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1.
Effects of supplemental degradable (DIP) and undegradable (UIP) intake protein on forage intake, BW change, body condition score (BCS), postpartum interval to first estrus, conception rate, milk production and composition, serum metabolites and metabolic hormones, and calf gain were determined using 36 primiparous Gelbvieh x Angus rotationally crossed beef cows. On d 3 postpartum, cows (average initial BW = 495 +/- 10 kg and BCS = 5.5 +/- 0.1) were randomly assigned to one of three dietary supplements (12 cows/treatment). Date of parturition was evenly distributed across treatment (average span of calving date among treatments = 2.4 +/- 2.5 d). Individually fed (d 3 through 120 postpartum) dietary supplements were 0.82 kg of corn and 0.23 kg of soybean meal per day (DIP), the DIP + 0.12 kg of blood meal and 0.13 kg of corn gluten meal per day (DIP + UIP), and 0.82 kg of corn, 0.07 kg of blood meal, and 0.08 kg of corn gluten meal per day in an isonitrogenous replacement of soybean meal (UIP IsoN). Cows had ad libitum access to native grass hay (8.5% CP) and trace-mineralized salt. Total OM intake was greater (P = 0.06) for DIP + UIP than UIP IsoN cows. At 30 d postpartum, DIP + UIP cows produced more milk than UIP IsoN, with DIP being intermediate; however, at 60 d postpartum, DIP + UIP and DIP cows were not different, but both had greater milk production than UIP IsoN (treatment x day interaction; P = 0.08). A treatment x day interaction (P = 0.06) for BCS resulted from DIP + UIP cows having the greatest BCS at 60, 90, and 120 d d postpartum and DIP having greater BCS than UIP IsoN cows only on d 60 postpartum. Serum insulin concentrations were highest (treatment x day interaction; P = 0.09) for DIP + UIP cows at 30 d postpartum but did not differ among treatment thereafter. Serum insulin-like growth factor-binding protein (IGFBP)-2 (34 kDa) and -3 (40 and 44 kDa) were greatest (P < 0.0003) for DIP cows. Serum urea-N concentrations were greater (P < 0.01) in DIP + UIP cows than in either DIP or UIP IsoN cows. However, postpartum interval to first estrus, conception rate, and calf weaning weights were unaffected (P = 0.35, 0.42, and 0.64, respectively) by treatment. Although UIP in addition to or in replacement of DIP affected milk production and blood metabolites, the productivity of these primiparous beef cows was not altered. Thus, the type of supplemental protein does not seem to influence productivity of primiparous beef cows in production systems with conditions similar to our experimental conditions.  相似文献   
2.
Continuous measurement and imaging of the intracellular free calcium ion concentration ([Ca2+]i) of mitotic and interphase PtK1 cells was accomplished with the new fluorescent Ca2+ indicator fura-2. No statistically significant difference between basal [Ca2+]i of interphase and mitotic cells was detected. However, mitotic cells showed a rapid elevation of [Ca2+]i from basal levels of 130 nM to 500 to 800 nM at the metaphase-anaphase transition. The [Ca2+]i transient was brief, lasting approximately 20 seconds and the elevated [Ca2+]i appeared uniformly distributed over the entire spindle and central region of the cell. The close temporal association of the [Ca2+]i transient with the onset of anaphase suggests that calcium may have a signaling role in this event.  相似文献   
3.
4.
Blood samples from 13 cases of snakebite, 6 in dogs and 7 in cats, were tested for activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrin/fibrinogen degradation products (FDP). Four cases were tested for fibrinogen concentration. Based on the results of a commercially available ELISA test, 9 cases were caused by tiger snakes (Notechis scutatus) and 1 case by a brown snake (Pseudonaja textilis). Three other cases had clinical signs and increased creatine phosphokinase values which suggested tiger snake envenomation. Although the period post-envenomation varied, results indicated a marked prolongation of the APTT and PT in 5 of 6 dogs. Three of these 5 dogs also had increased FDP values and 3 (of 3 examined) were hypofibrinogenaemic. Clinical manifestations of this coagulopathy were: haematoma formation after venepuncture (3 cases), gingival petechiae (1 case) and hyphaema (1 case). In contrast, there was minimal or no prolongation of the APTT and PT values, and no increase in FDP, in all 7 cats. Furthermore, no cat exhibited clinical signs of a coagulopathy.  相似文献   
5.
6.
Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H2O2) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H2O2 (250 μm ). The sperm were treated with melatonin in the presence or absence of H2O2 for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H2O2 (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H2O2 groups were lower than H2O2 only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.  相似文献   
7.

Aim

A prospective, observational study to determine the prevalence of post‐exercise conditions at Australian Greyhound race meetings and to assess association with race performance and other environmental, race‐ and dog‐related factors was undertaken.

Methods

A total of 4020 starters were observed (2813 Greyhounds, 1009 trainers, 536 races, 52 race meets, 48 race dates and 11 race tracks) following a race. The presence of diaphragmatic flutter (DF), ataxia, seizure, collapse or sudden death was recorded. Risk factors were screened by univariable logistic regression prior to multivariable backward stepwise model building.

Results

In this study, 962 starters (n = 768 dogs) had DF (23.9%), 16 starters were ataxic (0.4%) and there were no observed cases of collapse, seizure or sudden death. Race track location, increasing race distance, race grade based on increasing 1st place prize value, lower (earlier) race number at the meeting, age, a previous observation of DF at the last start, females, colour (white) and better finishing position were all associated with an increased risk of a Greyhound being observed with DF. However, when logistic regression assessing the random effect of dog was performed, the presence of previous DF was not significant. In this cohort, DF was common following strenuous exercise in Greyhounds and on its own does not appear to result in reduced performance or distress to the animal.

Conclusion

The incidence of ataxia was low and collapse, seizure and sudden death were not observed. However, even though uncommon, ataxia has welfare concerns for racing Greyhounds that warrants further investigation.  相似文献   
8.
Metalloproteases that selectively hydrolyze connective tissue proteins may tenderize meat without creating texture problems associated with myofibrillar protein degradation. Our objective was to characterize the activity of bovine placental proteases to determine whether they can improve meat tenderness through disruption of the connective tissue matrix. Enzymes were extracted, crudely purified, and proteolytic activity was assessed against gelatin and collagen under varying pH and temperature conditions using both SDS-PAGE and zymography. Gelatin zymography revealed proteolysis between 57 and 63 kDa, with decreased activity as buffer pH decreased from pH 7.4 to 5.4 (37 degrees C). Proteolytic activity was pronounced at 37 degrees C, moderate at 25 degrees C, and absent at 4 degrees C following 48-h incubation (pH 7.4). Placental enzymes were metalloproteases inhibited by excess EDTA. Maximum proteolysis was achieved in the presence of Ca2+, with or without Mg2+ and Zn2+. Absence of Ca2+ decreased proteolytic activity. Complete degradation of both the 125- and 120-kDa proteins of the alpha-chains of gelatin was achieved following enzyme incubation for 6 h at 37 degrees C or 24 h at 25 degrees C. No degradation was observed following enzyme incubation with native Type I collagen. Given the marked decrease in enzyme activity at pH 5.4 and 4 degrees C (standard industry conditions), bovine placental metalloproteases would not be expected to contribute to connective tissue degradation or improve meat tenderness.  相似文献   
9.
Objective To determine the effect of 1-Deamino-8-D-argi-nine vasopressin on plasma concentrations of von Willebrand factor and factor VIII in Greyhound blood donors, and to compare the response of 1-Deamino-8-D-arginine vaso-pressin injection on plasma concentrations of von Willebrand factor between groups with different resting plasma concentrations of von Willebrand factor.
Animals Fifteen Greyhound blood donors were used. Dogs were grouped into three categories depending on their von Willebrand factor concentrations.
Procedure Desmopressin was administered subcuta-neously at 1 mg/kg to all dogs. Plasma von Willebrand factor and factor VIII concentrations were measured before and 10, 20, 30, 45, 60, 90 and 120 min after desmopressin injection.
Results The von Willebrand factor and factor VIII concentrations in all dogs increased significantly and remained higher than base-line throughout the 2 h period.
Conclusion Desmopressin is useful in increasing von Willebrand factor concentrations in Greyhound blood donors, including those with low resting concentrations.  相似文献   
10.
The objective of the study was to compare three different oxidizing systems commonly present in muscle foods for their influence on the biochemical properties of muscle proteins. Myofibrillar protein isolate (MPI) prepared from pork serratus ventralis muscle was suspended (30 mg protein/mL) in 15 mM piperazine-N,N-bis(2-ethane sulfonic acid) buffer (pH 6.0). Oxidation was induced by incubating the protein suspension at 4 degrees C for 24 h with (i) a hydroxyl radical-generating system (HRGS: 10 microM FeCl3, 0.1 mM ascorbic acid, and 0.05-5.0 mM H2O2), (ii) a lipid-oxidizing system (LOS: 0.05-5.0 mM linoleic acid and 3750 units of lipoxidase/mL), or (iii) a metmyoglobin-oxidizing system (MOS: 0.05-0.5 mM metmyoglobin). Changes in oxidized MPI were measured as Ca- and K-ATPase activities, formation of protein carbonyls and 2-thiobarbituric acid-reactive substances (TBARS), loss of protein thermal stability, and protein aggregation. The three oxidizing matrixes induced complex MPI changes; for example, the Ca- and K-ATPase activities were altered mainly by low-concentration oxidants, but the changes were unique for each oxidizing system. The carbonyl content in MOS-treated MPI was the highest, while the TBARS production, changes in thermal properties, and loss of the myosin heavy chain were the greatest in HRGS-treated MPIs. Overall, the hydroxyl radical-producing medium appeared to be the most oxidative to myofibrillar proteins under the experimental conditions employed in the study.  相似文献   
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