| 1. |
- Zeng, Z. K., et al.
(författare)
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A new Buttiauxella phytase continuously hydrolyzes phytate and improves amino acid digestibility and mineral balance in growing pigs fed phosphorous-deficient diet
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94:2, s. 629-638
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Tidskriftsartikel (refereegranskat)abstract
- Ten ileal T-cannulated pigs (19.26 ± 1.06 kg) were used to evaluate the effects of a novel Buttiauxella phytase on apparent ileal digestibility (AID) of AA and apparent total tract digestibility (ATTD) and hindgut disappearance of DM, GE, CP, crude fiber, NDF, and ADF as well as minerals balance. Pigs were fed in a duplicated 5 × 4 incomplete Latin square design (5 diets with 4 periods). Each period consisted of a 5-d adjustment period followed by a 3-d total collection of feces and urine and then a 2-d collection of ileal digesta. The 5 diets included a P-deficient basal diet (0.43% Ca and 0.38% total P) that was supplemented with 0 (negative control [NC]), 500, 1,000, or 20,000 phytase units (FTU)/kg phytase and a positive control (PC) diet that was P adequate (0.64% Ca and 0.52% total P). The addition of phytase to the NC diet improved (P < 0.05) AID of phytate from 11.1 to 62.8, 70.6, and 90.5% at the inclusion rates of 500, 1,000, and 20,000 FTU/kg, respectively. In general, phytase supplementation at a dose of 20,000 FTU/kg further increased (P < 0.05) AID of Ca, total P, and phytate and reduced (P < 0.05) the ileal phytate concentration compared with diets with 500 or 1,000 FTU/kg phytase. Pigs fed the diet with 20,000 FTU/kg phytase but not diets with 500 and 1,000 FTU/kg phytase showed improved (P < 0.05) ATTD of CP and AID of DM, GE, CP, Leu, Lys, Thr, Val, Asp, and Ser compared with pigs fed the PC or NC diet. However, hindgut disappearance of crude fiber and NDF (P < 0.05) were reduced in pigs fed the diet with 20,000 FTU/kg phytase compared with pigs fed the PC or NC diet. Pigs fed diets with 500 or 1,000 FTU/ kg phytase had greater ATTD and retention of Ca and P than pigs fed the NC diet but less compared with pigs fed the diet with 20,000 FTU/kg phytase. Supplementation of 20,000 FTU/kg phytase to the NC diet improved (P < 0.05) digestibility of Na, Mn, and Zn as well as retention (%) of Zn. Increasing phytase supplementation doses from 0 to 1,000 FTU/kg linearly improved (P < 0.05) retention of Mg; meanwhile, digestibility of Mg and Mn and AID of Thr showed a linear increase trend (P = 0.084). In conclusion, supplementation of the novel Buttiauxella phytase at doses up to 20,000 FTU/kg hydrolyzed most of the phytate (90%) and consequently further improved mineral and protein utilization.
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| 2. |
- Groenen, M. A., et al.
(författare)
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Analyses of pig genomes provide insight into porcine demography and evolution
- 2012
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 491:7424, s. 393-398
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Tidskriftsartikel (refereegranskat)abstract
- For 10,000 years pigs and humans have shared a close and complex relationship. From domestication to modern breeding practices, humans have shaped the genomes of domestic pigs. Here we present the assembly and analysis of the genome sequence of a female domestic Duroc pig (Sus scrofa) and a comparison with the genomes of wild and domestic pigs from Europe and Asia. Wild pigs emerged in South East Asia and subsequently spread across Eurasia. Our results reveal a deep phylogenetic split between European and Asian wild boars approximately 1 million years ago, and a selective sweep analysis indicates selection on genes involved in RNA processing and regulation. Genes associated with immune response and olfaction exhibit fast evolution. Pigs have the largest repertoire of functional olfactory receptor genes, reflecting the importance of smell in this scavenging animal. The pig genome sequence provides an important resource for further improvements of this important livestock species, and our identification of many putative disease-causing variants extends the potential of the pig as a biomedical model.
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| 3. |
- Xie, Z., et al.
(författare)
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Physiological responses to salinity change and diel-cycling hypoxia in gills of Hong Kong oyster Crassostrea hongkongensis
- 2023
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 570
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Tidskriftsartikel (refereegranskat)abstract
- Global climate change is a frequent cause of salinity fluctuation in seawater, especially in aquaculture sites. Moreover, anthropologic activities often cause seawater eutrophication with the consequence that hypoxia ap-pears often during nighttime. The Hong Kong oyster Crassostrea hongkongensis, as a species that inhabits estuarine and coastal waters, is faced with such challenges. In this study, oyster physiological changes were considered to be closely related to hypoxia and salinity changes. Physiological indices were examined in Hong Kong oysters by employing six treatments to shed light into the effects of diel-cycling hypoxia (periodical hypoxia) and salinity change. Three salinities (10%o, low salinity; 25%o, normal salinity; and 35%o, high salinity) and two types of dissolved oxygen (normoxia, 6 mg/L throughout the day) and periodical hypoxic condition (6 mg/L at daytime for 12 h and 2 mg/L at nighttime for 12 h) were set. After 14-and 28-day exposures, gill tissues were sampled to detect changes in gill ATP production, mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species production (ROS), and gill respiratory metabolic enzymes. Results indicated that periodical hypoxia and salinity change led to increased hexokinase (HK) and pyruvate kinase (PK) (p < 0.05). By contrast, they had no significant effect on mitochondrial number (MN). Adenosine-triphosphate (ATP) production only increased in the early exposure. In addition, low salinity with periodical hypoxia resulted in decreased MMP, lactate dehy-drogenase (LDH), and succinate dehydrogenase (SDH, p < 0.05). On the contrary, periodical hypoxia with high salinity led to increases in ATP and ROS and decreases in SDH, MMP, and LDH (p < 0.05). These results revealed that when diel-cycling hypoxia occurs with salinity change, the gill metabolism of Hong Kong oysters are gradually dominated by glycolysis while aerobic respiration decreases. Moreover, gill functions could be affected although energy accumulation exists during early exposure. Therefore, long-term exposure to periodical hypoxia with salinity change poses risk to the health and growth of Hong Kong oysters, impairing oyster aquaculture and coastal ecosystem health.
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| 4. |
- Xu, X., et al.
(författare)
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Landscape Metrics and Land-Use Patterns of Energy Crops in the Agricultural Landscape
- 2023
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Ingår i: Bioenergy Research. - : Springer Nature. - 1939-1234 .- 1939-1242. ; 16:4, s. 2178-2191
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Tidskriftsartikel (refereegranskat)abstract
- Energy crops are a new player in the traditional agricultural landscape. The present paper analyses the land uses surrounding and the spatial characteristics of the main energy crops in Sweden (willow, poplar, hybrid aspen and reed canary grass) compared to traditional agricultural crops during the period 2006–2018. Spatial metrics (number of shape characterising points, shape index and rectangularity ratio) are calculated for each field, as well as the nearby land uses at varying distances, at radius: 500 m, 1000 m, 2000 m and 5000 m. A total of 1560 energy crop fields are studied in the 2006 dataset and 3416 fields in the 2018 dataset, which are compared to 58,246 fields with cereal crops in 2006 and 131,354 fields in the 2018 dataset. Results show that, despite being established on previous agricultural land, energy crops present a different spatial profile compared to traditional agricultural crops. Field shapes present less complexity than before, and the overall spatial features become more regular with time in both cases of energy crops and cereals, suggesting an increasing trend in cost-efficient agricultural practices and planning. Important differences concerning land use diversity at different scales are found between plantations versus grasses. In general, willow plantations are located in agriculture-dominated areas (> 70% at 500 m, > 50% at 2000 m), whereas reed canary grass is in forest-dominated landscapes (> 30% at 500 m, > 60% at 2000 m); both contribute to diversifying existing land uses although with varying effects. The results of this study are a basis to assess the impacts of energy crops at landscape level and can translate into applications in energy policy and planning.
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