Control of fertility outcome in artificially inseminated gilts and old sows. 2: Addition of oxytocin to boar semen. Its effect on length of insemination, pregnancy rate and litter size]

Toleration-oriented insemination was applied to 1,373 oestrous sows that had undergone bio-engineering treatment, with two insemination portions having been used for each oestrous. Five International Units of oxytocin were added immediately before insemination proper to the semen applied to 315 gilts and 377 old sows. The control group included 296 gilts and 385 old sows inseminated in parallel. Semen intake, on average, was complete between four and eight minutes with the majority of gilts and between four and seven minutes with most of the old sows, but no evidence was obtained as to any action of the oxytoxin upon intake intensity. The treated gilts were superior to the controls by 6.3 per cent in pregnancy rate and by 56 born piglets to each 100 first inseminations. Superiority, consequently, was significant. In both gilts and old sows added oxytocin prolonged insemination by more than five minutes and gave clearly better fertility results.     

The dose precision of PMSG in young and old sows in the process of biotechnical ovulation synchronization. 1. Comparison of diagnostic laparotomy

Treatment was applied, on two farms, to 272 gilts and 169 adult sows, 24 hours after discontinuation of Suisynchron application to the gilts or weaning of piglets of adult sows. Included were 600, 800 or 1,000 IU of PMSG for the gilts and 750, 1,000 oder 1,250 IU of the same batch (Pregmagon-Dessau) for the adult sows for ovarian stimulation. This was followed by application of 500 IU of HCG to the gilts or 300 micrograms Gn-RH vet. "Berlin-Chemie" + 300 IU HCG to the adult sows for synchronised ovulation. Laparotomy was performed on the gilts on the fifth day from PMSG application and on the adult sows on the fourth day. Average ovariotropic stimulation was "mild" in response to lower doses (14.8 follicles in gilts and 20.4 follicles in adult sows) but was "pronounced" in response to medium doses (19.4 or 22.7 follicles, respectively). The pharmacological concept of "mild" exogenic ovarian stimulation by low dosage at the threshold of effectiveness should deserve more attention, last but not least, for breeding aspects. The two groups of animals on both farms differed considerably from one another with regard to reactivity, which cannot be etiologically interpreted for the time being.     

Evaluation of drop versus trickle-feeding systems for crated or group-penned gestating sows

A total of 160 gilts were used to evaluate the effects of pen vs. crated housing systems and drop- vs. trickle-fed feeding systems on sow productivity, occurrence of lesions during farrowing and weaning, immune measures, and behavioral responses during 2 consecutive gestation periods. Of the 160 eligible gilts, 117 farrowed in parity 1, and of those, 72 farrowed in parity 2. The gilts were randomly assigned to represent 1 of 4 factorially arranged treatment groups: pen drop-fed, crate drop-fed, pen trickle-fed, or crate trickle-fed. Replicate blocks were used for each parity with 5 sows per block initially in each treatment. At weaning, sows housed in pens had greater (P < 0.05) backfat thickness than sows housed in crates. The piglet weaning weight was greater (P < 0.05) for sows fed with the single drop compared with the trickle-feeding system. Lesions scores and all other productivity measures did not differ among treatments. An interaction was observed for percentage of neutrophil phagocytosis (P < 0.05) between penning and feeding systems. In pens, drop-fed sows had greater phagocytosis than trickle-fed sows, but in crates, drop-fed sows had a tendency for lower phagocytosis than trickle-fed sows. All other immune measures were not different among treatments. The occurrence of oral-nasal-facial (ONF) behaviors (chewing, rooting, and rubbing) and active behaviors increased, and lying behavior decreased (P < 0.05), from 0800 to 1200 for all sows. During the 0800 to 1200 period, crate drop-fed sows displayed more (P < 0.05) ONF and active behaviors than did sows in the 3 other treatments. Sows housed in groups of 5 had a greater (P < 0.05) duration of standing in the 0400 to 0800 period compared with crated sows. Housing systems had complex effects on sow behavioral sequences, but penned sows had more sequences associated with stress than did crated sows. Also, crate drop-fed gilts and sows expressed more ONF behaviors than gilts and sows in other treatments. Generally, productivity, skin lesions, and immune measures were not different, but behaviors at certain times of day and behavioral sequences were different for sows in pens and crates with drop or trickle-feeding systems. None of the environments evaluated were associated with significant physiological stress responses among the sows. Thus, sows were able to adapt within each environment through behavioral mechanisms without the need to invoke major physiological adjustments.     

Effect of L-carnitine supplementation on performance parameters in gilts and sows

The effect of L-carnitine supplementation during pregnancy and lactation on performance parameters of sows was studied. The trial comprised a total of 127 sows (40 gilts, 87 mature sows) which were divided into a control and a treatment group. All animals were fed individually and received basic feed mixtures for pregnancy and lactation with low carnitine concentrations (gestation diet: 4.7 mg/kg feed, lactation diet: 12.5 mg/kg feed). The rations of the sows in the treated group were supplemented with 125 mg L -carnitine per head and day during pregnancy and 250 mg L -carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L -carnitine supplement. L -carnitine supplementation resulted in higher sow liveweight gains between day 1 and day 85 of pregnancy. The number of piglets per litter and the number born alive did not differ between the control sows and those treated with L -carnitine. However, the L -carnitine-supplemented sows produced only half as many non-viable piglets as the control animals. Moreover, litter weight and mean birth weight of piglets from L -carnitine-treated sows were higher than in the control sows. This effect was more marked in gilts (+8% higher litter weight, +9% higher piglet weight) than in sows (+7% and +6%, respectively). Piglets from sows whose ration was supplemented with L -carnitine showed higher liveweight gains during the suckling period (+12% for gilts, +4% for sows), which is why litter weights post weaning were also higher among the sows treated with L -carnitine than in the control sows (+14% for gilts, +10% for sows). Overall, the study shows that dietary supplementation with L -carnitine during pregnancy and lactation improves the reproductive performance of sows.     

Evidence that oxidative stress is higher in replacement gilts than in multiparous sows

The recent success obtained in term of increasing the litter size of sows has not correlated with a reduction of replacement rate. There is thus an increased economic demand for gilts with optimal reproductive potential and longevity. Unfortunately, replacement gilts are known to be more susceptible to diseases and less productive than multiparous sows. Interestingly, reproductive performance, resistance to diseases and longevity could all be largely affected by oxidative stress. To investigate whether oxidative stress conditions could account for the poor longevity of gilts, three distinct groups of conventional Yorkshire × Landrace sows were formed based on their similar age and parity (gilts, second parity sows as well as fourth to fifth parity sows). All animals were slaughtered during the post‐ovulatory period, and blood as well as tissue samples were collected. Biomarkers of oxidative damage to proteins (carbonyls) and DNA (8‐OHdG) were analysed in samples. Specific mRNA expression of major antioxidants such as glutathione peroxidases 1, 3 and 4 (GPx1, GPx3, GPx4) as well as superoxide dismutases 1 and 2 (Sod1, Sod2) were monitored in liver and kidney samples by quantitative RT‐PCR. Specific enzymatic activities of both GPx and SOD were measured by spectrophotometric assays. The plasma concentration of protein carbonyls was significantly different between the three groups with the highest concentration being observed in gilts (p ≤ 0.001). The mRNA expression levels of GPx1 and GPx4 were also significantly increased in the liver of gilts when compared to multiparous sows (p ≤ 0.05). SOD2 enzymatic activity was found to be higher in the liver of gilts than multiparous sows (p ≤ 0.05). Taken together, these results indicate that replacement gilts sustain significantly higher oxidative conditions than multiparous sows. Current findings may contribute to the design of nutritional regimens that will increase the productivity of gilts by counteracting oxidative stress.     

PMSG dosage precision in young and old sows in the course of biotechnical ovulation synchronization. 3. Fertility and litter effects

One single PMSG batch, Pregmagon-Dessau, was compared with other PMSG doses on 2,126 adult sows and 1,700 gilts from five farms. Additional comparisons were made with other Pregmagon or Prolosan batches on 1,178 adult sows and 1,026 gilts. All experiments were made in the context of a programme for ovulation synchronisation and term-oriented insemination. Doses of 700, 800, 900, and 1,000 IU were tested on adult sows and 600, 800, and 1,00 on gilts, with the mean dose of 800IU being found to be sufficient or superior to other doses for fertility results. Doses for adult sows could be adjusted and related to present and previous litter numbers, with the dosage being between 700IU (treatment for third litter) and 700 to 800IU (treatment following average to high previous litter. The preferential dose for gilts was found to be 800IU. Higher PMSG doses (up to 1,000IU) should not be used in synchronisation of ovulation and term-oriented insemination unless extraordinary conditions were safely established.     

Effects of magnesium on the performance of sows and their piglets

The objective of this study was to evaluate the effects of supplemental magnesium(Mg) on the performance of gilts and parity 3 sows and their piglets.Fifty-six gilts(Trial 1) and 56 sows(Trial 2) were assigned to one of 4treatments according to their mating weight,respectively.The treatments comprised corn-soybean meal based gestation and lactation diets(0.21%magnesium) supplemented with 0,0.015,0.03,or 0.045%Mg from mating until weaning.The results showed that magnesium supplementation significantly(P 0.05) reduced the weaning to estrus interval in both gilts and sows.There were significant effects(P 0.05) of supplemental magnesium on the total number of piglets born,born alive and weaned in sows.In late gestation and lactation,the digestibility of crude fiber(quadratic effects,P 0.05),and crude protein(P 0.05),were significantly influenced by magnesium in gilts and sows,respectively.There were differences among the 4 groups in terms of the apparent digestibility of dry matter and crude fiber in sows(P 0.05) during both early and late gestation.The apparent digestibility of gross energy was increased for sows in late gestation(P 0.05),and lactation(quadratic effects,P 0.05).At farrowing and weaning,serum prolactin levels and alkaline phosphate activities linearly increased in sows as the Mg supplementation increased(P 0.05).Serum Mg of sows at farrowing and serum urea nitrogen of sows at weaning was significantly influenced by Mg supplementation(P 0.05).The Mg concentration in sow colostrum and the serum of their piglets were increased by supplemental magnesium(P 0.05).In addition,growth hormone levels were linearly elevated(P 0.05) in the serum of piglets suckling sows.Our data demonstrated that supplemental magnesium has the potential to improve the reproduction performance of sows,and the suitable supplemental dose ranged from 0.015%to 0.03%.     

Efficacy of altrenogest in synchronizing estrus in two swine breeding programs and effects on subsequent reproductive performance of sows.

In two herds that used different breeding and housing schemes, altrenogest (15 mg/d) was fed for 14 d to gilts or 10 d to sows in .45 kg of a diet formulated to meet or exceed their nutrient requirements. In Herd 1 (five breeding seasons per year), 63 of 123 gilts and 40 of 70 sows in seven replications were fed in individual crates to ensure proper intake. In Herd 2 (continuous breeding), 244 of 484 gilts in 20 replications received the treated feed in individual feeding stalls to which animals had free access. Average and median days to estrus were reduced (P less than .01) for treated gilts and sows compared with controls in both herds. Of 29 treated gilts that did not mate or become pregnant, three had cystic follicles, compared to 1 of 14 controls. There were no statistically significant treatment differences in litter size born or number of stillborn pigs in either herd, but farrowing rates of cycling gilts were 8% lower (P less than .05) in Herd 2 for treated gilts than for controls. Overall, altrenogest could be a valuable tool for improving reproductive efficiency by allowing producers to better control the estrous cycle.     

Effects of feeding schedule on body condition, aggressiveness, and reproductive failure in group-housed sows

A total of 208 sows and 288 gilts (PIC line C29) were used to determine the influence of feeding frequency (2 vs. 6 times/d, floor fed) on performance and welfare measurements on a commercial sow farm. Treatments consisted of feeding similar amounts of feed to each sow (2.5 kg) or gilt (2.05 kg) over 2 (0700 and 1530) or 6 times daily (0700, 0730, 0800, 1530, 1600, and 1630). There were 8 sows or 12 gilts in each pen. Gilts and sows were moved to pens 1 to 4 d after breeding. In sows, there were no differences (P > 0.10) in ADG, backfat change, or variation in BW. There was a trend (P < 0.08) for sows fed twice daily to farrow more total pigs born, but number born alive or other reproductive performance traits were not different (P > 0.10) among treatments. Sows fed 6 times per day had increased vocalization during the morning (P < 0.07) and afternoon (P < 0.01) feeding periods compared with sows fed twice daily. Sows fed twice daily had more skin (P < 0.01) and vulva (P < 0.04) lesions as well as a small increase in feet and leg (P < 0.01) and hoof (P < 0.02) problems. In this commercial facility, the standard management protocol required moving gilts to a different gestation facility on d 42. On d 42, two pens of gilts with similar breeding dates and treatment were combined and moved to another facility with larger pens until farrowing. Gilts fed 6 times daily had a tendency for greater ADG (P < 0.07) from d 0 to 42 and a tendency for greater (P < 0.09) backfat on d 42. After movement to the larger groups from d 42 to farrowing, ADG was similar (P > 0.10) for gilts fed 2 or 6 times daily. Gilts fed twice daily had lower BW variation at d 42 (P < 0.04) and tended to at farrowing (P < 0.10). In gilts, there were no differences (P > 0.10) for reproductive performance, skin and vulva lesions, and feet and leg scores. In conclusion, there were few growth, farrowing, or aggression differences among gilts fed 2 or 6 times daily. This suggests that either feeding method is suitable for group-housed gilts. Among sows, feeding frequency resulted in few growth or farrowing performance differences. Feeding 6 times daily resulted in a small but significant reduction in skin and vulva lesions and structural problem scores while increasing vocalization. Increasing the feeding frequency from 2 to 6 times daily does not appear to have a negative or positive impact on performance or welfare of group-housed gilts and sows.     

Experimental studies on the stimulation of prenatal development in swine by PMSG treatment in early pregnancy. 1. Clinical results of embryonic development in young slaughtered sows and litter results in young and old sows after PMSG treatment on the 11th day of pregnancy

Thirty-eight gilts were slaughtered on the 25th and 39th days of pregnancy, after they had received 400 I.U. PMSG treatment on the eleventh day of pregnancy. Treated and untreated animals in a group of 140 gilts and 195 adult sows were compared with each other for post-farrowing fertility performance. Weight development of embryos obtained from the slaughtered sows depended on the number of embryos alive. The survival rate of embryos from treated sows was about 5% higher than that recorded from untreated animals. Clearly increased litter sizes which, however, were associated with lower piglet birth weights were recorded from farrowing gilts and adult sows, following PMSG treatment. The conclusion is drawn that PMSG treatment, via luteotrophic action of luteinising hormone, is capable of stabilising pregnancy-related corpora lutei, resulting in higher litter sizes. Further studies will be necessary, and emphasis will have to be laid on the problem of weight development of newborn piglets, following litter-size boosting treatment.     

Comparison of three methods of feeding sows in gestation and the subsequent effects on lactation performance

A total of 684 sows from breeding groups over 6 wk was used to compare three methods of feeding during gestation on gestation and lactation performance. Control gilts and sows were fed according to body condition based on a scale of 1 to 5 (1 = thin, 5 = fat). Sows were visually assessed for body condition at breeding and were assigned a daily feed allowance to achieve a BCS of 3 at farrowing. Treatment 2 used feeding levels based on backfat thickness (measured between d 0 and 5 after breeding) and weight at weaning for sows or service for gilts. Feed allowance was calculated to achieve a target backfat of 19 mm at farrowing, and remained constant from d 0 to 101 of gestation. Feed allowances were based on modeled calculations of energy and nutrient requirements to achieve target sow maternal weight and backfat gains. Treatment 3 was identical to Treatment 2, except that feeding pattern was altered for thin sows and gilts (<15 mm at service) in an attempt to reach 19 mm by d 36 of gestation. Sows were weighed at the previous weaning, and gilts were weighed at service, with both weighed again between d 112 and 114 of gestation. Backfat was measured between d 0 and 5, and again between d 108 and 113 of gestation. At farrowing, sows on Treatments 2 and 3 had 19 and 19.1 mm of backfat, respectively, whereas control sows tended to have greater (P < 0.07) backfat (20 mm). On average, sows targeted to gain 6 to 9 mm of backfat failed to reach target gains regardless of feeding method. Feeding sows in gestation based on backfat (Treatments 2 and 3) resulted in a numerically higher proportion of sows in the target backfat range of 17 to 21 mm (40.2, 53.3, and 52.6% for control and Treatments 2 and 3, respectively) at farrowing and a numerically lower percentage of fat sows (>21 mm), but no difference in the percentage of thin sows (<17 mm) compared with feeding based on body condition. In conjunction with this observation, sows fed based on BCS were fed higher (P < 0.05) feeding levels in gestation than were sows fed based on backfat depth. Gestation feeding method had no effect on performance during lactation. Feed intake in lactation was lower (P < 0.05) for high backfat sows (>21 mm) at farrowing compared with sows with <21 mm. The high proportion of sows in the optimal backfat category demonstrates that feeding based on backfat and BW has potential for facilitating more precise feeding during gestation.     

Clinical study results of the embryonic development in gilts and brooding performance of gilts and sows after HCG treatment on the 11th day of pregnancy

Forty-four pregnant gilts were slaughtered on the 32nd and 33rd days of pregnancy, after 30 of them had received 100 or 400 IU of HCG on the eleventh day of pregnancy. Both doses had resulted in higher number of living embryos. Embryo survival rates of treated sows were up to 14.9 percent higher than those of untreated animals. Higher numbers of embryos had no adverse effect on their mass development. Fertility was measured of 77 HCG-treated and untreated gilts as well as of 54 adult sows. The number of non-pregnant sows which returned to oestrus was higher in the group of gilts and adult sows which had received treatment. The number of pregnant animals in the treated adult sow group was seven percent higher than that in the control group. Increased litter sizes were additionally recordable from those gilts and adult sows that had received HCG injections. Yet, those higher litter sizes were associated with lower weight of live-born piglets. In further studies more attention should be given to possible stimulation of LH secretion in early gravidity.     

The dose precision of PMSG for gilts and old sows in procedures for ovulation synchronization. 2. Organometric and histometric findings after diagnostic slaughtering

An account is given in this paper of organometric and histometric findings obtained, on three farms, N, B, and D, from ovaries, uteri, and oviducts of biotechnologically treated gilts and adult sows, using differentiated PMSG doses (600, 800, and 1,000 IU on gilts and adult sows of N and B; 500, 1,000, and 1,500 IU on gilts of D). Ovulation potentials were within the biological normal in response to low dosage (with an average of 12 to 15 follicles in gilts and 17 in adult sows). The 800 IU dose caused significant stimulation, which had to be interpreted as overstimulation for PMSG-sensitive probands of N. Ovarian reaction and induced cycle should by duly considered for interpretation of histometric findings.     

Impact of diet deprivation and subsequent over-allowance during prepuberty. Part 2. Effects on mammary gland development and lactation performance of sows

The impact of diet deprivation and subsequent over-allowance in prepubertal gilts on their mammary development and mammary gene expression at the end of gestation and their lactation performance over 2 parities was determined. Seventy-seven gilts were reared under a conventional (control, CTL; n = 41) or an experimental (treatment, TRT; n = 36) dietary regimen. The experimental regimen provided 70 (restriction diet, RES) and 115% (over-allowance diet, OVER) of the protein and DE contents provided by the CTL diet. Experimental diets were fed ad libitum starting at 27.7 ± 3.4 kg of BW as follows: 3 wk RES, 3 wk OVER, 4 wk RES, and 4 wk OVER. All gilts were bred, and 34 were slaughtered on d 110 of gestation (18 CTL and 16 TRT) to collect mammary tissue for compositional analyses and gene expression measurements. Remaining gilts (23 CTL and 20 TRT) were maintained for 2 parities, and litter performance data were obtained. Blood samples for hormonal and metabolite assays were obtained on d 110 of gestation from all sows slaughtered at that time and from 14 sows per treatment on d 2 and 17 of lactation in the first parity. Milk samples were obtained from these same sows on d 17 of lactation in both parities. There was a tendency for mammary parenchymal tissue to contain less protein in TRT than CTL sows (P < 0.10), and relative mRNA abundance of the signal transducer and activator of transduction 5B gene was increased in parenchyma from TRT sows (P < 0.05). Circulating prolactin (P < 0.05) and milk lactose concentrations (P < 0.01) were less, whereas milk protein content was greater (P < 0.05) in TRT sows than CTL sows on d 17 of lactation. Nevertheless, growth rate of suckling piglets over the first 2 parities was unaffected by treatment. In conclusion, the use of a diet deprivation and over-allowance regimen in the growing-finishing period did not have beneficial effects on mammary gene expression or on sow and piglet performance.     

Individual differences in dunging patterns in loose-housed lactating sows

This research investigated individual differences in dunging patterns in loose-housed lactating sows. Farrowing pens were divided into six sectors and in study 1 each sector was given a dung score from 0 (no manure) to 3 (≥2 deposits). There were significant positive correlations between dung score and the weight of manure within sectors. In study 2, pen cleanliness was scored in 24 farrowing pens for loose-housed sows on three consecutive days in weeks 3, 4 and 5 of lactation (9 observations). One-third of the sows received a dung score of 0 for the solid floor area, in seven to nine of the observations. These sows could be categorized as ‘clean’ sows. However, 46% of sows scored 0 in the solid floor area for less than two observations, and these sows could be categorized as ‘dirty’ sows. Overall, older parity sows were ‘cleaner’ than gilts and mid-parity sows.     

Vaccination of sows against Mycoplasma hyopneumoniae with Hyoresp

The aim of the study was to investigate the serological reactions of pregnant sows to vaccination with Hyoresp. Further investigations were performed in the offspring of these sows to follow the dynamics of maternal antibodies and the reaction to vaccination at different points in time. The study was conducted in three farrow-to-finish herds endemically infected with M. hyopneumoniae. A total of 30 gilts and 31 sows were vaccinated 8 and 4 weeks ante partum with Hyoresp (Merial GmbH) or given phys. saline solution as a placebo. The offspring was divided into three groups receiving Hyoresp at 1 and 4 or at 4 and 8 weeks of age. The control group was treated with phys. saline solution at 1 and 4 weeks of age. Before vaccination, antibodies against M. hyopneumoniae were detected in 85% of the gilts and 68% of the sows, confirming the endemic infection of the herds. Vaccination of the sows induced a significant increase in the antibody concentration in serum within four weeks and enhanced the concentration of antibodies in the colostrum. As expected, significantly enhanced levels of antibodies were also detected during the first four weeks of life of the offspring of vaccinated sows. The piglets' serological reaction to vaccination at 1 and 4 weeks of age showed marked interferences with maternal antibodies, so that a reaction could be demonstrated only at 8 weeks of age. The serological reaction of piglets vaccinated at 4 and 8 weeks of age was much stronger than that of piglets vaccinated earlier. Surprisingly, the vaccination status of the sow had no effect on the serological response of the piglets in either vaccination scheme. Maternal antibodies are known to reduce the risk of M. hyopneumoniae infections in piglets. Vaccinating the sows against M. hyopneumoniae may thus be an option for farrowing-to-finish herds with an enhanced risk for infections due to ineffective separation of different age groups, poor gilt acclimatisation or high gilt replacement rates.     

The effect of pregnancy order on various biochemical and hematological values in sows]

The following blood indices were determined in the blood of 34 pregnant sows of the Large White breed under standard feeding conditions: haemoglobin, haematocrit, leucocytes, and--in the blood serum, --total protein, glucose, urea, bilirubin, cholesterol, enzyme activity (AP, GOT, GPT, GGTP) and mineral concentrations (Ca, P--inorg., Mg, Na, K, Fe, Cu, Zn, Mn). The blood was sampled in the first and third pregnancy at an average live weight of 165.12 and 197.36 kg, at an average age of 318 and 630 days and at an about the same average length of pregnancy in the time of both samplings (59 days). In younger, still growing gilts (first pregnancy) a significantly (P less than 0.05) lower content of total protein, magnesium, iron and copper was revealed, as compared with adult sows. The content of glucose, calcium, potassium and manganese in the blood serum of the gilts was significantly (P less than 0.05) higher than in sows in their third pregnancy. The adult sows showed a significantly (P less than 0.05) lowered activity of alkaline phosphatase and gamma-glutamyl transpeptidase, as distinct from gilts.     

Efficacy, safety, and residue evaluation of levamisole gel formulation in sows

Anthelmintic efficacy, safety, and residue studies were conducted in sows and gilts with a levamisole gel containing 11.5% levamisole HCl. In 12 sows and 12 gilts, 8 mg of levamisole HCl equivalent/kg of body weight orally was 100% (resinate) and 91.1% (gel) effective against 55-day-old Ascaris suum and 100% (gel) and 96.1% (resinate) effective against Oesophagostomum dentatum. In 20 sows given levamisole gel (8 mg of levamisole HCl/kg) orally just before breeding, 4 to 6 weeks after breeding, 4 to 6 weeks before farrowing, and just before farrowing, there were no adverse effects. Transient salivation was noticed in five sows after treatment. In 4 groups of 4 sows each given levamisole gel orally to provide 8, 24, 40, or 80 mg of levamisole HCl/kg, adverse clinical signs were not observed in sows treated with 8 mg/kg. Transient salivation was noticed in one sow given 24 mg/kg, two sows given 40 mg/kg, and four sows given 80 mg/kg. Multiple emesis and chomping occurred in one sow given 80 mg/kg. Levamisole residues in edible tissues from sows given 8 mg of levamisole gel/kg orally were less than 0.1 mg/kg of muscle and fat in sows killed on posttreatment day (PTD) 3 and less than 0.1 mg/kg of kidney in sows killed on PTD 5. Liver residues averaged 0.78 mg/kg in sows killed on PTD 3 and were reduced to 0.31 mg/kg in sows killed on PTD 5. The 99% upper tolerance limit with 95% confidence on the withdrawal time to assure levamisole residues of less than 0.10 mg/kg in liver tissue was 11 days.     

Development of a method of diagnosing ovarian disorders in sows and gilts using uterine ultrasonography

In ultrasonographic diagnosis of ovarian disorders and the estrous cycle in sows, transverse observation of the uterus yielded more characteristic findings than observation of sagittal sections. Transverse ultrasonography revealed that the low progesterone (P) type uterus showed a round structure, while the high P type uterus showed a flattened structure. These results corresponded well with rectal palpation findings: the low P type uterus had a hard, pipe-like structure and the high P type a soft, balloon-like structure. For gilts, we employed a minimum convex type transrectal prostate probe that had an approximately 18 cm insertion handle. The images of the uterus obtained thereby were a similar to those obtained from sows. The above results suggest that it should be possible to diagnose and treat many ovarian disorders in sows and gilts based only on the ultrasonograhic findings. In short, ultrasonograhic findings of a round structure of the uterine wall might be an indication for PMSG (pregnant mare serum gonadotropin) treatment, while findings of a flattened structure might be an indication for PGF(2) (alpha) administration.