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G Caja - One of the best experts on this subject based on the ideXlab platform.
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invited review current production trends farm structures and economics of the Dairy Sheep and goat sectors
Journal of Dairy Science, 2018Co-Authors: Giuseppe Pulina, M J Milan, M P Lavin, Alexandros Theodoridis, E Morin, J Capote, D L Thomas, A H D Francesconi, G CajaAbstract:ABSTRACT Dairy small ruminants account for approximately 21% of all Sheep and goats in the world, produce around 3.5% of the world's milk, and are mainly located in subtropical-temperate areas of Asia, Europe, and Africa. Dairy Sheep are concentrated around the Mediterranean and Black Sea regions, where their Dairy products are typical ingredients of the human diet. Dairy goats are concentrated in low-income, food-deficit countries of the Indian subcontinent, where their products are a key food source, but are also present in high-income, technologically developed countries. This review evaluates the status of the Dairy Sheep and goat sectors in the world, with special focus on the commercially and technically developed industries in France, Greece, Italy, and Spain (FGIS). Dairy small ruminants account for a minor part of the total agricultural output in France, Italy, and Spain (0.9 to 1.8%) and a larger part in Greece (8.8%). In FGIS, the Dairy Sheep industry is based on local breeds and crossbreeds raised under semi-intensive and intensive systems and is concentrated in a few regions in these countries. Average flock size varies from small to medium (140 to 333 ewes/farm), and milk yield from low to medium (85 to 216 L/ewe), showing substantial room for improvement. Most Sheep milk is sold to industries and processed into traditional cheese types, many of which are Protected Denomination of Origin (PDO) cheeses for gourmet and export markets (e.g., Pecorino, Manchego, and Roquefort). By comparing break-even milk price among FGIS countries, we observed the following: (1) most Greek and French Dairy Sheep farms were unprofitable, with the exception of the intensive Chios farms of Greece; (2) milk price was aligned with cost of production in Italy; and (3) profitable farms coexisted with unprofitable farms in Spain. In FGIS, Dairy goat production is based on local breeds raised under more extensive systems than Sheep. Compared with Sheep, average Dairy goat herds are smaller (36 to 190 does/farm) but milk yield is greater (153 to 589 L/doe), showing room for improvement. Goat milk is mainly processed on-farm into Dairy products for national markets, but some PDO goat milk cheeses (e.g., Murcia al Vino) are exported. Processed goat milk is sold for local human consumption or dehydrated for export. Mixed Sheep-goat (e.g., Feta) and cow-Sheep-goat milk cheeses are common in many countries. Strategies to improve the Dairy Sheep and goat sectors in these 4 countries are proposed and discussed.
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cost structure and profitability of assaf Dairy Sheep farms in spain
Journal of Dairy Science, 2014Co-Authors: M J Milan, F Frendi, R Gonzalezgonzalez, G CajaAbstract:Abstract Twenty Dairy Sheep farms of Assaf breed, located in the Spanish autonomous community of Castilla y Leon and included in a group receiving technical support, were used to study their production cost structure and to assess their economic profitability during 2009. On average, farms had 89.2±38.0 ha (own, 38%), 592±63 ewes, yielded 185.9±21.1×10 3 L/yr (i.e., 316±15 L/ewe), and were attended by 2.3±0.2 annual working units (family, 72%). Total annual income was €194.4±23.0×10 3 /yr (€1.0=$1.3) from milk (78.6%), lamb (13.2%), culled ewes (0.5%), and other sales (0.8%, wool and manure), and completed with the European Union Sheep subsidy (6.9%). Total costs were €185.9±19.0×10 3 /yr to attend to feeding (61.6%), labor (18.2%), equipment maintenance and depreciation (7.6%), finances (3.0%), animal health (2.5%), energy, water and milking supplies (2.2%), milk recording (0.5%), and other costs (4.4%; assurances, shearing, association fees, and so on). Mean Dairy Sheep farm profit was €8.5±5.8×10 3 /yr (€7.4±8.3/ewe) on average, and varied between –€40.6 and €81.1/ewe among farms. Only 60% of farms were able to pay all costs, the rest had negative balances. Nevertheless, net margin was €31.0±6.5×10 3 /yr on average, varying between €0.6 and €108.4×10 3 /yr among farms. In this case, without including the opportunity costs, all farms had positive balances. Total annual cost (TAC; €/ewe) and total annual income (TAI; €/ewe) depended on milk yield (MY; L/ewe) and were TAC=161.6 + 0.502 MY (R 2 =0.50), and TAI=78.13 + 0.790 MY (R 2 =0.88), respectively, with the break-even point being 291 L/ewe. Conversely, farm TAC (€/yr) and farm TAI (€/yr) were also predicted as a function of the number of ewes (NOE) per flock, as TAC=18,401 + 282.8 NOE (R 2 =0.89) and TAI=330.9 NOE (R 2 =0.98), with the break-even point being 383 ewes/flock. Finally, according to the increasing trend expected for agricultural commodity prices, it was calculated that a 10% increase of concentrate price will require 5.2% milk price increase for constant profit. Similarly, a 10% increase of forage price will require 2.0% milk price increase to maintain profitability. Under these scenarios of increasing the commodity prices of key feedstuffs, a change of flock feeding should be expected to compensate the losses in farm profitability. Most Assaf Dairy Sheep farms studied were economically profitable, with flock size, milk yield, and feeding costs key for their profitability.
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structure and performance of awassi and assaf Dairy Sheep farms in northwestern spain
Journal of Dairy Science, 2011Co-Authors: M J Milan, G Caja, R Gonzalezgonzalez, A M Fernandezperez, X SuchAbstract:Abstract Data of 69 Dairy Sheep farms (70% Assaf and 30% Awassi crossbred), located in the Spanish Autonomous Community of Castilla y Leon and grouped for receiving technical advice, were used to study their structure and performance. Farm surface was 55.4ha, on average. Approximately 25% of the farms did not have cultivation land, and the other 75% had, on average, 73ha (from which 67% were devoted to forage). Farms used 2.1 annual work units (familiar, 90%), 493 ewes, and yielded 147,000 L/yr of milk. Farmers were tenant (84%), younger than 45 yr (70%), had new houses, and were grouped in cooperatives (83%). Sheep were fed indoors (occasional grazing only) in modern loose stalls and had machine milking. Planned mating (summer to fall) was done in 91% of farms (hormonal treatment, 54%) but artificial insemination was scarce (23%). Annual milk sales averaged 309 L/ewe (fat, 6.5%; protein, 5.3%; log 10 somatic cell count, 5.7), and milk was sent to local Dairy industries for cheese production, and 1.35 lambs/ewe were harvested as milk-fed lambs (lechazo). Artificial lamb rearing was done in 38% of farms (automatic, 81%; manual, 19%). Total mixed rations were used in 33% of farms, and the rest used rationed concentrate (including self-produced cereals) according to physiological stage of the ewes (0.45 to 1.97 kg/d) and ad libitum forage (dehydrated, 70%; hay, 68%; fresh, 25%; silage, 12%). The concentrate-to-forage ratio ranged between 32 and 61%. In total, 68% of farms bought more than half of the forage, and 87% of them bought more than half of the required concentrates. According to structural, productive, and managerial traits, 4 types of farms were differentiated by using multiple correspondence analysis and cluster analysis. Type groups were: 1) large-surface farms, devoted to cereal and forage production, predominantly with Awassi crossbreed Sheep and a high level of self-consumed commodities (12% of the farms); 2) large flocks with intermediate farm surfaces devoted to forage production and predominantly with Assaf Sheep (30% of the farms); 3) high-yielding farms, with intermediate sized flocks of Assaf Sheep and very intensive management (42% of the farms); and, 4) no-land farms predominantly with Assaf Sheep (16% of the farms). In conclusion, the Dairy Sheep farms studied showed more adoption of intensive production systems than traditional farms, which resulted in higher milk and lamb yields. Despite all of them being based on familiar units, as traditional farms, they were highly dependent on external resources and became more vulnerable, faced with future uncertainties of the market.
Ramón A. Juste - One of the best experts on this subject based on the ideXlab platform.
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milk production losses in latxa Dairy Sheep associated with small ruminant lentivirus infection
Preventive Veterinary Medicine, 2020Co-Authors: Ramón A. Juste, I. Leginagoikoa, Monica Villoria, Eva Ugarte, E. MinguijónAbstract:Visna/Maedi is a disease of Sheep caused by small ruminant lentivirus (SRLV) infection that is widespread throughout the world and that has been recognized to be present in the Basque Country (Spain) since the early 1980′s. Nearly seven decades of studies have improved the knowledge on its clinical signs and epidemiology. However, its slow progressive nature, subclinical most of the time, makes difficult to assess its real impact on productive traits, a question of critical importance to balance out the economic costs it causes and the benefits of designing and deploying an eradication program. Development of a Dairy breeding program since the 90 s in the local Latxa Sheep population has provided data on milk productivity in several flocks where SRLV infection prevalence has been continuously monitored. This study analyses retrospectively the association between SRLV prevalence and production variables during ten yearly lactations in three Latxa Dairy flocks with medium-high SRLV seroprevalence. Our results indicate that average standard lactation of seropositive Sheep was 6.7 % lower than controls. The largest differences (p < 0.001) were observed at the ewe lifetime peak of production between second and fourth lactations. Lifelong milk and lamb production data indicated even a higher impact, with costs rising up to nearly 50 €/ewe/year. This substantial production decrease associated with subclinical SRLV infection in Latxa Dairy Sheep supports the benefit of establishing a SRLV control program. A rough cost-benefit analysis indicated that even in a medium-yielding breed, testing expenses would be largely covered by milk production improvement.
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coxiella burnetii shedding and environmental contamination at lambing in two highly naturally infected Dairy Sheep flocks after vaccination
Research in Veterinary Science, 2011Co-Authors: Ianire Astobiza, Ramón A. Juste, Ana Hurtado, Francisco Ruizfons, J F Barandika, Ines Povedano, Ana L GarciaperezAbstract:Abortion due to Coxiella burnetii was confirmed in the 2007/08 season in two naturally-infected Dairy Sheep flocks. Proportion of C. burnetii shedders and bacterial loads in vaginal mucus were high among aborted or lambed ewes, as was within-flock seroprevalence. Before the next reproductive season (2008/09) 75% of ewes and 50% of replacement lambs were vaccinated (Coxevac, CEVA Sante Animale) keeping the remaining as untreated controls. Compared with the previous year results when abortion outbreak started, a great reduction in the percentage of abortions, in the number of shedders and in the bacterial burden excreted by the ewes was found in both flocks. However, seroconversion in non-vaccinated yearlings from both flocks and the presence of C. burnetii DNA in bioaerosols taken at Sheep premises at lambing indicated that infection was still active. No differences were observed between vaccinated and control groups in terms of proportion of C. burnetii shedders. These results suggest that optimal results of vaccination in heavily infected flocks may not be obtained in a short-term period.
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border disease virus seroprevalence correlates to antibodies in bulk tank milk and reproductive performance of Dairy Sheep flocks
Journal of Dairy Science, 2010Co-Authors: Ana L Garciaperez, Ramón A. Juste, G. Aduriz, Francisco Ruizfons, J F Barandika, Ana HurtadoAbstract:Abstract There is a great need to establish effective tools to control border disease virus (BDV) in European Dairy Sheep flocks. Hence, our main aim was to investigate the accuracy of analyzing anti-BDV antibodies in bulk-tank milk (BTM) in detecting the real BDV seroprevalence in Dairy Sheep flocks. Furthermore, the relevance of BDV to reproductive performance of Dairy Sheep flocks prompted us to search for the association between BDV seroprevalence and reproductive parameters. For these purposes, 34 flocks were selected based on different percentages of antibody inhibition (AIP) values in BTM as estimated by ELISA. Serum samples from 10 replacement lambs older than 6 mo, 10 ewes 1 to 2 yr old, and 10 ewes >2 yr old were collected and analyzed for the presence of anti-BDV antibodies by ELISA. A negative relationship between BDV AIP in BTM and within-flock seroprevalence was observed. Flocks with a high AIP (>80%) had an average of 2.5% seropositive animals; flocks with a moderate AIP (46–79%) had 11.4% seropositive animals; and finally, flocks with an AIP ≤45% showed a high flock seroprevalence (57.2%). Ten out of 34 flocks showed a high BDV seroprevalence in lambs, suggesting the presence of persistently infected animals in the flock. The observed AIP values in BTM from these likely BDV-infected flocks were indicative of a high seroprevalence. The analysis of reproductive-parameters data collected from these flocks showed no differences in fertility or prolificacy in relation to BDV circulation rates. Nonetheless, lamb mortality was significantly greater in flocks with low-moderate seroprevalence (10–30%), probably as a result of a first-time contact with BDV of previously naive ewes. These findings suggest that testing of BTM samples may be useful in inferring the BDV seroprevalence in a flock.
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kinetics of coxiella burnetii excretion in a commercial Dairy Sheep flock after treatment with oxytetracycline
Veterinary Journal, 2010Co-Authors: Ianire Astobiza, Ramón A. Juste, Ana Hurtado, J F Barandika, Ana L GarciaperezAbstract:Abstract The kinetics of C oxiella burnetii excretion were studied in Dairy Sheep using a flock that had a previous history of abortion and a positive polymerase chain reaction (PCR) test for C . burnetii in milk from the bulk-tank. An ELISA used to test sera antibodies revealed a high within-flock seroprevalence (54%). Fifty individual milk samples analysed by PCR showed a high number of milk shedders in the flock (38%). In the following breeding cycle, 75% of the animals in the flock were double treated with oxytetracycline (OTC) at days +100 and +120 of gestation, while the remaining 25% of the animals were kept as untreated controls. The percentage of shedders at lambing was similar between groups. Of the treated ewes, 82% shed the bacteria in their vaginal fluids vs. 72% of the untreated ewes. Shedding was also high in faeces (61% of treated vs. 77% of untreated ewes) and milk (57% of treated vs. 50% of untreated ewes). At 2 and 6 weeks later, treated animals continued shedding the bacteria and there were no significant differences in the number of shedders between treated and control groups. Moreover, the bacteria were excreted in faeces for 5 months after parturition, for 3 months in vaginal discharges and for 4 months in milk, which suggested that OTC treatment neither prevented the shedding of bacteria, nor limited the duration of bacterial excretion.
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short communication investigation of coxiella burnetii occurrence in Dairy Sheep flocks by bulk tank milk analysis and antibody level determination
Journal of Dairy Science, 2009Co-Authors: Ana L Garciaperez, Ana Hurtado, J F Barandika, Ianire Astobiza, R Atxaerandio, Ramón A. JusteAbstract:To estimate the prevalence of Coxiella burnetii in the Dairy Sheep population from the Basque Country (northern Spain), a study was carried out combining molecular and serological techniques. First, bulk-tank milk samples from 154 flocks belonging to the Latxa Breed Farmers Association were analyzed by PCR, with 22% of flocks testing positive for C. burnetii. Then, a selection of 34 flocks (7 PCR positive and 17 negative) was investigated for the presence of serum antibodies by ELISA test on 1,011 ewes (approximately 30 ewes per flock). A total of 8.9% of the animals were seropositive, 67.6% of the flocks had at least one seropositive animal, but only in 14.7% of them was seroprevalence greater than 25%. Older ewes showed a significantly greater prevalence (17.5%) compared with yearlings (7.5%) or replacement lambs (1.5%). A marginally significant association was found between seroprevalence and PCR detection of C. burnetii in bulk-tank milk. The widespread distribution of C. burnetii in the region advocates for the implementation of Q fever control strategies and highlights the potential risk of Sheep as a reservoir and infection source for other domestic and wildlife species and the human population.
M J Milan - One of the best experts on this subject based on the ideXlab platform.
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invited review current production trends farm structures and economics of the Dairy Sheep and goat sectors
Journal of Dairy Science, 2018Co-Authors: Giuseppe Pulina, M J Milan, M P Lavin, Alexandros Theodoridis, E Morin, J Capote, D L Thomas, A H D Francesconi, G CajaAbstract:ABSTRACT Dairy small ruminants account for approximately 21% of all Sheep and goats in the world, produce around 3.5% of the world's milk, and are mainly located in subtropical-temperate areas of Asia, Europe, and Africa. Dairy Sheep are concentrated around the Mediterranean and Black Sea regions, where their Dairy products are typical ingredients of the human diet. Dairy goats are concentrated in low-income, food-deficit countries of the Indian subcontinent, where their products are a key food source, but are also present in high-income, technologically developed countries. This review evaluates the status of the Dairy Sheep and goat sectors in the world, with special focus on the commercially and technically developed industries in France, Greece, Italy, and Spain (FGIS). Dairy small ruminants account for a minor part of the total agricultural output in France, Italy, and Spain (0.9 to 1.8%) and a larger part in Greece (8.8%). In FGIS, the Dairy Sheep industry is based on local breeds and crossbreeds raised under semi-intensive and intensive systems and is concentrated in a few regions in these countries. Average flock size varies from small to medium (140 to 333 ewes/farm), and milk yield from low to medium (85 to 216 L/ewe), showing substantial room for improvement. Most Sheep milk is sold to industries and processed into traditional cheese types, many of which are Protected Denomination of Origin (PDO) cheeses for gourmet and export markets (e.g., Pecorino, Manchego, and Roquefort). By comparing break-even milk price among FGIS countries, we observed the following: (1) most Greek and French Dairy Sheep farms were unprofitable, with the exception of the intensive Chios farms of Greece; (2) milk price was aligned with cost of production in Italy; and (3) profitable farms coexisted with unprofitable farms in Spain. In FGIS, Dairy goat production is based on local breeds raised under more extensive systems than Sheep. Compared with Sheep, average Dairy goat herds are smaller (36 to 190 does/farm) but milk yield is greater (153 to 589 L/doe), showing room for improvement. Goat milk is mainly processed on-farm into Dairy products for national markets, but some PDO goat milk cheeses (e.g., Murcia al Vino) are exported. Processed goat milk is sold for local human consumption or dehydrated for export. Mixed Sheep-goat (e.g., Feta) and cow-Sheep-goat milk cheeses are common in many countries. Strategies to improve the Dairy Sheep and goat sectors in these 4 countries are proposed and discussed.
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cost structure and profitability of assaf Dairy Sheep farms in spain
Journal of Dairy Science, 2014Co-Authors: M J Milan, F Frendi, R Gonzalezgonzalez, G CajaAbstract:Abstract Twenty Dairy Sheep farms of Assaf breed, located in the Spanish autonomous community of Castilla y Leon and included in a group receiving technical support, were used to study their production cost structure and to assess their economic profitability during 2009. On average, farms had 89.2±38.0 ha (own, 38%), 592±63 ewes, yielded 185.9±21.1×10 3 L/yr (i.e., 316±15 L/ewe), and were attended by 2.3±0.2 annual working units (family, 72%). Total annual income was €194.4±23.0×10 3 /yr (€1.0=$1.3) from milk (78.6%), lamb (13.2%), culled ewes (0.5%), and other sales (0.8%, wool and manure), and completed with the European Union Sheep subsidy (6.9%). Total costs were €185.9±19.0×10 3 /yr to attend to feeding (61.6%), labor (18.2%), equipment maintenance and depreciation (7.6%), finances (3.0%), animal health (2.5%), energy, water and milking supplies (2.2%), milk recording (0.5%), and other costs (4.4%; assurances, shearing, association fees, and so on). Mean Dairy Sheep farm profit was €8.5±5.8×10 3 /yr (€7.4±8.3/ewe) on average, and varied between –€40.6 and €81.1/ewe among farms. Only 60% of farms were able to pay all costs, the rest had negative balances. Nevertheless, net margin was €31.0±6.5×10 3 /yr on average, varying between €0.6 and €108.4×10 3 /yr among farms. In this case, without including the opportunity costs, all farms had positive balances. Total annual cost (TAC; €/ewe) and total annual income (TAI; €/ewe) depended on milk yield (MY; L/ewe) and were TAC=161.6 + 0.502 MY (R 2 =0.50), and TAI=78.13 + 0.790 MY (R 2 =0.88), respectively, with the break-even point being 291 L/ewe. Conversely, farm TAC (€/yr) and farm TAI (€/yr) were also predicted as a function of the number of ewes (NOE) per flock, as TAC=18,401 + 282.8 NOE (R 2 =0.89) and TAI=330.9 NOE (R 2 =0.98), with the break-even point being 383 ewes/flock. Finally, according to the increasing trend expected for agricultural commodity prices, it was calculated that a 10% increase of concentrate price will require 5.2% milk price increase for constant profit. Similarly, a 10% increase of forage price will require 2.0% milk price increase to maintain profitability. Under these scenarios of increasing the commodity prices of key feedstuffs, a change of flock feeding should be expected to compensate the losses in farm profitability. Most Assaf Dairy Sheep farms studied were economically profitable, with flock size, milk yield, and feeding costs key for their profitability.
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structure and performance of awassi and assaf Dairy Sheep farms in northwestern spain
Journal of Dairy Science, 2011Co-Authors: M J Milan, G Caja, R Gonzalezgonzalez, A M Fernandezperez, X SuchAbstract:Abstract Data of 69 Dairy Sheep farms (70% Assaf and 30% Awassi crossbred), located in the Spanish Autonomous Community of Castilla y Leon and grouped for receiving technical advice, were used to study their structure and performance. Farm surface was 55.4ha, on average. Approximately 25% of the farms did not have cultivation land, and the other 75% had, on average, 73ha (from which 67% were devoted to forage). Farms used 2.1 annual work units (familiar, 90%), 493 ewes, and yielded 147,000 L/yr of milk. Farmers were tenant (84%), younger than 45 yr (70%), had new houses, and were grouped in cooperatives (83%). Sheep were fed indoors (occasional grazing only) in modern loose stalls and had machine milking. Planned mating (summer to fall) was done in 91% of farms (hormonal treatment, 54%) but artificial insemination was scarce (23%). Annual milk sales averaged 309 L/ewe (fat, 6.5%; protein, 5.3%; log 10 somatic cell count, 5.7), and milk was sent to local Dairy industries for cheese production, and 1.35 lambs/ewe were harvested as milk-fed lambs (lechazo). Artificial lamb rearing was done in 38% of farms (automatic, 81%; manual, 19%). Total mixed rations were used in 33% of farms, and the rest used rationed concentrate (including self-produced cereals) according to physiological stage of the ewes (0.45 to 1.97 kg/d) and ad libitum forage (dehydrated, 70%; hay, 68%; fresh, 25%; silage, 12%). The concentrate-to-forage ratio ranged between 32 and 61%. In total, 68% of farms bought more than half of the forage, and 87% of them bought more than half of the required concentrates. According to structural, productive, and managerial traits, 4 types of farms were differentiated by using multiple correspondence analysis and cluster analysis. Type groups were: 1) large-surface farms, devoted to cereal and forage production, predominantly with Awassi crossbreed Sheep and a high level of self-consumed commodities (12% of the farms); 2) large flocks with intermediate farm surfaces devoted to forage production and predominantly with Assaf Sheep (30% of the farms); 3) high-yielding farms, with intermediate sized flocks of Assaf Sheep and very intensive management (42% of the farms); and, 4) no-land farms predominantly with Assaf Sheep (16% of the farms). In conclusion, the Dairy Sheep farms studied showed more adoption of intensive production systems than traditional farms, which resulted in higher milk and lamb yields. Despite all of them being based on familiar units, as traditional farms, they were highly dependent on external resources and became more vulnerable, faced with future uncertainties of the market.
Baldassare Portolano - One of the best experts on this subject based on the ideXlab platform.
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genome wide linkage disequilibrium and genetic structure in sicilian Dairy Sheep breeds
BMC Genetics, 2014Co-Authors: Salvatore Mastrangelo, Maria Teresa Sardina, Marco Tolone, Rosalia Di Gerlando, Lina Tortorici, Baldassare PortolanoAbstract:Background The recent availability of Sheep genome-wide SNP panels allows providing background information concerning genome structure in domestic animals. The aim of this work was to investigate the patterns of linkage disequilibrium (LD), the genetic diversity and population structure in Valle del Belice, Comisana, and Pinzirita Dairy Sheep breeds using the Illumina Ovine SNP50K Genotyping array.
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parentage verification of valle del belice Dairy Sheep using multiplex microsatellite panel
Small Ruminant Research, 2013Co-Authors: Artur J M Rosa, Maria Teresa Sardina, Salvatore Mastrangelo, Marco Tolone, Baldassare PortolanoAbstract:Abstract The aim of this work was to develop and evaluate a PCR based microsatellite markers multiplex system for parentage verification of Sicilian Valle del Belice Dairy Sheep. A total of 85 samples of blood and hair were collected and genotyped for 24 microsatellite markers in multiplex electrophoresis runs. A total of 269 alleles were detected across the 24 loci investigated. The PIC considering all loci was equal to 0.736, showing that this microsatellite panel was very polymorphic and highly informative. A parentage test was performed on 64 families generated with multiple sires. Results indicated 20.3% and 29.7% misidentification rates for females and males, respectively. In 8 cases, out of 13 maternal exclusions, the real mother was identified among other females within the flock. The observed misidentification rates indicated the necessity of keeping more efficient collection of genealogical records, in order to properly control inbreeding or implement a breeding program. The parentage test presented here could be a helpful tool on verifying or even reconstructing the current pedigree data of Valle del Belice Dairy Sheep breed.
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economic values for production and functional traits in valle del belice Dairy Sheep using profit functions
Small Ruminant Research, 2011Co-Authors: Marco Tolone, Valentina Riggio, D O Maizon, Baldassare PortolanoAbstract:Abstract A deterministic static model was used to estimate the economic values (EV) of production (MY, milk yield; BW, birth weight; and ADG, average daily gain) and functional traits (ASR, adult survival rate; LSR, lamb survival rate; FE, fertility; PR, prolificacy; and LW ewe , mature weight of ewe) in Valle del Belice Dairy Sheep. In this study, values for the biological parameters and the production traits used in the model were taken from real data, by surveying 15 Valle del Belice farmers and reflected the production circumstances of pasture based Dairy production systems. In this system feed cost accounted for 95% of total variable costs, whereas fixed costs were low and reflected traditional and small ruminants’ husbandry system. A base situation with a fixed number of animals was considered to estimate the EV for the traits considered in this study. Economic values were positive for production traits: € 0.31 (MY, kg), € 4.40 (BW, kg) and € 0.15 (ADG, g) and for functional traits: € 2.15 (ASR, %), € 0.78 (LSR, %), € 2.64 (FE, %), € 0.39 (PR, %), except for LW ewe that was negative (€ −0.08, kg). Sensitivity analysis of EV to changes in prices indicated that future economic values for traits might change dependent on output and price levels, in particular on milk and meat price level. This study suggests that genetic improvement of milk production, lamb and adult survival rate, fertility and prolificacy will have a positive effect on profitability of pasture based Dairy production system.
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effect of heat stress on production of mediterranean Dairy Sheep
Journal of Dairy Science, 2005Co-Authors: R Finocchiaro, Baldassare Portolano, J B C H M Van Kaam, I MisztalAbstract:A study on heat stress in Mediterranean Dairy Sheep was undertaken with the objective to examine the relationship between milk production and heat stress, to estimate the additive genetic variances of milk production traits and heat tolerance, and to investigate the possibility of future selection for increased heat tolerance. Production data included 59,661 test-day records belonging to 6624 lactations of 4428 lactating ewes from 17 flocks collected from 1994 through 2003. The traits investigated were daily milk yield, fat and protein percentage, and daily yield of fat-plus-protein. The pedigree file consisted of 5306 animals; in addition to the 4428 animals with records, 188 male and 690 female ancestors were included. Heat stress was modeled by using data from a weather station. Apart from the effects of the weather conditions of the milk recording test-day, the effects of the preceding 1, 2, and 3 d were determined. Because longer periods of heat stress might have a more severe effect than shorter periods, 2-, 3-, and 4-d periods were also considered, by averaging the weather data measurements. Fixed regression analyses were based on models that included effects of flock nested within year of test-day, DIM (days in milk) class x parity class, and several types of weather indicators. The preferred model using the temperature-humidity index (THI) gave a smoother pattern than did the model with temperature x humidity interaction. Both daily milk and fat-plus-protein yield appeared to decrease at THI > or = 23, in all periods considered. Based on the 4-d period, yield decreased for each unit increase of THI above 23 [-62.8 g/unit (-4.2%) for daily milk yield and -8.9 g/unit (-4.9%) for daily fat-plus-protein yield]. Fat and protein percentages appeared to be unaffected by heat stress. A test-day repeatability model was applied for estimation of genetic parameters. The genetic correlations between the general additive effect and the additive effect of heat tolerance were negative (approximately -0.8) for both daily milk and fat-plus-protein yields in all periods considered. Therefore, milk yield is antagonistic with heat tolerance, and selection only for increased milk production will reduce heat tolerance.
J M Astruc - One of the best experts on this subject based on the ideXlab platform.
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a validation study of loci associated with mastitis resistance in two french Dairy Sheep breeds
Genetics Selection Evolution, 2019Co-Authors: Claire Oget, J M Astruc, Charlotte Allain, David Portes, Gilles Foucras, Alessandra Stella, Julien Sarry, Gwenola Tosserklopp, Rachel RuppAbstract:The identification of loci associated with resistance to mastitis or of the causative mutations may be helpful in breeding programs for Dairy Sheep as it is for cattle worldwide. Seven genomic regions that control milk somatic cell counts, an indirect indicator of udder infection, have already been identified in Sheep (Spanish Churra, French Lacaune and Italian Sardinian–Lacaune backcross populations). In this study, we used a 960 custom-designed ovine single nucleotide polymorphism (SNP) chip in Lacaune and Manech Tete Rousse Dairy Sheep to validate these seven genomic regions associated with mastitis. The most significant SNP (rs868996547) on Ovis aries chromosome (OAR) 3 was a previously described mutation in the suppressor of cytokine signalling 2 (SOCS2) gene. An antagonist effect of this causal candidate between health and growth in Lacaune Sheep was confirmed. Effects of the mutation on the infectious status of the udder, i.e. increases in milk somatic cell counts and bacteria shedding, were also identified. This SNP was not present in the data available on Manech Tete Rousse. Three other regions associated with mastitis were also confirmed on OAR16 (Manech Tete Rousse), 19 (Lacaune) and 2 (both breeds). For the OAR2 region, we validated previously detected SNPs in several other breeds (Sarda, Churra, and Chios). For significant SNPs in the four mastitis regions, the effect varied from 0.24 to 0.67 phenotypic standard deviation of the traits. Two of the mastitis quantitative trait loci (QTL) regions (OAR2 and 16) that we validated here were also associated in opposite ways with milk production traits in both populations. These results indicate, at least in part, a genomic basis for the trade-off between milk production and mastitis resistance. Four of the seven mastitis QTL regions that were previously identified in independent populations, were confirmed in this study, which demonstrates partial sharing of mastitis-related genetic mechanisms between different distant Dairy Sheep populations.
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within and across breed genomic predictions and genomic relationships for western pyrenees Dairy Sheep breeds latxa manech and basco bearnaise
Journal of Dairy Science, 2014Co-Authors: A Legarra, G Baloche, F Barillet, J M Astruc, C Soulas, X Aguerre, F Arrese, L Mintegi, M Lasarte, F MaeztuAbstract:Genotypes, phenotypes and pedigrees of 6 breeds of Dairy Sheep (including subdivisions of Latxa, Manech, and Basco-Bearnaise) from the Spain and France Western Pyrenees were used to estimate genetic relationships across breeds (together with genotypes from the Lacaune Dairy Sheep) and to verify by forward cross-validation single-breed or multiple-breed genetic evaluations. The number of rams genotyped fluctuated between 100 and 1,300 but generally represented the 10 last cohorts of progeny-tested rams within each breed. Genetic relationships were assessed by principal components analysis of the genomic relationship matrices and also by the conservation of linkage disequilibrium patterns at given physical distances in the genome. Genomic and pedigree-based evaluations used daughter yield performances of all rams, although some of them were not genotyped. A pseudo-single step method was used in this case for genomic predictions. Results showed a clear structure in blond and black breeds for Manech and Latxa, reflecting historical exchanges, and isolation of Basco-Bearnaise and Lacaune. Relatedness between any 2 breeds was, however, lower than expected. Single-breed genomic predictions had accuracies comparable with other breeds of Dairy Sheep or small breeds of Dairy cattle. They were more accurate than pedigree predictions for 5 out of 6 breeds, with absolute increases in accuracy ranging from 0.05 to 0.30 points. They were significantly better, as assessed by bootstrapping of candidates, for 2 of the breeds. Predictions using multiple populations only marginally increased the accuracy for a couple of breeds. Pooling populations does not increase the accuracy of genomic evaluations in Dairy Sheep; however, single-breed genomic predictions are more accurate, even for small breeds, and make the consideration of genomic schemes in Dairy Sheep interesting.
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assessment of accuracy of genomic prediction for french lacaune Dairy Sheep
Journal of Dairy Science, 2014Co-Authors: G Baloche, J M Astruc, Andres Legarra, Guillaume Salle, H Larroque, Christele Robertgranie, F BarilletAbstract:Abstract Genomic selection in Lacaune Dairy Sheep was investigated based on genotypes from the OvineSNP50 BeadChip (Illumina Inc., San Diego, CA). Historical artificial insemination progeny-tested rams formed a population of 2,892 genotyped rams. Additional ungenotyped rams and females were included by single-step genomic BLUP (ssGBLUP). Three prediction strategies were tried: pseudo-BLUP (using all rams and daughter yield deviations), pseudo-ssGBLUP (using all rams and daughter yield deviations), and regular ssGBLUP (using all phenotypes and pedigree in an animal model). The population linkage disequilibrium was determined, with an average squared correlation coefficient of 0.11 for markers closer than 0.1cM (lower than in Dairy cattle). The estimated effective population is 370 individuals. Gain in accuracy of genomic selection over parent averages ranged from 0.10 to 0.20. Highest accuracies and lowest bias were found using regular ssGBLUP. Transition to a genomic breeding scheme is possible but costs need to be carefully evaluated.
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genomic selection in the french lacaune Dairy Sheep breed
Journal of Dairy Science, 2012Co-Authors: S I Duchemin, Francis Barillet, G Baloche, J M Astruc, Andres Legarra, H Larroque, Christele Robertgranie, Carine Colombani, E ManfrediAbstract:Genomic selection aims to increase accuracy and to decrease generation intervals, thus increasing genetic gains in animal breeding. Using real data of the French Lacaune Dairy Sheep breed, the purpose of this study was to compare the observed accuracies of genomic estimated breeding values using different models (infinitesimal only, markers only, and joint estimation of infinitesimal and marker effects) and methods [BLUP, Bayes Cπ, partial least squares (PLS), and sparse PLS]. The training data set included results of progeny tests of 1,886 rams born from 1998 to 2006, whereas the validation set had results of 681 rams born in 2007 and 2008. The 3 lactation traits studied (milk yield, fat content, and somatic cell scores) had heritabilities varying from 0.14 to 0.41. The inclusion of molecular information, as compared with traditional schemes, increased accuracies of estimated breeding values of young males at birth from 18 up to 25%, according to the trait. Accuracies of genomic methods varied from 0.4 to 0.6, according to the traits, with minor differences among genomic approaches. In Bayes Cπ, the joint estimation of marker and infinitesimal effects had a slightly favorable effect on the accuracies of genomic estimated breeding values, and were especially beneficial for somatic cell counts, the less heritable trait. Inclusion of infinitesimal effects also improved slopes of predictive regression equations. Methods that select markers implicitly (Bayes Cπ and sparse PLS) were advantageous for some models and traits, and are of interest for further quantitative trait loci studies.
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The French Lacaune Dairy Sheep breed: use in France and abroad in the last 40 years
Livestock Production Science, 2001Co-Authors: Francis Barillet, C. Marie, M. Jacquin, G. Lagriffoul, J M AstrucAbstract:Abstract The situation of the Lacaune Dairy Sheep breed has evolved dramatically during the last 40 years. In the 1960s, this dual purpose breed had a low milk yield and was compared in its local basin of production (the Roquefort area) with foreign high milk yield breeds, i.e. Friesian and Sarda breeds. The results showed very disappointing performances, both for lamb production for the Sarda breed, and for mortality for genotypes with more than 50% Friesian genes, the Friesian breed appearing to be poorly adapted to the local conditions. Therefore, in the 1970s a synthetic line called FSL (3/8 Friesian, 3/8 Sarda, 2/8 Lacaune) was created to avoid having more than 50% of the genes coming from an imported breed. Since the Lacaune genetic improvement program had become fully efficient in the 1980s, a crossbreeding strategy was disregarded in the Roquefort area. The Lacaune breed is now one of the high milk yield breeds, efficiently selected for milk yield and milk composition, type traits, and, in the near future, also for somatic cell count and udder score. Since 1992, 17 countries have officially imported Lacaune germplasm from France. However, to our knowledge, few comparisons are available, except in Spain with the Churra and Manchega breeds, and initially in Switzerland and Germany, and then in Canada, with the Friesian breed. The results appeared to be favorable for the Lacaune breed, in agreement with French experiments carried out with two divergent (high and low milk yield) Lacaune lines for a group of production traits including feed efficiency and milkability. However, we suggest to candidate importers: (i) to import Lacaune from the French Breeders Association to obtain the best available germplasm; (ii) to verify the adaptation of the Lacaune breed to their local breeding conditions, and/or to improve their husbandry systems (especially feeding) to account for the high milk yield of the breed.
