Footwall refrigeration along a detachment fault: implications for the thermal evolution of core complexes

Oxygen isotope compositions of epidote and quartz from chloritic breccias that underlie the detachment fault in the metamorphic core complex of the Whipple Mountains yielded quartz-epidote fractionations that range from 4.1 to 6.4 per mil and increase systematically toward the fault. These fractionations give mean temperatures that decrease from approximately 432 degrees C at 50 meters below the fault to approximately 350 degrees C at 12 meters below the fault. This extreme thermal gradient of 82 degrees C over 38 meters (2160 degrees C per kilometer) is best explained by advective heat extraction by means of circulating surface-derived fluids. Models of lithospheric extension consider only conductive cooling resulting from tectonic denudation and thus require revision to include fluid-induced fault-zone refrigeration.     

Muscle strain injuries of the hindlimb in eight horses: diagnostic imaging,management and outcomes

Objective To describe the clinical presentation, ultrasound findings, management and outcome in horses with muscle tear injuries of the hindlimbs. Design Retrospective case series Procedure Medical records of eight horses were reviewed and information on signalment, history, presenting complaint, physical examination findings and further diagnostic tests were recorded. Diagnosis of muscle injury was determined by the presence of abnormal ultrasound findings, compared with the contralateral limb, and, when required, nuclear scintigraphy. Follow-up information was obtained via telephone interviews with owners, trainers and referring veterinarians. Results Muscle tears causing lameness were identified in the middle gluteal (3), semitendinosus (1), semimembranosus (2) and gracilis (2) muscles. Tears were classified by ultrasound imaging as partial (6) or complete (2). The degree of lameness did not appear to be indicative of the extent of injury or of completion of healing. Long-term follow-up was available for seven horses and the outcome was favourable in six cases. Conclusions and clinical relevance Ultrasonography is useful in the diagnosis and assessment of moderate to severe muscle strain injuries. The prognosis appears to be favourable in most cases, although recurrence of injury and lameness can delay the return to athletic activity and an inferior outcome with persistent gait abnormality may occur.     

Preliminary Study in Immature Canine Oocytes Stained with Brilliant Cresyl Blue and Obtained From Bitches with Low and High Progesterone Serum Profiles

This study was conducted: (i) to observe the features and levels of blue colour impregnation in morphologically selected immature canine cumulus oocyte complexes (COCs) stained with the brilliant cresyl blue (BCB) dye, as indicators of quality, and integrity of nuclear oocyte chromatin configuration before in vitro maturation (IVM); (ii) to observe the relationship between the influence of serum progesterone (SP) concentrations from ovary donors and BCB staining of immature dog oocytes. The results showed that out of 138 canine COCs, germinal vesicle (GV) stage prevailed in BCB+ oocytes at percentages of 67.4% (60/89), which were statistically higher than those observed in BCB+/− (52.2%; 23/44) and BCB− (20%; 1/5) oocytes (p = 0.023). Oocytes BCB+ were interpreted as those having completed their growth and therefore possessing the capacity to mature and develop in vitro . Ooplasm and cumulus cells (CCs) of canine oocytes were BCB staining independent. Ooplasm blue colour staining reaction varied between grown oocytes, revealing different levels of glucose-6-phosphate dehydrogenase activity among and within oocytes. Additionally, SP profile of ovary donors was not a relevant indicator for selection of oocytes screened with the BCB stain. Similar numbers of high quality oocytes were observed to be BCB+, BCB+/− and BCB− between groups of females with SP varying from 0 to 2.5 ng/ml (n = 5), and those with SP varying from 2.6 to 16.7 ng/ml (n = 4) (p = 0.680). It may be inferred that bitches with low and high SP profiles have grown oocytes in their ovaries, as determined by the BCB absorbance in their ooplasms.     

Daylight effect on melatonin secretion in adult female guanacos (Lama guanicoe)

The wild South American camelids developed a strategy of seasonal reproduction during spring and summer with singleton birth. The photoperiod is one of the factors that may modulate this seasonality where light would be translated into a hormonal signal. This study evaluated the influence of changes in daily light intensity on melatonin concentration in captive guanacos under a long‐day photoperiod (16 hr light/8 hr dark; 33 ‘28′S). Mean melatonin concentration was 28.3 ± 20.3 pg/ml, with a maximum of 52.14 ± 17.19 pg/ml at 23:30 and minimum of 14.29 ± 6.64 pg/ml at 08:30 (p < .001). There was a negative association between light intensity and melatonin concentration (r = ?0.57; p < .001). The results indicate that guanacos respond to variation in daily environmental light with a hormonal response and point to a circannual rhythm as a function of the photoperiod.     

Effect of vitamin E on improving fresh pork quality in Berkshire- and Hampshire-sired pigs

This study was designed to evaluate the effects of vitamin E supplementation on pork quality of two genotypes with distinct differences in pork quality traits. Pigs (n = 240; BW = 87 +/- 0.35 kg) were allotted by weight to one of 20 treatments (4 pens/treatment, 3 pigs/pen) in a 2 x 2 x 5 factorial randomized complete block design. Factors included 1) genotype (Berkshire or Hampshire sired), 2) sex (gilts or barrows), and 3) vitamin E level (12.1, 54.7, 98.8, 174.0, and 350.6 IU of vitamin E/kg diet). Hampshire-sired pigs had greater average daily gain (1.05 vs 0.98 kg) and gain:feed (0.30 vs 0.27) and less average daily feed intake (ADFI) (3.46 vs 3.62 kg) than Berkshire-sired pigs (P < 0.001) for the 6-wk study. Hampshire-sired barrows consumed more feed (3.54 vs 3.38 kg/d) and were less efficient (0.29 vs 0.31) than Hampshire-sired gilts (P < 0.05), but this sex difference was not observed in Berkshire-sired pigs (interaction, P < 0.05). Berkshire-sired pigs had greater backfat (34.1 vs 21.1 mm; P < 0.001), reduced longissimus muscle area (37.6 vs 46.3 cm2; P < 0.001), reduced lean percentage (53.0 vs 55.8; P < 0.001), and a greater head-on yield (79.8 vs 79.2; P < 0.05). Vitamin E increased (P < 0.05) ADFI linearly (P < 0.05), but had no effects on carcass composition. Loin chops from Hampshire-sired pigs had reduced ultimate pH (5.64 vs 5.91), greater drip loss (92.2 vs 66.3 mg), and increased Minolta L* (52.6 vs 48.6), a* (8.9 vs 7.5), and b* (6.9 vs 5.2) values compared to Berkshire-sired pigs (P < 0.001). Vitamin E had no effect on pH, temperature, drip loss, and L* or a* values, but tended (P < 0.07) to increase b* values linearly (P < 0.06). Oxidation as indicated by thiobarbituric acid reactive substances (TBARS) was greatest in Hampshire-sired gilts at the lowest level of vitamin E, and decreased linearly (P < 0.001) with additional vitamin E. However, TBARS responded in a cubic fashion (P < 0.05) to vitamin E in Hampshire-sired barrows and were not affected in Berkshire-sired gilts or barrows (three-way interaction, P < 0.02). Hampshire-sired pigs had greater TBARS than Berkshire-sired pigs (0.053 vs 0.047 mg malondialdehyde equivalents/kg). Vitamin E supplementation increased serum concentrations of vitamin E on d 21 (1.06 to 4.79 microg/mL) and d 42 (1.02 to 2.82 microg/mL) and increased tissue concentrations of vitamin E (1.99 to 4.83 microg/g) linearly (P < 0.001). Vitamin E supplementation was not effective in improving fresh meat quality in genotypes with poor or superior meat quality traits.     

Reproductive Performance of Ewes after 5-Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F2α

Three experiments were conducted with a total of 1579 ewes to examine reproductive performance in response to synchronization of oestrus during the breeding season, using controlled internal drug releasing (CIDR-G) inserts in regimens designed to provide high concentrations of circulating progesterone. In experiment 1, treatment with two CIDR-G inserts for 12 days produced conception rate (79%) and prolificacy (1.9) to first service equivalent to breeding at natural oestrus (56% and 2.0, respectively). Pregnancy rates to two service periods were 90 and 79%, respectively. In experiments 2 and 3, progesterone was delivered by a single CIDR-G insert for 5 days in combination with prostaglandin F2alpha (PGF2alpha; 5 mg i.m., twice, 3 h apart) the day before (experiment 2), or at insert removal (experiment 3). The combined treatments improved rates of synchronization of oestrus (p<0.01) by 23 and 20% points, respectively, and pregnancy rates to the first service period by 19 (p<0.05) and 13 (p<0.01) percentage points, respectively, compared to treatment with PGF2alpha alone. It is concluded that the combination of treatment for 5 days with a CIDR-G insert and two injections of 5 mg PGF2alpha, the day before, or the day of insert removal, were effective treatments to obtain high fertility at synchronized oestrus in ewes during the breeding season.