineral contents of milk were influenced, with an increase in Ca content noted. Overall, these results indicate that BSY represents an alternative feedstuff for ruminants' nutrition, which could have the potential to induce changes in ruminal fermentation and milk composition that are beneficial for consumers. [ABSTRACT FROM AUTHOR]

Simple Summary: In our research, candidate genes related to sheep-milk production were revealed by a genome-resequencing analysis and a genome-signal-selection analysis, and a RT-qPCR experiment was performed to prove the expression levels of these candidate genes, the results showed that the FCGR3A gene's expression level had a significant negative relationship with sheep-milk production. Natural selection and domestication have shaped modern sheep populations into a vast range of phenotypically diverse breeds. Among these breeds, dairy sheep have a smaller population than meat sheep and wool sheep, and less research is performed on them, but the lactation mechanism in dairy sheep is critically important for improving animal-production methods. In this study, whole-genome sequences were generated from 10 sheep breeds, including 57 high-milk-yield sheep and 44 low-milk-yield sheep, to investigate the genetic signatures of milk production in dairy sheep, and 59,864,820 valid SNPs (Single Nucleotide Polymorphisms) were kept after quality control to perform population-genetic-structure analyses, gene-detection analyses, and gene-function-validation analyses. For the population-genetic-structure analyses, we carried out PCA (Principal Component Analysis), as well as neighbor-joining tree and structure analyses to classify different sheep populations. The sheep used in our study were well distributed in ten groups, with the high-milk-yield-group populations close to each other and the low-milk-yield-group populations showing similar classifications. To perform an exact signal-selection analysis, we used three different methods to find SNPs to perform gene-annotation analyses within the 995 common regions derived from the fixation index (FST), nucleotide diversity (Ɵπ), and heterozygosity rate (ZHp) results. In total, we found 553 genes that were located in these regions. These genes mainly participate in the protein-binding pathway and the nucleoplasm-interaction pathway, as revealed by the GO- and KEGG-function-enrichment analyses. After the gene selection and function analyses, we found that FCGR3A, CTSK, CTSS, ARNT, GHR, SLC29A4, ROR1, and TNRC18 were potentially related to sheep-milk-production traits. We chose the strongly selected genes, FCGR3A, CTSK, CTSS, and ARNT during the signal-selection analysis to perform a RT-qPCR (Reale time Quantitative Polymerase Chain Reaction) experiment to validate their expression-level relationship with milk production, and the results showed that FCGR3A has a significant negative relationship with sheep-milk production, while other three genes did not show any positive or negative relations. In this study, it was discovered and proven that the candidate gene FCGR3A potentially contributes to the milk production of dairy sheep and a basis was laid for the further study of the genetic mechanism underlying the strong milk-production traits of sheep. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The continuous increase in the cost of feeds and the need to improve the sustainability of animal production require the identification of alternative feeds, such as those derived from the agro-industrial sector, that can be effectively used for animal nutrition. Since these by-products (BP) are sources of bioactive substances, especially polyphenols, they may play an important role as a new resource for improving the nutritional value of animal-derived products, being effective in the modulation of the biohydrogenation process in the rumen, and, hence, in the composition of milk fatty acids (FA). The main objective of this work was to evaluate if the inclusion of BP in the diets of dairy ruminants, as a partial replacement of concentrates, could improve the nutritional quality of dairy products without having negative effects on animal production traits. To meet this goal, we summarized the effects of widespread agro-industrial by-products such as grape pomace or grape marc, pomegranate, olive cake, and tomato pomace on milk production, milk composition, and FA profile in dairy cows, sheep, and goats. The results evidenced that substitution of part of the ratio ingredients, mainly concentrates, in general, does not affect milk production and its main components, but at the highest tested doses, it can depress the yield within the range of 10–12%. However, the general positive effect on milk FA profile was evident by using almost all BP at different tested doses. The inclusion of these BP in the ration, from 5% up to 40% of dry matter (DM), did not depress milk yield, fat, or protein production, demonstrating positive features in terms of both economic and environmental sustainability and the reduction of human–animal competition for food. The general improvement of the nutritional quality of milk fat related to the inclusion of these BP in dairy ruminant diets is an important advantage for the commercial promotion of dairy products resulting from the recycling of agro-industrial by-products. [ABSTRACT FROM AUTHOR]

Simple Summary: The New Zealand dairy sheep industry is relatively new, and more studies are needed to support New Zealand dairy sheep farms for more efficient production. The objective of the present study was to model the lactation curves of dairy sheep from a New Zealand commercial flock, providing information on the lactation yields of milk, fat, protein, and lactose. The factors affecting the lactation yields and lactation persistency of dairy sheep were described. The low production per ewe and the large variation between animals reported in the present study indicate that there is room for improvement in lactation yields and in lactation persistency in dairy sheep in New Zealand, and this could be achieved through the improvement of farming systems and through the building of a national genetic improvement programme targeted at dairy sheep. Lactation curves were modelled for dairy sheep in a New Zealand flock, providing information on the lactation yields of milk, fat, protein, and lactose, corrected for 130 days of milking. From 169 ewes, a total of 622 test-day records were obtained during the milk production season of 2021–2022 (from October to January). The flock produced an average of 86.1 kg of milk, 5.1 kg of fat, 4.5 kg of protein, and 4.1 kg of lactose, and moderate to large coefficients of variation were observed (27–31%) for these traits. The lactation persistency of milk, fat, protein, and lactose yields ranged from 52.3 to 72.7%. Analyses of variance for total yield and persistency were performed with an animal model that included the fixed effects of age (parity number), litter size, coat colour, and milking frequency (days in twice-a-day milking) and random residuals. Age and milking frequency were the only factors that significantly affected the yields of milk, fat, protein, and lactose. Age significantly affected the lactation persistency of milk and lactose yields, whereas litter size affected the persistency of protein, and milking frequency affected the persistency of fat. This study on this single flock provides valuable experience for a larger-scale animal breeding programme in New Zealand. [ABSTRACT FROM AUTHOR]

Simple Summary: During the peri-parturient period, the development of the fetus and the production of the colostrum and milk lead to increased requirements of energy and minerals, which, in turn, predispose ruminants to the risk of metabolic diseases, such as hypocalcemia. Feed additives could provoke or prevent hypocalcemia. The aim of the study was to investigate the effect of sugar beet pulp administration during the dry period, alone or together with anionic salts, on the serum concentrations of calcium, magnesium, phosphate, and potassium, during the peri-parturient period of Chios dairy sheep. The results revealed a benefi cial effect of sugar beet pulp and anionic salts administration during the dry period in preventing peri-parturient hypocalcemia. Sugar beet pulp is a popular by-product of sugar extraction; however, it can potentially cause depletion of Ca availability due to its oxalic content. The experiment examined the effect of sugar beet pulp and anionic salts administration during the dry period on the serum concentration of calcium, magnesium, phosphate, and potassium of dairy sheep. Eighty-seven sheep were divided into three groups (A, B, and C) according to their body condition score (BCS) and age at 40 days before the expected lambing. All groups received alfalfa hay, mixed grass straw, and a concentrate supplement. The concentrate fed to groups B and C contained sugar beet pulp. The nutritional value fed to all three groups was similar, except for Dietary Cation Anion Difference (DCAD). Animals of group A had a DCAD of +198 mEq/kg, animals of group B of +188 mEq/kg, and animals of group C were fed 20 gr/d ammonium chloride to achieve a negative DCAD (−52 mEq/kg). All groups were fed the same ration after lambing. Blood samples were collected 30 d, 20 d, 17 d, 14 d, 10 d, 7 d, and 4 d before lambing (a.p.), 6 h, 12 h, 24 h, 7 d, 10 d, and 15 d after lambing (p.p) for calcium, magnesium, phosphate, and potassium, and 30 d a.p., 7 d, and 15 d p.p. for beta hydroxybutyrate acid (BHBA) concentrations. Urine samples were also collected 20 d, 10 d, 4 d a.p., and 7 d p.p for the evaluation of pH levels. Ca levels of the control group decreased earlier and were lower at 4 d a.p. compared to those of group B and C. Additionally, the control group showed lower p values compared to group C at 20 d and 17 d a.p. P levels recovered earlier post parturition in young (age 1–1.5 years old) compared to older ewes. Group C had lower urine pH values throughout the pre-parturient period, reflecting the acidifying effect of the administered ammonium chloride, without any side effect on macromineral blood concentration. Feeding sugar beet pulp and systemic acidifying before parturition is considered safe and might even be beneficial in preventing hypocalcemia. [ABSTRACT FROM AUTHOR]

Simple Summary: Contagious agalactia (CA), caused by Mycoplasma agalactiae (M. agalactiae), is a very important disease in dairy sheep. It is distributed worldwide, and causes a marked drop or even complete loss of milk production, arthritis, keratoconjunctivitis, pneumonia, and septicemia. The current study represents the first investigation evaluating the synergistic effect of combining Staphylococcus aureus (S. aureus) within the M. agalactiae vaccine. Apart from the previously known benefits of combined vaccines, such as reduced production costs, time and effort saving, simplifying the immunization schedule, and minimizing the stress of multiple vaccinations, the current study recorded for the first time that the involvement of S. aureus in inactivated vaccines against M. agalactiae elicited a higher antibody response against M. agalactiae, detected by ELISA, than the monovalent M. agalactiae vaccine. The humoral immune response and hematological parameters were significantly improved and manifested by the increased antibody titre, total leukocytic count, neutrophils, and blood platelets. Moreover, the local glandular immunity of the udder, assessed by the somatic cell count (SCC), was enhanced. In Italy, dairy sheep farming represents a vital agro-industry sector, but it is still challenged by contagious agalactia (CA), which is endemic there, and vaccination is the most economical and sustainable tool for control. This study aimed to evaluate the combined Mycoplasma agalactiae (Ma)-Staphylococcus aureus (Sa) vaccine (Ma–Sa) against the Ma monovalent vaccine in ewes. Twelve primiparous Ma-free ewes were randomly grouped into three equal groups: first, the control group injected with placebo, second, the group vaccinated with the Ma monovalent vaccine, and third, the group vaccinated with Ma–Sa combined vaccine, with two S/C doses at 45-day intervals. The animals were examined for serological, hematological, and somatic cell count (SCC) changes for 17 successive weeks. A significant increase in anti-Ma antibody mean titers, leukocytes, and platelets was observed in the vaccinated animals, with the highest values in those who received the combined vaccine. Neutrophils were high only in the animals who received the combined vaccine. SCC was lower in the vaccinated animals during the first six weeks. This study concludes that the combined Ma–Sa vaccines enhance immune response and potentiate its efficacy against Ma. This improvement might be attributed to the sensitization/activation effect of S. aureus on platelets, which are recoded to act as a key regulator for the coordination of all components of the innate immune system. Even though this study included a small number of animals, its findings about the potentialities of this inactivated vaccine in the control of CA are strongly encouraging. Further confirmation might be needed through additional replicates and a challenge study is needed before proceeding with widespread use. [ABSTRACT FROM AUTHOR]

The characterization of miRNAs from sheep milk and their effect on milk yield and composition in sheep are remain unclear. Therefore, the aim of this study was to determine the expression pattern of several important miRNAs, which are associated with lactation in the sheep milk between high and low lactating-yield ewe groups. In addition to experimentally obtained miRNA expression results, the miRNA target genes were determined by bioinformatics analysis to identify biological pathways involved. miRNAs found to differ significantly in the expression level between the groups were oar-miR-181a, oar-miR-23a, oar-miR-27a, oar-miR-16b and oar-miR-374. Also, oar-miR-27a was shown negative correlation with milk protein and lactose contents while oar-miR-16b was shown negative correlation with milk yield in the high milk yield group. The highest connected hub genes for miR-27a target genes were determined as MAPK14 and PPARG. Also, six genes (HSPA4L, DNAJA2, ATP6V1B2, PPP2R1A, PPP2R1B, and PRKAR2A) were detected as hub genes for miR-16b. In this study, the relationship between expression profiles of several important miRNAs in sheep milk and milk yield and milk composition were investigated for the first time in high and low lactating yield groups. [ABSTRACT FROM AUTHOR]

• Feed efficiency (FE) biomarkers were identified in the milk transcriptome of ewes. • We evaluate the effects of using different FE indices over the milk transcriptome. • Gene expression shows potential for predicting sheep FE with machine learning. • The impact of sustainability strategies on the sheep dairy industry was assessed. • Prepubertal protein restriction lacks impact on FE in Assaf ewes at first lactation. In recent years, rising prices for high-quality protein-based feeds have significantly increased nutrition costs. Consequently, investigating strategies to reduce these expenses and improve feed efficiency (FE) have become increasingly important for the dairy sheep industry. This research investigates the impact of nutritional protein restriction (NPR) during prepuberty and FE on the milk transcriptome of dairy Assaf ewes (sampled during the first lactation). To this end, we first compared transcriptomic differences between NPR and control ewes. Subsequently, we evaluated gene expression differences between ewes with divergent FE, using feed conversion ratio (FCR), residual feed intake (RFI), and consensus classifications of high− and low-FE animals for both indices. Lastly, we assess milk gene expression as a predictor of FE phenotype using random forest. No effect was found for the prepubertal NPR on milk performance or FE. Moreover, at the milk transcriptome level, only one gene, HBB , was differentially expressed between the NPR (n = 14) and the control group (n = 14). Further, the transcriptomic analysis between divergent FE sheep revealed 114 differentially expressed genes (DEGs) for RFI index (high-FE RFI = 10 vs low-FE RFI = 10), 244 for FCR (high-FE FCR = 10 vs low-FE FCR = 10), and 1 016 DEGs between divergent consensus ewes for both indices (high-FE consensus = 8 vs low-FE consensus = 8). These results underscore the critical role of selected FE indices for RNA-Seq analyses, revealing that consensus divergent animals for both indices maximise differences in transcriptomic responses. Genes overexpressed in high-FE consensus ewes were associated with milk production and mammary gland development, while low-FE consensus genes were linked to higher metabolic expenditure for tissue organisation and repair. The best prediction accuracy for FE phenotype using random forest was obtained for a set of 44 genes consistently differentially expressed across lactations, with Spearman correlations of 0.37 and 0.22 for FCR and RFI, respectively. These findings provide insights into potential sustainability strategies for dairy sheep, highlighting the utility of transcriptomic markers as FE proxies. [ABSTRACT FROM AUTHOR]

• Effect of data truncation in genetic evaluations of selection candidates is studied. • Removing old data reduces prediction bias, without compromising prediction accuracy. • Genomic evaluations were outstanding, compared with traditional evaluations. • Depth of pedigree had a small influence in the prediction ability of selection candidates. • Data truncation is a useful procedure to be implemented in breeding programmes. Along the last decades, the genetic evaluation methodology has evolved, improving breeding value estimates. Many breeding programmes have historical phenotypic records and large number of generations, but to make use of them could result in more inconveniences than benefits. In this study, the prediction ability of genotyped young animals was assessed by simultaneously evaluating the removal of historical data, two pedigree deepness and two methodologies (traditional BLUP and single−step genomic BLUP or ssGBLUP), using milk yield records of 40 years of three Latxa dairy sheep populations. The linear regression method was used to compare predictions of young rams before and after progeny testing, with six cut-off points, by intervals of 4 years (from 1992 to 2012), and statistics of ratio of accuracies, bias, and dispersion were calculated. The prediction accuracy of selection candidates, when genomic information was included, was the highest in all Latxa populations (between 0.54 and 0.69 with full data set). Nevertheless, the deletion of historical phenotypic data resulted on moderate accuracy gain in the bigger data size populations (mean gain 2.5%), and the smaller population took advantage of a moderate data deletion (2.7% gain by removing data until 2004), reducing accuracy when more records were removed. The bias of validation individuals was lower when the breeding value was predicted based on genomic information (between 2.1 and 13.9), being lower when the biggest amount of data was deleted in the bigger data size populations (5.2% reduction), and the smaller population was benefited from data deletion between 1996 and 2008 (3.8% bias reduction). Meanwhile, the slope of estimated genetic trend was lower when less data were included, and an overestimation of the unknown parent group estimates was observed. The results indicated that ssGBLUP evaluations were outstanding, compared with traditional BLUP evaluations, while the depth of pedigree had a very small influence, and deletion of historical phenotypic data was beneficial. Thus, Latxa routine genetic evaluations would benefit from truncating phenotypic records between 2000 and 2004, the use of two pedigree generations and the implementation of ssGBLUP methodology. [ABSTRACT FROM AUTHOR]

Simple Summary: Artificial insemination (AI) is a powerful tool for animals' genetic improvement. However, its application in sheep remains relatively limited due to inconsistent results, since the success of the method is dependent on many factors. In our study, we investigated the impact of housing conditions during the summer period on the fertility of dairy sheep in Greece, after cervical AI with cooled semen. The pregnancy rate was found to be negatively affected by the ambient temperature and Temperature-Humidity Index inside the shed, space availability, frequency of bedding renewal, and outdoor access. Appropriate housing conditions could help to increase pregnancy rates following AI during the summer months. The objective was to assess the effect of housing conditions during the summer months on the success rates of cervical artificial insemination (AI) with cooled semen, in intensively reared dairy ewes in Greece. The study involved 2083 Lacaune ewes from 23 flocks that were serviced during May to September. An estrous synchronization protocol with the insertion of progestogen sponges for 14 days and eCG administration at sponge removal, was used. All ewes were inseminated 54–57 h after sponge removal with cooled semen (15 °C) from 10 Lacaune rams. Pregnancy diagnosis was performed via trans-dermal ultrasonography at 35–40 days after AI. Data recording started the day after sponge placement (15 days prior to AI), and lasted up to 14 days after AI. Daily records included temperature, relative humidity, and Temperature-Humidity Index (THI) inside the shed. Available space and volume per animal, frequency of bedding renewal, access to a yard, and indoor light were also recorded in each farm. Binary logistic regression of data records showed that temperature and THI increases at days −15 to +4 around AI (day 0) had a negative effect on pregnancy rates (reducing the likelihood of pregnancy by 3–6% and 7%, respectively). The latter also decreased significantly (p < 0.05) in farms with high stocking density, non-frequent bedding renewal, and outdoor access by ewes (by 30%, 34%, and 44%, respectively). Overall, the results indicate that appropriate housing conditions are warranted to increase the success of AI in dairy ewes during the summer months. [ABSTRACT FROM AUTHOR]

Simple Summary: Studies on the management factors that affect milk components at the farm level are important for understanding how to transfer the results from experimental study. Plant phenological stages and partially fresh herbage intakes affect the lactose and milk fatty acid profile. The botanical composition of the grassland partially affects the milk's phenol content. A few small relationships between plant phenols and milk colour could be of interest to explain the changes in milk colour parameters. The fatty acid profile, vitamins A and E, cholesterol, antioxidant power colour and the phenols profile of Sarda sheep milk from 11 commercial sheep flocks managed under permanent grassland were investigated. In each farm, the structural and managerial data and milk samples were collected during four periods (sampling dates, SD): January, March, May, and July. Data from the milk composition (fat, protein, casein, lactose, and somatic cell count), 68 fatty acids, 7 phenols, 1 total gallocatechin equivalent, ferric reducing antioxidant power, vitamins A and E, cholesterol, degree of antioxidant protection, and the colour (b *, a * and L *) were analyzed by multivariate factorial analysis using a principal component analysis approach. A proc mixed model for repeated measurement to point out the studied factors affecting significant macro and micro milk composition was also used. Only the first five components were detailed in this paper, with approximately 70% of the explained variance detected. PC1 presented the highest positive loadings for milk lactose, de novo FA synthesis and the BH intermediate, whereas OBCFA had negative loadings values. The PC2, LCFA, UFA, MUFA, vitamins E, and DAP showed positive loadings values, while SFA had a negative value. The PC3 showed a high positive loading for total phenols and non-flavonoids. PC4 presented a high positive loading for the milk macro-composition and negative values for n-3 FAs. The PC5 is characterized by high positive loadings for the a * and L * colour parameters whereas negative loadings were detected for the milk flavonoids content. These preliminary results could help to establish future threshold values for the biomarkers in milk sourced from grazing dairy sheep in natural, permanent pasture-based diets. [ABSTRACT FROM AUTHOR]

The milk yield and lactation persistency of 85 F4 crosses between Pleven blackhead sheep and the Assaf sheep breed were studied based on the performance of 932 controls. It was ascertained that under the conditions of intense production system- a year-round barn breeding and standardized, good quality feeding, the average 180-day-period daily milk yield upon first lactation was 1.584±0.028 kg, and for a 300-day period it was 1.500±0.027 kg. Up to 180th lactation day, the percentage of ewes milked was 82,4, and up to day 300 – 55.3%. No reliable differences in the milk yield (P > 0.05) were ascertained upon lambing during 4 periods- March, July, August and September which serves to prove that the cross-breeds may be successfully used for a yearround milk production. The lactation persistency was reliably influenced (P < 0.001) by the month of lambing. The lactation peak was reached at the end of the first month post lambing (2.024 kg/d), the milk yield was retained until the end of the second month (97.6% of the maximum) and after that it gradually decreased reaching 63.2% on day 120 and 51.9% of the maximum on day 180. The most stable lactation is reported for the sheep which lambed in the spring- it started at the lowest level of 1.541 kg/d (on day 15 after lambing), reached the peak of 2.112 kg/d at the end of the second month and as of the latter period until the 120th lactation day, it remained higher when compared with that of the other groups. The sheep which lambed in July exhibited the highest dynamics – their lactation started at the highest level (2.442 kg/d), reached its maximum (2.563 kg/d) but until the middle of the second month, the milk yield sharply decreased (1.734 kg/d) and after that it maintained the level of the other groups. The sheep which lambed in August and September had milk yield of respectively 1.723 kg/d and 1.910 kg/d during the first control, the peak was registered at the third control (45th day) and was respectively 2.126 kg/d and 2.110 kg/d for the two months. [ABSTRACT FROM AUTHOR]

Simple Summary: Sheep meat in Greece is considered a by-product of dairy production, associated with undefined quality and low revenues. Production is based on slaughtering of young lambs and consists of light carcasses. Heavy carcasses are scarce and mainly derived from rams and ewes that are no longer appropriate for dairy farming due to age, health or productivity issues; no dietary treatments or fattening protocols are implemented prior to slaughter. Improving production sustainability implies more efficient use of available resources, including local fat-tailed sheep that are reared in high numbers for their milk, although their carcasses are undervalued; supportive research data are scarce. Hence, we used objective methods to assess the quality of carcasses of fat-tailed sheep slaughtered at different live weights (representing five developmental stages, from young lambs to adult sheep) and to compare them with carcasses of thin-tailed sheep, which are considered superior. We found that quality of fat-tailed sheep carcasses was equal or higher compared to thin-tailed. Differences between sexes and developmental stages existed. Slaughtering of fat-tailed sheep at higher live weights (50–70% of the average adult sheep weight) will benefit production quality and quantity, improving profitability and sustainability of the sector. Sheep farming in Greece is focused on milk production. Meat is considered a by-product and consists mainly light carcasses of undefined quality. The main challenge of the sector is to ensure sustainability, and hence efforts are towards efficient use of available resources, including undervalued carcasses of local fat-tailed sheep. The objective here was twofold: (i) to assess the carcass quality of fat-tailed sheep slaughtered at different live weights and (ii) to compare them with carcasses from thin-tailed sheep. In total, 146 fat-tailed and 97 thin-tailed dairy sheep were used. They belonged to five live-weight categories (LWC), representing 25%, 35%, 50%, 70% and 100% of mature body weight. Carcass length/weight/yield/pH and wither height were recorded. Muscle fiber minimum Feret's diameter and meat color/tenderness/moisture/lipid and protein content were determined. Sex and LWC differences in fat-tailed sheep were assessed. Parametric and non-parametric tests were used to compare with thin-tailed sheep, considering the effects of LWC, sex and their interactions with sheep population (fat-tailed/thin-tailed). Most traits were significantly different (p < 0.05) between groups of fat-tailed sheep. Carcass yield of fat-tailed sheep was significantly higher compared to thin-tailed (p < 0.01). Interactions of sheep population with LWC or sex affected wither height, carcass pH, meat color and tenderness (p < 0.05). Fat-tailed sheep meat quality is equal or higher compared to thin-tailed. Finishing weights corresponding to 50 and 70% LWC may improve capitalization of fat-tailed carcasses. [ABSTRACT FROM AUTHOR]

Simple Summary: Livestock farming faces the necessity of reducing the use of medicines, particularly antimicrobials, without compromising animal welfare as one main challenge. A strategy to improve animal health, specifically in breeding stock, relies on improved nutrition of the mothers during late pregnancy and on management factors during early life. These could affect mother and offspring physiological functions (calostrogenesis, fetal development or maturation of lamb's immune system) and potentially modulate their stress-response capabilities. We studied the effect of pre-partum omega-3 (n-3) polyunsaturated fatty acids supplementation on ewe colostrum composition and immunological quality and whether changes resulted in any advantage on lambs' passive immunization and on their physiological, behavioral, and inflammatory responses when subjected to a post-weaning stressor to confer stress resilience. Gestational supplementation with nutrients rich in essential fatty acids was effective to enhance colostrum quality related to biologically active molecules, such as conjugated linoleic acid, which plays a role in the regulation of the immune response. Stress resilience was studied by assessing lamb's behavioral response after exposing lambs to a combination of stressors and by measuring plasma cortisol concentrations and immunological responses to specific circulating cytokines. This work highlights the complex relationship between late pregnancy nutrition in the mothers and immune system development in the offspring and explores the potential for programming nutrition interventions to develop more resilient livestock and to tackle the need for a reduction in the use of antibiotics. We studied the effect of pre-natal supplementation with n-3 α-linolenic acid (ALA) combined with a tannin-rich forage on colostrum composition and immunological quality and whether these changes had advantageous effects on lambs' survival and stress reaction to a post-weaning stressor. Forty-eight Latxa ewes were fed during the last five weeks of pregnancy with two experimental diets: a control diet based on a neutral concentrate and forage (tall fescue hay; CO-FES), and a supplemented diet based on polyunsaturated (PUFA)-rich concentrate and tanniferous forage (sainfoin; ALA-SAIN). After parturition, twenty ewes had their blood and colostrum sampled, and their lambs were monitored until post-weaning. Lambs were afterwards subjected to (i) an aversive handling period (AHP) followed by a behavioral assessment and (ii) inflammatory and lymphocyte proliferation challenge. Feeding ALA-SAIN resulted in changes in colostrum fatty acid composition, specifically higher α-linoleic acid (p < 0.001), conjugate linoleic acid (p = 0.005), vaccenic acid (p = 0.006) and long-chain n-3 PUFA (p = 0.004). Pre-partum nutrition did not affect lamb immunoglobulin (Ig) G apparent efficacy absorption, but circulating IgG tended to be higher (p = 0.054) in ALA-SAIN lambs. ALA-SAIN lambs interacted more frequently with other lambs (p = 0.002), whereas ALA-SAIN females spent more time closer to other lambs (p < 0.001). Plasma cortisol was higher (p = 0.047) and plasma interleukin (IL)-2 lower (p = 0.003) in CO-FES lambs. This research highlights the importance of prenatal nutrition on the immune system stimulation and lambs' behavior as a strategy to improve lambs' health and welfare during early life. [ABSTRACT FROM AUTHOR]

The main factors determining the composition of the milk are the breed, the stage of lactation and the applied feeding system. The aim of the present study was to trace the influence of the protein source in the ration of sheep on the quantity and composition of milk. All animals participating in the experiment received corn silage and alfalfa hay ad libitum, so that in the morning there were 5 to 10% edible residues. In addition, a standardized amount of barley and wheat is included in the ration of all animals. The difference in nutrition consists in the fact that the animals of the different groups received a different protein source, which made it possible to form one control group and four experimental groups, in which the influence of nonprotein nitrogenous compounds (urea), sunflower meal, soybean meal and silage beer mash. The difference in milk productivity between the group of ewes fed soybean meal (1,653 l) and that fed a ration with urea included (1,545 l) was only 7%. The average daily milk yield was 21.63% higher in the group fed with soybean meal (1.653 l), compared to the group receiving beer mash (1.359 l). The average milk yield when feeding sheep with Urea supplement (1%) is reliably higher by 13.70% than that fed with beer mash. Protein in milk, total milk protein and milk fat were significantly higher in rations based on soybean meal (6.150%, 82.22 g and 101.6 g, respectively), compared to rations based on beer mash, sunflower meal and the addition of Urea. The lowest yield of milk fat and milk protein was observed in the group fed the sunflower meal based ration, 61.43g and 56.52g, respectively. The highest consumption of forage to produce 1 l of milk observed when feeding rations based on sunflower meal (2.44 kg/l milk), and the lowest - when feeding rations based on soybean meal (1.78 kg/l milk), which is 27% lower. The CP consumption per liter of milk is 36.2% higher (415.93 g) when feeding sunflower meal than when feeding soy meal (305.41 g). [ABSTRACT FROM AUTHOR]

Bacteria are the most abundant microorganisms in the rumen microbiota and play essential roles, mainly fermenting plant compounds that yield fatty acids. In this study, we aimed at assessing stability of both bacterial composition and of its associations with rumen and milk fatty acids phenotypes over a 1-week period. The study was performed using 118 Lacaune dairy ewes from the INRAE Experimental Unit of La Fage. Rumen and milk samples were obtained from the ewes twice, 1 week apart, and microbiota composition, volatile and long-chain fatty acid concentrations were analyzed. Bacterial composition was assessed using 16S rRNA gene sequencing, and microbiota and fatty acids were analyzed as compositional data. As we worked with relative abundances expressed in a constrained space, the centered log-ratio transformation enabled to transform data to work with multivariate analyses in the Euclidian space. Bacterial composition differed between the 2 weeks of sampling, characterized by different proportions of the two main phyla, Bacteroidetes and Firmicutes. The repeatability of the operational taxonomic units (OTUs) was low, although it varied significantly. However, 66 of them presented a repeatability of over 0.50 and were particularly associated with fatty acid phenotypes. Even though the OTUs from the same bacterial families presented similar correlations to fatty acids in both weeks, only a few OTUs were conserved over the 2 weeks. We proved with the help of sequencing data that there is significant change in microbial composition over a week in terms of abundance of different families of bacteria. Further studies are required to determine the impact of bacterial composition alterations over 1 week, and the specificities of the highly repeatable OTUs. [ABSTRACT FROM AUTHOR]

Environmental factors affect daily milk production in dairy animals. The aim of this study was to quantify the effects of environmental factors, specifically mean temperature (°C), relative humidity (%), temperature–humidity index (THI), solar radiation (°), pluvial precipitation (mm) and lunar calendar (full moon, waxing quarter, waning quarter, new moon), on milk production (kg/d). The analysis was based on 96,195 morning and evening milking records documented on 109 consecutive days, from 869 Lacaune ewes. Ewes were housed in groups of 174 individuals. The analysis was performed in two independent procedures, a Pearson correlation analysis and a multivariate analysis of the ewe's interrelationships, which was based on the total variance estimate and a Varimax-rotated factorial analysis. Milk yield (kg/d) was significantly (p < 0.05) negatively correlated with mean temperature (-0.24), relative humidity (-0.16), THI (-0.24), and radiation (-0.18), which suggests that the higher these environmental factors, the lower the milk yield. Lunar calendar had a significant (p < 0.01) effect on milk production yield; specifically, yields were higher on the full moon and new moon (2.25 ± 0.05 kg/day) than they were on the crescent or waning moon (2.17 ± 0.05 kg/day). In conclusion, ewes that had been exposed to higher mean temperature, relative humidity, THI and solar radiation had the lowest milk yield, and milk yields are highest on full and new moons. The results of this work may be helpful in making predictions for milk production in Lacaune ewes in the Mediterranean region throughout the year. [ABSTRACT FROM AUTHOR]

Pastoral systems face increasing pressure from competing global markets, food sector industrialization, and new policies such as Europe's post-2020 Common Agriculture Policy. This pressure threatens the use of extensive sheep-grazing systems in mountain areas of low productivity but high natural value. Using information gathered at a long-term research setting in a mountainous area of the Basque Country (northern Spain), we assessed the multiple benefits of extensive dairy sheep grazing systems from multiple perspectives using indicators pertaining to ecological, socio-economic, and food quality domains. In this way, we address the benefits that would be lost if sheep grazing abandonment persists in mountain regions. Our results show that the benefits of extensive dairy sheep grazing in the research area include the production of healthy and high-quality foods and multiple ecological benefits including biodiversity conservation. Extensive dairy sheep grazing also contributes to rural development by generating employment and income in marginal, low-productivity lands that can support few economic alternatives. In particular, we found that sheep farmers who produce high-value products, such as cheese, have enhanced their economic profitability and are less dependent on public subsidies. However, careful attention to sustainable practices, support for new generations of farmers, and streamlined supply chains are required. These would contribute to ensure socio-economic benefits for farmers, avoid the ecological costs associated with grazing abandonment, and enhance ecosystem services for the whole society. [ABSTRACT FROM AUTHOR]

Simple Summary: Milk production is the most economically crucial dairy sheep trait and constitutes the major genetic enhancement purpose via selective breeding. Also, mastitis is one of the most frequently encountered diseases, having a significant impact on animal welfare, milk yield, and quality. The aim of this study was to identify genomic region(s) associated with the milk production traits and somatic cell score (SCS) in Valle del Belice sheep using single-step genome-wide association (ssGWA) and genotyping data from medium density SNP panels. We identified several genomic regions (OAR1, OAR2, OAR3, OAR4, OAR6, OAR9, and OAR25) and candidate genes implicated in milk production traits and SCS. Our findings offer new insights into the genetic basis of milk production traits and SCS in dairy sheep. The objective of this study was to uncover genomic regions explaining a substantial proportion of the genetic variance in milk production traits and somatic cell score in a Valle del Belice dairy sheep. Weighted single-step genome-wide association studies (WssGWAS) were conducted for milk yield (MY), fat yield (FY), fat percentage (FAT%), protein yield (PY), protein percentage (PROT%), and somatic cell score (SCS). In addition, our aim was also to identify candidate genes within genomic regions that explained the highest proportions of genetic variance. Overall, the full pedigree consists of 5534 animals, of which 1813 ewes had milk data (15,008 records), and 481 ewes were genotyped with a 50 K single nucleotide polymorphism (SNP) array. The effects of markers and the genomic estimated breeding values (GEBV) of the animals were obtained by five iterations of WssGBLUP. We considered the top 10 genomic regions in terms of their explained genomic variants as candidate window regions for each trait. The results showed that top ranked genomic windows (1 Mb windows) explained 3.49, 4.04, 5.37, 4.09, 3.80, and 5.24% of the genetic variances for MY, FY, FAT%, PY, PROT%, and total SCS, respectively. Among the candidate genes found, some known associations were confirmed, while several novel candidate genes were also revealed, including PPARGC1A, LYPLA1, LEP, and MYH9 for MY; CACNA1C, PTPN1, ROBO2, CHRM3, and ERCC6 for FY and FAT%; PCSK5 and ANGPT1 for PY and PROT%; and IL26, IFNG, PEX26, NEGR1, LAP3, and MED28 for SCS. These findings increase our understanding of the genetic architecture of six examined traits and provide guidance for subsequent genetic improvement through genome selection. [ABSTRACT FROM AUTHOR]

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The objectives of this study were to investigate temperature distribution at the sheep hoof and evaluate the reliability and diagnostic performance of infrared thermography (IRT) for the detection of footrot and white line disease (WLD) lesions in intensively reared dairy sheep. Hoof lesions were clinically assessed, and IRT was used to measure temperature distribution on hoof superficial tissue in 600 multiparous ewes. Binary regression models were developed and validated, and receiver operating characteristic curves were estimated to assess the predictive value and diagnostic performance of IRT for the detection of hoof lesions. The most sensitive prediction model for the detection of IFR was based on the difference between ambient and hoof heel temperature (sensitivity: 83.3%, specificity: 47.8%, and threshold value: 6.5 ◦C), whereas the most specific prediction model was based on the difference between ambient and coronary band temperature (sensitivity: 51.9%, specificity: 79.7%, and threshold value: 11.3 ◦C). In the case of WLD, the diagnostic performance of IRT had limited predictive value. IRT could be a useful tool for hoof health screening in dairy sheep. However, it must be cautiously adapted in cases where environmental, operating, and operator variables are not effectively controlled. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify genomic regions underlying milk production traits in the Valle del Belice dairy sheep using regional heritability mapping (RHM). Repeated measurements for milk yield (MY), fat percentage and yield (F% and FY) and protein percentage and yield (P% and PY), collected over a period of 6 years (2006–2012) on 481 Valle del Belice ewes, were used for the analysis. Animals were genotyped with the Illumina 50k SNP chip. Variance components, heritabilities and repeatabilities within and across lactations were estimated, fitting parity, litter size, season of lambing and fortnights in milk, as fixed; and additive genetic, permanent environment within and across lactations, flock by test‐day interaction and residual as random effects. For the RHM analysis, the model included the same fixed and random effects as before, plus an additional regional genomic additive effect (specific for the region being tested) as random. While the whole genomic additive effect was estimated using the genomic relationship matrix (GRM) constructed from all SNPs, the regional genomic additive effect was estimated from a GRM matrix constructed from the SNPs within each region. Heritability estimates ranged between 0.06 and 0.15, with repeatabilities being between 0.14 and 0.24 across lactations and between 0.23 and 0.39 within lactation for all milk production traits. A substantial effect of flock‐test‐day on milk production traits was also estimated. Significant genomic regions at either genome‐wide (p <.05) or suggestive (i.e., one false positive per genome scan) level were identified on chromosome (OAR) 2, 3 and 20 for F% and on OAR3 for P%, with the regions on OAR3 in common between the two traits. Our results confirmed the role of LALBA and AQP genes, on OAR3, as candidate genes for milk production traits in sheep. [ABSTRACT FROM AUTHOR]

The aim of the present study was to establish live weight, Body condition score (BCS), body dimensions and phenotypic correlations between them in young female breeding animals of Bulgarian dairy synthetic population (BDSP). The object of research were 137 ewe lambs of the flock, bred at the Agricultural Institute in Stara Zagora for a period of 3 years. Live weight of animals and body dimensions were performed at 6, 9 and 18 months of age and Body condition score was assessed. In addition, the phenotypic dependences between indicators were calculated. The data were processed with Statistica software product. Based on the obtained results, it could be summarized that the live weight and bone system of the animals increased more intensively in the period from 6 to 9 months of age, which was accompanied by an increase in BCS. During the next period (after 9 months of age) there was a certain slowdown in the growth rate and a decrease in BCS, but an increase in live weight. The values of the two indicators at the age of 18 months however showed that the physiological condition of the animals was suitable for their inclusion in the breeding process. The highest values of phenotypic correlations were found between live weight, BCS and body dimensions at 6 months of age. At the next two ages (9 and 18 months), these dependencies declined. Live weight, body length, chest depth and croup width maintained a high level of correlation with the body volume. The highest phenotypic correlations between BCS and other indicators were established in animals at 6 months and the lowest ones at 9 months of age [ABSTRACT FROM AUTHOR]

In this study, we conducted a genome-wide association study (GWAS) for five milk production traits in the Valle del Belice sheep. Repeated measurements for milk yield (MY), fat percentage and yield (F% and FY) and protein percentage and yield (P% and PY) on 481 ewes, were available for the analysis. The animals were genotyped using the Illumina Ovine 50k BeadChip. Weighted deregressed breeding values (DEBVw) were used as phenotypes for GWAS analysis. A total of 23 genome-wide significant SNPs were identified: 3 associated with MY, 9 with FY, and 11 with P%. Several SNPs mapped within known candidate genes or previously reported QTL for milk production traits in livestock species. Additional interesting markers were identified on OAR3 for FY and P%. These SNPs supported some previous findings and also added new information useful to understand the genetic mechanisms underlying the milk production and quality traits in dairy sheep. A total of 23 significant SNPs were detected. Several SNPs mapped within known candidate genes or previously reported QTL for milk production traits. These results could provide information to understand the genetic architecture of milk production traits in dairy sheep. [ABSTRACT FROM AUTHOR]

The present study examines the dynamics of the population and the breeding status of the Bulgarian dairy synthetic population, controlled by the breeding association of the Bulgarian dairy sheep breeds as of 2011, when the breeding organisation was established, until now. It has been ascertained that during the first 5 years, the number of sheep under selection control increased 8.4 times- from 7035 to 59243 but after that it decreased and in 2020 it is 34868. The controlled sheep are reared in 212 farms- approximately 164 sheep in each of them. When compared to the initial period, the number of farms has increased by 8.5 times but the average number of sheep has decreased by 13.7%. The number of young animals secures the reproduction of the ewes- 18.2%, and the rams-16.8%. This low reproduction percentage along with the small difference in the productivity of the elite and controlled units of the breed point to a relatively low genetic progress in the main productive features. So as the selection effect to be increased, it is recommended that the potential fathers selection be performed in the entire controlled part of the breed under the open nucleus breeding system, more young animals to be left for breeding which in turn will provide the opportunity for refining of the group, and a system for assessment of rams based on the qualities of their progeny be elaborated and applied. [ABSTRACT FROM AUTHOR]

By 2050, the earth's population is expected to be more than 9 billion. The need for secure food and water supply will force agriculture to increase production. The major greenhouse gases (GHGs) from the livestock sector are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) throughout the production process. These gases are the key contributor to an increasing earth's surface temperature. Global warming occurs as a result of gases emitted by humans into the atmosphere, creating a greenhouse effect. The livestock sector contributes between 25 and 40% of anthropogenic methane emissions. Human-derived animal production contributes to global warming by producing 9% of CO2 emissions, 35-40% of CH4, and 65% of N2O gas emissions. Carbon footprint is a measure of the damage that human activities cause to the environment in terms of the amount of GHGs produced as a unit of CO2. The most common method used in carbon footprint calculations is the Tier 1-2-3 approach developed by the intergovernmental panel on climate change (IPCC). In this study, the carbon footprint of a dairy sheep farm in Niğde province was calculated using Tier 1 method to determine global warming potential. The carbon footprint of this farm from both sources like N20 and CH4 was 85535.2 CO2eq year-1. The estimation of GHGs is very obligatory to evaluate global warming stress and avoidance from some fatal diseases. [ABSTRACT FROM AUTHOR]

The present study aims to identify margins for the improvement of dairy animal welfare and production based on the quality of the human−animal relationship (HAR). The main tool proposed to improve the quality of HAR in dairy animals is training of stock-people by targeting their attitude and behaviour. Given that a good quality HAR may benefit the welfare of dairy animals and productivity, new technologies, by monitoring the handling routine on farm, may be more effective in promoting good practices. In particular, the implementation of new technologies may allow identification of specific inappropriate behaviours to be targeted at stockperson level, thus increasing the efficacy of training. However, an issue related to the introduction of new technologies in the farms, particularly in those that follow traditional farming practices, is the resistance to innovation which may be encountered. [ABSTRACT FROM AUTHOR]

Summary: Milk production is one of the most important characteristics of dairy sheep, and the identification of genes affecting milk production traits is critical to understanding the genetics and improve milk production in future generations. Three statistical techniques, namely GWAS, ridge‐regression BLUP and BayesC π, were used to identify SNPs in significant association with three milk production traits (milk yield, fat yield and protein yield) in a crossbred dairy sheep population. The results suggested that chromosomes 1, 3, 4, 5, 7 and 11 were likely to harbor genes important to milk production because these chromosomes had the greatest top‐100‐SNP variance contributions on the three milk production traits. The GWAS analysis identified between 74 and 288 genome‐wide significant SNP (P < 0.05) whereas the BayesCπ model revealed between six and 63 SNPs, each with >95% posterior probability of inclusion as having a non‐zero association effect on at least one of the three milk production traits. Positional candidate genes for milk production in sheep were searched, based on the sheep genomic assembly OAR version 3.1, such as those which map position coincided with or was located within 0.1 Mbp of a genome‐wide suggestive or significant SNP. These identified SNPs and candidate genes supported some previous findings and also added new information about genetic markers for genetic improvement of lactation in dairy sheep, but keeping in mind that the majority of these positional candidate genes are not necessarily true causative loci for these traits and future validations are thus necessary. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of diets containing different dried by‐products on milk and blood plasma antioxidant capacity of dairy ewes. Thirty‐six Sarda ewes were assigned to four treatments: control (CON; no by‐product), 100 g/day of grape marc (GM), 100 g/day tomato pomace (TP) and 75 g/day of exhausted myrtle berries (EMBs). The superoxide dismutase (SOD), glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GSH‐Px) in blood, and SOD, GR and lactoperoxidase (LPO) in milk were determined. Total antioxidant capacity (FRAP and ABTS assays), malondialdehyde (MDA) and protein carbonyls (PCs) were also measured. Milk fatty acid profile was investigated by gas chromatography. The results showed higher antioxidant capacity measured by FRAP or ABTS assays and a reduction in MDA in GM plasma than CON. All by‐products enhanced the protection of milk proteins by oxidation, as evidenced by lower values of PCs compared with CON. GM supplementation increased PUFAn‐6, due to increase in C18:2n‐6, the main component of GM compared with CON. All by‐products did not modify the nutritional indexes of milk fat. In conclusion, dietary GM may enhance protection against oxidative condition of dairy ewes, whereas TP and EMB need further research to define the optimum inclusion level in sheep diet. [ABSTRACT FROM AUTHOR]

This work aimed to use 16S ribosomal RNA sequencing with the Illumina MiSeq platform to describe the milk microbiota from 50 healthy Assaf ewes. The global observed microbial community for clinically healthy milk samples analysed was complex and showed a vast diversity. The core microbiota of the sheep milk includes five genera: Staphylococcus, Lactobacillus, Corynebacterium, Streptococcus and Escherichia/Shigella. Although there are some differences, some of these genera are common with the microbiota core pattern of milk from other species, especially with dairy cows. The microbial composition of the studied samples, based on the definition of amplicon sequence variants, was analysed through a correlation network. A preliminary analysis by grouping the milk samples based on their somatic cell count (SCC), which is considered an indicator of subclinical mastitis (SM), showed certain differences for the core of the samples identified as SM. The differences in the microbiota diversity pattern among samples might also suggest that subclinical mastitis would be associated with the significant increase in some genera that are inhabitants of the mammary gland and a remarkable concomitant reduction in the microbial diversity. Additionally, we have also presented here a preliminary analysis to assess the impact of the sheep milk microbiome on SCC, as an indicator of subclinical mastitis. The results here reported provide a first characterization of the sheep milk microbiota and settle the basis for future studies in this field. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to investigate the effects of addition of walnut shell biochar (WSB) and chicken manure biochar (CMB) to dairy ewes' diet. In in vitro experiment, the effects of different levels of WSB and CMB (0.5, 1, and 1.5% diet dry matter (DM)) on rumen fermentation characteristics were assessed in a completely randomized design with seven treatments and three replicates. Treatments were as follows: basal diet without biochar (control), basal diet with 0.5, 1, and 1.5% WSB, and basal diet with 0.5, 1, and 1.5% CMB. Addition of 1% WSB and 1.5% CMB to the diet linearly decreased methane production and ammonia-N concentrations and increased pH compared to control (P < 0.001). Inclusion of WSB and CMB to the diet did not change volume of gas production and total volatile fatty acids (VFA) and proportion of acetate, propionate, and butyrate. In the second experiment, six milking Kermanian ewes were used in a replicated Latin square design with three treatments and three 21-day periods to evaluate the effects of 1% WSB and 1.5% CMB (based on results obtained from in vitro trial) on intake, digestibility, and milk yield and composition. Dietary inclusion of 1% WSB and 1.5% CMB resulted in more milk yield (P < 0.01), milk protein (P < 0.05), and solids not fat (SNF) (P < 0.001). Blood glucose and total protein increased (P < 0.01) in ewes fed 1% WSB and 1.5% CMB in comparison to ewes fed control diet. Apparent digestibility coefficients of DM (P < 0.01) and OM (P < 0.10) were increased with inclusion of 1% WSB and 1.5% CMB in diet. Neutral detergent fiber (NDF) digestibility was also increased in WSB-fed ewes (P < 0.01). The lack of negative effects of 1% WSB and 1.5% CMB coupled with the observed reduction in methane emission and ammonia concentration and also improvement in milk production suggested that biochars can be beneficially incorporated in dairy ewes' ration as a low-cost feed additive. [ABSTRACT FROM AUTHOR]

The identification of genes involved in phenotypes related to milk quality is important for both economic and health aspects in livestock production. The aim of this study was to assess the level of gelsolin gene expression in two breeds of dairy sheep – Sarda and Gentile – with pronounced differences in quantitative and qualitative milk traits. Gelsolin, a type of actin-modulating proteins is involved in the processes of actin remodeling during cell growth and apoptosis; therefore a role of this protein in mammary changes during lactation was here hypothesized. Individual milk samples were collected three times during lactation from 26 ewes of the two breeds. The differential gene expression of gelsolin in the two breeds and the three lactation times was estimated by quantitative PCR on RNA extracted from milk somatic cells. Correlations of gelsolin gene expression with milk yield and quality and days of lactation were also estimated. The results showed that gelsolin gene expression was significantly higher in the Sarda compared to the Gentile at each lactation stage, in agreement with the longer lactation duration and the higher daily milk yield of the first breed. Significant correlations of gelsolin gene expression were found with milk fat content in Sarda breed (−0.46, P <0.05). Gelsolin expression analysis confirmed the link between gelsolin gene function and milk fat content of sheep. [ABSTRACT FROM AUTHOR]

Dairy sheep produce an effluent stream from the milking parlour that is either applied directly to land via a sump and spray irrigator, or is stored in an effluent pond before application. In order to characterise this effluent stream, a monitoring programme was undertaken with effluent samples collected from two case study sheep milking farms over two lactation seasons (2014/2015 and 2015/2016), and a third over one lactation period (2015/2016). Typical effluent volumes generated ranged between 4 and 10 L ewe−1 day−1for the 130–200-day lactation. The mean physical and chemical attributes of effluent samples generated by the milking parlours were: 0.54% dry matter (DM), 220 g nitrogen (N) m−3, 32 g phosphorus (P) m−3, 150 g potassium (K) m−3and 22 g sulphur (S) m−3. The mean nutrient concentrations of dairy sheep effluent are lower than values reported for dairy goat (P & S only) and dairy cow effluents (N, P, K and S). [ABSTRACT FROM AUTHOR]

Genetic evaluation of dairy sheep for lactation yields at 150 days of milk, fat, protein and lactose, and for live weight, somatic cell score, first let-down time and yield, and litter size at birth was performed in a New Zealand flock. From 123 crossbred ewes, 479 monthly flock tests were obtained during the season 2015/2016. Lactation curves were derived using a random regression model with orthogonal polynomials of order 4. Breeding values were estimated from a multiple-trait animal model using heritabilities and genetic correlations published in the literature, and phenotypic standard deviations obtained from the data set. This model can be extended to other dairy sheep farmers to create selection schemes at an industry level and start a systematic breeding program for the emerging dairy sheep industry. [ABSTRACT FROM AUTHOR]

The economic evaluation of farm animal genetic resources plays a key role in developing conservation programs. However, to date, the link between diversity as assessed by neutral genetic markers and the functional diversity is not yet understood. Two genome-wide comparisons, using over 44,000 Single Nucleotide Polymorphisms, identified the markers with the highest difference in allele frequency between the Alpago endangered breed and two clusters, composed of four specialized dairy sheep, and four meat breeds respectively. The genes in proximity of these markers were mapped to known pathways of the Gene Ontology to determine which ones were most represented. Our results indicated that the differences of the Alpago breed from the more productive sheep rely upon genes involved in cellular defense and repair mechanisms. A higher number of different markers and genes were detected in the comparison with the specialized dairy sheep. These genes play a role in complex biological processes: metabolic, homeostatic, neurological system, and macromolecular organization; such processes may possibly explain the evolution of gene function as a result of selection to improve milk yield. [ABSTRACT FROM PUBLISHER]

For the past 2 decades, the Spooner Agriculture Research Station (ARS) of the University of Wisconsin-Madison operated the only dairy sheep research flock in North America. The objectives of the present study were to 1) obtain estimates of genetic parameters for lactation and reproductive traits in dairy ewes, 2) estimate the amount of genetic change in these traits over time, and 3) quantify the level of inbreeding in this flock over the last 20 yr. Multiple-trait repeatability models (MTRM) were used to analyze ewe traits through their first 6 parities. The first MTRM jointly analyzed milk (180-d-adjusted milk yield [180d MY]), fat (180-d-adjusted fat yield [180d FY]), and protein (180-d-adjusted protein yield [180d PY]) yields adjusted to 180 d of lactation; number of lambs born per ewe lambing (NLB); and lactation average test-day somatic cell score (LSCS). A second MTRM analyzed 180d MY, NLB, LSCS, and percentage milk fat (%F) and percentage milk protein (%P). The 3 yield traits were moderately heritable (0.26 to 0.32) and strongly genetically correlated (0.91 to 0.96). Percentage milk fat and %P were highly heritable (0.53 and 0.61, respectively) and moderately genetically correlated (0.61). Milk yield adjusted to 180 d was negatively genetically correlated with %F and %P (-0.31 and -0.34, respectively). Ewe prolificacy was not significantly (P > 0.67) genetically correlated with yield traits, %P, or LSCS but lowly negatively correlated with %F (-0.26). Lactation somatic cell score was unfavorably genetically correlated with yield traits (0.28 to 0.39) but not significantly (P > 0.09) correlated with %F, %P, and NLB. Withintrait multiple-trait models through the first 4 parities revealed that 180d MY, 180d FY, 180d PY, %F, and %P were strongly genetically correlated across parity (0.67 to 1.00). However, the genetic correlations across parity for NLB and LSCS were somewhat lower (0.51 to 0.96). Regressing predicted breeding values for 180d MY, without and with the addition of breed effects, on ewe year of birth revealed a positive genetic gain of 2.30 and 6.24 kg/yr, respectively, over the past 20 yr in this flock. Inbreeding coefficients of ewes with an extended pedigree ranged from 0.0 to 0.29, with an average of 0.07. To optimize genetic gains and avoid excessive inbreeding, the development of a national genetic improvement program should be a top priority for the growing dairy sheep industry. [ABSTRACT FROM AUTHOR]