The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
C Peris - One of the best experts on this subject based on the ideXlab platform.
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quantitative estimation of the impact of caprine arthritis encephalitis virus infection on milk production by dairy goats
Veterinary Journal, 2013Co-Authors: Bernardo Martineznavalon, C Peris, Ernesto A Gomez, Bernat Peris, Maria Luz Roche, Concepcion Caballero, E Goyena, E BerriatuaAbstract:This retrospective study investigated milk production losses associated with serological evidence (serostatus) of caprine arthritis encephalitis virus (CAEV) infection over one Lactation in 4543 Murciano-Granadina goats from 22 herds in Spain. The seroprevalence of infection was 18%, ranging from 0% to 2% in 11 herds, 7% to 60% in 10 herds and was 100% in one herd. Seropositive does had significantly shorter Lactations, produced less milk and milk fat, lactose and dry extract and had higher somatic cell counts than their seronegative counterparts, although differences in milk production between seropositive and seronegative animals were noted between herds. Mixed regression models confirmed the association between CAEV seropositivity and reduced milk production. The adjusted, least squares mean (LSM) test-day milk yield was 10% less in seropositive compared to seronegative does and this difference varied according to Lactation Number. In contrast, differences in the LSM of milk fat, lactose and dry extract percentages between seropositive and seronegative goats were only between 0.1% and 0.2% and did not increase with Lactation Number. The findings of this study provide strong evidence that CAEV-infection can be a major cause of reduction in milk yield in goats and its control should be considered as part of dairy goat herd health schemes.
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effect of estrus synchronization on daily somatic cell count variation in goats according to Lactation Number and udder health status
Journal of Dairy Science, 2013Co-Authors: Amine Mehdid, J R Diaz, A Marti, G Vidal, C PerisAbstract:Abstract Two repeated experiments were carried out in 2 different years to study the effect of estrus on somatic cell count (SCC) in dairy goats. In the first year, 36 Murciano-Granadina goats were used [12 primiparous and 24 multiparous; 22 healthy and 14 with an intramammary infection (IMI)] and, after a 6-d pre-experimental period, were divided into 2 groups according to Lactation Number, udder health status, SCC, and milk production. One group was kept as a control, whereas the other received an estrus synchronization hormonal treatment lasting 11d. At 24, 48, and 72h after cessation of the hormone treatment, goats were placed in contact with a buck to confirm that they were in estrus. For 32 consecutive days (6 pre-experimental, 11 in hormone treatment, and 15 post-treatment) the SCC per gland and udder were monitored in all animals. In the second year, we repeated the same experimental design using a total of 38 Murciano-Granadina breed goats (12 primiparous and 26 multiparous; 26 healthy and 12 with IMI). Throughout this experiment, milk yield and composition were also recorded daily for each goat. Upon termination of the hormonal treatment, the SCC in udder milk increased significantly in the treatment group compared with the control group over 3 consecutive days. This increase was observed for year (1 and 2), parity (primiparous and multiparous), and udder health status (healthy and IMI). The log 10 SCC (cells/mL) increased from 5.5±0.09 before estrus to 6.04±0.09 during treatment; therefore, the geometric mean of the SCC increased 3.5 times during treatment. The maximum values obtained in healthy glands of primiparous goats (geometric mean=0.37 million cells/mL) were lower than in healthy glands (1.1 million cells/mL) or infected glands (1.7 million cells/mL) of multiparous goats. The increase in SCC observed during estrus (200% increase in geometric means) could not be explained by the changes in milk production, which only fell by 13%. During estrus, the percentage of protein and dry matter in the milk also increased significantly. We concluded that it is necessary to consider the presence of estrus to correctly interpret milk SCC, as an indirect method for detecting IMI or as a commercial milk quality parameter.
Persson K Waller - One of the best experts on this subject based on the ideXlab platform.
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bovine subclinical mastitis caused by different types of coagulase negative staphylococci
Journal of Dairy Science, 2009Co-Authors: B M Thorberg, Marielouise Danielssontham, Ulf Emanuelson, Persson K WallerAbstract:Subclinical mastitis caused by intramammary infections (IMI) with coagulase-negative staphylococci (CNS) is common in dairy cows and may cause herd problems. Control of CNS mastitis is complicated by the fact that CNS contain a large Number of different species. The aim of the study was to investigate the epidemiology of different CNS species in dairy herds with problems caused by subclinical CNS mastitis. In 11 herds, udder quarter samples were taken twice 1 mo apart, and CNS isolates were identified to the species level by biochemical methods. The ability of different CNS species to induce a persistent infection, and their associations with milk production, cow milk somatic cell count, Lactation Number, and month of Lactation in cows with subclinical mastitis were studied. Persistent IMI were common in quarters infected with Staphylococcus chromogenes, Staphylococcus epidermidis, and Staphylococcus simulans. The results did not indicate differences between these CNS species in their association with daily milk production, cow milk somatic cell count, and month of Lactation in cows with subclinical mastitis. In cows with subclinical mastitis, S. epidermidis IMI were mainly found in multiparous cows, whereas S. chromogenes IMI were mainly found in primiparous cows.
M P Molina - One of the best experts on this subject based on the ideXlab platform.
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short communication goat colostrum quality litter size and Lactation Number effects
Journal of Dairy Science, 2013Co-Authors: T Romero, M C Beltran, M Rodriguez, Marti A De Olives, M P MolinaAbstract:The quality of colostrum of Murciano-Granadina goats was studied to establish the transition period and the time when milk can be marketed. Forty-three dairy goats were used: 19 primiparous (15 single births; 4 multiple births) and 24 multiparous (10 single births; 14 multiple births). Samples were collected every 12 h during the first week postpartum. Physicochemical parameters and somatic cell count were determined. Analysis of variance with repeated measures was used to study the effect of different factors: postpartum time, litter size, Lactation Number, their interactions, and production level on colostrum. Postpartum time had a significant effect on all parameters studied, which decreased along the first week of Lactation, whereas lactose, pH, and conductivity increased. Based on these results, colostrum secretion takes place until 36 h postpartum (hpp). In relation to other factors of variation studied, the Lactation Number influenced most colostrum components, whereas the litter size only affected the pH value, protein and lactose content. The production level influenced only the protein and dry matter contents, with an inverse relationship. Milk produced during the period between 36 and 96 hpp is considered transition milk, which should not be commercialized. Milk collected after 4 d postpartum (96 hpp) could be marketed, ensuring that its composition does not present a risk in the dairy industry.
Amine Mehdid - One of the best experts on this subject based on the ideXlab platform.
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effect of estrus synchronization on daily somatic cell count variation in goats according to Lactation Number and udder health status
Journal of Dairy Science, 2013Co-Authors: Amine Mehdid, J R Diaz, A Marti, G Vidal, C PerisAbstract:Abstract Two repeated experiments were carried out in 2 different years to study the effect of estrus on somatic cell count (SCC) in dairy goats. In the first year, 36 Murciano-Granadina goats were used [12 primiparous and 24 multiparous; 22 healthy and 14 with an intramammary infection (IMI)] and, after a 6-d pre-experimental period, were divided into 2 groups according to Lactation Number, udder health status, SCC, and milk production. One group was kept as a control, whereas the other received an estrus synchronization hormonal treatment lasting 11d. At 24, 48, and 72h after cessation of the hormone treatment, goats were placed in contact with a buck to confirm that they were in estrus. For 32 consecutive days (6 pre-experimental, 11 in hormone treatment, and 15 post-treatment) the SCC per gland and udder were monitored in all animals. In the second year, we repeated the same experimental design using a total of 38 Murciano-Granadina breed goats (12 primiparous and 26 multiparous; 26 healthy and 12 with IMI). Throughout this experiment, milk yield and composition were also recorded daily for each goat. Upon termination of the hormonal treatment, the SCC in udder milk increased significantly in the treatment group compared with the control group over 3 consecutive days. This increase was observed for year (1 and 2), parity (primiparous and multiparous), and udder health status (healthy and IMI). The log 10 SCC (cells/mL) increased from 5.5±0.09 before estrus to 6.04±0.09 during treatment; therefore, the geometric mean of the SCC increased 3.5 times during treatment. The maximum values obtained in healthy glands of primiparous goats (geometric mean=0.37 million cells/mL) were lower than in healthy glands (1.1 million cells/mL) or infected glands (1.7 million cells/mL) of multiparous goats. The increase in SCC observed during estrus (200% increase in geometric means) could not be explained by the changes in milk production, which only fell by 13%. During estrus, the percentage of protein and dry matter in the milk also increased significantly. We concluded that it is necessary to consider the presence of estrus to correctly interpret milk SCC, as an indirect method for detecting IMI or as a commercial milk quality parameter.
D V Armstrong - One of the best experts on this subject based on the ideXlab platform.
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season and Lactation Number effects on milk production and reproduction of dairy cattle in arizona
Journal of Dairy Science, 1992Co-Authors: D E Ray, T J Halbach, D V ArmstrongAbstract:Records representing 19,266 Holstein cows from Arizona DHIA data over a 5-yr period were analyzed to determine the effects of season and Lactation Number on milk production and reproduction. Seasons were winter (December, January, and February), spring (March, April, and May), summer (June, July, and August), and fall (September, October, and November). Traits analyzed by least squares ANOVA were 305-d FCM, complete Lactation milk, calving interval, and services per conception. All sources of variation were significant except the interaction between Lactation Number and season of calving for complete Lactation milk. Milk production was depressed for cows calving in summer and fall. First Lactation cows had lowest milk production, and highest production occurred in either Lactation 4 or 5. Cows calving in spring and summer had reduced reproductive performance, as measured by calving interval and services per conception. First Lactation cows had lowest values for both reproductive traits. Previous days dry was negatively related to milk production for spring calvings but was positively related for all other seasons. Cows with higher milk production had reduced reproductive performance. Partial regression coefficients for calving interval and services per conception were 12 d and .25 services per conception per 1000 kg of 305-d FCM, respectively. Despite the negative effects of thermal stress, milk production and fertility in this study were not depressed as severely as in previous research reported from Arizona. Calving schedules may be adjusted to minimize the adverse effect of heat stress.
