The study evaluated the long-term influence of feeding ground barley treated with lactic acid (LA) alone or with LA and heat on performance, energy and protein balance in dairy cows. Thirty cows were fed three diets differing in the treatment of barley grain, either unprocessed ground barley (Control), ground barley steeped in 1% LA at room temperature (LA-treated barley) or ground barley steeped in 1% LA with an additional heating at 55°C (LAH-treated barley). Cows were studied from week 3 to 17 post-partum. Dry matter intake (DMI), milk yield and composition and body weight (BW) were measured daily. Estimated energy and protein balances were calculated and blood samples were collected three times during the experiment and analysed for common metabolites of energy and lipid metabolism. Digestibility of different treated barley and other dietary ingredients was investigated in vivo using four wethers. The treatment of barley with LA and LAH increased the digestibility of organic matter (OM) by approximately 5% and the content of metabolisable energy by 0.5–0.6 MJ/kg DM. Data showed no effect of feeding diets containing LA- or LAH-treated barley at 39% of DM on overall DMI, BW, BW change, milk production and composition and on the blood variables studied. Diet influenced the estimated balances of net energy of lactation (p 0.01) and the content of utilisable protein at the duodenum (p = 0.07) with cows fed the diet with LA-treated barley showing improved balances. In conclusion, feeding diets containing LA- or LAH-treated barley had no influence on performance, milk composition and blood metabolites, but LA treatment without heat seems to improve the energy balance of cows.

Myxobolus cerebralis is a cnidarian-myxozoan parasite that causes salmonid whirling disease. M. cerebralis alternates between two hosts: (1) a vertebrate salmonid and (2) an invertebrate oligochaete, Tubifex tubifex. There is no successful treatment for salmonid whirling disease. MyxSP-1 is a M. cerebralis serine protease implicated in whirling disease pathogenesis. We hypothesized that short-interfering RNA (siRNA)-induced RNA interference (RNAi) can silence MyxSP-1 in the invertebrate host and abrogate the M. cerebralis life cycle. This would preclude whirling disease infection in the salmonid host. To test this hypothesis, we first developed a siRNA delivery protocol in T. tubifex. Second, we determined the effective dose for siRNA treatment of M. cerebralis-infected T. tubifex. M. cerebralis- infected T. tubifex were treated with different concentrations of MyxSP-1 or negative control siRNAs (1μM, 2μM, 5μM or 7μM) at 15ÊC for 24h, 48h, 72h and 96h, respectively. We monitored MyxSP-1 knockdown using real-time quantitative PCR (qPCR). siRNA treatment with MyxSP-1 siRNA at 2μM concentration for 24h at 15ÊC showed maximum significant MyxSP-1 knockdown in T. tubifex. Third, we determined the time points in the M. cerebralis life cycle in T. tubifex at which siRNA treatment was most effective. M. cerebralis- infected T. tubifex were treated with MyxSP-1 or negative control siRNAs (2μM concentration for 24h at 15ÊC) at 24 hours post-infection (24hpi), 48hpi, 72hpi, 96hpi, 1 month post-infection (1mpi), 2mpi and 3mpi, respectively. We observed that siRNA treatment of T. tubifex was most effective at 1mpi, 2mpi and 3mpi. Fourth, we immersed specific-pathogen- free rainbow trout fry in water inhabited by MyxSP-1 siRNA-treated T. tubifex (at 1mpi, 2mpi and 3mpi). The salmonids did not develop whirling disease and showed significant MyxSP-1 knockdown. We also observed long-term RNAi in T. tubifex. Together these results demonstrate a novel RNAi-based therapeutic proof of concept in vivo against salmonid whirling disease.

Background: Myxozoan parasites pose emerging health issues for wild and farmed salmonid fish. Rainbow trout (Oncorhynchus mykiss) is a particularly susceptible species to Tetracapsuloides bryosalmonae (Malacosporea), the etiological agent of Proliferative Kidney Disease (PKD), and to Myxobolus cerebralis (Myxosporea), the etiological agent of Whirling Disease (WD). The objective of this study was to investigate the impact of myxozoan co-infections on the pathogenesis of PKD and WD in the rainbow trout. Methods: Two groups of rainbow trout (96 fish each) were primarily infected with T. bryosalmonae and triactinomyxons of M. cerebralis; after 30 days half of the fish in each group were co-infected with these parasites vice versa and remaining half was continued as single infection. Mortalities and clinical signs were recorded at different time points. Histopathology and immunohistochemistry were performed to assess the extent of each infection and estimate the parasite burden between groups. Results: Fish firstly infected with M. cerebralis and co-infected with T. bryosalmonae exhibited exacerbated pathological changes of both parasitic diseases and elicited a higher mortality rate. A higher kidney swelling index (grade 4) appeared together with more severe cartilage destruction and displacement, when compared to the pathological changes in fish upon single infections with T. bryosalmonae or M. cerebralis. Conversely, fish firstly infected with T. bryosalmonae and co-infected with M. cerebralis also exhibited typical pathological changes of both parasitic diseases, but with a lower mortality rate, similar as caused by the single T. bryosalmonae or M. cerebralis infection. WD clinical signs were milder, without skeletal deformities, while kidney swelling index was similar to single infection with T. bryosalmonae (grade 2 to 3). Conclusions: In this study, a co-infection with myxozoan parasites was for the first time successfully achieved in the laboratory under controlled conditions. The impact of co-infections in concurrent myxozoan infections mainly depends on the primary pathogen infecting the host, which could alter the outcomes of the secondary pathogen infection. The primary M. cerebralis infection followed by T. bryosalmonae had a much more serious impact and elicited a synergistic interaction. Contrasting results were instead seen in rainbow trout primarily infected with T. bryosalmonae and then coinfected with M. cerebralis.

Background: Myxozoan parasites pose emerging health issues for wild and farmed salmonid fish. Rainbow trout (Oncorhynchus mykiss) is a particularly susceptible species to Tetracapsuloides bryosalmonae (Malacosporea), the etiological agent of Proliferative Kidney Disease (PKD), and to Myxobolus cerebralis (Myxosporea), the etiological agent of Whirling Disease (WD). The objective of this study was to investigate the impact of myxozoan co-infections on the pathogenesis of PKD and WD in the rainbow trout. Methods: Two groups of rainbow trout (96 fish each) were primarily infected with T. bryosalmonae and triactinomyxons of M. cerebralis; after 30 days half of the fish in each group were co-infected with these parasites vice versa and remaining half was continued as single infection. Mortalities and clinical signs were recorded at different time points. Histopathology and immunohistochemistry were performed to assess the extent of each infection and estimate the parasite burden between groups. Results: Fish firstly infected with M. cerebralis and co-infected with T. bryosalmonae exhibited exacerbated pathological changes of both parasitic diseases and elicited a higher mortality rate. A higher kidney swelling index (grade 4) appeared together with more severe cartilage destruction and displacement, when compared to the pathological changes in fish upon single infections with T. bryosalmonae or M. cerebralis. Conversely, fish firstly infected with T. bryosalmonae and co-infected with M. cerebralis also exhibited typical pathological changes of both parasitic diseases, but with a lower mortality rate, similar as caused by the single T. bryosalmonae or M. cerebralis infection. WD clinical signs were milder, without skeletal deformities, while kidney swelling index was similar to single infection with T. bryosalmonae (grade 2 to 3). Conclusions: In this study, a co-infection with myxozoan parasites was for the first time successfully achieved in the laboratory under controlled conditions. The impact of co-infections in concurrent myxozoan infections mainly depends on the primary pathogen infecting the host, which could alter the outcomes of the secondary pathogen infection. The primary M. cerebralis infection followed by T. bryosalmonae had a much more serious impact and elicited a synergistic interaction. Contrasting results were instead seen in rainbow trout primarily infected with T. bryosalmonae and then coinfected with M. cerebralis.

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Overgrown claws make walking painful, increase difficulty in finding food, and increase susceptibility to foot problems. This study highlights the effect of surgical claw trimming on the behavior, physiological indices, and ruminal activity of sheep. Twenty sheep that had severe claw overgrowth were divided into 2 groups: the trimmed group (T), subjected to the process of claw trimming, and the overgrown claw group, the control group (C). Claw morphometric measurements (toe length, claw height, sole length, sole width, heel height, dorsal hoof angle, fetlock angle, and dew claws length), gait analysis, behavioral patterns (feeding, rumination, drinking, standing, walking, and resting), hematological and blood biochemical indices (complete blood count, plasma cortisol, glucose, lactate, copper, and tumor necrosis factorea levels), and ruminal function tests (ruminal PH, and count and activity of ruminal fauna) were evaluated in both groups. The overgrown claw trimming improved sheep behavior, gait scoring, physiological indicators, and ruminal activity.

Overgrown claws make walking painful, increase difficulty in finding food, and increase susceptibility to foot problems. This study highlights the effect of surgical claw trimming on the behavior, physiological indices, and ruminal activity of sheep. Twenty sheep that had severe claw overgrowth were divided into 2 groups: the trimmed group (T), subjected to the process of claw trimming, and the overgrown claw group, the control group (C). Claw morphometric measurements (toe length, claw height, sole length, sole width, heel height, dorsal hoof angle, fetlock angle, and dew claws length), gait analysis, behavioral patterns (feeding, rumination, drinking, standing, walking, and resting), hematological and blood biochemical indices (complete blood count, plasma cortisol, glucose, lactate, copper, and tumor necrosis factorea levels), and ruminal function tests (ruminal PH, and count and activity of ruminal fauna) were evaluated in both groups. The overgrown claw trimming improved sheep behavior, gait scoring, physiological indicators, and ruminal activity.

Overgrown claws make walking painful, increase difficulty in finding food, and increase susceptibility to foot problems. This study highlights the effect of surgical claw trimming on the behavior, physiological indices, and ruminal activity of sheep. Twenty sheep that had severe claw overgrowth were divided into 2 groups: the trimmed group (T), subjected to the process of claw trimming, and the overgrown claw group, the control group (C). Claw morphometric measurements (toe length, claw height, sole length, sole width, heel height, dorsal hoof angle, fetlock angle, and dew claws length), gait analysis, behavioral patterns (feeding, rumination, drinking, standing, walking, and resting), hematological and blood biochemical indices (complete blood count, plasma cortisol, glucose, lactate, copper, and tumor necrosis factorea levels), and ruminal function tests (ruminal PH, and count and activity of ruminal fauna) were evaluated in both groups. The overgrown claw trimming improved sheep behavior, gait scoring, physiological indicators, and ruminal activity.

Overgrown claws make walking painful, increase difficulty in finding food, and increase susceptibility to foot problems. This study highlights the effect of surgical claw trimming on the behavior, physiological indices, and ruminal activity of sheep. Twenty sheep that had severe claw overgrowth were divided into 2 groups: the trimmed group (T), subjected to the process of claw trimming, and the overgrown claw group, the control group (C). Claw morphometric measurements (toe length, claw height, sole length, sole width, heel height, dorsal hoof angle, fetlock angle, and dew claws length), gait analysis, behavioral patterns (feeding, rumination, drinking, standing, walking, and resting), hematological and blood biochemical indices (complete blood count, plasma cortisol, glucose, lactate, copper, and tumor necrosis factorea levels), and ruminal function tests (ruminal PH, and count and activity of ruminal fauna) were evaluated in both groups. The overgrown claw trimming improved sheep behavior, gait scoring, physiological indicators, and ruminal activity.