Responses of simultaneously recorded intraperitoneal and subcutaneous temperatures of Black Bedouin goats to transient thyrosuppression during cold stress

Unlike poikilotherms, homeotherms resist wide amplitudes of core body temperature (T_core) fluctuation when exposed to reasonably variant ambient temperature (T_a) extremes. The degree of cold/heat thermotolerance varies tremendously amongst mammalian species. Thermotolerance can be partially inferred by the extent of resistance in body temperature displacement from normothermia when subjected to thermal stress. Regulation of thyroid calorigenic hormones is primarily contingent upon thermal homeostasis. Thyrosuppression generally exacerbates cold stress and hence may be a useful tool to examine the extent of cold-tolerance. An experiment was conducted to examine the extent of cold-tolerance on artificially goitrous Black Bedouin goats. Ten goat kids (initial Avg. BW = 30.6 ± 0.4 kg) were fitted with two miniature temperature data loggers, intraperitoneally and subcutaneously to identify core (T_core) and subcutaneous (T_sq) temperature responses, respectively, to chronically (47 days) cold (< 10 °C) environment along with or without oral administration of the thyreostat propylthiouracil (PTU 20 mg/kg BW/day). Five animals served as controls (CON) whereas the remaining five were treated with PTU for 31 out of the overall 47-day observation period. Despite its 74.5%-evoked transient depression of circulating free thyroxine (FT4), PTU-treatment failed (P > 0.10) to cause significant displacements in T_core or T_sq as compared to CON values throughout the 52-day trial period. As a function of T_a, T_core − T_sq thermal gradient revealed a significantly (P < 0.01) linear regression (r² = 0.41), to indirectly infer a graded blood redistribution from peripheral to splanchnic vascular beds with the fall in T_a. In the light of the current findings, it can be deduced that– in addition to the fact that it is superior in terms of heat-tolerance– the Black Bedouin goat is also profoundly cold-tolerant. Furthermore, our recently developed technique in concurrently recording T_core and T_sq proves efficient and feasible to simultaneously record temperatures of different body sites in free-roaming animals, thereby overcoming potentially erroneous artifacts caused by frequent experimenter intrusion.     

Insights into xylem vulnerability to cavitation in Fagus sylvatica L.: phenotypic and environmental sources of variability

Xylem vulnerability to cavitation is a key parameter in understanding drought resistance of trees. We determined the xylem water pressure causing 50% loss of hydraulic conductivity (P(50)), a proxy of vulnerability to cavitation, and we evaluated the variability of this trait at tree and population levels for Fagus sylvatica. We checked for the effects of light on vulnerability to cavitation of stem segments together with a time series variation of P(50). Full sunlight-exposed stem segments were less vulnerable to cavitation than shade-exposed ones. We found no clear seasonal change of P(50), suggesting that this trait was designed for a restricted period. P(50) varied for populations settled along a latitudinal gradient, but not for those sampled along an altitudinal gradient. Moreover, mountainside exposure seemed to play a major role in the vulnerability to cavitation of beech populations, as we observed the differences along north-facing sides but not on south-facing sides. Unexpectedly, both north-facing mountainside and northern populations appeared less vulnerable than those grown on the southern mountainside or in the South of France. These results on beech populations were discussed with respect to the results at within-tree level.     

Effect of bitter vetch (Vicia ervilia) seeds as a replacement protein source of soybean meal on performance and carcass characteristics of finishing Awassi lambs

The objective of this study was to evaluate the effects of replacing the protein source of soybean meal (SBM) with different levels of bitter vetch seeds (BVS) in the diets of finishing Awassi ram lambs on performance, and carcass characteristics. Diets were designed based on replacing SBM with BVS as a percentage of the diet. Diets were: control (0% BVS), substituting 5% of SBM (5% BVS), 10% of SBM (10% BVS) and the entire SBM in the ration with BVS (15% BVS). Forty eight lambs (18.74?±?3.95 kg initial body weight and 70 days of age) were randomly assigned to 4 treatment diets (12 lambs/treatment). Lambs were given an adaptation period of 10 days and the experiment lasted for 84 days. At the end of the trial, a digestibility experiment was performed and 6 lambs from each treatment were slaughtered to evaluate carcass characteristics. Average daily gain tended (P?=?0.07) to be higher for lambs fed 10% BVS when compared to the other diets. Neutral detergent fiber digestibility was higher (P?<?0.01) in control diet compared to the other diets. Fat depth (C) and leg fat depth (L3) tended (0.05?<?P?<?0.1) to be affected by BVS levels in the diet. Leg total lean % was the highest (P?<?0.05) in 5% BVS and 10% BVS diets. These results suggest that substituting SBM with BVS in the diets did not influence performance or carcass characteristics of lambs. However, the cost of ration formulation decreases since SBM is a very expensive component of the ration.     

Renal efficiency underlies adaptive heterothermy of heat-stressed hypohydrated goats

Tropical Animal Health and Production - We investigated the thermotolerance of the F1 progeny (Black Bedouin × Damascus crossbreed) to summer conditions alongside that of two pure breeds. Male...     

Effect of feeding calcium salts on performance of nursing Awassi ewes

Twenty nursing Awassi ewes (BW = 50 ± 2.35 kg, age = 4.5 ± 1.2 years) with their lambs were used to evaluate the effects of feeding calcium salts in lactation diets on performance and pre-weaning growth of their lambs. Treatments were 0% calcium salts (CON) or 5% calcium salts (FAT). At the end of the study, a digestibility experiment was performed. Milk yield was greater (P < 0.05) for ewes fed the FAT diet than the CON diet. Milk composition was similar (P > 0.05) between diets. However, milk energy value (kcal/day) tended to be greater (P = 0.07) for the FAT diet than the CON diet. Concentrations of milk C18:1c9 and C20:0 were greater (P < 0.05) in ewes fed the FAT diet than the CON diet. However, concentration of trans-10, cis-12 CLA was lower (P = 0.05) in the FAT diet than in the CON diet. No differences in feed intake and body weight change were detected between diets. Digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber were similar (P > 0.05) for diets. For lambs, weaning weight was not affected by treatments. However, average daily gain and total gain were greater (P = 0.053) for the FAT diet than the CON diet. Results suggest that supplementing lactating ewes with calcium salts at the beginning of lactation phase improves daily milk yield of ewes and pre-weaning growth of their lambs with no major negative impact on feed intake and digestibility.     

Thermoregulatory response of dairy cows fed ergotized barley during summer heat stress.

Claviceps purpurea infects the seed heads of cereal grains and grasses and produces ergopeptine alkaloids that cause hyperthermia and agalactia in cattle during periods of heat stress. A field experiment was undertaken to examine the effects of ergopeptine alkaloids found in barley on thermal status of dairy cattle during periods of heat stress. Production end points were also measured to identify the effect of the change in thermal status. Contaminated barley screenings containing known levels of ergopeptine alkaloids were fed to lactating Holstein cattle (10 microg total ergopeptine alkaloids/kg BW/day) for 10 days during summer heat stress. Air temperature increased 14.4 C during the first 8 days of treatment and then declined the same during the last 2 days. Extreme daily values for rectal temperature and respiration rate, using averages of all animals, showed maximum increases of 2.3 C and 56.8 breaths/minute, respectively, during this period. Group afternoon milk production decreased 2 kg/day during the heat stress period, with no measurable change in feed intake. A greater level of hyperthermia occurred in cattle consuming the diet with ergopeptine alkaloids, with only marginal symptoms of ergot toxicosis reflected in feed intake and milk production. Therefore, the ergopeptine alkaloid dose used in this study represents a level for minimal induction of the ergot toxicity response.     

Randomized double blind comparison between sciatic-femoral nerve block and propofol-remifentanil, propofol-alfentanil general anesthetics in out-patient knee arthroscopy

The aim of this study is the evaluation preparation and discharge times as well as the side-effects, patient satisfaction and costs after out-patient knee arthroscopy performed with a combined sciatic-femoral nerve block or a propofol-remifentanil, propofol-alfentanil general anesthetics. Sixty patients, (remifentanil group 1, n = 20), (alfentanil group 2, n = 20) and a combined sciatic-femoral nerve block (PNB group 3, n = 20). In group 1, anesthesia was induced with remifentanil (1 mic kg(-1) followed by 0.5 mic kg(-1) min(-1) i.v), in group 2 alfentanil (20 mic kg(-1) followed by 2 mic kg(-1) min(-1) i.v, in both groups (group 1, 2) propofol was given 2 mg kg(-1) i.v followed by 9 mg kg(-1) h(-1) i.v. Patients then received atracurium 0.6 mg kg(-1) i.v. to facilitate endotracheal intubation. In the PNB group (group 3), patients received a sciatic-femoral nerve block with ropivacaine 25 mL 0.75 mg using a multiple injection technique aided by a nerve stimulator and a short, bevelled, Teflon-coated stimulating needle. There was no significant difference in the duration of stay in the post anesthesia care unit and day surgery unit between groups, there was significant increase in the time to first urination in PNB group than the other two groups. Also there was no significant difference in the stay in delay surgery. The cost of disposal materials, preoperative and post operative times were higher in PNB group. The cost of drugs was higher in remifentanil and alfentanil groups than PNB group; the total cost was insignificant in the three groups. In conclusion, this prospective randomized study suggests that in patients undergoing out-patient arthroscopy, a combined sciatic-femoral nerve block (using a small volume of ropivacaine 0.75%) compared with a propofol-remifentanil or propofol-alfentanil general anesthetics techniques may provide similar intraoperative analgesic efficacy, a shorter length of stay in the PACU and an increased likelihood of bypassing the first phase of postoperative recovery.     

Comprehensive assessment of benthic diatom (Amphora coffeaeformis) as a feed additive in Nile tilapia (Oreochromis niloticus) diet

Four hundred and fifty Nile tilapia (Oreochromis niloticus), each weighing ca. 4 g, were randomly allocated into five equal groups in triplicate. The first group acts as control (A0). A1, A2, A3 and A4 groups were fed on rations supplemented with diatom, Amphora coffeaeformis, at 2.5, 5.0, 7.5 and 10%, respectively, for 63 days. Assessment of fish growth, biochemical composition, erythrocyte alterations, gonadal maturation, serum biomarkers, and liver and intestinal pathogens was carried out to identify fish welfare. Fish were challenged by Aeromonas hydrophila injection for an additional 14 days; then, mortality rate and some blood parameters were monitored. Results demonstrated that Amphora sp. insignificantly impacted fish growth, but it induced significant depletion in lipid content. Blood smear investigation indicated erythrocyte alterations in A4 group compared with A0 group. Male gonadosomatic index and relative fecundity demonstrated an increment in A3 and A4 groups respectively. A boost in fish immunity of A3 group was demonstrated through serum biomarkers and pathogenic bacterial identification in liver and intestine compared with other groups. Cumulative mortality of stressed fish was 90% in the A0 group and decreased to 30% in the A3 group. Blood analysis of stressed fish indicated higher tolerance in the A3 group. In conclusion, Amphora sp. can be used as an immunostimulant for increasing disease resistance under stress conditions.