Dairy Sheep Flocks Research Articles

Costs, income and economic efficiency of dairy sheep flocks

Article Details: Received: 2020-10-12 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.98-101 The objective of this study was to analyse costs and incomes from milk/cheese and lamb production in dairy sheep flocks and to evaluate their economic efficiency by calculating the profit/loss that is expressed as the difference between these two economic indicators. Costs were calculated taking into account their individual item structure, revenues were calculated taking into account sales of milk/cheese and lamb production. The analysis included three-year period i.e. years 2017, 2018 and 2019. The object of investigations were twelve and thirteen dairy sheep flocks per year, respectively. Economic indicators were expressed in Eur per feeding day (costs) and/or in Eur per ewe and year (costs, sales, subsidies, profit/loss). Milk and lamb sales did not cover up costs spent on production and accounting for subsidy improved economic efficiency of dairy sheep only to a lower extent. Sheep farming thus produced with the loss. Across years, milk and lamb sales almost unchanged, whereas costs notably increased. No ability to cover up costs with revenues could become an obstacle for further survival of this livestock sector. The increase of both milk yield and lamb production is therefore needed. Keywords: small ruminants, expences, revenues, profit/loss References de Rancourt , M. et al. (2006). Mediterranean sheep and goats production: An uncertain future. Small Ruminant Research , 62, 167–179. https://doi.org/10.1016/j.smallrumres.2005.08.012 Eurostat. (2016). Livestock population in livestock units by type EU-28. Retrieved October, 2, 2020 from https://ec.europa.eu/eurostat/data/database FAOSTAT. (2019). Food and agricultural data. Retreived October 2, 2020 from http://www.fao.org/faostat/en/#data Gunlu, A. et al. (2003). Relationship between average milk production costs and some selected technical and socio-economic factors surrounding dairy herds. Indian Journal Animal Sciences , 73(10), 1159–1162. Krupova, Z. et al. (2012). Review of methodologies for costs calculating of ruminants in Slovakia. Jornal of Central European of Agriculture , 13(3), 426–445. https://doi.org/0.5513/JDEA01/13.3.1068 Krupova, Z. et al. (2013). Economics of dairy sheep breeding in the year 2011. Agromagazine , 15(1), 12–13. Krupova, Z. et al. (2014). Impact of variation in production traits, inputs costs and product prices on profitability in multi-purpose sheep. Spanish Jornal of Agricultural Research , 12(4), 902–912. https://doi.org/10.5424/sjar/2014124-6166 Michalickova, M. et al. (2014). Determinants of economic efficiency in dairy cattle and sheep. Slovak Jornal of Animal Science , 47(1), 39–50. Milan, M. J. et al. (2014). Cost structure and profitability of Assaf dairy sheep farms in Spain. Journal of Dairy Science , 97, 5239–5249. https://doi.org/10.3168/jds.2013-7884 Oravcova, M. and Peskovicova, D. (2008). Genetic nad environmental trends for milk production trends in sheep estimated with test-day model. Asian-Australasian Journal of Animal Science , 21(8), 1088–1096. https://doi.org/10.5713/ajas.2008.70700 Oravcova, M. et al. (2020). Costs in dairy sheep flocks in the year 2019. Agromagazine , 22(10), 10. Pamukova, D. and Momchilov, H. (2017). Analysis of revenues and production costs of dairy sheep farms. Trakia Journal of Sciences , 15(Suppl. 1), 277–281. https://doi.org/10.15547/tjs.2017.s.01.050 Trubacova, A. et al. (2019). Costs of agricultural products in the Slovak Republic in 2018. Bratislava: National Agricultural and Food Centre-RIEAF. Tzouramani, I. et al. (2011). An assessment of of the economic performance of organic dairy sheep farming in Greece. Livestock Science , 141, 136–142. https://doi.org/10.1016/j.livsci.2011.05.010

Extensive Countrywide Field Investigation of Somatic Cell Counts and Total Bacterial Counts in Bulk-Tank Raw Milk in Sheep Flocks in Greece.

Objectives were to investigate somatic cell counts (SCC) and total bacterial counts (TBC) in the raw bulk-tank milk of sheep flocks in Greece, to study factors potentially influencing increased SCC and TBC in the bulk-tank milk of sheep and to evaluate possible associations of SCC and TBC with milk content. Throughout Greece, 325 dairy sheep flocks were visited for collection of milk sampling for somatic cell counting, microbiological examination and composition measurement. Geometric mean SCC were 0.488 × 106 cells mL−1; geometric mean TBC were 398 × 103 cfu mL−1; 228 staphylococcal isolates were recovered form 206 flocks (63.4%). Multivariable analyses revealed annual incidence risk of clinical mastitis, age of the farmer and month into lactation period (among 53 variables) to be significant for SCC > 1.0 × 106 cells mL−1 and month into lactation period at sampling and availability of mechanical ventilators (among 58 variables) to be significant for TBC > 1500 × 103 cfu mL−1. Negative correlation of SCC with fat, total protein and lactose and positive correlation of SCC with added water were found. With SCC > 1.0 × 106 cells mL−1, significant reduction of protein content (2%) was observed, whilst in flocks with SCC > 1.5 × 106 cells mL−1, significantly lower annual milk production per ewe (42.9%) was recorded.

An on-farm rotational grazing trial: restricting access time to pasture did not affect the productivity of a dairy sheep flock in spring

In the Mediterranean area, semi-extensive mixed farming systems characterise the inland landscape and guarantee the maintenance of several agroecosystem services. Rationed and rotational grazing have been proposed as efficient agroecological practices for sustainable intensification. Previous studies have highlighted that, during spring, restricted access time to pasture of below four hours per day decreases herbage intake and milk production of rotationally stoked ewes. The aim of this study was to assess the effect of restricted access time on daily herbage intake and milk productivity of Sarda ewes under rotational grazing management in a real farm located in southern Tuscany. The entire flock of 145 lactating ewes was allotted two homogenous groups and rotationally stoked on a grass-legume mixed pasture and fed about 1.7 kg of DM ewe–1 d–1 of supplementation. Each group was then assigned to the following treatments: two hours per day of access time to pasture, from 10:00 to 12:00 CET, and four hours per day of access time to pasture, from 10:00 to 14:00 CET. Data on herbage yield and quality, dry matter intake and milk yield were collected from April 5 to May 10, 2018. The rotational grazing schedule was conducted allowing for abundant herbage and exploiting high-nutritive biomass of the upper horizon sward. The results of our on-farm experiment showed that restricting daily access time to pasture down two hours did not reduce the potential daily herbage intake and the milk performance of dairy ewes rotationally stocked on a mixed pasture in spring. Our study also highlighted the capacity of ewes to self-regulate the herbage intake in order to meet their energy requirements, when neutral detergent fibre is not a limiting factor. Our outcomes should encourage researchers and farmers to co-design further on-farm experiments.
 Highlights - The challenge lies in comparing data of dairy sheep productivity collected at real farm condition with previous data measured in Mediterranean research stations. - In this study, no difference in milk production was found between ewes allowed to graze two hours and four hours per day in spring. - The ewes’ herbage intake rate correlates positively with pasture quality and a mixed pasture with a high share of legumes led to a high intake rate. - We believe that the outcomes in this manuscript can contribute to increase knowledge about the sustainable management of small ruminant dairy farms in the contest of rural areas.

Monitoring Coxiella burnetii Infection in Naturally Infected Dairy Sheep Flocks Throughout Four Lambing Seasons and Investigation of Viable Bacteria

Progression of Coxiella burnetii infection in four naturally infected sheep flocks, and in their farm environment, was monitored throughout four lambing seasons. Flocks with an active infection were selected based on the presence of C. burnetii DNA in bulk-tank milk (BTM) and a high seroprevalence in yearlings during the previous milking period (Spring 2015). During four consecutive lambing seasons (2015/16–2018/19), samples were collected within 1 week after each lambing period from animals (vaginal swabs, milk and feces from ewes, and yearlings) and the environment (dust indoor sheep premises). BTM samples and aerosols (outdoors and indoors) were monthly collected between lambing and the end of milking. Real-time PCR analyses showed different trends in C. burnetii shedding in the flocks, with a general progressive decrease in bacterial shedding throughout the years, interrupted in three flocks by peaks of reinfection associated with specific management practices. A significant relationship was found between C. burnetii fecal shedding and the bacterial burden detected in dust, whereas shedding by vaginal route affected the detection of C. burnetii in indoor aerosols. Three genotypes were identified: SNP8 (three flocks, 52.9% of the samples), SNP1 (two flocks, 44.8% samples), and SNP5 (one flock, two environmental samples). Coxiella burnetii viability in dust measured by culture in Vero cells was demonstrated in two of the flocks, even during the fourth lambing season. The results showed that infection can remain active for over 5 years if effective control and biosafety measures are not correctly implemented.

Diversity of breeding practices is linked to the use of collective tools for the genetic management of the Corsican sheep breed

For breeding schemes based on a diversity of production systems, there is a growing challenge in combining standardised tools for the collective genetic improvement of a breed and the selection of a flock able to respond to the specific constraints of the farm and the farmer’s objectives. In order to progress on this question, it is necessary to gain better knowledge of how farmers who use one or several of these tools select the future breeding animals of their flocks, and the conditions under which they use these collective tools. We took the example of dairy sheep farming in Corsica (France) and of two collective tools for the Corsican breed’s management: the use of milk recording data within and outside of the breeding scheme and the buying of rams from the breeding scheme’s cooperative. The tools’ use and perception were described by means of interviews with farmers (n = 40). Cross-analysis of farms’ descriptors and the use of collective tools was performed by statistical analysis using available databases on dairy sheep flocks in Corsica. A diversity of breeding practices was associated to the use of milk recording data and to the purchase of rams sold by the breeding scheme’s cooperative. Flock size, milking method and type of land use influenced these breeding practices and the adoption or mistrust of a collective genetic improvement tool. Dissemination of genetic progress through rams from the breeding scheme is possible, provided that a diversity of breeding practices and production environments is represented in the nucleus flocks.HighlightsParticipating in the breeding scheme of the Corsican breed did not hinder the use of various replacement and culling practices in dairy sheep farmsModalities of use of the milk recording tool are multiple and driven by work organisation, perception of the breeding scheme and the farm projectRams sold by the breeding scheme’s cooperative are present in several commercial farms with varying characteristics

Identification of potential functional variants underlying ovine resistance to gastrointestinal nematode infection by using RNA-Seq.

In dairy sheep flocks from Mediterranean countries, replacement and adult ewes are the animals most affected by gastrointestinal nematode (GIN) infections. In this study, we have exploited the information derived from an RNA-Seq experiment with the aim of identifying potential causal mutations related to GIN resistance in sheep. Considering the RNA-Seq samples from 12 ewes previously classified as six resistant and six susceptible animals to experimental infection by Teladorsagia circumcincta, we performed a variant calling analysis pipeline using two different types of software, gatk version 3.7 and Samtools version 1.4. The variants commonly identified by the two packages (high-quality variants) within two types of target regions - (i) QTL regions previously reported in sheep for parasite resistance based on SNP-chip or sequencing technology studies and (ii) functional candidate genes selected from gene expression studies related to GIN resistance in sheep - were further characterised to identify mutations with a potential functional impact. Among the genes harbouring these potential functional variants (930 and 553 respectively for the two types of regions), we identified 111 immune-related genes in the QTL regions and 132 immune-related genes from the initially selected candidate genes. For these immune-related genes harbouring potential functional variants, the enrichment analyses performed highlighted significant GO terms related to apoptosis, adhesion and inflammatory response, in relation to the QTL related variants, and significant disease-related terms such as inflammation, adhesion and necrosis, in relation to the initial candidate gene list. Overall, the study provides a valuable list of potential causal mutations that could be considered as candidate causal mutations in relation to GIN resistance in sheep. Future studies should assess the role of these suggested mutations with the aim of identifying genetic markers that could be directly implemented in sheep breeding programmes considering not only production traits, but also functional traits such as resistance to GIN infections.

Bulk tank somatic cell count and total bacterial count are affected by target practices and milking machine features in dairy sheep flocks in Castilla y León region, Spain

To study the effect of main flock target practices and milking machine features on the variation of bulk tank milk (BTM) somatic cell count (SCC) and total bacterial count (TBC) in dairy sheep flocks, a total of 3458 records of BTM SCC and TBC, corresponding to 340 audited flocks from the Consorcio de Promoción del Ovino of Castilla y León region (Spain), were collected throughout 12 months before testing the technical features of their milking machines. Average values were established for flock size (485.6 ewes), replacement rate (21.1%), parlor capacity (35.7 places), number of milking units (13.8), milking vacuum (36.2 kPa), pump air capacity at 50 and 36 kPa (106.4 and 158.3 L/min per milking unit), manual reserve (122.3 L/min per milking unit), air, milk and milking unit system consumptions (8.0 to 12.5 L/min per milking unit), internal diameters of the main air and milk pipes (5.9 mm and 4.2 mm per milking unit), pulsation rate and ratio (161.1 c/min and 57.4%), age and time since the last revision of the milking installation (16.3 years and 48.1 months), BTM temperature (3.4 °C) and washing water temperature at water-heater outlet (62.1 °C). Antibiotic dry therapy, time since last milking machine revision, and warm water temperature were critical factors influencing BTM SCC and TBC variation. Optimised BTM quality was also obtained for flocks with a greater size and foreign breeds, confined and post-dipped, with daily bedding maintenance, a low-level milk pipeline system, the presence of pulsation airline, greater manual reserve, smaller milk system consumption, and greater main air and pulsation pipe diameters. Greater milk pipe diameters and pulsation rates ≥180 c/min were associated with smaller SCC, but greater TBC, whereas pulsation ratios ≥60% increased SCC, but decreased TBC. Overall, results will allow for the optimisation of educational and risk management programs in the dairy sheep sector to improve flock mammary health and BTM hygiene.

Antimicrobial Resistance and Distribution of Staphylococcus spp. Pulsotypes Isolated from Goat and Sheep Bulk Tank Milk in Southern Spain.

Bulk tank milk from 58 dairy goat and sheep flocks located in southern Spain was examined to determine the prevalence and distribution of Staphylococci. A total of 45 isolates were obtained and characterized to determine the species, antimicrobial resistance profile, and genetic similitude by pulse-field gel electrophoresis (PFGE) using SmaI. Staphylococcus aureus isolates were confirmed by polymerase chain reaction (PCR) analysis of nuc, and resistance to methicillin was determined by PCR analysis of mecA. A total of 10 different staphylococcal species were identified, 22.2% and 77.8% of which were coagulase positive and negative, respectively. Twenty-two (48.89%) isolates were resistant to at least one antimicrobial agent. Higher antimicrobial resistance values were obtained against tetracycline (28.9%) and penicillin (22.2%). Two isolates (S. aureus and Staphylococcus lentus) were resistant to cefoxitin; however, none of the 45 isolates harbored mecA. Thirty pulsotypes were detected by PFGE. Interestingly, some isolates of S. aureus, S. lentus, Staphylococcus simulans, and Staphylococcus caprae showed high genetic similarity (>80%). These data suggest that genetically similar staphylococcal isolates circulate among goat and sheep dairy herds, and their different resistance patterns could be influenced by the management systems used.

Evaluation of bulk tank milk PCR and bulk tank milk modified ELISA tests for the detection of paratuberculosis at the herd level in goat and sheep dairies in Ontario, Canada

Early identification of dairy goat herds and dairy sheep flocks infected with Mycobacterium avium ssp. paratuberculosis is important for controlling this infection and minimizing economic losses. The objective of this study was to evaluate 2 bulk tank milk (BTM) paratuberculosis tests (PCR and modified ELISA) as potential herd-level tests. These tests were compared with the results obtained from testing 20 randomly selected lactating animals per farm (>2 yr) with an individual animal test (fecal culture, fecal PCR, serum ELISA, and milk ELISA). The study was conducted using 29 dairy goat herds and 21 dairy sheep flocks in Ontario, Canada, visited between October 2010 and August 2011. The sensitivity of the BTM PCR was poor in both the dairy goat herds (0.0%) and dairy sheep flocks (25.0%), but exhibited 100% specificity in both species. In comparison, the BTM modified ELISA demonstrated higher sensitivity. In goats, sensitivity ranged from 33.3 to 34.8% when fecal culture and PCR were the reference tests, respectively (specificities were both 100%), and 71.4 to 87.5% when the milk and serum ELISA, respectively, were the reference tests (specificities were 86.4 and 95.2%). The BTM modified ELISA in dairy sheep demonstrated comparable sensitivities, but lower specificities. When fecal culture and PCR were the reference test, sensitivities were 50.0 and 46.7%, respectively (specificities were 77.8 and 83.3%). The sensitivities when the milk and serum ELISA were the reference tests were 87.5 and 72.7%, respectively (specificities were 92.3 and 100%). Fecal PCR was the only individual animal test to identify significantly more farms as positive than the BTM PCR and modified ELISA test in both species. Therefore, whereas the BTM modified ELISA may provide an organization or control program with a high level of confidence that a BTM-positive farm is actually positive (high positive predictive value), if a producer wishes to increase the odds that a positive farm will test positive, so as not to miss an infection, then sampling and testing 20 animals with fecal PCR will better meet that objective.

Antimicrobial Resistance and Virulence Characterization of E. Coli Isolated from Subclinical Mastitic Sheep and Goats

Mastitis is one of the most serious healthy and economic problems in all dairy sheep and goat flocks. Examination of 200 milk samples collected from apparently healthy sheep and goats using California mastitis test (CMT) showed that 94 (47%) were CMT positive. Standard methods for isolation and identification of E. coli could identify 19 strains. Five different serogroups were successfully identified among 19 E. coli strains, the serogroups were O1 (21.1%), O26 (21.1%), O114 (15.8%), O148 (15.8%) and finally O125 (10.4%), in addition to 3 untypable strains. The antimicrobial susceptibility results for erythromycin and cefoxtin revealed all E. coli isolates were resistant to erythromycin (100%) followed by high frequencies of resistance observed to cefoxtin 18 isolates (94.7%). Phylogenetic grouping of E. coli by triplex PCR using two genes (chuA and yjaA) and an anonymous DNA fragment tspE4C2 indicated that 5/6 were B2 group and 1/6 was A group. Detection of virulence genes of 6 E. coli. isolates showed that 2/6 harbored eaeA gene and none of 6 isolates harbored CFA/I gene. While, the mph A erythromycin resistance gene were present in 4/6.but 2/6 isolates harbored bla CTX cefoxitin resistance gene.

Clinical characteristics of lameness and potential risk factors in intensive and semi-intensive dairy sheep flocks in Greece

Objectives of the study were to present descriptive epidemiological characteristics of lameness in intensively and semi-intensively reared flocks of Chios-breed dairy sheep in Greece, as well as to identify potential factors that may affect development, severity and duration of the disorder. In total, 1618 ewes in nine flocks were used for assessment of locomotion score and detailed clinical examination, which were performed fortnightly throughout a milking period. Subsequently, two logistic regression models were employed to assess impact of various variables on occurrence and severity of lameness. Mean lameness incidence in the nine flocks under surveillance during the milking period was 6.8% (110 cases in 1618 ewes); between flocks range of the incidence was 0.4%-22.0%. In 48% of the cases, lameness was considered to be severe. Foot-rot was found to be the commonest lameness-causing disorder, accounting for 66% of all cases. During the investigation, incidence of lameness in relation to the causing factor was 4.5% for foot-rot, 1% for white line abscesses, 1% for white line disease, <0.5% for pedal joint abscesses and <0.5% for hoof injuries. Farm size, stocking density, parity of the ewes and lambing season were identified as significant risk factors for dairy sheep lameness occurrence. Finally, stocking density was also found to affect lameness severity.

Analysis of fieldwork activities during milk production recording in dairy ewes by means of individual ear tag (ET) alone or plus RFID based electronic identification (EID)

In compliance with EU Reg. 21/2004, the individual electronic identification (EID) of sheep is mandatory in EU Countries since the 1st of January 2008. However, the impact of innovation within animal identification systems has not yet been carried out to quantify benefits during common fieldwork in real dairy sheep flocks. In particular, systematic milk production record represents a fundament to monitor real time performance of each single ewe, before a cumulative datum about flock output. The rational management of dairy ewes should rely on technological tools to create sub-groups according to production performance in a quick and reliable way. This trial aimed to investigate efficacy, reliability and efficiency associate to two different identification systems for monitoring individual milk production throughout the lactation in sheep flocks. Qualitative and quantitative indicators for each criterion, were useful for the assessment of activities and output correctness. Experimental activities were carried in two different farms of Sardinia. In both farms, animals were individually identified by means of an endoruminal ceramic bolus (transponder HDX 134.2 kHz, according to ISO Standards 11784–11785) and by conventional plastic ear tag. In both farms, during milking, groups of ewes were monitored (24 animals per round) by 2 trained technicians. In EID ewes, equipment to check individual transponder’s code and data recording consisted of a handy reader (Gesimpex Com. S.L., Barcelona, Spain); in ET ewes, individual ET code and milk production were visually inspected and typed on a handy data store equipment (ABB Immediate Business System PLC – Radix). Time needed for accomplishment of activities was taken for the two identification systems with a chronometer. In the two farms, a total of 553 animals were monitored for five times (controls were scheduled monthly) throughout the lactation period. Average time for reading and recording individual code and production for EID vs. ET resulted 6″/sheep vs. 11″/sheep. Transponder’s code resulted correctly checked and repeatedly associated in 100% of readings. EID system of diary ewes shows to improve production recording and data transfer in comparison with conventional ET system with advantageous technical relationships between fieldwork activities.

Case study using commercial dairy sheep flocks: Comparison of the fat nutritional quality of milk produced in mountain and valley farms

The study was conducted under real grazing conditions and addressed the hypothesis that the fatty acid composition of milk from ewes reared in mountain farms is more beneficial from human health perspective compared to milk from valley farms. Bulk raw milk from six commercial flocks was sampled during the milking period from May to June. Flocks were managed under extensive grazing but, according to usual local practices in valley farms, sheep diet was supplemented with a small amount of concentrate in May. Botanical species from mountain and valley areas where commercial flocks grazed were also collected. Sheep milk from mountain farms showed higher fat content that was richer in α-linolenic acid and its biohydrogenation intermediates, long-chain saturated, branched-chain, and cis-monounsaturated fatty acids compared to milk from valley farms. Differences in fatty acid profile of botanical species plus the concentrate supplementation given to sheep in May were the factors that mostly influenced the fatty acid composition of milk from mountain compared to valley farms. Overall, this approach has evidenced that milk produced in mountain regions of northern Spain would add value to the ‘mountain product’ label, and would contribute to maintain a resilient and sustainable dairy production system in these areas.

Evaluation of fecal culture and fecal RT-PCR to detect Mycobacterium avium ssp. paratuberculosis fecal shedding in dairy goats and dairy sheep using latent class Bayesian modeling.

BackgroundThe study’s objective was to evaluate the ability of fecal culture (FCUL) and fecal PCR (FPCR) to identify dairy goat and dairy sheep shedding Mycobacterium avium ssp. paratuberculosis. A cross-sectional study of the small ruminant populations was performed in Ontario, Canada between October 2010 and August 2011. Twenty-nine dairy goat herds and 21 dairy sheep flocks were visited, and 20 lactating females > two years of age were randomly selected from each farm resulting in 580 goats and 397 sheep participating in the study. Feces were collected per rectum and cultured using the BD BACTEC™ MGIT™ 960 system using a standard (49 days) and an extended (240 days) incubation time, and underwent RT-PCR based on the hsp-X gene (Tetracore®). Statistical analysis was performed using a 2-test latent class Bayesian hierarchical model for each species fitted in WinBUGS.ResultsExtending the fecal culture incubation time statistically improved FCUL sensitivity from 23.1 % (95 % PI: 15.9-34.1) to 42.7 % (95 % PI: 33.0-54.5) in dairy goats and from 5.8 % (95 % PI: 2.3-12.4) to 19.0 % (95 % PI: 11.9-28.9) in dairy sheep. FPCR demonstrated statistically higher sensitivity than FCUL (49 day incubation) with a sensitivity of 31.9 % (95 % PI: 22.4-43.1) in goats and 42.6 % (95 % PI: 28.8-63.3) in sheep.ConclusionsFecal culture demonstrates such low sensitivity at the standard incubation time it cannot be recommended as a screening test to detect shedding of MAP in either goats or sheep. Extending the incubation time resulted in improved sensitivity; however, it is still disappointingly low for screening purposes. Fecal PCR should be the screening test of choice in both species; however, it is important to recognize that control programs should not be based on testing alone when they demonstrate such low sensitivity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0814-5) contains supplementary material, which is available to authorized users.

Effect of farm characteristics and practices on hygienic quality of ovine raw milk used for artisan cheese production in central Italy.

A survey on ovine dairy farms directly transforming own-produced milk, in the Italian Marche region, was carried out to assess flock and milking practices that may influence milk hygienic-sanitary conditions. A census survey established that 24 dairy farms were located in this region. Bulk milk samples were collected throughout the milking period in each dairy farm in 2013. Analyzed variables were: (i) chemical parameters such as fat, protein and lactose content, dry matter and pH; and (ii) total bacterial (TBC) and somatic cell counts (SCC). Chemical parameter values were in agreement with published data while, geometric mean (GM) log10 SCC was 5.91 and TBC GM was 57 978 colony forming units/mL, in compliance with Eropean Union criteria. A positive correlation was found between SCC and TBC when GMs of all farm data were considered (Spearman's rho = 0.7925; P = 0.0001). Statistical analysis did not show significant correlation between SCC or TBC GM and dairy farm principal characteristics. Although SCC levels detected in the present study should suggest the need to implement mastitis control programs, Marche's dairy sheep flocks revealed a good hygienic condition level. This is an important aspect in implementing safety for end users of the final product.

Application of integrated production and economic models to estimate the impact of Schmallenberg virus for various sheep production types in the UK and France

ObjectiveThe present study aimed to estimate and compare the economic impact of Schmallenberg virus (SBV) in different sheep production holdings using partial budget and gross margin analyses in combination with...

Staphylococcus aureus and Escherichia coli prevalence in ovine bulk tank milk

To analyse the effect of bulk tank Staphylococcus aureus and Escherichia coli presence on total bacterial count (BTTBC) and somatic cell count (BTSCC), and to study the factors influencing their prevalence, a total of 752 bulk tank milk samples from 205 dairy sheep flocks belonging to Consortium for Ovine Promotion (CPO) were collected between January and December 2011. Four samplings were carried out in each flock, one per season, throughout one year. Respectively, Staph. aureus and Esch. coli were present in 26.5% and 17.4% of the samples and in 58.5% and 50.7% of the flocks throughout the year. Esch. coli significantly contributed to BTSCC and BTTBC variation, but only a statistical tendency for increased BTSCC was evidenced in the case of Staph. aureus positive samples. Thus, BTSCC and BTTBC were useful variables for monitoring, at least partially, the presence of Esch. coli in bulk tank milk, whereas BTSCC was more useful in the case of Staph. aureus. Some variation factors for specific pathogens, such as season, antibiotic dry therapy, milking type and breed, were also analysed. Season was the most important effect associated with the variation of bulk tank Staph. aureus and Esch. coli prevalence. Staph. aureus had a higher prevalence in winter and spring (i.e., early lactation period), while Esch. coli prevalence was higher in autumn and winter, coinciding with a rainy weather. Lower Staph. aureus prevalence was for dry-treated flocks pointing out this mastitis control practice in the flocks is related with a reduction of contagious mammary pathogens. Finally, hand milking flocks evidenced a higher prevalence for both pathogens than those with machine milking. As a whole, these results are useful for monitoring these pathogens in bulk tank milk and highlight the need for establishing analytical surveillance programmes in dairy sheep flocks.

Successful Visna/maedi control in a highly infected ovine dairy flock using serologic segregation and management strategies

A control system for Visna/maedi virus (VMV) infection based on serologic segregation and management strategies was applied in an infected Spanish dairy Manchega breed sheep flock (n=670) that was affected by a severe respiratory process associated to VMV. The control started in 2004 and consisted on the serological study of animals, segregation in two different flocks (seropositive and seronegative), separate management of flocks, selection of young female lambs for replacement only from seronegative ewes offspring, immediate removal of seropositive animals detected in the seronegative flock and a management tending toward the reduction and final culling of the seropositive flock. The serological control was repeated yearly or twice a year, approximately. Initial VMV seroprevalence of the undivided flock was 66.4% (January 2004) that descended to 47.3%, 12.8%, 2.2% and 0.2% between July 2004 and May 2006. Residual seroprevalence fluctuated slightly thereafter with a peak of 2.2% in April 2008. After segregation, number of animals in the seronegative flock was 378 that descended to 323 in October 2005. Since then, this number has increased steadily reaching 650 sheep in December 2011. The seropositive flock was progressively reduced by culling until its total disappearance in June 2010. This work presents the detailed results obtained in the control strategy against VMV in a single dairy sheep flock by implementing a segregation system based on serologic testing. The system is highly successful, as it reduces to residual levels VMV infection in about two years without the need of culling a high number of animals, as required by other methods. Moreover, the original size flock was been recovered within 8 years and has led to a subjective improvement of animal health and welfare in the flock. The residual seroprevalence could be eliminated at this stage by applying more sensitive molecular or other serological techniques to reach eradication.

Impact of maedi-visna in intensively managed dairy sheep

Maedi-visna (MV) is a slow lentiviral disease of sheep that has a significant economic impact in many sheep-producing regions although there remains a paucity of data relating to actual production losses resulting from this disease. The objective of this study was to evaluate direct losses, through death or culling, from two dairy sheep flocks with high seroprevalences of infection over a 2year period. Maedi-visna was found, either alone or in combination with other diseases, to be the most common disease diagnosed in these sheep, and the major cause of direct animal losses in the two flocks.Moderate to severe lesions associated with MV were found in 52% and 80% of the sheep, respectively, affecting the lungs, brain and/or mammary glands. Despite the similarity of the two flocks under study in terms of breed, number of animals, geographical proximity, and inter-change of rams, a striking difference was observed regarding the clinical presentation of the disease: in one flock the respiratory form was dominant while in the other 70% of animals died or were culled because of neurological signs.

PRNP genotyping in dairy sheep flocks: A sampling strategy for application in breeding programmes for scrapie eradication

Flock PRNP genotyping, defined as mass ewe genotyping at flock level using bulk tank milk samples would facilitate selection programmes aiming at increasing genetic resistance to scrapie. The objective of this study was the application and evaluation of a flock PRNP genotyping strategy. The strategy was tested for the estimation of the prevalence of the most undesirable PRNP polymorphism, valine at codon 136 (V136), in a flock consisting of 330 Chios dairy ewes with known individual genotypes, one of which was heterozygous for V136. A novel quantitative real-time Ligase Chain Reaction method was used for genotyping. Four monthly bulk tank milk samplings at the first four months of lactation took place. Different flock sizes were simulated using the collective milk of different numbers of ewes. Linear regression analysis, descriptive statistics and a linear model were used for the evaluation of the accuracy of flock PRNP frequency quantification. The accuracy was affected by the sampling month, number of monthly samplings and flock size. The V136 polymorphism was detected in all samples. Nevertheless, higher numbers of samplings were associated with more accurate estimation of the V136 frequency. As a general recommendation, three to four monthly samplings are sufficient for the determination of PRNP frequency profile at flock level. However, if the method is used as a screening tool for just the detection (and not the quantification) of a specific PRNP polymorphism, only one sampling is adequate.