The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
T.b. Mcfadden - One of the best experts on this subject based on the ideXlab platform.
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The Milk Yield Response to Frequent Milking in Early Lactation of Dairy Cows Is Locally Regulated
Journal of dairy science, 2007Co-Authors: Emma H. Wall, T.b. McfaddenAbstract:Abstract Frequent milking during Early Lactation of dairy cows increases milk production throughout Lactation; however, whether this response is regulated systemically via lactogenic hormones, locally in the mammary gland, or both is unknown. We hypothesized that the effects of frequent milking on milk production during Early Lactation are regulated via local mechanisms. Ten multiparous cows were assigned at parturition to unilateral frequent milking [UFM; twice daily milking of the left udder half (2×), or 4 times daily milking of the right udder half (4×)] for d 1 to 21 of Lactation. After treatment, cows were milked twice daily for the remainder of Lactation. At the first milking after calving, milk yield from individual quarters was measured to verify that udder halves produced equal amounts of milk prior to treatment. Thereafter, individual quarters were milked on d 3 and 7, weekly for the first 5 wk of Lactation, and once every 3 mo for the remainder of Lactation. During UFM, cows produced 3.9±0.7 kg/d more from the side milked 4× than the side milked 2×. Upon cessation of treatment, milk production from the side milked 4× decreased, but remained at 1.8±0.5 kg/d more than the side milked 2× for the remainder of Lactation. After milk yield was corrected to the equivalent of a whole-udder basis, acute milk yield responses to frequent milking were found to be consistent with previous reports. Moreover, we observed greater persistency in the milk yield response, which lasted throughout Lactation. We conclude that both immediate and persistent effects on milk production of frequent milking during Early Lactation are regulated at the level of the mammary gland. Our results demonstrate that UFM is a valid and efficient model for investigating the effects of frequent milking during Early Lactation in dairy cows.
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Mammary response to exogenous prolactin or frequent milking during Early Lactation in dairy cows.
Journal of dairy science, 2006Co-Authors: Emma H. Wall, Geoffrey E. Dahl, Heather M. Crawford, S.e. Ellis, T.b. McfaddenAbstract:Abstract Frequent milking of dairy cows during Early Lactation results in a persistent increase in milk yield; however, the mechanism underlying this effect is unknown. We hypothesized that increased exposure of the mammary gland to prolactin (PRL) mediates the milk yield response. Fifteen multiparous Holstein cows were assigned to 3 treatments for the first 3 wk of Lactation: twice daily milking with (2× + PRL) or without (2×) supplemental exogenous PRL, or 4 times daily milking (4×). Mammary biopsies were obtained at 7 DIM, and rates of [ 3 H]thymidine incorporation into DNA in vitro were determined. Mammary expression of suppressors of cytokine signaling (SOCS)-1, -2, and -3; the long form of PRL-receptor; and α-lactalbumin mRNA was measured by real-time reverse-transcription PCR. Incorporation of [ 3 H]thymidine into DNA was not affected by frequent milking or PRL treatment; however, analysis of autoradiograms revealed that stromal cell proliferation was greater in 4× cows. Mammary expression of SOCS-1 was not affected by milking frequency or PRL treatment. Expression of SOCS-2 mRNA was increased with frequent milking or PRL treatment, whereas expression of SOCS-3 mRNA was reduced by frequent milking or exogenous PRL. Abundance of PRL-receptor mRNA was reduced, whereas α-lactalbumin mRNA was increased with PRL treatment. These results demonstrate that the bovine mammary gland is responsive to exogenous PRL during Early Lactation. In addition, differences in the response to frequent milking or exogenous PRL during Early Lactation indicate distinct effects of PRL and milk removal on the mammary function of dairy cows.
Björn Kuhla - One of the best experts on this subject based on the ideXlab platform.
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Proteomics and the Characterization of Fatty Liver Metabolism in Early Lactation Dairy Cows
Proteomics in Domestic Animals: from Farm to Systems Biology, 2018Co-Authors: Björn Kuhla, Klaus Lønne IngvartsenAbstract:The high-yielding dairy cow faces major adaptions during the transition period from late pregnancy to Early Lactation where physiological changes occur in support of the dramatically increase in milk yield. The coordinated physiological changes secure mobilization of nutrients and energy from the body tissue that, in part, covers the rapid increase in nutrient needs for milk production in Early Lactation. Large amounts of energy are released from fat tissue as non-esterified fatty acids (NEFAs) which together with a depressed increase in energy intake are bringing the cow into a state of negative energy balance. Approximately 25% of the NEFA passes through the liver, where it is metabolized or esterified to triglyceride. When the latter becomes excessive, fatty liver or hepatic lipidosis generally as a subclinical disease state will occur. This chapter investigates realizations in the molecular factors potentially causing fatty liver in the transition cow discovered using proteomics.
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metabolic response to heat stress in late pregnant and Early Lactation dairy cows implications to liver muscle crosstalk
PLOS ONE, 2016Co-Authors: Franziska Koch, Ole Lamp, Mehdi Eslamizad, Joachim M Weitzel, Björn KuhlaAbstract:Climate changes lead to rising temperatures during summer periods and dramatic economic losses in dairy production. Modern high-yielding dairy cows experience severe metabolic stress during the transition period between late gestation and Early Lactation to meet the high energy and nutrient requirements of the fetus or the mammary gland, and additional thermal stress during this time has adverse implications on metabolism and welfare. The mechanisms enabling metabolic adaptation to heat apart from the decline in feed intake and milk yield are not fully elucidated yet. To distinguish between feed intake and heat stress related effects, German Holstein dairy cows were first kept at thermoneutral conditions at 15°C followed by exposure to heat-stressed (HS) at 28°C or pair-feeding (PF) at 15°C for 6 days; in late-pregnancy and again in Early Lactation. Liver and muscle biopsies and plasma samples were taken to assess major metabolic pathway regulation using real-time PCR and Western Blot. The results indicate that during heat stress, late pregnant cows activate Cahill but reduce Cori cycling, prevent increase in skeletal muscle fatty acid oxidation, and utilize increased amounts of pyruvate for gluconeogenesis, without altering ureagenesis despite reduced plane of nutrition. These homeorhetic adaptations are employed to reduce endogenous heat production while diverting amino acids to the growing fetus. Metabolic adaptation to heat stress in Early Lactation involves increased long-chain fatty acid degradation in muscle peroxisomes, allowance for muscle glucose utilization but diminished hepatic use of amino acid-derived pyruvate for gluconeogenesis and reduced peroxisomal fatty acid oxidation and ATP production in liver of HS compared to PF cows in Early Lactation. Consequently, metabolic adaptation to heat stress and reduced feed intake differ between late pregnancy and Early Lactation of dairy cows to maintain energy supply for fetus development or milk production simultaneously reducing endogenous heat production.
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Involvement of skeletal muscle protein, glycogen, and fat metabolism in the adaptation on Early Lactation of dairy cows.
Journal of Proteome Research, 2011Co-Authors: Björn Kuhla, Gerd Nürnberg, Dirk Albrecht, S. Görs, Harald M. Hammon, Cornelia C. MetgesAbstract:During Early Lactation, high-yielding dairy cows cannot consume enough feed to meet nutrient requirements. As a consequence, animals drop into negative energy balance and mobilize body reserves including muscle protein and glycogen for milk production, direct oxidation, and hepatic gluconeogenesis. To examine which muscle metabolic processes contribute to the adaptation during Early Lactation, six German Holstein cows were blood sampled and muscle biopsied throughout the periparturient period. From pregnancy to Lactation, the free plasma amino acid pattern imbalanced and plasma glucose decreased. Several muscle amino acids, as well as total muscle protein, fat, and glycogen, and the expression of glucose transporter-4 were reduced within the first 4 weeks of Lactation. The 2-DE and MALDI-TOF-MS analysis identified 43 differentially expressed muscle protein spots throughout the periparturient period. In Early Lactation, expression of cytoskeletal proteins and enzymes involved in glycogen synthesis and in the TCA cycle was decreased, whereas proteins related to glycolysis, fatty acid degradation, lactate, and ATP production were increased. On the basis of these results, we propose a model in which the muscle breakdown in Early Lactation provides substrates for milk production by a decoupled Cori cycle favoring hepatic gluconeogenesis and by interfering with feed intake signaling.
Henk Hogeveen - One of the best experts on this subject based on the ideXlab platform.
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Cost estimation of heifer mastitis in Early Lactation by stochastic modelling.
Veterinary microbiology, 2008Co-Authors: Kirsten Huijps, Sarne De Vliegher, Theo Lam, Henk HogeveenAbstract:Heifer mastitis, reflected by an elevated somatic cell count (SCC) in Early Lactation (SCCel), results in a decreased milk production, a higher risk for subclinical and clinical mastitis during Lactation, and an elevated culling hazard. The aims of this study were to calculate the costs of heifer mastitis defined as an elevated SCC in Early Lactation, and to show the variation of these costs in the Dutch/Belgian dairy sector. A stochastic model, in which the variation and uncertainty of heifer mastitis are taken into the account, was developed with input data from literature and expertise. Costs were estimated, using default values. The mean costs for an elevated SCCel that cured were on average euro 13/heifer present on a farm (range: euro 0-118), for an elevated SCC at calving proceeding in subclinical mastitis on average euro 5/heifer present on a farm (range: euro 0-euro 82), and for a clinical heifer mastitis case associated with an elevated SCC after calving on average euro 270. On average this results in euro 13/heifer present on a farm (range: euro 0-137). Combined, these three cost aspects result in a total cost of on average euro 31/heifer present on a farm (range: euro 0-220). The large variation in the costs is very important regarding farm management and farm support. The difference in costs reflects also the difference in room for investment. When the costs that can be prevented are estimated at farm level, these data can be of help in setting goals in herd health advice and farm management.
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Cost estimation of heifer mastitis in Early Lactation by stochastic modelling
Veterinary Microbiology, 2008Co-Authors: Kirsten Huijps, Theo J.g.m. Lam, Sarne De Vliegher, Henk HogeveenAbstract:Abstract Heifer mastitis, reflected by an elevated somatic cell count (SCC) in Early Lactation (SCCel), results in a decreased milk production, a higher risk for subclinical and clinical mastitis during Lactation, and an elevated culling hazard. The aims of this study were to calculate the costs of heifer mastitis defined as an elevated SCC in Early Lactation, and to show the variation of these costs in the Dutch/Belgian dairy sector. A stochastic model, in which the variation and uncertainty of heifer mastitis are taken into the account, was developed with input data from literature and expertise. Costs were estimated, using default values. The mean costs for an elevated SCCel that cured were on average €13/heifer present on a farm (range: €0–118), for an elevated SCC at calving proceeding in subclinical mastitis on average €5/heifer present on a farm (range: €0–€82), and for a clinical heifer mastitis case associated with an elevated SCC after calving on average €270. On average this results in €13/heifer present on a farm (range: €0–137). Combined, these three cost aspects result in a total cost of on average €31/heifer present on a farm (range: €0–220). The large variation in the costs is very important regarding farm management and farm support. The difference in costs reflects also the difference in room for investment. When the costs that can be prevented are estimated at farm level, these data can be of help in setting goals in herd health advice and farm management.
Thomas R. Overton - One of the best experts on this subject based on the ideXlab platform.
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Performance of Early-Lactation dairy cows as affected by dietary starch and monensin supplementation.
Journal of dairy science, 2015Co-Authors: M.m. Mccarthy, C.m. Ryan, T. Yasui, G.d. Mechor, Thomas R. OvertonAbstract:The objective of this study was to evaluate the effect of postpartum dietary starch content and monensin supplementation throughout the periparturient period and into Early Lactation on production performance of dairy cows during Early Lactation. Prior to parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% NDF, 22.7% ADF, 15.5% CP) or low-starch (LS; 21.5% starch, 36.9% NDF, 25.2% ADF, 15.4% CP) total mixed ration with a daily topdress of either 0mg/d of monensin or 450mg/d monensin (MON), continuing with prepartum topdress treatment assignment. From d 22 through 63 postpartum, cows were fed HS and continued with their assigned daily topdress. Interactions of starch content and MON supplementation were not significant for any of the variables measured. Cows fed HS from wk 1 to 3 postpartum had higher Early-Lactation milk yields (starch × week interaction) compared with LS cows, but HS cows also had lower percentages of milk fat, true protein, lactose, and total solids during the same period, resulting in similar yields of energy-corrected milk (ECM) between starch treatments. Cows fed HS had higher Early-Lactation dry matter intake (DMI; starch × week interaction) and lost less body condition score during wk 1 to 3, contributing to improved energy balance postpartum. No effect of starch treatment was observed on apparent total-tract dry matter or starch digestibilities assessed during d 18 to 19 (±2) postpartum, although cows fed the LS diet had greater apparent total-tract NDF digestibility compared with cows fed the HS diet. Cows fed MON had higher DMI and higher milk yields during the first 9 wk of Lactation. However, all cows had similar yields of ECM because of trends for lower milk fat content during Early Lactation. In part because of similar yields of ECM between these treatments and higher DMI for cows fed MON, ECM per DMI during the first 9 wk of Lactation was not affected by MON treatment. There was no effect of MON treatment on apparent total-tract dry matter, NDF, or starch digestibilities. Overall, cows fed more propiogenic diets in Early Lactation (HS or MON) had increased milk yield and DMI during the immediate postpartum period, indicating that diets with greater propiogenic capacity do not have detrimental effects on Early-Lactation DMI.
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The effects of increased milking frequency during Early Lactation on milk yield and milk composition on commercial dairy farms.
Journal of Dairy Science, 2011Co-Authors: F. Soberon, D.m. Galton, C.m. Ryan, Daryl V. Nydam, Thomas R. OvertonAbstract:Abstract Increased milking frequency (IMF) during Early Lactation has the potential for carryover responses following the return to normal herd milking frequency. The objective was to determine the consistency of response of cows in commercial dairy farms to IMF during Early Lactation. Cows (n = 398) were assigned randomly at calving within each of the 4 participating farms to 1 of 2 treatments. The control group was milked twice-daily (2×) during the entire Lactation. The IMF group was milked 4-times daily (4×) starting on d 1 to 7, depending on farm, until d 21 postcalving and 2× thereafter. Cows in the IMF group were milked at the beginning and again at the end of the normal milking routine. Milking intervals differed across the farms for the 4× cows with a minimum interval of 3.5, 4.0, 5.0, and 6 h for each of the 4 farms, respectively. The milk yield of cows subjected to IMF increased by 2.2 ± 0.4 kg/d during the first 7 mo of Lactation. Interactions of treatment with Lactation group (primiparous vs. multiparous) were not significant. Although percentages of fat and protein in milk were decreased by Early Lactation IMF (3.69% ± 0.03 fat and 3.05% ± 0.02 true protein for control vs. 3.57% ± 0.03 fat and 2.99% ± 0.02 true protein for IMF), overall yields of protein were increased by IMF (1.02 ± 0.01 vs. 0.98 ± 0.01 kg/d). Early Lactation IMF did not affect udder health as assessed by somatic cell count linear score. Cows subjected to IMF were 1.4 times more likely classified as subclinically ketotic than the control cows. Early Lactation IMF has the potential to increase milk yield on commercial dairy farms. Although the direction of response was the same on all farms, the magnitude of the response was different among farms and appears influenced by management practices specific to each farm, which included, but were not limited to, housing system, stocking density, nutrition, genetics, and other covariates differing among farms.
Emma H. Wall - One of the best experts on this subject based on the ideXlab platform.
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The Milk Yield Response to Frequent Milking in Early Lactation of Dairy Cows Is Locally Regulated
Journal of dairy science, 2007Co-Authors: Emma H. Wall, T.b. McfaddenAbstract:Abstract Frequent milking during Early Lactation of dairy cows increases milk production throughout Lactation; however, whether this response is regulated systemically via lactogenic hormones, locally in the mammary gland, or both is unknown. We hypothesized that the effects of frequent milking on milk production during Early Lactation are regulated via local mechanisms. Ten multiparous cows were assigned at parturition to unilateral frequent milking [UFM; twice daily milking of the left udder half (2×), or 4 times daily milking of the right udder half (4×)] for d 1 to 21 of Lactation. After treatment, cows were milked twice daily for the remainder of Lactation. At the first milking after calving, milk yield from individual quarters was measured to verify that udder halves produced equal amounts of milk prior to treatment. Thereafter, individual quarters were milked on d 3 and 7, weekly for the first 5 wk of Lactation, and once every 3 mo for the remainder of Lactation. During UFM, cows produced 3.9±0.7 kg/d more from the side milked 4× than the side milked 2×. Upon cessation of treatment, milk production from the side milked 4× decreased, but remained at 1.8±0.5 kg/d more than the side milked 2× for the remainder of Lactation. After milk yield was corrected to the equivalent of a whole-udder basis, acute milk yield responses to frequent milking were found to be consistent with previous reports. Moreover, we observed greater persistency in the milk yield response, which lasted throughout Lactation. We conclude that both immediate and persistent effects on milk production of frequent milking during Early Lactation are regulated at the level of the mammary gland. Our results demonstrate that UFM is a valid and efficient model for investigating the effects of frequent milking during Early Lactation in dairy cows.
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Mammary response to exogenous prolactin or frequent milking during Early Lactation in dairy cows.
Journal of dairy science, 2006Co-Authors: Emma H. Wall, Geoffrey E. Dahl, Heather M. Crawford, S.e. Ellis, T.b. McfaddenAbstract:Abstract Frequent milking of dairy cows during Early Lactation results in a persistent increase in milk yield; however, the mechanism underlying this effect is unknown. We hypothesized that increased exposure of the mammary gland to prolactin (PRL) mediates the milk yield response. Fifteen multiparous Holstein cows were assigned to 3 treatments for the first 3 wk of Lactation: twice daily milking with (2× + PRL) or without (2×) supplemental exogenous PRL, or 4 times daily milking (4×). Mammary biopsies were obtained at 7 DIM, and rates of [ 3 H]thymidine incorporation into DNA in vitro were determined. Mammary expression of suppressors of cytokine signaling (SOCS)-1, -2, and -3; the long form of PRL-receptor; and α-lactalbumin mRNA was measured by real-time reverse-transcription PCR. Incorporation of [ 3 H]thymidine into DNA was not affected by frequent milking or PRL treatment; however, analysis of autoradiograms revealed that stromal cell proliferation was greater in 4× cows. Mammary expression of SOCS-1 was not affected by milking frequency or PRL treatment. Expression of SOCS-2 mRNA was increased with frequent milking or PRL treatment, whereas expression of SOCS-3 mRNA was reduced by frequent milking or exogenous PRL. Abundance of PRL-receptor mRNA was reduced, whereas α-lactalbumin mRNA was increased with PRL treatment. These results demonstrate that the bovine mammary gland is responsive to exogenous PRL during Early Lactation. In addition, differences in the response to frequent milking or exogenous PRL during Early Lactation indicate distinct effects of PRL and milk removal on the mammary function of dairy cows.
