The effect of reduced balanced protein diet on the behavior of female broiler breeders in 2 generations.

The behavior of 2 generations of broiler breeders undergoing a 25% reduced balanced protein (RP) dietary treatment was investigated in the current study. There were 2 treatments for the F0 generation: control (C) breeders fed with standard C diets and RP breeders fed with RP diets. The female progeny of each treatment was again subjected to 2 dietary treatments, resulting in 4 treatments for F1 generation: C/C, C/RP, RP/C, and RP/RP (breeder feed in F0/F1 generation). To maintain the target body weights throughout the trial, breeders on RP diet received on average 10% more feed than C diet breeders. The behavior of the breeders at 8h30 (30 min before feeding at 9h00), 12h00, and 15h30 in weeks 23 and 37 of the F0 generation and in week 6, 11, and 22 of the F1 generation was observed. Litter scratching, feather pecking, and object pecking were occasionally increased by RP diet feeding which indicated feeding frustration. Drinking behavior decreased dramatically by the RP dietary feeding and resulting in a better litter condition which could benefit dust bathing behavior. In addition, feeding the breeders RP diet in the F0 generation decreased litter scratching (week 6) and feather pecking (week 22, 15h30) but increased sitting (week 11, 15h30) and drinking (a tendency in week 6 and a significant effect in week 11) behavior of offspring breeders (F1 generation). In general, breeders fed with reduced balanced protein diets, to some extent, spent less time drinking and their offspring could have an adaptation to the maternal RP diet. The mechanism of this adaptation still needs to be further investigated. In general, positive effects were found by reducing protein level of breeder diets. However, negative side effects such as feeding frustration were also observed, which merit further study.

The learning ability and memory retention of broiler breeders: 1 effects of reduced balanced protein diet on reward based learning.

Learning and mental abilities of farm animals are important for their adaptation to new environments and could serve as an indicator for welfare and performance. This study assessed the learning ability and memory retention of broiler breeders through a T-maze test with a reward v. no reward set-up. Feed supplemented with or without meal worms served as a reward. Two trials were conducted with either parent stock (PS) breeders or pure line A (PL) breeders and with the same dietary treatment namely a control (C) group fed with standard commercial diets and a reduced balanced protein (RP) group fed with RP diets (25% reduction of CP and amino acids). To maintain similar target BW, the RP group received on average 10% more feed. A tonic immobility (TI) test was performed to estimate the fearfulness of PS breeders. Most breeders were capable of completing the T-maze tests, but the C group needed less time compared with the RP group when their own feed was given as a reward. However, when meal worms were provided as an extra incentive, the RP group completed the maze significantly faster than the C group. Compared to the C breeders, the RP breeders remained longer in a TI state, indicating a higher level of fearfulness. Long-term memory retention in the T-maze test was observed in both groups. It is concluded that the RP diet had no influences on the learning ability of the reward v. no reward discrimination test and its memory retention of broiler breeders. The increased amount of time the RP breeders needed to solve the test was probably due to a higher sense of fear. Furthermore, the RP diet enhanced the motivation of breeders to obtain an alternative feed such as meal worms.

The learning ability and memory retention of broiler breeders: 2 transgenerational effects of reduced balanced protein diet on reward-based learning.

The effect of reduced balanced protein (RP) diet in the F0 and F1 generation of broiler breeders on the learning ability and memory retention of the F2 generation was investigated by means of a reward v. no reward discrimination T-maze test. There were two treatments for the F0 generation: control (C) group, reared on standard commercial diets, and reduced balanced protein (RP) group, fed with RP diets (25% reduction in CP and amino acids). The female F0-progeny of each treatment was again separated into the two dietary treatments, resulting in four treatments for the F1 generation: C/C, C/RP, RP/C and RP/RP (breeder feed in F0/F1 generation). The RP diets fed breeders received on average 10% more feed than C diets fed breeders to achieve a similar target BW. The F2 generation was composed of four treatments coming from the female F1-progeny of the four treatments and were all fed with C diet (namely C/C/C, C/RP/C, RP/C/C and RP/RP/C). All four F2 generation groups were able to complete the T-maze learning test with a slight difference in success rate but a significant difference within groups was observed regarding the time needed to complete the test. In general, the RP/RP/C group needed more time for completing the test compared with the other three groups and the shortest time was recorded for the RP/C/C group. At similar ages, breeders with early learning experience spent significantly less time in completing the test compared with unexperienced breeders. Long-term memory retention was observed in all four groups whereas the learning ability in solving the test decreased with age. It took longer for the breeders to complete the test at older ages. In conclusion, under our experimental conditions, the RP dietary treatment in previous generations had no influence on the T-maze learning ability and memory retention of broiler breeders of the third generation, although it might have effects on the working performance in the T-maze learning test of F2 generation breeders.

A two-level pen for fattening pigs: Effects on behavior, performance, and postslaughter measurements.

Concurrent with a tendency toward higher slaughter weights of fattening pigs, minimum requirements for space allowance are increasing. Allowing pigs more space in existing standard pens, however, leads to a decrease in the number of pigs per pen, which jeopardizes the economic viability of the pig farm. A possible solution includes creating a two-level pen by constructing a second level in an existing pen, to enable an increase in space allowance per pig with the same number of pigs. We investigated the effect of such a pen on the behavior, performance, and postslaughter results of fattening pigs during the entire fattening period (30 to 110 kg). A total of 444 pigs were distributed over standard control pens (0.74 m/pig) and two-level pens (0.99 m/pig). Feed was provided only in a trough at the ground level of the pen. The results show that the increased space allowance and choice of levels in two-level pens influenced the pigs' behavior in a positive way, as they performed less manipulation of pen mates ( < 0.0001). Moreover, pigs lay down more ( = 0.0007) and showed less head knocking ( = 0.005) in two-level pens, suggesting that they were calmer. In line with the behavioral results, pigs in two-level pens had fewer lesions on tails ( = 0.006), ears ( = 0.008), and shoulders ( = 0.01). Growth performance was not affected ( > 0.05), but postslaughter measurements revealed fewer livers with white spots in pigs from two-level pens. This result might be related to lower disease pressure in pens with lower stocking densities. In conclusion, a two-level pen seemed to have positive effects on the behavior of pigs (in terms of pen mate manipulation) and the increase in space allowance seemed to make the pigs calmer. The use of the second level by heavier pigs should, however, be further studied to investigate whether this extra space could be fully counted for the minimal space requirements.

Sire line of pigs affects weaning weight, growth performance, and carcass characteristics of offspring.

Today, early weaning is more frequently applied by the modern pig breeder to obtain more litters per year. In addition, more and more European pig breeders apply a batch management system, which allows weaning to occur at fixed time points but entails that the offspring are treated at the litter level and not as individuals. Both evolutions might result in weaning lightweight piglets, which can cause, e.g., growth retardation of the offspring. Hence, the objective of this research was to improve the weaning weight of piglets of the same age by breeding with a highly conformed sire line. Therefore, a total of 23 sows were inseminated, 10 sows with semen of a well-conformed sire line (sire line B) and 13 sows with semen of a less conformed boar (sire line A). In total, 299 offspring were observed to monitor behavior, growth performance, and carcass characteristics. Subsequently, linear mixed models were developed to analyze the growth performance and carcass characteristics wherein only variables classified as significant ( < 0.05) were introduced as fixed factors. Results indicate that no significantly increased weaning weight could be accomplished by breeding with semen of sire line B. This could be due to the significant ( < 0.05) shorter gestation length of sows inseminated with semen of sire line B. However, the offspring of sire line B was defined by better carcass classification characteristics. Furthermore, this study presents that the mean birth weight of each piglet was significantly lower if a bigger litter size was recorded. When considering behavior, it was observed that piglets that did not seclude themselves from the litter had a significantly greater daily weight gain from birth to weaning compared to piglets that showed signs of isolation from the litter. A significantly greater daily gain from birth to slaughter was established for piglets with a greater birth weight. Also, results indicate that barrows had a significantly greater daily growth from weaning to slaughter than gilts. To conclude, this research determines that breeding with highly conformed sire lines does not improve the weaning weight of the offspring and thus cannot serve as a solution for early weaning. However, more research is required by performing more experiments with a greater number of boars and sows to confirm this result. In general, this study allows researchers to continue to improve and standardize the weaning weight of piglets of the same age.

International online survey to assess current practice in equine anaesthesia.

REASONS FOR PERFORMING STUDY: Multicentre Confidential Enquiries into Perioperative Equine Fatalities (CEPEF) have not been conducted since the initial CEPEF Phases 1-3, 20 years ago. OBJECTIVES: To collect data on current practice in equine anaesthesia and to recruit participants for CEPEF-4. STUDY DESIGN: Online questionnaire survey. METHODS: An online questionnaire was prepared and the link distributed internationally to veterinarians possibly performing equine anaesthesia, using emails, posters, flyers and an editorial. The questionnaire included 52 closed, semiclosed and open questions divided into 8 subgroups: demographic data, anaesthetist, anaesthesia management (preoperative, technical equipment, monitoring, drugs, recovery), areas of improvements and risks and motivation for participation in CEPEF-4. Descriptive statistics and Chi-squared tests for comparison of categorical variables were performed. RESULTS: A total of 199 questionnaires were completed by veterinarians from 14 different countries. Of the respondents, 43% worked in private hospitals, 36% in private practices and 21% in university teaching hospitals. In 40 institutions (23%) there was at least one diplomate of the European or American colleges of veterinary anaesthesia and analgesia on staff. Individual respondents reported routinely employ the following anaesthesia monitoring modalities: electrocardiography (80%), invasive arterial blood pressures (70%), pulse oximetry (60%), capnography (55%), arterial blood gases (47%), composition of inspired and expired gases (45%) and body temperature (35%). Drugs administered frequently or routinely as part of a standard protocol were: acepromazine (44%), xylazine (68%), butorphanol (59%), ketamine (96%), diazepam (83%), isoflurane (76%), dobutamine (46%), and, as a nonsteroidal anti-inflammatory drug, phenylbutazone (73%) or flunixin meglumine (66%). Recovery was routinely assisted by 40%. The main factors perceived by the respondents to affect outcome of equine anaesthesia were the preoperative health status of the animal and training of the anaesthetist. CONCLUSIONS: Current practice in equine anaesthesia varies widely, and the study has highlighted important topics relevant for designing a future prospective multicentre cohort study (CEPEF-4). The Summary is available in Chinese - see Supporting information.

Interactions between climatological variables and sheltering behavior of pastoral beef cattle during sunny weather in a temperate climate.

Concerns in regard to thermal discomfort experienced by cattle are increasing, especially in the summer time. It is important to determine whether or not pastured beef cattle would make use of shade during sunny circumstances in a temperate climate. If so, scientifically based guidelines may need to be formulated for translation into legislation aiming to protect animal welfare. Approximately 255 beef cattle on 18 pastures were observed from July 2010 through November 2010 in central Belgium. Pastures having either natural or artificial shelter for animal protection but similar with respect to agricultural and climatological characteristics were included in the study. The analysis of data focused on the effect of weather conditions on sheltering behavior of cattle, with pasture as a random factor. During sunny weather, ambient temperature had a significant influence on the use of shade (P < 0.0001): the greater the environmental temperature was, the more cattle on a pasture were located in a shaded area. Ambient temperature (Ta) and relative humidity (RH) both tended to have a positive relation with shade use. However, the expected impact of their combined effect was not found, probably because of the strong negative correlation between RH and Ta (r = -0.7122) in the studied region. Greater wind speed (WS) reduced the need for shade, even at a greater Ta (P < 0.0001). Both Ta and solar radiation (RAD) influenced use of shade, but the interaction or combined effect was not significant. The variability of shade use between the pastures in this study could be explained by the surface of shade present on the pasture. It is rather self-evident that cows made more use of shade when a greater percentage of the surface area was shaded, but the presence of remaining nonshaded area kept the alternative choice reliable. On the basis of the fact that more cattle being observed in a shaded area was associated with a higher dry air temperature, it can be concluded that providing shelter could also be valuable for pastured cattle living in a temperate region.

Pharmacokinetic profile and pharmacodynamic effects of romifidine hydrochloride in the horse.

Romifidine HCl (romifidine) is an α(2)-agonist commonly used in horses. This study was undertaken to investigate the pharmacokinetics (PK) of romifidine following intravenous (i.v.) administration and describe the relationship between PK parameters and simultaneously recorded pharmacodynamic (PD) parameters. Romifidine (80 µg/kg) was administered by i.v. infusion over 2 min to six adult Thoroughbred horses, and plasma samples were collected and analyzed using liquid chromatography-mass spectrometry. Limit of quantification was <0.1 ng/mL. PD parameters and arterial blood gases were measured for 300 min following romifidine administration. Statistical PD data analysis included mixed-effect modeling. After i.v. administration of romifidine, the plasma concentration-vs.-time curve was best described by a two-compartmental model. Terminal elimination half-life (t(1/2ß) ) was 138.2 (104.6-171.0) min and volumes for central (V(c)) and peripheral (V(2)) compartments were 1.89 (0.93-2.39) and 2.57 (1.71-4.19) L/kg, respectively. Maximum plasma concentration (C(max)) was 51.9 ± 13.1 ng/mL measured at 4 min following commencement of drug administration. Systemic clearance (Cl) was 32.4 (25.5-38.4) mL · min/kg. Romifidine caused a significant reduction in heart rate and cardiac index and an increase in mean arterial pressure (P < 0.05). Sedation score and head height values were significantly different from the baseline values for 120 min (P < 0.05). The decline in cardiovascular and sedative effects correlated with the decline in plasma romifidine concentration (P < 0.05). In conclusion, a highly sensitive analytical technique for the detection of romifidine in equine plasma allowed detailed description of its PK profile. The drug produces long-lasting sedation in horses that corresponds with the long terminal elimination half-life of the drug.

Behavior of piglets after castration with or without carbon dioxide anesthesia.

Surgical castration of male piglets without anesthesia is a routine management practice conducted on commercial pig farms. For animal welfare reasons, it would be beneficial to develop methods of practical pain relief. The objective of this study was to evaluate the effect of providing CO2 anesthesia before castration on the behavior of piglets for up to 8 d after castration in comparison with piglets castrated without anesthesia. In 3 successive replicates, the behavior of 186 male piglets castrated with (n = 95) or without (n = 91) anesthesia was observed for up to 8 d after castration. All piglets in a given replicate were castrated on the same day, before 8 d of age. Behavioral observations were carried out in accordance with a continuous focal sampling procedure that began immediately after castration and continued for a period of 1 wk. Barrows anesthetized with CO2 before castration displayed more interactive behaviors during the overall observation period than the other barrows (P = 0.0412), which may indicate better welfare. Assessing all observation periods separately, differences in activity at the udder, lying, walking, and interactive behaviors appeared to support the beneficial effect of providing CO2 anesthesia before castration. However, these differences varied over time between treatment groups. The most important conclusion was that piglets castrated with or without CO2 anesthesia displayed behaviors indicative of pain and discomfort for up to 6 d after castration. Therefore, additional analgesia may be necessary to eliminate the long-term pain caused by castration even in piglets anesthetized with CO2 before castration.

Contemporary use of acepromazine in the anaesthetic management of male horses and ponies: a retrospective study and opinion poll.

REASON FOR PERFORMING STUDY: Current use of acepromazine in the anaesthetic management of male horses and ponies and associated risks are largely unknown. OBJECTIVES: To explore anaesthetic acepromazine use and related adverse effects in the male horse. METHODS: Of 8533 anaesthetised horses and ponies medical records of male animals treated perianaesthetically with acepromazine were reviewed. Demographic data, time and dose of acepromazine administration, co-administered drugs, quality of induction and recovery from anaesthesia, arterial blood pressures, and occurrence of penile dysfunction were recorded. Practising ACVA and ECVAA diplomates were polled on the use of acepromazine and its effects on blood pressure and penile dysfunction in the equine. RESULTS: Of all animals, 12% females and 11% males (n=575 including 42% stallions) received perianaesthetic acepromazine, predominantly for premedication. Anaesthetic induction was smooth in 566 animals. Lowest mean arterial pressures averaged 65±9 mmHg. Recovery was good or very good in 70% of all animals and 74% stood after 1-2 attempts. In 14 horses (2.4%; 7 stallions, 7 geldings), penile prolapse occurred for 0.5-4 h and in one stallion (0.2%) for >12 but <18 h post recovery. Most surveyed anaesthesiologists use acepromazine in stallions (occasionally 63%; frequently 17%) but more frequently in geldings (occasionally 34%; frequently 59%) and mares (occasionally 38%; frequently 59%), primarily for premedication with other sedatives and analgesics. Persistent intraoperative hypotension was not frequently reported. Only 5% of surveyed anaesthesiologists recall penile prolapse post acepromazine administration lasting for >12 h and only one recalls 3 cases of irreversible penile prolapse in 20 years of anaesthesia practice. CONCLUSIONS AND POTENTIAL RELEVANCE: The extremely low risk of permanent penile dysfunction (≤1 in 10,000 cases) does not justify more restricted use of acepromazine in the intact male vs. geldings and mares.

Pharmacokinetic profile and behavioral effects of gabapentin in the horse.

Gabapentin is being used in horses although its pharmacokinetic (PK) profile, pharmacodynamic (PD) effects and safety in the equine are not fully investigated. Therefore, we characterized PKs and cardiovascular and behavioral effects of gabapentin in horses. Gabapentin (20 mg/kg) was administered i.v. or p.o. to six horses using a randomized crossover design. Plasma gabapentin concentrations were measured in samples collected 0-48 h postadministration employing liquid chromatography-tandem mass spectrometry. Blood pressures, ECG, and sedation scores were recorded before and for 12 h after gabapentin dosage. Nineteen quantitative measures of behaviors were evaluated. After i.v. gabapentin, the decline in plasma drug concentration over time was best described by a 3-compartment mammillary model. Terminal elimination half-life (t(1/2γ) ) was 8.5 (7.1-13.3) h. After p.o. gabapentin terminal elimination half-life () was 7.7 (6.7-11.9) h. The mean oral bioavailability of gabapentin (± SD) was 16.2 ± 2.8% indicating relatively poor absorption of gabapentin following oral administration in horses. Gabapentin caused a significant increase in sedation scores for 1 h after i.v. dose only (P < 0.05). Among behaviors, drinking frequency was greater and standing rest duration was lower with i.v. gabapentin (P < 0.05). Horses tolerated both i.v. and p.o. gabapentin doses well. There were no significant differences in and . Oral administration yielded much lower plasma concentrations because of low bioavailability.

Pulmonary gas exchange in anaesthetised horses mechanically ventilated with oxygen or a helium/oxygen mixture.

REASON FOR PERFORMING STUDY: It is unknown whether administration of gas-mixtures high in inspired fraction of oxygen (FiO2) under general anaesthesia may increase formation of pulmonary atelectasis and impair gas exchange. OBJECTIVE: To evaluate the effects of different FiO2 on pulmonary gas exchange in isoflurane-anaesthetised horses breathing a helium/oxygen (He/O2) mixture. METHODS: Thirty healthy mature horses were sedated with i.v. acepromazine (0.02 mg/kg bwt), detomidine (0.002 mg/kg bwt) and xylazine (02-0.4 mg/kg bwt). General anaesthesia was induced with i.v. 5% guaifenesin to effect, diazepam (0.1 mg/kg bwt) and ketamine (2 mg/kg bwt), and maintained with isoflurane. Fifteen horses (Group HX) were ventilated mechanically with gas mixtures of successively increasing FiO2 (0.25-030, 0.50-0.55, > 0.90), obtained by blending 02 with Heliox (70% He/30% O2). The other 15 horses (Group O) were ventilated immediately with 100% O2 (FiO2 > 0.90). After 20 min of ventilation at the different FiO2 levels in Group HX and after 60 min in Group O, PaO2 and PaCO2 were measured and the alveolar to arterial PO2 gradient (P(A-a)O2) was calculated. Data analysis included robust categorical regression with clustering on horse (P < 0.05). RESULTS: Inhalation of a He/O2 mixture with FiO2 as low as 0.25-030 ensured adequate arterial oxygenation and was associated with a smaller P(A-a)O2 gradient than inhalation of pure O2 (P < 0.05). In Group HX, PaO2 increased with each rise in FiO2 and so did P(A-a)O2 (P < 0.05). The PaO2 was significantly lower and the P(A-a)O2 higher in Group O compared to Group HX at a FiOz >0.90 (P < 0.05). CONCLUSIONS AND POTENTIAL RELEVANCE: Administration of a He/O2 gas mixture low in FiO2 can better preserve lung function than ventilation with pure oxygen. A step-wise increase of FiO2 using a He/O2 gas mixture might offer advantages with respect to pulmonary gas exchange over an immediate exposure to 100% 2O2.

Pharmacodynamic effects and pharmacokinetic profile of a long-term continuous rate infusion of racemic ketamine in healthy conscious horses.

Ketamine (KET) possesses analgesic and anti-inflammatory activity at sub-anesthetic doses, suggesting a benefit of long-term KET treatment in horses suffering from pain, inflammatory tissue injury and/or endotoxemia. However, data describing the pharmacodynamic effects and safety of constant rate infusion (CRI) of KET and its pharmacokinetic profile in nonpremedicated horses are missing. Therefore, we administered to six healthy horses a CRI of 1.5 mg/kg/h KET over 320 min following initial drug loading. Cardiopulmonary parameters, arterial blood gases, glucose, lactate, cortisol, insulin, nonesterified fatty acids, and muscle enzyme levels were measured, as were plasma concentrations of KET and its metabolites using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Levels of sedation and muscle tension were scored. Respiration and heart rate significantly increased during the early infusion phase. Glucose and cortisol significantly varied both during and after infusion. During CRI all horses scored 0 on sedation. All but one horse scored 0 on muscle tension, with one mare scoring 1. All other parameters remained within or close to physiological limits without significant changes from pre-CRI values. The mean plasma concentration of KET during the 1.5 mg/kg/h KET CRI was 235 ng/mL. The decline of its plasma concentration-time curve of both KET and norketamine (NKET) following the CRI was described by a two-compartmental model. The metabolic cascade of KET was NKET, hydroxynorketamine (HNK), and 5,6-dehydronorketamine (DHNK). The KET median elimination half-lives (t1/2alpha and t1/2beta) were 2.3 and 67.4 min, respectively. The area under the KET plasma concentration-time curve (AUC), elimination was 76.0 microg.min/mL. Volumes of C1 and C2 were 0.24 and 0.79 L/kg, respectively. It was concluded that a KET CRI of 1.5 mg/kg/h can safely be administered to healthy conscious horses for at least 6 h, although a slight modification of the initial infusion rate regimen may be indicated. Furthermore, in the horse KET undergoes very rapid biotransformation to NKET and HNK and DHNK were the major terminal metabolites.

Effects of isovolemic resuscitation with hemoglobin-based oxygen carrier Hemoglobin glutamer-200 (bovine) on systemic and mesenteric perfusion and oxygenation in a canine model of hemorrhagic shock: a comparison with 6% hetastarch solution and shed blood.

OBJECTIVE: To study Hemoglobin glutamer-200 bovine (Hb-200), 6% hetastarch (HES) and shed whole blood (WB) resuscitation in canine hemorrhagic shock. STUDY DESIGN: Prospective laboratory investigation. Animals Twelve adult dogs [29 +/- 1 kg (mean +/- SD)]. METHODS: Anesthetized dogs were instrumented for recording systemic and mesenteric hemodynamic parameters and withdrawal of arterial, mixed and mesenteric venous blood, in which hematological, oxygenation, blood gas and acid-bases variables were determined. Recordings were made before [baseline (BL)], after 1 hour of hypovolemia and immediately and 3 hours post-resuscitation with 30 mL kg(-1) of either Hb-200, HES, or WB. RESULTS: Blood withdrawal (average 34 +/- 2 mL kg(-1)) caused significant hemodynamic changes, metabolic acidosis and hyperlactatemia characteristic for hemorrhagic shock. Only WB transfusion restored all variables. Hemoglobin glutamer-200 bovine infusion returned most hemodynamic parameters including cardiac output and mesenteric arterial blood flow to BL but increased mean arterial pressure above BL (p < 0.05). However, Hb-200 failed to restore total Hb and arterial oxygen content (CaO2), leaving systemic (DO2I) and mesenteric O2 delivery (DO2Im) below BL (p < 0.05). Nevertheless, acid-base variables recovered completely after Hb-200 resuscitation, and met-hemoglobin (Met-Hb) levels increased (p < 0.05). Hetastarch resuscitation returned hemodynamic variables to or above BL but further decreased total Hb and CaO2, preventing recovery of sDO2I and mDO2I (p < 0.05). Thus, systemic and mesenteric O2 extraction stayed above BL (p < 0.05) while acid-base variables recovered to BL, although slower than in Hb-200 and WB groups (p < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Resuscitation with Hb-200 seemed to resolve metabolic acidosis and lactatemia more rapidly than HES, but not WB; yet it is not superior to HES in improving DO2I and DO2Im. The hyperoncotic property of solutions like Hb-200 that results in rapid volume expansion with more homogenous microvascular perfusion and the ability to facilitate diffusive O2 transfer accelerating metabolic recovery may be the key mechanisms underlying their beneficial effects as resuscitants.

Growth factor and receptor mRNA expression in the intestine of horses with large colon volvulus: a pilot study.

REASONS FOR PERFORMING STUDY: Growth factors (GF) are important for maintenance and repair of intestinal mucosal structure and function, but there have been no studies investigating growth factor (GF) or growth factor receptor (GF-R) mRNA expression in the intestine of horses with large colon volvulus (LCV). OBJECTIVES: (1) To determine mRNA expression for epidermal growth factor (EGF), EGF receptor (EGF-R), insulin-like growth factor-I (IGF), IGF receptor (IGF-R), vascular endothelial growth factor (VEGF) and VEGF receptor (VEGF-R) in the intestine of horses with an LCV compared to normal intestine. (2) To measure the correlation between histological intestinal injury and mRNA expression. METHODS: In 5 horses, samples were collected from the mid-jejunum (small intestine, SI), pelvic flexure (PF) and right dorsal colon (RDC) prior to creation of the LCV (NORM), 1 h following creation of the LCV (ISCH) and 1 h following correction of the LCV (REPER). In 2 clinical cases of LCV, samples were collected from the PF and RDC. Samples were assessed histologically for the amount of intestinal injury. The mRNA expressions of growth factors and receptors were determined using qRT-PCR. RESULTS: VEGF and VEGF-R mRNA expression was greater in horses with an LCV compared to NORM. Expression of IGF-R mRNA increased in the SI during ISCH and REPER. CONCLUSION AND POTENTIAL RELEVANCE: The increase compared to NORM in VEGF and VEGF-R mRNA expression in horses with LCV may be important in early intestinal healing and may also explain, in part, the increase in vascular permeability in horses with a LCV. Expression of IGF and IGF-R in the SI warrants further investigation and may be important for understanding post operative complications in horses with SI lesions.

Influence of supplemental magnesium, tryptophan, vitamin C, vitamin E, and herbs on stress responses and pork quality.

This study investigated the effects of supplemental Mg, Trp, vitamin C, vitamin E, and herbs on stress responses, skin lesions, and meat quality of slaughter pigs (106.0 +/- 8.6 kg of BW). These 5 supplements were tested in 4 similar experiments. In Exp. 1, 2 treatments were tested: 1) control treatment without supplementation, and 2) supplementation of an herbal product (2.5 g/L of drinking water for 2 d). Eighty-eight pigs per treatment were involved, of which 40 were selected for meat quality measurements (over 4 replicates). The experimental design of Exp. 2 and 3 was the same as Exp. 1, except that in Exp. 2 Mg (3 g/L of drinking water for 2 d) was supplemented and in Exp. 3 Trp (6 g/kg of feed, as-fed basis) was supplemented. In Exp. 4, 3 treatments were tested: 1) control treatment without supplementation, 2) supplementation of vitamin C (300 mg/kg of feed for 21 d, as-fed basis), and 3) supplementation of vitamin E (150 mg/kg of feed for 21 d, as-fed basis). In Exp. 4, 66 pigs per treatment were used, of which 42 were evaluated for meat quality (over 6 replicates). Pigs supplemented with vitamin E ate less than control (P = 0.03) or vitamin C-supplemented pigs (P = 0.03). Pigs were transported to a commercial slaughterhouse and were slaughtered after a lairage period. Blood sampling at slaughter revealed no differences between the control and supplemented pigs in plasma cortisol, glucose, lactate, or creatine kinase concentrations. Pigs provided with Mg (P = 0.002) or Trp (P = 0.04) had lower plasma NEFA concentrations than control pigs, and pigs supplemented with vitamin C had greater concentrations than the control (P = 0.03) or vitamin E-supplemented pigs (P = 0.01). Supplementation of the herbal product increased the frequency of pigs with shoulder (P = 0.05) and loin lesions (P = 0.03), whereas Mg lowered the incidence of loin lesions (P = 0.01). Measurements of pH and temperature in the LM and biceps femoris 45 min postmortem revealed no differences among treatments, and no influence of treatments on LM pH, electrical conductivity, and water holding capacity was observed 48 h postmortem. Compared with the control loins, loins of pigs supplemented with vitamin C (Japanese color scale, L*, and a* value; P < 0.05) or vitamin E (Japanese color scale and a* value; P < 0.03) were redder and less pale, and the loin of vitamin E-supplemented pigs was more yellow (b* value; P = 0.04). Generally, Mg could lower loin damage, whereas vitamin C and vitamin E supplementation resulted in a color improvement of the loin.

Head current during and blood splashes after electrical stunning in relation to characteristics of the pig's body.

In order to evaluate electrical stunning in relation to the incidence of blood splashes, meat quality and carcass quality parameters, 2035 pigs, heterozygous for the halothane gene, were observed during slaughter at a commercial slaughterhouse. The head current during electrical stunning is significantly higher (P<0.01) in gilts with a lower live weight (P<0.0001) or cold carcass weight (P<0.0001) and a higher lean meat percentage (P<0.0001). Also the incidence of blood splashes in the ham is significantly higher in gilts (P<0.0001) with a higher lean meat percentage (P=0.0028; odds ratio=1.11), a lower live weight (P=0.003; odds ratio=0.98) and a lower type number (P=0.0074; odds ratio=0.64). For barrows, no significant parameters were revealed. These results suggest that the variability in incidence of blood splashes can be explained by the variability of current density depending both on sex and body characteristics. Thus, electrical stunning can be improved by providing an energy level, based on the body characteristics of the pig.

Variability in the eruption of the permanent incisor teeth in sheep.

The incisor teeth of 176 sheep of six breeds were inspected every two to three months for a year to record the shedding of the deciduous teeth and the eruption of the permanent teeth. In all the breeds the permanent central incisors erupted at between 12 and 18 months of age. In 96 per cent of the sheep the permanent middle incisors erupted at between 18 and 26 months; and in 92 per cent the permanent lateral incisors erupted at between 24 and 36 months of age. The permanent corner teeth erupted at between 32 and 44 months in 96 per cent of the sheep. The gingival redness and swelling accompanying the eruption of a permanent tooth disappeared within two months. In 14 cases two pairs of incisors erupted during the year, in 18 cases the incisors erupted asymmetrically, and in 22 cases no incisors erupted. Rotation of one incisor was observed in five sheep and was combined with dental deviation in one.

Effect of supplemental tryptophan, vitamin E, and a herbal product on responses by pigs to vibration.

Economic losses related to increased stress during the transport of pigs are well documented. The effects of supplementing of tryptophan (Trp), vitamin E, or a herbal product via feed or drinking water were investigated in terms of effects on stress response in pigs during transport simulation. The study consisted of three analogous experiments. For the testing in each experiment, the pigs (23.5+/-3.2 kg) were allocated to one of two treatments, with and without supplementation of a product. The applied doses were Trp (5 g/L drinking water for 3 d), vitamin E (additional amount of 300 mg/kg feed for 21 d, as-fed basis), and Sedafit (2.5 g/L drinking water for 2 d). Sedafit is a commercial herbal product containing Valeriana officinalis L. and Passiflora incarnata L. as active components. In each experiment of the study, at least 47 pigs were involved, which were treated in groups of 3. The day before transport simulation, a Holter device was attached to the pigs to produce an electrocardiogram during the night (rest values), as well as during vibration in the transport simulator (1.2 Hz, 1 m/s2), where the behavior of the pigs (standing-sitting-lying) was also observed. Samples of saliva (taken before, during, and after [3x] vibration) and blood (taken before and after vibration) were analyzed for cortisol and intermediate metabolites (glucose, lactate, creatine kinase, and nonesterified fatty acids), respectively. Pigs supplemented with Trp tended to spend more time lying down during the second hour of vibration (P < 0.05). Vitamin E decreased the peak heart rate (P < 0.05), ventricular ectopic beats (P < 0.01), and ST elevation (P < 0.10). The supplementation of Sedafit resulted in smaller increases of the investigated heart variables (minimum heart rate, P < 0.05; ventricular ectopic beats, P < 0.05; ST elevation, P < 0.01) during and after stress evocation compared with the control group. None of the tested products influenced the intermediate metabolites; one possible explanation for this finding may be that peak values were reached before the time of bleeding. In conclusion, Trp had a positive behavioral effect in this experiment, and vitamin E and Sedafit mediated an increase in some heart variables, suggesting sedative and antianxiety effects.

Serum fluoride concentrations, biochemical and histopathological changes associated with prolonged sevoflurane anaesthesia in horses.

The volatile anaesthetic sevoflurane is degraded to fluoride (F-) and a vinyl ether (Compound A), which have the potential to harm kidney and liver. Whether renal and hepatic injuries can occur in horses is unknown. Cardiopulmonary, biochemical and histopathological changes were studied in six healthy thoroughbred horses undergoing 18 h of low-flow sevoflurane anaesthesia. Serum F- concentrations were measured and clinical laboratory tests performed to assess hepatic and renal function before and during anaesthesia. Necropsy specimens of kidney and liver were harvested for microscopic examination and compared to pre-experimental needle biopsies. Cardiopulmonary parameters were maintained at clinically acceptable levels throughout anaesthesia. Immediately after initiation of sevoflurane inhalation, serum F- levels began to rise, reaching an ongoing 38-45 micromol 1(-1) plateau at 8 h of anaesthesia. Serum biochemical analysis revealed only mild increases in glucose and creatinine kinase and a decrease in total calcium. Beyond 10 h of anaesthesia mild, time-related changes in urine included increased volume, glucosuria and enzymuria. Histological examination revealed mild microscopic changes in the kidney involving mainly the distal tubule, but no remarkable alterations in liver tissue. These results indicate that horses can be maintained in a systemically healthy state during unusually prolonged sevoflurane anaesthesia with minimal risk of hepatocellular damage from this anaesthetic. Furthermore, changes in renal function and morphology observed after sevoflurane inhalation are judged minimal and appear to be clinically irrelevant; they may be the result of anaesthetic duration, physiological stressors, sevoflurane (or its degradation products) or other unkown factors associated with these animals and study conditions.