Effect of housing system and boar exposure on estrus expression in weaned sows

Reproductive efficiency depends on detection of estrus, which may be influenced by housing and boar exposure. This experiment investigated the effects of housing system and boar contact on measures of estrus in weaned sows. Mixed-parity sows were randomly assigned to be weaned into gestation crates away from boars (AWC, n = 45), into pens away from boars (AWP, n = 42), or into pens adjacent to a mature boar (ADJ, n = 46). Estrus detection was initiated at approximately 0700 (0 h) and again at 0.25-, 0.5-, 1-, 2-, 4-, and 8-h intervals beginning on d 4 and continuing through d 7 following weaning. Estrus detection involved observation of the standing response after application of nose-to-nose boar exposure, backpressure, and side rubbing. For the AWC sows, a mature boar was moved to the front of the crates for a 10-min period and then removed. Sows housed in AWP were moved approximately 15 m to an empty pen adjacent to a mature boar for a 10-min period, and then returned to their pen. Sows housed ADJ were not moved and estrus detection was performed in their home pen for a 10-min period. The proportion of sows expressing estrus within 7 d from weaning was lowest for ADJ (80%, 37/46) compared with AWP (98%, 41/42) and AWC (96%, 43/45; P < 0.05). There was an effect of interval from weaning to estrus on the percentage of sows expressing estrus, but there was no interaction with treatment. Sows in AWC and AWP (4.7 d) had decreased (P = 0.01) intervals from weaning to estrus compared with ADJ (5.2 d). The duration of estrus was also shorter (P < 0.001) for ADJ (45 h) compared with AWC (58 h) or AWP (62 h). There was a treatment x interval x day of estrus effect for the percentage of sows expressing estrus. After detection of the first standing response on the first day of estrus, only 62 to 82% of sows were detected standing over the next 2 h for all treatments. However, at 4 to 8 h, this increased to 85 to 98% for the AWC and AWP sows, but <73% of the ADJ sows were detected during this period. On the second day of estrus, estrus expression was not influenced by interval for the AWC and AWP sows and was between 90 to 100% during the 8-h period, whereas ADJ sow detection rates were between 68 to 88%. These data suggest that housing sows adjacent to boars negatively affects estrus expression and detection. In addition, refractory behavior occurs in approximately 30 to 40% of sows and is influenced by housing relative to the boar, day of estrus, and interval from last boar exposure.     

不同管理方式下临产母猪产仔性能的对比分析

试验研究了采用不同管理方式对临产母猪产仔性能的影响。选取某生态养殖场4栋猪舍共160头母猪分成8组进行对比试验,其中1、2组和5、6组为试验组,3、4组和7、8组为对照组。在正常饲养管理的基础上．将1、2组母猪提前1周赶入分娩室并肌注氯前列烯醇0．1mg／头;3、4组母猪提前1周赶入分娩室但不注射氯前列烯醇;5、6组母猪待能挤出奶后赶入分娩室并肌注氯前列烯醇0．1mg／头;7、8组母猪待到能挤出奶后赶入分娩室但不注射氯前列烯醇。结果表明：产前注射药物的母猪其产活仔数比不注射药物的母猪高且差异显著（P〈O．05）,死胎和木乃伊胎比例显著下降（P〈0．05）,而且母猪的分娩时间明显集中;挤出奶水时再进产房的母猪其产活仔数比提前1周再进产房显著增加（P〈0．05）,死胎率和木乃伊胎率显著减少（P〈0．05）。可见,注射氯前列烯醇和待挤出奶水时再进产房的母猪均可提高母猪的窝均产活仔数,降低死胎率;试验5、6组的母猪产仔性能最佳。其次是7、8组。     

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.     

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.     

Fertilization and blastocyst development in oocytes obtained from prepubertal and adult pigs

Polyspermic fertilization and embryo quality are important issues for the in vitro production of pig embryos. We hypothesized that oocyte donor (prepubertal gilt vs. sow) affects polyspermy and blastocyst development in vitro and that the sexual maturity of the oocyte donor affects the response to sperm concentration in the fertilization medium. In Exp. 1, oocytes of sows and gilts were mounted and stained 12 h after insemination to provide fertilization data. In Exp. 2, putative embryos were developed in vitro to 144 h post-insemination before mounting. In both experiments, cumulus-oocyte complexes (COC) were collected from ovaries of prepubertal gilts and adult sows. Sperm were added after maturation of COC for 40 to 44 h. Sperm from two boars at 0.5 to 5.0 x 10(6) sperm/mL was used for insemination. More (P < 0.01) monospermic fertilizations were observed in oocytes derived from gilts than for oocytes from sows. There were fewer (P < 0.02) penetrated sperm per fertilized oocyte in oocytes from gilts compared with sows. There were effects of semen donor (boar) on the percentage of monospermic (P < 0.01) and polyspermic (P < 0.002) fertilizations, and on the number of penetrated sperm/fertilized oocyte (P < 0.02). In Exp. 2, cleavage and blastocyst formation was evaluated at 2 and 6 d postinsemination, respectively. More (P < 0.001) blastocysts developed from sow-derived oocytes than from gilt-derived oocytes. More (P < 0.05) total cells per blastocyst were observed in embryos from sow-derived oocytes than from gilt-derived oocytes. Semen donor affected the percentage of oocytes cleaving (P < 0.02), and a boar x sperm concentration interaction affected (P < 0.05) the incidence of blastocyt formation. Results indicate that sexual maturity of the donor is not responsible for the high incidence of polyspermy in porcine in vitro fertilization. However, blastocyst development is improved by the use of oocytes from sows rather than from prepubertal gilts.     

饲粮阴离子配比对母猪生殖机能与血清生化指标的影响

选取胎次相近、体况相似、健康状况良好的长×大二元杂交空怀母猪100头,将其均分成5组,每组20头。第1、2、3、4、5组母猪被分别喂以D1、D2、D3、D4、D5试验饲粮。在饲养试验期间,测定母猪窝产仔数,仔猪初生重、成活率、断奶重,母猪产后发情间隔天数（空怀天数）、返情率等繁殖指标;并分别于母猪采食试验饲粮后5d、孕后30d、产仔后7d,每组取8头母猪前腔静脉采血,测定血清中Cl-、Na＋、HCO3-、FSH、LH、Pg含量,GPT、GOT活性等生化参数。根据各项指标测定的结果可推断：第3组母猪饲粮中阴离子的配比（即添加：NaCl 0．40％、NaHC3。0．40％）最宜;其次是第4组母猪饲粮中阴离子的配比（即添加：NaCl0．40％、NaHCO。0．80％）较宜;再次是第2组母猪饲粮中阴离子的配比（即添加：NaCl0．40％、NaHCO30．80％）。第1、5组母猪饲粮中阴离子的配比似乎不够理想,即母猪饲粮中添加的NaCl过少（0．20％）或过多（0．80％）。     

Responses to delayed estrus after weaning in sows using oral progestagen treatment

Oral progestagen treatment extends the weaning-to-estrus interval (WEI) in weaned sows. Particularly in lower parity sows, this allows recovery from lactational catabolism and improves sow productivity. However, the optimal duration of progestagen treatment in contemporary dam-line sows is unclear. Therefore, sows (n = 749) weaned over consecutive 3-wk periods in June and July and classified as parity 2 and 3 (P2-3); 4, 5, and 6 (P4-6); or parity 7 or higher (P7+) were organized into 2 breeding groups using 1 of 3 strategies: 1) oral progestagen for 2 d before and 12 d after weaning (M14; n = 249); 2) oral progestagen for 2 d before and 5 d after weaning (M7; n = 250); or 3) no progestagen treatment (M0; n = 250). Progestagen (altrenogest) was administered directly into the sow's mouth at a dosage of 6.8 mL (15 mg of altrenogest) daily. Sows were bred using artificial insemination at first detection of estrus after weaning (M0) or altrenogest withdrawal, and every 24 h thereafter, until they no longer exhibited the standing reflex. The WEI for M0 sows was 5.1 +/- 0.1 d. Estrus was recorded sooner (P < 0.001) after withdrawing treatment in M14 than in M7 sows (6.9 +/- 0.1 vs. 7.4 +/- 0.1 d, respectively). More (P < 0.001) M14 sows (88.6 +/- 2.5%) were bred within 10 d of altrenogest withdrawal than M7 (72.8 +/- 2.8%) sows, or within 10 d of weaning in M0 sows (78.8 +/- 2.6%). Reproductive tracts were recovered after slaughter at d 30 or 50 of gestation. For P2-3 sows, ovulation rate (least squares mean +/- 95% confidence interval) in M7 (23.1 +/- 1.0) was greater (P < 0.001) than in M14 (20.7 +/- 1.0) or M0 (19.7 +/- 1.0) sows; no differences were detected in P4-6 and P7+ sows. At d 30, M7 and M14 sows had more (P < 0.01) embryos (16.4 +/- 0.6 and 15.8 +/- 0.4, respectively) than M0 (13.9 +/- 0.5) sows. At d 50 of gestation, number of fetuses in M14 sows (13.6 +/- 0.4) was greater (P < 0.001) than in M0 (11.8 +/- 0.4) and M7 (12.2 +/- 0.3) sows. Use of oral progestagen to delay the return to postweaning estrus for greater than 18 d appears to have potential for improving weaned sow productivity. Given the incidence of high ovulation rates and associated evidence of intrauterine crowding of embryos around d 30 of gestation, the changing dynamics of prenatal loss resulting from longer periods of progestagen treatment may represent an additional production advantage.     

Pig weaning weight and changes in hematology and blood chemistry of sows injected with recombinant porcine somatotropin during lactation

Weaning weight of pigs on d 18 to 21 of age was used to determine the effects of recombinant porcine somatotropin (rpST) on lactational performance of their dams. Crossbred Landrace x Yorkshire sows (n = 180, 202 to 270 kg BW) were assigned to receive daily i.m. injections of either 0, 8, or 16 mg of rpST on lactation d 7 to 20. Initially, injections of 16 mg of rpST/d caused 100% mortality (four sows); thus, a dose of 4 mg of rpST/d replaced 16 mg. Subsequently, 5 of 19 and 1 of 17 sows died in response to daily injections of 8 and 4 mg of rpST, respectively, resulting in termination of the experiment. Before termination, 48 sows (16 from each of the 0-, 4-, and 8-mg treatment groups) completed a lactation of 18 to 21 d in duration. Analysis of these data indicated that daily injection of lactating sows with rpST increased (P less than .05) weaning weight of pigs only if they were from litters that averaged greater than or equal to 2.6 kg/pig on lactation d 7. The BW of sows was decreased by rpST (P = .07). Subsequent experiments revealed 1) that rpST-induced death of lactating sows was caused from hemorrhaging of ulcers that developed at the pars esophagea, 2) that there was vacuolation of the liver and kidney of dead sows, and 3) that daily injection of 16 mg of rpST into nonlactating growing pigs (50 to 100 kg BW) for 28 d did not cause death or any observable illness in spite of 100% mortality of lactating sows after two to nine injections.     

Efficacy of ivermectin against the swine kidney worm, Stephanurus dentatus

Ivermectin in solution was given subcutaneously (in the neck) at the rate of 0.5 mg/kg of body weight to 5 sows naturally infected with kidney worm (Stephanurus dentatus). Six similar sows were used as nontreated controls. A total of 114 kidney worms were recovered from daily urine samples of 4 of the 5 treated sows (the 5th sow's samples were negative) during the first 4 days after treatment. Ten kidney worms were recovered from daily urine samples of 1 control sow on the 2nd and 3rd days of the post-treatment period. Examination of urine samples from treated sows for kidney worm eggs showed a precipitous numerical decrease. Treated animals became negative between the 5th and 12th days after treatment, and remained negative until necropsy on the 61st day. Compared with control sows, hatchability of eggs and survival of larvae from treated sows was reduced by 9% and 7%, respectively. Kidney worms were not recovered at necropsy from the treated sows, and a total of 392 kidney worms were recovered from the control sows (av 65).     

Ovulation and embryonic developmental rate following hCG-stimulation in sows

The hCG induced ovulation in sows was studied by use of ultrasonography, and an investigation of the development and diversity of the zygotes/embryos was performed at 24 h after ovulation. Crossbred sows (N = 48) were weaned (day 0) and checked for heat twice daily from day 3 onwards. From day 4, the ovaries were transrectally scanned twice daily. On day 4, the sows were given an injection of 750 iu hCG i.m. and inseminated 27 +/- 2 h (X +/- SD) and 38 +/- 1 h later. From 38 to 48 h after the hCG injection, the ovaries were scanned at 60 to 90 min intervals. At 24 h after ovulation the oviducts were surgically flushed in 18 sows. Out of the 48 sows, 34 showed heat at 12-36 h after the hCG-treatment and 14 showed heat before the hCG treatment. In the former group of sows, 20 (59%) ovulated within the interval of 38 to 48 h after the hCG treatment, and the follicular size immediately before ovulation was 7.8 +/- 0.6 mm. Among the sows which showed heat before hCG treatment only 7 (50%) ovulated within the above interval and the preovulatory follicle size was larger (8.3 +/- 0.5, p < 0.05) than in the former group of sows, which showed heat after the hCG treatment. The flushing of 18 sows yielded a total of 243 ova, 70 (29%) 1-cell stages, 160 (66%) 2-cell stages and 13 (5%) 4-cell stages. A pronounced difference in the degree of variation in embryonic development was seen between sows: 4 animals yielded 1- to 4-cell stages, one exclusively 2-cell stage. In conclusion, the control of ovulation in sows by hCG treatment will affect the follicular growth and the exact timing of ovulation can not always be relied on. It is strongly recommended to use ultrasonography to monitor the time of ovulation if this parameter is important. Ova recovered at 24 +/- 1 h after the median time of ovulation revealed a pronounced diversity (1- to 4-cell stage) within sows. No obvious relation with this embryonic diversity and the follicular size at ovulation was seen in these data.     

Protection against neonatal Escherichia coli diarrhoea in pigs by vaccination of sows with a new vaccine that contains purified enterotoxic E. coli virulence factors F4ac, F4ab, F5 and F6 fimbrial antigens and heat-labile E. coli enterotoxin (LT) toxoid

The efficacy of a new vaccine against neonatal Escherichia coli diarrhoea in piglets containing purified F4ab, F4ac, F5 and F6 fimbriae and detoxified heat-labile toxin (LT) was tested in challenge experiments by the method described by the European Pharmacopoeia (3rd edn, EDQM, Council of Europe, Strasbourg, France). A group of 11 young sows from a herd without E. coli problems was vaccinated 6-8 and 2-4 weeks prior to expected farrowing and another group of nine young sows were non-vaccinated controls. Escherichia coli antibody titres were determined in serum samples taken from the sows before first vaccination and before farrowing and in colostrum samples. The newborn piglets were allowed to suckle colostrum from their mother immediately after birth. The piglets were marked with individually numbered ear tags. Approximately 12 h after birth, 118 piglets from vaccinated sows and 79 piglets from non-vaccinated control sows were challenged by oral instillation of 5 ml of a freshly prepared culture of one of the challenge strains [O8:K87:F4ab (LT+) or O149:K91:F4ac (LT+) or O9:K30:F5 or O9:K103:F6 respectively]. The challenge cultures contained as a mean 6.8x10(9) CFU/ml. After challenge the piglets were observed for 7 days and mortality and morbidity were recorded. Vaccinated sows developed significant levels of antibody titres in colostrum and serum. Control sows stayed at a low/seronegative level. The protective efficacy was excellent because 66.7-87.5% of the piglets from vaccinated sows remained without clinical signs after challenge. Only 0.0-28.0% of the piglets from non-vaccinated sows remained healthy and more than 47.1% of the piglets in this group died after challenge. It is concluded that the new vaccine is very effective in protection of piglets against neonatal E. coli diarrhoea.     

Peri-oestrus hormone profiles and follicle growth in lactating sows with oestrus induced by intermittent suckling.

This study describes follicle dynamics, endocrine profiles in multiparous sows with lactational oestrus compared with conventionally weaned sows (C). Lactational oestrus was induced by Intermittent Suckling (IS) with separation of sows and piglets for either 12 consecutive hours per day (IS12, n = 14) or twice per day for 6 h per occasion (IS6, n = 13) from day 14 of lactation onwards. Control sows (n = 23) were weaned at day 21 of lactation. Pre-ovulatory follicles (> or =6 mm) were observed in 100% of IS12, 92% of IS6 and 26% of C sows before day 21 of lactation and in the remaining 74% C sows within 7 days after weaning. All sows with pre-ovulatory follicles showed oestrus, but not all sows showed ovulation. Four IS6 sows and one IS12 sow developed cystic follicles of which two IS6 sows partially ovulated. Follicle growth, ovulation rate and time of ovulation were similar. E(2) levels tended to be higher in IS sows (p = 0.06), the pre-ovulatory LH surge tended to be lower in IS12 (5.1 +/- 1.7 ng/ml) than in C sows (8.4 +/- 5.0 ng/ml; p = 0.08) and P(4) levels were lower in IS12 and IS6 than in C sows (at 75 h after ovulation: 8.8 +/- 2.4 ng/ml vs 7.0 +/- 1.4 ng/ml vs 17.1 +/- 4.4 ng/ml; p < 0.01). In conclusion, sows with lactational oestrus induced by IS are similar to weaned sows in the timing of oestrus, early follicle development and ovulation rates, but the pre-ovulatory LH surge and post-ovulatory P(4) increase are lower.     

Management program for improving sow and gilt performance by feeding dichlorvos

Treated sows were on a special management program which consisted of feeding 1,000 mg of dichlorvos to the sow each day for the last 30 days of gestation. The dichlorvos was delivered as a slow-release formulation. The late gestation treatment signigicantly (P less than 0.01) improved the productivity of the sows by improving the performance of their litters. The litters from treated sows were superior in 4 ways: (1) increased number of pigs born alive per litter (2.3%); (2) increased pig birth weights (9.6%); (3) improved survival of pigs born alive; and (4) improved growth rate to market weight. The litters from treated sows were 11.6%, 16.5%, and 12.4% heavier than control litters at birth, weaning (35 days), and market (160 days), respectively.     

Feeding sorghum ergot (Claviceps africana) to sows before farrowing inhibits milk production

Objective To assess the impact of feeding different amounts of sorghum ergot to sows before farrowing. Design Fifty‐one pregnant sows from a continually farrowing piggery were sequentially inducted into the experiment each week in groups of four to seven, as they approached within 14 days of farrowing. Diets containing sorghum ergot sclerotia within the range of 0 (control) up to 1.5% w/w (1.5% ergot provided 7 mg alkaloids/kg, including 6 mg dihydroergosine/kg) were randomly allocated and individually fed to sows. Ergot concentrations were varied with each subsequent group until an acceptable level of tolerance was achieved. Diets with ergot were replaced with control diets after farrowing. Post‐farrowing milk production was assessed by direct palpation and observation of udders, and by piglet responses and growth. Blood samples were taken from sows on three days each week, for prolactin estimation. Results Three sows fed 1.5% ergot for 6 to 10 days preceding farrowing produced no milk, and 87% of their piglets died despite supplementary feeding of natural and artificial colostrums, milk replacer, and attempts to foster them onto normally lactating sows. Ergot inclusions of 0.6% to 1.2% caused lesser problems in milk release and neo‐natal piglet mortality. Of 23 sows fed either 0.3% or 0.6% ergot, lactation of only two first‐litter sows were affected. Ergot caused pronounced reductions in blood prolactin, and first‐litter sows had lower plasma prolactin than multiparous sows, increasing their susceptibility to ergot. Conclusion Sorghum ergot should not exceed 0.3% (1 mg alkaloid/kg) in diets of multiparous sows fed before farrowing, and should be limited to 0.1% for primiparous sows, or avoided completely.     

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.     

Effect of farrowing duration, parity number and the type of anti-inflammatory drug on postparturient disorders in sows: a clinical study

The aim of the present study was to investigate the effects of farrowing duration, parity number, and type of anti-inflammatory drug used postpartum on the incidence of postparturient disorders in sows. The duration of farrowing and postparturient disorders were examined in 64 sows at Days 0, 1, 2, and 3 after farrowing. The sows were classified according to parity number (1, 2–4, and 5–7), duration of farrowing (<2, 2–2.9, 3–3.9, and 4–8 h), and the type of anti-inflammatory drugs (flunixin méglumine and dipyrone). The farrowing duration was 178.0?±?73.5 min (2.96 h). The percentage of sows with fever increased from 40 to 100 % when the farrowing duration increased from <2 to 4–8 h. On Day 1 of the postpartum, 93.7 % of primiparous sows had fever, while 52.6 and 47.6 % of sows parity 2–4 and 5–7 had a fever (P?<?0.05). The presence of vaginal discharge on Day 1 of the postpartum was higher in sows of parity 5–7 than sows of parity 2–4 (85.7 and 52.6 %, P?=?0.029). The use of flunixin méglumine after parturition in sows reduced the percentage of sows with a fever from 61.3 to 22.6 % within 2 days (P?=?0.002), while, the percentage of sows with a fever was not decreased in sows treated with dipyrone. It can be concluded that the incidence of postparturient disorders in sows was affected by sow parity, farrowing duration and the type of anti-inflammatory drug used. Sows with a farrowing duration of ≥4 h were at a high risk of having fever at Day 1 after parturition.     

羟甲基丁酸钙盐对妊娠后期-哺乳期母猪繁殖性能、乳成分及仔猪生长性能的影响

文章旨在评估日粮中添加羟甲基丁酸钙盐对妊娠后期到哺乳期母猪繁殖性能、乳成分及仔猪生长性能的影响.试验选择32头胎次接近的二元母猪,随机分为2组,每组4个重复,每个重复4头猪.对照组母猪在妊娠后期和哺乳期饲喂基础日粮,处理组母猪在妊娠和哺乳期饲喂基础日粮+8?mg/kg羟甲基丁酸钙,试验从分娩前6?d到仔猪21?d断奶....     

不同剂型酸化剂对哺乳母猪生产性能、初乳成分和肠道菌群结构的影响

本试验旨在比较2种不同剂型酸化剂对哺乳母猪生产性能、初乳成分和肠道菌群结构的影响。试验选择30头体况相近、预产期接近的2~4胎长大二元杂交母猪,随机分成3个组,每组10个重复,每个重复1头母猪。在试验期间各组母猪分别饲喂基础饲粮(对照组)、基础饲粮+0.3%吸附型酸化剂(A组)、基础饲粮+0.1%微囊型酸化剂(B组)。预试期7 d(母猪分娩前7天)、正试期26 d(从母猪分娩开始至泌乳结束)。结果表明:与对照组相比,A组和B组母猪的泌乳期平均日采食量分别提高4.9%(P0.05)和5.3%(P0.05),仔猪断奶均重分别提高2.6%(P0.05)和7.4%(P0.05)。A组和B组的母猪初乳中乳脂、乳蛋白、尿氮素、免疫球蛋白G和免疫球蛋白A含量均高于对照组(P0.05),而乳糖含量则低于对照组(P0.05)。与对照组相比,B组母猪饲粮蛋白质消化率显著提高(P0.05),且粪便中大肠杆菌数量显著降低(P0.05);A组母猪粪便中大肠杆菌数量显著降低(P0.05)。由此可见,微囊型酸化剂在提高仔猪断奶重以及哺乳母猪饲粮蛋白质消化率和改善肠道菌群结构方面有一定功效,而吸附型酸化剂在改善哺乳母猪肠道菌群结构方面有一定功效。     

Post-mortem Examination of Sows Genital Organs Culled for Reproductive Disturbances and Immunohistochemical Studies on ERα and PR A Receptors in the Anoestral Sows Uterus

The aim of present study was post-mortem examination of ovaries, uterus and plasma oestradiol-17beta (E2) and progesterone (P4) concentrations in the blood of sows with reproductive disturbances and the distribution of oestradiol receptor (ERalpha), as well as progesterone (PR-A) in the anoestrous sows uteri. Reproductive organs of 150 crossbred sows (Lithuanian White x Danish Landrace) culled for the reasons of reproductive disturbances, were collected in local abattoir over a period of 3 months (September-November). Organs were assessed to determine the stage of the oestrous cycle or anoestrus and their development. Blood samples were collected for E2 and P4 analysis from the jugular vein 1 h prior to slaughter. For this study uterine samples only from pathological anoestrous sows were subjected to immunohistochemical staining to assess the distribution of ERalpha and PR-A in surface epithelium, subepithelial connective tissue, glandular epithelium and myometrium. Macroscopic examination of the ovaries showed that 68.7% sows had active cycling ovaries, 26.6% sows were anoestrus, ovaries were small without CL, and 4.7% of sows had multiple follicular cysts. In anoestrous sows (n = 27) the number and intensity of the nuclear staining of ERalpha varied between different uterine tissue compartments. The highest number (>80%) and the strongest intensity (+++) of positively stained cells for ERalpha was seen in myometrium and glandular epithelium. In other uterine wall compartments the number and intensity of positively stained for ERalpha nuclei was lower (+/++). The PR-A was absent from all tissue compartments. The intensity of the nuclear staining for ERalpha varied not only between the different uterine compartments but also between the sows. The 11.1% of the sows presented ERalpha in surface epithelium, 74.1% of the sows in glandular epithelium and 63.0% of sows in the myometrium.     

Vaccination of pregnant sows against transmissible gastroenteritis with two attenuated virus strains and different inoculation routes

Summary Two attenuated transmissible gastro-enteritis (T. G. E.) virus strains were used for vaccination experiments in sows. Four different experiments were carried out (see Table 1). In each experiment, 9 sows were vaccinated during pregnancy and 3 sows served as controls. They were kept together in one farrowing house. The sows were due to farrow at about the same time. The sows and their litters were challenged shortly after farrowing by exposing 3 piglets of 2 control litters to virulent TGE virus. The following vaccination schedules were used (see Table 1): twice intramuscularly with TGE-vac (a commercially available TGE-vaccine), one oral administration followed by an intramuscular vaccination with an attenuated TGE Purdue (Pu) strain, twice orally with Pu strain in enteric coated capsules, and one direct intra intestinal administration followed by 2 intramuscular vaccinations or 3 intramuscular vaccinations with the Pu strain. All sows, except most of those treated with enteric coated capsules, seroconverted demonstrably (Table 2). The geometric mean seroneutralization (SN) titer log 2 varied from 4.1 to 7.5 after the first vaccination and from 7.6 to 10 after the second vaccination. None of the vaccination schedules resulted in an effective lactogenic immunity. The morbidity in the piglets was 100% within 3 to 5 days after challenge. The mortality rate varied from 44 to 80% in litters from vaccinated sows and from 71 to 100% in litters from control sows (see Table 3). Clinical signs were observed in 33,3% of the control sows and in 36% of the vaccinated sows. No correlation was found between the titer of SN antibodies in the sera of the piglets and their survival rate (Table 4). A rapid decrease in antibody concentration was observed, during the first week of lactation in milk samples collected from 4 orally and intramuscularly vaccinated sows (Table 5).