A comparison of anesthetic risk factors and outcomes in light and draft horses

As a result of anatomic and physiologic differences, draft breeds may be at greater risk of developing anesthetic complications. The aim of the study was to evaluate and compare anesthetic management of draft (DR) and light (LT) horses. A case‐matched retrospective study of 371 clinical case records of DR (124 cases) and LT (247 cases) horses presented for general anesthesia between 1991 and 1998 was performed. Data were tabulated and comparisons were made using Student's t‐test (significance p < 0.05). Prior to induction, there were significant differences in mean body weight, rectal temperature, PCV, RBC, and serum TP concentration between DR and LT breeds. There were differences in mean doses of pre‐operative butorphanol (LT 21 µg kg^?1; DR 17 µg kg^?1), induction guaifenesin (LT 99 mg kg^?1; DR 88 mg kg^?1), and intraoperative ketamine (LT 0.35 mg kg^?1; DR 0.56 mg kg^?1) required. There were no significant differences in the mean doses of pre‐operative xylazine, detomidine, or induction barbiturate administered. The mean, average, and maximum concentrations of inspired halothane were significantly higher for DR than for LT horses. Draft horses received 33% less intraoperative IV fluids (8.2 mL kg^?1 hour^?1) than LT horses. Mean anesthetic duration, time to extubation, and standing recovery were not significantly different. Induction complications were not reported for either group. Rates of occurrence of intraoperative bradycardia, hypercarbia, hypoxemia, and metabolic acidosis (SBE, TCO₂, and bicarbonate concentration) did not differ significantly. Average MAP was greater in DR horses, but neither the degree nor the mean duration of hypotension differed between DR and LT horses. Mean PaO₂ was significantly lower in DR (246 mm Hg, 32.8 kPa) than in LT (305 mm Hg, 40.7 kPa) breeds. Draft horses were at greater relative risk of hypoventilation than LT horses. The greater MAP and requirement for halothane and intraoperative ketamine may indicate problems in achieving and maintaining a surgical plane of anesthesia. Draft horses may be at a greater risk of ventilation–perfusion mismatching.     

Incidence of the endothelin receptor B mutation that causes lethal white foal syndrome in white-patterned horses

OBJECTIVE: To determine incidence of the Ile118Lys endothelin receptor B (EDNRB) mutation responsible for overo lethal white syndrome (OLWS) and its association with specific types of white patterning. ANIMALS: 945 horses of white-patterned bloodlines and 55 solid-colored horses of other breeds. PROCEDURE: Horses were genotyped by use of allele-specific polymerase chain reaction to determine incidence of the Ile118Lys EDNRB mutation. RESULTS: Genotypes detected were homozygous Ile118, homozygous Lys118, and heterozygous. All foals with OLWS were homozygous for the Ile118Lys EDNRB mutation, and adults that were homozygous were not found. White patterning was strongly associated with EDNRB genotype. Color patterns with highest incidence (> 94%) of heterozygotes were frame overo, highly white calico overo, and frame blend overo. White-patterned bloodlines with lowest incidence of heterozygotes (< 21 %) were tobiano, sabino, minimally white calico overo, splashed white overo, nonframe blend overo, and breeding-stock solid. The mutation was not detected in solid-colored horses from breeds without white patterning. CONCLUSIONS AND CLINICAL RELEVANCE: In homozygotes, the Ile118Lys EDNRB mutation causes OLWS. In heterozygotes, the mutation is usually responsible for a frame overo phenotype. The frame pattern can be combined with other white patterns, making accurate estimation of EDNRB genotype by visual inspection difficult. Wide range of incidence of heterozygotes in various subtypes of white-patterned horses indicates different genetic control of these color patterns. Determination of EDNRB genotype by use of a DNA-based test is the only way to determine with certainty whether white-patterned horses can produce a foal affected with OLWS.     

Reproductive performance of totally confined sheep bred with semen extended in a lactose-egg yolk-glycerol buffer and stored at 5 degrees C.

Two experiments were carried out in January and May 1975 to study reproductive performance (fertility, prolificacy and fecundity) of totally confined sheep synchronized for estrus. The main objective of the first experiment was to compare reproductive performance of ewes bred naturally to those bred by artificial insemination. Semen for artificial insemination was collected by either artificial vagina or electroejaculation and stored for up to 36 hours at 5 degrees C. A second objective was to evaluate the effect of pregnant mares' serum gonadotrophin on the reproductive performance of ewes synchronized for estrus. Fertility was 53% for ewes bred by natural mating, 34% for ewes receiving pregnant mares' serum gonadotrophin and bred by artificial insemination, and 9% for those not receiving pregnant mares' serum gonadotrophin and bred by artificial insemination. There was no difference in fertility between ewes bred with semen collected by artificial vagina or by electroejaculation. A similar pattern was observed for fecundity. Average prolificacy was 2.0 with no significant differences among mating methods or pregnant mares' serum gonadotrophin application being observed. In the second experiment, the reproductive performance of ewes inseminated with semen stores at 5 degrees C for 48 to 60 hours was compared to that of ewes inseminated with semen stores for 24 to 36 hours. No significant differences in the reproductive performance were detected. Although average fertility (9%) and fecundity (19%) were low, prolificacy averaged 2.0 lambs per ewe lambing.     

Frequency domain analysis of heart rate variability in horses at rest and during exercise

The pattern of variation in heart rate on a beat-to-beat basis contains information concerning sympathetic (SNS) and parasympathetic (PNS) contributions to autonomic nervous system (ANS) modulation of heart rate (HR). In the present study, heart period (RR interval) time series data were collected at rest and during 3 different treadmill exercise protocols from 6 Thoroughbred horses. Frequency and spectral power were determined in 3 frequency bands: very low (VLF) 0-< or = 0.01, low (LO) >0.01-< or = 0.07 and high (HI) >0.07-< or = 0.5 cycles/beat. Indicators of sympathetic (SNSI = LO/HI) and parasympathetic (PNSI = HI/TOTAL) activity were calculated. Power in all bands fell progressively with increasing exercise intensity from rest to trot. At the gallop VLF and LO power continued to fall but HI power rose. SNSI rose from rest to walk, then fell with increasing effort and was lowest at the gallop. PNSI fell from rest to walk, then rose and was highest at the gallop. Normalised HI power exceeded combined VLF and LO power at all gaits, with the ratio HI to LO power being lowest at the walk and highest at the gallop. ANS indicators showed considerable inter-horse variation, and varied less consistently than raw power with increasing physical effort. In the horses studied, the relationship between power and HR changed at exercise intensities associated with heart rates above approximately 120-130 beats/min. At this level, humoral and other non-neural mechanisms may become more important than autonomic modulation in influencing heart rate and heart rate variability (HRV). HRV at intense effort may be influenced by respiratory-gait entrainment, energetics of locomotion and work of breathing. HRV analysis in the frequency domain would appear to be of potential value as a noninvasive means of assessing autonomic modulation of heart rate at low exercise intensities, only. The technique may be a sensitive method for assessing exercise response to experimental manipulations and disease states.     

Heart rate, blood biochemistry and performance of horses competing in a 100 km endurance ride

To determine whether a clinical examination was adequate to assess the fitness of horses in an endurance ride, and to characterise the relationship between a clinical assessment of the horse's fitness and its blood biochemistry, 23 horses were monitored before, during and after an 87 to 100 km endurance ride. Blood samples were taken before the ride, at three checkpoints on the ride, immediately after the ride and one day later for the determination of packed cell volume, total protein, lactate, glucose, non-esterified fatty acids, creatine phosphokinase, aspartate aminotransferase and plasma electrolytes. Heart rate measurements appeared to be a reliable indicator of the metabolic status of endurance horses suggesting that veterinary examinations according to the official Fédération Equestre Internationale rules are adequate to protect the health and welfare of horses competing in endurance races.     

The hen's egg: Shell cracking at impact on a heavy,stiff body and factors that affect it

1. Eggs from hens of three strains were dropped on to a heavy, stiff, smooth, plane body with impact at the equator of the shell; the height of drop, h_c, just sufficient to produce shell failure was measured and the corresponding impact velocity, v_c, calculated.

2. A small but commercially important percentage of the well‐formed eggs of one strain cracked when h_c was as low as 3–3 mm and v_c 250 mm/s.

3. Characteristics of the egg found to affect h_c and v_c included the overall thickness of its shell, thickness of its weak inner shell layer and average shell curvature, all measured at the point of impact, and its weight; its age also had a small effect (additional to that mediated through loss of weight); so did the degree of shell ridging.

4. No effect of shell colour was found.

5. Shell damage was typically a single hair‐crack that ran either round the equator or towards a pole.     

Reproductive performance,pre-weaning growth rate and pre-weaning lamb mortality of djallonké sheep in Ghana

Summary Production records for a flock of Djallonké sheep kept in the forest belt of Ghana were analysed to determine the effects of some environmental factors on the performance of the breed. The period under study covered April 1969 to November 1979. The mean ages at first conception and first lambing and the mean lambing interval were 498, 638 and 264 days respectively. The overall twinning rate and prolificacy were 30·7 and 130·6% respectively. The season of birth and age of dam had significant (P<0·05) effects on prolificacy and twinning rate. The birth weights of the lambs were affected significantly (P<0·05) by age of dam, type of birth, sex and season of birth with the mean birth weight being 1·77 kg. Weaning weight (mean of 8·36 kg) and pre-weaning growth rate (mean of 0·076 kg/day) were affected significantly (P<0·05) by types of birth. Type of birth significantly (P<0·05) affected pre-weaning mortality of lambs (overall mean of 20·95%).

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Resumen Se analizaron los registros de producción de un grupo de ovejas Djallonké, en la región boscosa marginal de Gana, para determinar los efectos de factores ambientales sobre el rendimiento de la raza. El per⫛odo del estudio, cubrió los meses de abril 1969 hasta noviembre 1979. La edad media a la primera monta, primer parto, e intervalo entre partos fue de 498, 638 y 264 días respectivamente. La rata de mellizos y prolificidad fue de 30.7% y 130.6% respectivamente. La estación al nacimiento y la edad de la madre tuvieron efectos significativos, sobre la rata de mellizos y prolificidad. El peso de los corderos al nacer, se afectó significativamente (P<0.05) por la edad de la madre, tipo de nacimiento, sexo y estación al necimiento, con un peso medio al nacer de 1.77 kg. El tipo de nacimiento afectó significativamente (P<0.05), el peso al destete (media de 8.5 kg), y la rata de crecimiento predestete (media de 0.076 kg/día). El tipo de necimiento, también afecto significativamente (P<0.05) la mortalidad predestete (media general de 20.95%).

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Résumé Les performances zootechniques d'un troupeau de moutons Djallonké dans la ceinturee forestière du Ghana ont été analysées pour déterminer l'influence de quelques facteurs de l'environnement sur les performances de la race. La période étudiée s'étendait d'avril 1969 à novembre 1979. L'age moyen à la première conception et au premier agnelage et l'intervalle moyen entre deux agnelages ont été respectivement de 498, 638 et 264 jours. Le taux global de naissances gemellaires et de prolificité ont été respectivement de 30,7 p. 100 et 130,6 p. 100. La saison de naissance et l'age de la mère ont influencé de fa?on significative (P<0,05) les taux de la prolificité et de naissances gemellaires. Le poids de naissance des agneaux a été affecté de fa?on significative (P<0,05) par l'age de la mère, le type de naissance, le sexe et la saison de naissance, le poids de naissance moyen se situant à 1,77 kg. Le poids au sevrage (moyenne de 8,36 kg) et le taux de croissance après sevrage (en moyenne 0,076 kg/jour) ont été influencés significativement (P<0,05) par les types de naissance. La mortalité des agneaux avant le sevrage (moyenne globale de 20, 95 p. 100) est aussi affecté de fa?on significative par le type de naissance (P<0,05).

     

Evaluation of the factors that affect the pregnancy rates during embryo transfer in beef heifers

The aim of this study was to evaluate the effects of the transfer side, transfer location, cervix transfer score, type and diameter of corpus luteum (CL) during embryo transfer on pregnancy rates in beef heifers. Progesterone-based synchronization and superovulation protocol were applied to Simmental cows used as donors (n = 168). Uterine flushings were performed on day 7 following artificial insemination. Obtained Code I (excellent or good) and II (fair) quality embryos were transferred to recipient beef heifers (n = 561). During embryo transfer, side of transfer (right or left), transfer location (the cranial or middle third of uterine horn), cervix transfer score (easy, moderate or difficult) and type (CLa, CLb and CLc) and diameter of CL were determined. Pregnancy rates following the transfer of Code I and II embryos were 44.66% and 33.07%, respectively (p < .05). The rates of pregnancy after transfers to the right and left uterine horn were 37% and 42.2%, respectively (p > .05). The pregnancy rates were 41.2%, 34.9% and 30.3% for cervix transfer scores as easy, moderate and difficult, respectively (p > .05). Pregnancy rates after transfer to the cranial third and middle third were 41.06% and 29.67%, respectively (p < .05). According to types of CL, pregnancy rates were 31.7%, 40.4% and 45.3% for CLa, CLb and CLc, respectively (p < .05). Moreover, it was found that as the CL diameter increased, the pregnancy rates increased. As a result, it was concluded that there was no effect of side of transfer and cervix transfer score, but embryo quality, transfer location, type and diameter of CL had significant effects on the pregnancy rate during embryo transfer in beef heifers.     

Normal electrocardiographic QT interval in race-fit Standardbred horses at rest and its rate dependence during exercise

ObjectivesCardiac repolarization, measured as QT and T_peak to T_end (T_pT_e) intervals on the ECG, is important, as irregularities caused by diseases, ventricular hypertrophy, drugs and genetic defects can trigger arrhythmias which predispose human patients to syncope and sudden cardiac death. In horses, repolarization is not well described and therefore QT analysis cannot yet be used diagnostically. Therefore, we sought to describe reference values for the normal QT and T_pT_e intervals in Standardbreds and to determine the best method for heart rate (HR) correction.Animals30 Standardbreds.MethodsQT and T_pT_e intervals were measured during rest and exercise and plotted against HR converted to R_peak to R_peak interval (RR). Data were fitted with relevant regression models. Intra- and inter-observer agreement was assessed using Bland–Altman analyses.ResultsData were best described by a piecewise linear model (r² > 0.97). Average prediction error of this model was smaller than for both Bazett and Fridericia corrections. Coefficient of repeatability of intra- and inter-observer variability was 8.76 ms and 5.64 ms respectively and coefficient of variation was 1.77% and 2.76% respectively. T_pT_e increased with RR in stallions.ConclusionsThe QT interval in Standardbred horses shortens with decreasing RR interval (increasing HR) as in humans, but in a markedly different order as it clearly follows a piecewise linear model. The equine QT interval can be measured easily and there is small intra- and inter-observer variability. This model of the equine QT interval provides clinicians with a method that could support a diagnosis of repolarization disturbances in horses.     

Effect of feed intake restriction on reproductive performance and pregnancy rate in Egyptian buffalo heifers

The objective of the present experiment is to study the effect of feed intake restriction on the reproductive performance and pregnancy rate in Egyptian buffalo heifers. Thirty anestrus buffalo heifers were randomly divided into two equal groups. The low feed intake (LFI, n?=?15, 50 % restriction) group was fed a diet that consists of 3 kg concentrate, 1 kg wheat straw, and 3 kg fresh alfalfa, while the high feed intake (HFI, n?=?15) group was fed double the amount given to the LFI group for 4 months. All animals were weighed, transrectally examined, and visually checked for the signs of estrus, and blood samples were collected. Heifers in heat were mated with one fertile bull. The number of heifers showing estrus activity was 93.3 % in HFI vs. 20 % in LFI (P?<?0.01). Ovarian activity started earlier (P?=?0.03) in the HFI than LFI group. The weight at breeding, the diameter of the dominant follicle, number of heifers showing ovulations, number of services per conception, pregnancy rate, and overall mean of progesterone and estrogen concentrations were significantly higher (P?<?0.01) in the HFI than in the LFI group. The level of serum total protein, albumin, globulin, glucose, total cholesterol, and calcium were significantly higher (P?<?0.05) in the HFI group. Restriction of the daily feed intake to 50 % from NRC recommendations impair reproductive performance in terms of increasing the age at first service and reducing the pregnancy rate in buffalo heifers. In conclusion, feed intake could be effective in improvement of reproductive performance in buffalo heifers and further studies should be done on large scale of buffaloes in this point.     

Effects of vitamin E and selenium administration on pregnant,heavy draft mares on placental retention time and reproductive performance and on white muscle disease in their foals

This study investigated the effects of administering vitamin E and selenium to pregnant heavy draft horsemares on the incidence of retained placenta and postpartum reproductive performance and on the prevention of the white muscle disease in their foals. In study A, 1,000 mg of vitamin E and 50 mg of selenium (E-SE 20 mL) were given to 22 mares 3 weeks before expected parturition (335 days counted from last mating), whereas 28 mares were used as controls. In study B, E-SE were administered 2 weeks before expected parturition at 2 dose levels, with 25 mares receiving 20 mL E-SE, 19 mares receiving 10 mL, and 29 mares kept as controls. Vitamin E and selenium were assayed in serum collected from some of the mares before administration of E-SE and again postpartum and from the foals immediately after birth. Serum selenium concentrations before E-SE administration were deficient (<65 ng/mL) in all mares (n = 48) but were increased in the postpartum sample from treated mares regardless of the dose or timing of administration (n = 31) (P = .05). Only study B mares were deficient in vitamin E prepartum, and both dose levels of E-SE had corrected this in the postpartum sample (P = .01). All foals were selenium deficient regardless of whether their dams had received E-SE or not, although concentrations were higher in foals from treated study A mares than from controls (P = .05). Mares with the highest selenium concentrations prepartum (40 ng/mL and over) had shorter placental retention times than mares with lower selenium concentrations (P = .05) and did not respond to E-SE with a further reduction in retention time. By contrast, mares with prepartum selenium concentrations between 20 and 40 ng/mL tended to respond to E-SE with a shortened placental retention time (P = .07). E-SE administration reduced the mean number of days from parturition to last mating (nonpregnant term) in study B mares (P = .05) and in mares with adequate prepartum vitamin E concentrations (>300 g/mL, P = .05). We conclude that maintaining high level serum vitamin E and selenium concentrations of prepartum mares is expected to increase fertility of selenium-deficient mares. Therefore, the regimen of vitamin E and selenium administrations to selenium deficient mares should be developed.     

Owners' perceptions of the health and performance of Pony Club horses in Australia

Pony Club is one of the leading junior equestrian organisations in the world, and was established to teach young people the many aspects of horsemanship. The aim of this study was to gain an understanding of the health and performance of Pony Club horses from the perspective of their owners. In-depth interviews were conducted with Pony Club members at two sites in Australia, and topics relating to participants' background with horses, horse attributes valued by participants, horse health and performance, and Pony Club-related matters. The in-depth interviews were taped, transcribed and analysed, by describing the themes and issues recorded in the dialogue and conducting cross-case analysis (finding similarities and dissimilarities between participants with respect to each of the above-mentioned topics). A total of 32 interviews were conducted. The participants' background with horses varied greatly. The horse attributes valued by > or =59% of participants included temperament, size, ability and suitability for riders. A range of issues relating to health and performance were important to > or =53% of participants, including horse temperament, nutrition, internal parasites, lameness and foot-care, and colic. Soundness and preventive health measures were rarely mentioned (< or =16% of participants). Friends or knowledgeable horse people were identified as the first point of contact for horse-health matters, and veterinarians were only used as a last resort or for serious problems. Members of Pony Club learned about their horses by trial and error. Optimal performance was described as a horse that was willing to do as the rider asked. Poor performance was usually the result of the horse misbehaving, and could include a resistance to rider commands, pigrooting and bucking.     

Epidemiologic study of salmonellae shedding in the feces of horses and potential risk factors for development of the infection in hospitalized horses

A study was designed to identify epidemiologic factors associated with the development and spread of salmonellae in horses in a veterinary teaching hospital, through a case-control study and a longitudinal follow-up prospective study. In the case-control study, 44 horses shedding salmonellae in feces were compared with 99 control horses not shedding salmonellae in feces; regarding breed, sex, age and initial diagnosis, none of the odds ratios for study factors was significant. The factors found to be associated with fecal shedding of salmonellae in the prospective study included diarrhea at the time of admission to the hospital, fever while hospitalized, and a change in diet while hospitalized. Horses identified to be shedding salmonellae in feces were not limited to those with clinical signs of salmonellosis; however, spread of salmonellae from a shedder without clinical signs of disease to other hospitalized horses was not identified. The most common serovars of Salmonella isolated were oranienburg and newport.     

Temporal and linear kinematics in elite and riding horses at the trot

Standard videography was used to determine the temporal and linear variables of 32 Spanish Purebreds at trot. Horses were organized into three groups: Group A (nonelite), comprising 13 stallions without any specific training program, which were hand led; Group B1 (elite), formed by 19 horses considered to be well-gaited and dressage trained, and which were also hand led; and Group B2 (ridden elite), comprising the same horses as the latter group but this time ridden. The horses ran at working trot, according to the trainers. Each animal was recorded using a Hi8 video camera. For temporal measurements, a 1/50 s time code was added to video images. Recordings were analyzed to provide times (seconds) at landing, mid-stance position, lift off and at subsequent landing in each limb. These data allowed the stride to be divided into its component phases by analysis of the variables for individual limbs, diagonal pairs and overall stride. The linear variables (meters) analyzed were stride length and overtracking, obtained for each stride from digitized images and calculated on a spreadsheet. Data were then compared between Groups A-B1 and Groups B1–B2.

Stride duration (0.639±0.064 vs 0.672±0.037 s) and stride length (247.7±21.9 vs 238.5±18.1 cm) of horses from A and B1 groups were similar; Group B1 was characterized by limb support and overlap values close to those of Group A; however, limb swing (forelimbs: 0.391±0.032 s; hind limbs: 0.374±0.027 s), diagonal swing (0.365±0.027 s) and inter-overlap (0.131±0.035) were of greater duration. Additionally, the proportion of horses with advanced placement was greater in Group B1.

Group B2 displayed greater stride duration (0.718± 0.054 s) and lower stride length (217.3±26.1 cm) than B1 group. The analysis revealed mounted horses to be characterized by limb and diagonal swings similar to those of Group B1; however, limb support and overlap were significantly greater, and inter-overlap and suspension phase were shorter.     

Clearance times and the forensic significance of the dietary anthelmintic pyrantel tartrate in performance horses

Six performance bred (Thoroughbred or Standardbred) mares were fed the anthelmintic pyrantel tartrate as a daily supplement for a period of 21 days to assure steady state concentrations would be achieved. The forensic "clearance times" and potential for analytical interference of pyrantel tartrate were then investigated. This investigation was intend- ed to enable guidelines to be established for veterinarians and trainers to avoid a "positive" test result for pyrantel which might violate existing rules or regulations. The analysis of blood and urine samples from these horses was conducted by the University of Kentucky Equine Drug Testing Laboratory, and were performed on samples obtained on days -3, -2, -1, 7, 14, 21, +1, +2, +3 and +4. Pyrantel tartrate was readily detected by standard thin layer chromatography analysis in urine samples on days 7, 14 and 21 during the administration portion of the study, and on day + 1 of the post-adminislxation time period. Further analysis of the positive urine samples by direct probe mass spectrometry confirmed the presence of pyrantel. In our analysis of equine serum samples pyrantel tartrate was not detected. Pyrantel positive urine samples were additionally ana- lyzed using enzyme-linked immunosorbent assays designed to detect fluphenazine,butorphanol, morphine, oxymorphone, fentanyl, sufentanil and etorphine, with no cross-reactivity found. We concluded that, from a drug testing perspective, the use of pyrantel is unlikely to interfere with normal post- race drug testing.     

Reproductive performance and profitability of heifers fed to weigh 272 or 318 kg at the start of the first breeding season

Reproductive performance and weaning weight of the first calf was determined in 221 Brahman crossbred heifers fed to weigh either 272 (TW1) or 318 kg (TW2) at the start of their first breeding season (target weight). Heifers were divided into light- (below average) and heavyweight (above average) groups on the basis of initial weight. Within each target weight, heifers were fed in three lots. One lot contained lightweight heifers, the second contained heavy heifers and the third was composed of one-half heavy- and one-half lightweight heifers. Heifers were fed for 200 d before the start of the first breeding season. More heifers in TW2 showed estrus and became pregnant in the first 20 d of the breeding season and more were pregnant at the end of the first breeding season. These same differences in reproductive performance were also noted the second year. Each heifer exposed in TW2 weaned 43.4 kg more calf than those in TW1. An average heifer in TW2 was fed 220 kg more corn and 100 kg less hay than a corresponding heifer in TW1. Estrus and pregnancy rate for lightweight heifers in TW1 and TW2 were not improved by sorting and feeding them separately.     

Reproductive performance of sows treated with a combination of pregnant mare's serum gonadotropin and human chorionic gonadotropin at weaning in the summer

During the summer and fall of 1987, sows from eight herds in three states were assigned randomly to receive either a combination of 400 IU of pregnant mare's serum gonadotropin with 200 IU of hCG (P.G. 600) or no treatment at weaning. A treatment x parity interaction was observed for days to first estrus after treatment and percentage anestrus (percentage of sows not achieving estrus within 10 d after weaning). Relative to primiparous control sows, primiparous sows given P.G. 600 expressed estrus sooner (P less than .02) after weaning (6.0 vs 7.8 +/- .6 d) and exhibited less (P less than .02) postweaning anestrus (15.6 vs 29.2 +/- 4.0%). Second parity sows that received P.G. 600 showed estrus sooner (P less than .06) than second-parity control sows (4.7 vs 6.4 +/- .7 d). Days to first estrus after treatment did not differ between groups for parity-three and older sows, and percentage anestrus was not different between treatments for parity-two and older sows. The herd X treatment interaction was significant for percentage recycled (percentage of successfully mated sows that returned to estrus), subsequent farrowing rate, and subsequent number of pigs born dead. Number of pigs born alive was lower for sows treated with P.G. 600 than for control sows (10.55 vs 10.10 +/- .18; P less than .02). In summary, treatment of sows weaned in the summer and fall with P.G. 600 had decreased days to postweaning estrus in parity-one and -two sows and reduced frequency of postweaning anestrus in primiparous sows.     

Plasma plasminogen concentrations in clinically normal horses: the effect of age, sex and pregnancy

Plasma concentrations of plasminogen were determined in 28 clinically normal horses, including 13 adult geldings, five non-pregnant mares, five pregnant mares and five yearlings (two fillies, three geldings). Plasminogen was quantitated by a chromogenic assay based on activation of plasmin by excess urokinase. The overall mean plasma plasminogen for these horses was 2.94 +/- 0.54 CTA units (casein units, as defined by the Committee on Thrombolytic Agents) per ml. There were no significant differences in mean plasma plasminogen values among adult geldings, non-pregnant mares, pregnant mares or yearling horses (P greater than 0.05).