Effects of various antibiotics on the control of bacteria in boar semen

Nine antibiotics were tested for the control of 11 bacterial genera isolated from boar semen. Of the antibiotics tested, the aminoglycosides dibekacin, amikacin and gentamicin proved fairly effective. Minimum inhibitory concentrations of those antibiotics were low (less than 6.25 micrograms/ml) compared to those of antibiotics commonly used for semen diluents. Seventy-four semen samples were stored at 15 degrees C by means of dialysis in the presence of dibekacin (100 micrograms/ml). After seven days' storage, about 80 per cent of the samples showed no bacterial growth and the mean values for sperm motility an normal acrosomes were 75.4 per cent and 82.7 per cent respectively. Twenty sows which were inseminated with semen stored for up to 14 days produced 16 litters and the average litter size was 9.9.     

Qualitative changes and the fertilizing capacity of sperm after 6 years of preservation of boar semen

Sperm motility, acrosome morphology, changes determined by the vital-lethal test and aspartate aminotransferase (AST) concentration in semen plasma were evaluated in the semen of four boars; the semen was stored for six years. No statistically significant changes in the percentage of motile spermatozoa were indicated when sperm motility was evaluated after four and six years of semen storage in liquid nitrogen. Neither did the fluctuation of the changes found on the basis of the vital-lethal test go beyond statistically insignificant values. After semen sample thawing in the BTS medium, the motility of spermatozoa was found to be somewhat higher than after thawing in the INRA-ITP medium, but after the termination of the thermoresistance test both media appeared to be equally effective. The AST level of the semen samples stored for four years was just slightly up on the initial values. After thawing in the BTS medium, AST level increased by 0.03 microcatal per litre of semen plasma, and in the INTRA-ITP medium by 0.06 microcatal per litre of semen plasma. The insemination of five sows with the semen stored for six years results in conception of two sows, i. e. 40%, and the average litter size was 7.5 piglets. It can be derived from the results that six years of boar semen storage in liquid nitrogen cause no further substantial changes in the structural and functional characteristics of spermatozoa.     

Relationship between sperm quality traits and field-fertility of porcine semen

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 10⁸ sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 10⁶ sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 10⁹ spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity.     

Distribution of Spermatozoa and Embryos in the Female Reproductive Tract after Unilateral Deep Intra Uterine Insemination in the Pig

The present study was performed to investigate the number of either the spermatozoa or the embryos in the reproductive tracts of sows after unilateral, deep, intra uterine insemination (DIUI). Two experiments were conducted, 10 sows were used in experiment I and eight sows were used in experiment II. Transrectal ultrasonography was used to examine the time when ovulation took place in relation to oestrus behaviour. The sows were inseminated with a single dose of diluted fresh semen 6-8 h prior to expected ovulation, during the second oestrus after weaning. In experimental I, five sows were inseminated by a conventional artificial insemination (AI) technique using 100 ml of diluted fresh semen, containing 3000 x 10(6) motile spermatozoa and five sows were inseminated by the DIUI technique with 5 ml of diluted fresh semen, containing 150 x 10(6) motile spermatozoa. The sows were anesthetized and ovario-hysterectomized approximately 24 h after insemination. The oviducts and the uterine horns on each side of the reproductive tracts were divided into seven segments, namely ampulla, cranial isthmus, caudal isthmus, utero-tubal junction (UTJ), cranial uterine horn, middle uterine horn and caudal uterine horn. Each segment of the reproductive tracts was flushed with Beltsville thawing solution (BTS) through the lumen. The total number of spermatozoa in the flushing from each segment were determined. In experimental II, eight sows were inseminated by the DIUI technique using 5.0 ml diluted fresh semen containing 150 x 10(6) motile spermatozoa. The sows were anesthetized 61.1 +/- 12 h after insemination (48-72 h) and the embryos were flushed from the oviduct through the proximal part of the uterine horn. It was revealed that, in experimental I, the spermatozoa were recovered from both sides of the reproductive tract in the AI-group, and from unilateral side of the reproductive tract in the DIUI-group (three sows from the left and two sows from the right sides). The number of spermatozoa recovered from the reproductive tracts was higher in the AI- than the DIUI-group (p < 0.001). In experiment II, fertilization occurred in five of eight sows (62.5%) after DIUI. The number of ova that ovulated were 16.4 +/- 2.6 per sow and the embryos numbering 11.4 +/- 2.3 per sow were recovered from both sides of the reproductive tract. In conclusion, the spermatozoa given by DIUI could be recovered from only one side of the reproductive tract of sows at approximately 24 h after DIUI via the flushing technique. However, embryos were found in both sides of the oviducts and the proximal part of the uterine horns 48-72 h after insemination, indicating that the fertilization occurred in both sides of the oviducts.     

Porcine Field Fertility with Two Different Insemination Doses and the Effect of Sperm Morphology

In swine artificial insemination, several dose regimens are applied, ranging from 1.5 x 10(9) to 6.0 x 10(9) spermatozoa per intra-cervical insemination dose. A lower sperm dose is more profitable for artificial insemination centres and offers a more effective use of superior boars. To evaluate fertility, 50 boars were used for a total of 10 773 homospermic first inseminations at a dose of 2 billion spermatozoa. In addition, 96 boars were used at a dose of 3 billion spermatozoa for 34 789 homospermic first inseminations. Fertility was determined by a 60-day non-return rate (NR%) of first inseminations. Litter size was registered by total number of piglets born separately in primiparous and multiparous farrowings. On average, a sow was inseminated 1.5 times. A significant decrease was observed in all three fertility parameters (NR%, litter size of both primiparous and multiparous farrowings) with a dose of 2 billion spermatozoa compared with a dose of 3 billion spermatozoa. The NR% was 75.8% and 84.0% (p < 0.001), the mean litter size of primiparous farrowings 10.1 and 10.7 (p < 0.001) and the mean litter size of multiparous farrowings 11.7 and 12.1 (p < 0.001) for 2 and 3 billion spermatozoa/dose, respectively. The proportion of normal spermatozoa in the sperm morphology analysis correlated significantly with NR% in both insemination regimens: p < 0.001, r = 0.604 and p < 0.05, r = 0.223 for 2 and 3 billion spermatozoa/dose, respectively. These results confirm that quantity can at least partly compensate for poor sperm quality. When the boars with <70% normal spermatozoa in the morphology evaluation were excluded from the data there were no correlation between the sperm morphology and NR%. However, the difference between the NR% and litter size remained statistically significant (p < 0.001) in favour for the bigger insemination dose. In conclusion, a decrease in sperm dose from 3 to 2 billion spermatozoa on commercial farms will severely decrease prolificacy at least under field conditions, where a sow is inseminated an average of 1.5 times/heat, and the semen is typically used within 3 days after collection. We recommend that under commercial circumstances the homospermic semen doses contain no <3 billion spermatozoa/dose.     

Effect of Cloprostenol Treatment at Artificial Insemination on Sow Fertility

In two experiments, we examined the effect of administration of cloprostenol at artificial insemination on fertility of multiparous sows. Lactation length was 21 days and only sows exhibiting estrus by 7 days after weaning were included. Cloprostenol was administered by IM injection (175 microg; n=126) or supplemented in the semen dose (525 microg; n=129). Control sows (n=130) received no hormone. In either experiment, there was no effect of any treatment on subsequent litter sizes. In experiment 1, there was no effect of treatment on farrowing rate, but in experiment 2, farrowing rate was higher (p < 0.05) in sows receiving cloprostenol by injection. Taken together, these results indicate no consistent effect of cloprostenol administration by intramuscular injection or by inclusion in the semen dose on sow fertility and so its routine use is not warranted.     

Oestrone sulphate measurements for the prediction of small or large litters in pigs

Serum from 88 pregnant sows and gilts was sampled 24 and 28 days after their first insemination or mating day. The oestrone sulphate (E1S) concentration in the samples was assessed with a commercially available radioimmunoassay kit modified for use with swine serum. The first aim was to test whether it was possible to predict litters of total number <10 piglets at term. The second aim was to compare the use of day 24 or day 28 samples, or of both, in this prediction. Day 24 E1S levels were positively correlated with litter size at term (R2 = 0.26; p <0.001). E1S levels on day 28 were correlated with the levels on day 24 in the same animals but could not be used for prediction of large or small litters. The odds ratio for a small litter size was 0.16 (p <0.01). This means that odds for a litter size <10 piglets decreased by 84% when E1S levels increased by 1.0 ng/ml.     

Reproductive failure associated with porcine parvovirus in an enzootically infected pig herd.

Two outbreaks of porcine parvovirus occurred in a unit of 380 sows, with a subsequent decrease in the size of gilts' litters. Of the 203 gilts and 64 primiparous sows which were seronegative at the time of insemination, 134 gilts and 55 primiparous sows seroconverted during pregnancy. Of the second parity sows nine of 271 were still seronegative at the time of insemination but all nine seroconverted during their third gestation. The gilts that seroconverted during their first pregnancy produced on average 0.9 fewer live piglets than the gilts that did not seroconvert. Second litter sows which seroconverted produced 0.3 fewer piglets than those which did not seroconvert. There were no significant differences between sows which seroconverted or did not seroconvert in the numbers of returns to service, or in the percentages of piglets which were born dead or died before weaning.     

Fluctuation in the concentration of sex steroids and aflatoxin B1 in the seminal plasma of boars and its relation to sperm production

The concentration of testosterone, 17-beta oestradiol and aflatoxin B1 were studied in the semen plasma of 21 boars of four breeds for the period of twelve months. The following spermiological parameters were investigated: semen volume, sperm concentration, percentage of abnormal spermatozoa, and survival of spermatozoa. The fertilizing capacity of ejaculates was evaluated according to the conception rate of sows and gilts after the first insemination, according to the average number of piglets per litter and average number of live-born piglets per litter. The highest aflatoxin B1 residues in sperm were recorded in March to May and were related with aflatoxin concentration in feed ration. The group of boars with fertility disorders had more aflatoxin in their sperm (up to 100 pmol . l-1), lower sperm concentration, lower survival of spermatozoa, and a larger proportion of abnormal spermatozoa. The year season had a significant influence on the concentration of the hormones. The highest average value of testosterone (10.2 +/- 1.28 nmol) was obtained in autumn and lower values were recorded in winter. The changes in 17-beta estradiol concentration were similar to the changes in testosterone content, with the maximum value in November (0.249 nmol X 1(-1]. The boars with reproduction disorders had a significantly lower concentration of 17-beta oestradiol. Significant correlations were found between the concentration of the hormones, semen volume, and sperm concentration. 17-beta oestradiol also had a significant positive correlation to abnormal spermatozoa and to the activity of aspartate aminotransferase.     

Influence of Postpartum Cloprostenol Treatment in Sows on Subsequent Reproductive Performance under Field Conditions

During the previous decade several studies focused on postpartum treatment with prostaglandin for improvement of reproductive performance in sows. The aim of the study was to investigate the effect of administration of a prostaglandin F_{2 α} (PGF_{2 α} ) analogue in sows within 24–48 h after farrowing on sow and litter performance. In five commercial farms, the sows were randomly assigned to either treatment A (2 ml cloprostenol, Planate^IM) or treatment B (2 ml physiological saline solution, i.m.). Fifteen per cent of all sows were at random selected for progesterone analysis. Litter performance was assessed by measuring pre-weaning mortality and average daily weight gain (ADG). Sow performance was assessed by measuring weaning-to-oestrus interval (WOI), the percentage of sows returning to oestrus and litter size during subsequent farrowing. Administration of a PGF_{2 α} analogue within 24–48 h postpartum had no effect on the rate of progesterone decline measured over 24 h compared with that of the controls. Litter performance and WOI were not affected by treatment. The subsequent litter size in sows of parity seven and more showed a significant difference of 1.98 piglets (p < 0.01) between both groups, to the benefit of the cloprostenol group. In conclusion, administration of a synthetic PGF_{2 α} analogue, cloprostenol, within 24–48 h after farrowing improved litter size at next farrowing in older (≥7 parity) sows.     

Size of pellets and individual properties of boar semen in relation to the number of motile spermatozoa following defrosting]

The second fraction of the ejaculate of five boars of the Landrace breed was used for the experiments. Non-diluted semen was kept in hydrogen atmosphere for three hours at + 5 degrees C; then it was frozen in solid carbon dioxide into 0.1 ml, 2.0 ml, and 5.0 ml pellets and in liquid nitrogen vapours into the shape of disk or cylinder 5 ml in volume. The pellets were de-frozen on a teflon pan at 42 degrees C without addition of any other diluent. Ejaculate in which at least 25% of the spermatozoa were motile was considered to be usable. No statistically significant difference was found between the motility of spermatozoa frozen in the 0.1 ml and 2.0 ml pellets, but it can be said that on an average the motility of the spermatozoa was lower in larger pellets; this could be observed mainly in the pellets with the volume of 5.0 ml. Large differences were revealed in the freezability of the semen of different boars, irrespective of the size of the frozen pellet. Insemination of 38 gilts with semen from 2.0 ml pellets gave a 57,8 % concentration rate (22 gilts) and the average litter size was 8.25 piglets.     

猪精液冷冻技术试验

从稀释液和解冻液的筛选，平衡时间、平衡温度、冷冻剂型的选择等方面进行试验。试验结果：猪精液冷冻后活率为３０％－６０％；解冻后的复苏率为５１．４２％－５８．７２％；保存３０天的冻精与保存３６０天的冻精受胎率无明显差异（Ｐ＞０．０１）；冻精保存期一年以上；输精受胎率达６３．６４％（６０％－６６．６６％），平均窝产仔６．１头。     

Stillbirth in the pig in relation to genetic merit for farrowing survival

The objectives of this study were to analyze the incidence of different categories of stillborn piglets in relation to genetic merit for farrowing survival of sows and litters and to analyze relationships of total number of piglets born per litter, average BW of the litter, and within-litter variation in BW with genetic merit for farrowing survival of sows and litters. Records of 336 purebred litters, produced by 307 first-to eighth-parity sows, were collected on a nucleus farm in Brouennes, France. Breeding values for farrowing survival were estimated for sows (EBVfs_maternal) and litters (EBVfs_direct) using a large data set from which information obtained in the current study was excluded. For each litter, BW, number of stillborn piglets (classified as nonfresh stillborn, prepartum stillborn, intrapartum stillborn, and postpartum stillborn), and number of live-born piglets were recorded. Birth weights of stillborn piglets were lower than BW of live-born piglets (P < 0.0001), except for prepartum stillbirths. The total number of stillborn piglets per litter and the number of stillborn piglets in each category decreased with increasing EBVfs_maternal (P < 0.01). An increase in EBVfs_direct was also associated with a decrease in the total number of stillborn piglets per litter (P < 0.01). This decrease was due to a decrease in the number of nonfresh, prepartum, and postpartum stillborn piglets but not to a decrease in the number of intrapartum stillborn piglets. Probabilities of stillbirth in relation to EBVfs_maternal were higher than probabilities of stillbirth in relation to EBVfs_direct. Total number of piglets born decreased with increasing EBVfs_direct (P = 0.0003), but was not related to EBVfs_maternal. Average BW of the litter (P < 0.0001) and within-litter variation in BW (P = 0.05) decreased with increasing EBVfs_maternal but were not related to EBVfs_direct. Selection for the maternal genetic component of farrowing survival seems a better strategy than selection for the direct genetic component. Selection for the maternal genetic component of farrowing survival reduces stillbirth in all categories and does not affect litter size.     

猪精液常温保存不同温度和时间的受胎试验

<正> 猪精液保存方法的改进,是保证生猪人工授精技术不断提高的主要环节。 目前,猪精液常温保存效果精子最长寿命为96小时,能使用时间为72—96小时。为了探讨延长猪精液常温保存时间的方法,我局于1980年6月至1981年7月,在番禺县南村区生猪人工授精站开展猪精液常温保存不同温度和时间的受胎试验。目的是通过试验     

The Post‐Cervical Insemination does not Impair the Reproductive Performance of Primiparous Sows

The study evaluated the reproductive performance of primiparous sows submitted to post‐cervical insemination (PCAI) compared with cervical artificial insemination (CAI). Difficulty with catheter introduction, the occurrence of bleeding or semen backflow during insemination, and volume and sperm cell backflow up to 60 min after insemination were also evaluated. Sows were homogenously distributed, according to body weight loss in lactation, lactation length, weaned piglets, weaning‐to‐oestrus interval and total born in previous farrowing, in two treatments: PCAI (n = 165) with 1.5 × 10⁹ sperm cells in 45 ml (2.4 ± 0.04 doses per sow) and CAI (n = 165) with 3 × 10⁹ sperm cells in 90 ml (2.5 ± 0.04 doses per sow). During PCAI, sows were inseminated in the absence of boars. Transabdominal real‐time ultrasonography was performed at oestrus onset, immediately before the first insemination and at 24 h after last insemination. There was no difference (P > 0.05) between treatments in farrowing rate (91.5% × 89.1%) and litter size (12.5 × 11.9 piglets born, respectively for PCAI and CAI sows). Successful passage of the intrauterine catheter in all the inseminations was possible in 86.8% (165/190) of sows initially allocated to PCAI treatment. Difficulty of introducing the catheter in at least one insemination did not affect the reproductive performance of PCAI sows (P > 0.05). Bleeding during insemination did not affect (P > 0.05) the farrowing rate in both treatments, but litter size was reduced in CAI and PCAI sows (P ≤ 0.06). Percentage of spermatozoa present in backflow within 1 h after insemination was greater in CAI than PCAI sows (P < 0.01). More than 85% of primiparous sows can be successfully post‐cervical inseminated with doses containing 1.5 × 10⁹ sperm cells in the absence of the boar during insemination without impairing the reproductive performance.     

Effect of season and outdoor climate on litter size at birth in purebred landrace and yorkshire sows in Thailand

The objective of the present study was to retrospectively investigate causes of variation on litter size at birth (total number of piglets born per litter (TB) and number of piglets born alive per litter (BA)) of Landrace (L) and Yorkshire (Y) sows in swine nucleus herds in Thailand. The data included sows farrowed during a four-year period from January 1998 to December 2001. The analyzed data set included observations on 8020 litters from 2199 L sows and 6919 litters from 1680 Y sows. Analysis of variance (ANOVA) was applied for statistical analyses using General Linear Mixed Model (MIXED) procedure of SAS. No breed difference was found for both TB and BA. Farrowing months significantly influenced TB and BA (P<0.001). Sows farrowed in August and September had a lower BA than sows farrowed from November to June (P<0.05). Effect of farrowing months on both TB and BA was more pronounced in primiparous compared with multiparous sows. Average minimum daily temperature during gestation negatively correlated with both TB and BA, average maximum daily temperature during gestation negatively correlated with BA and average daily humidity during gestation negatively correlated with both TB and BA. The correlations were stronger in L than in Y sows.     

The reproductive performance and factors affecting on-farm application of low-dose intrauterine deposit of semen in sows

The objective of this experiment was to determine the reproductive performance and factors that affect on-farm application of low-dose intrauterine insemination (IUI) in sows. Four hundred twenty-two sows were used in a simple arrangement of four treatments to determine the effect of spermatozoa per dose (0.5 x 10(9), 1 x 10(9), or 4 x 10(9) IUI, and 4 x 10(9) with a conventional catheter) on the main effects of conception, litter size, and farrowing rate. Following weaning at approximately 18 d after parturition, estrus detection was performed daily in the presence of a mature boar. At the time of estrus detection, sows were blocked for parity (1, 2, or 3+), weaning-to-estrus interval (WEI; 3, 4, or 5 d), and assigned randomly to be serviced twice with semen from the same boar(s). Treatment services were equally divided among three technicians. Delivery of acceptable numbers of spermatozoa per dose with either device (IUI or conventional) produced similar reproductive performances; however, farrowing rate, total pigs born, and total born alive decreased (P < 0.05) when suboptimal numbers (< or = 1 x 10(9)) of spermatozoa were used with IUI. Treatment interactions with parity were not detected and were removed from the final model. Treatment interactions with WEI on farrowing rate were detected (P < 0.05), and sows with WEI of 3 d had a markedly lower (P < 0.05) farrowing rate than all other treatment groups. The results from this experiment suggest that placement of semen at the beginning of the uterine horn with conventional volumes and spermatozoa numbers produces results similar to placement of semen in the cervical cavity with a conventional AI catheter. Although there is little published evidence of reproductive performances in a commercial setting with suboptimal numbers of spermatozoa, these results suggest that insemination beyond the cervix does not offset effects of suboptimal numbers of spermatozoa.     

A note on the effect of the halothane-type of sows on lifetime prolificacy and litter parity at culling

The effect of the Halothane-type of the sow on its lifetime prolificacy was studied on five farms. One-hundred and seventy Herdbook sows were typed according to the Halothane results of their progenies.The means and standard deviations of litter size at birth, litter size at weaning and number of litters per lifetime were 10.14 ± 1.33, 9.41 ± 1.28 and 4.85 ± 2.57, respectively. The farms had highly significant effects on all three traits. The Halothane-type influenced the number of litters produced per lifetime significantly. The means of the most extreme farms differed 0.95, 1.62 and 3.15 for litter size born, number of piglets reared and number of litters produced per lifetime, respectively. Halothane-negative sows produced 1.02 (P ⩽ 0.05) more litters than Halothane-positive sows.     

太湖猪高产综合技术研究试验

本文系对103头360窝太湖猪的繁殖性能进行系统研究。结果是60头母猪在6个繁殖周期中共繁殖360窝,平均繁殖周期158.33天,年产仔2.31胎。窝产仔16.35头,活仔15.10头,35日龄断奶育成14.44头,窝重83.48公斤。每头母猪年产仔37.69头,年产活仔34.81头,年提供断奶仔猪33.29头。其中窝产仔达到18头以上,出现1胎或连续4胎高产的母猪69头,占试验母猪群66.99％。     

Verification of the usefulness of Estrophan inj. Spofa in the control of reproductive parameters in sows after weaning of piglets]

Cloprostenol, a prostaglandin F2-alpha analogue, used in the Czechoslovak preparation Oestrophan ing. Spofa was tested by a new nontraditional use. The effect of cloprostenol use on reproductive parameters of sows after piglet weaning was followed in a set of 456 experimental and 434 control sows. The effect of single intramuscular instillation of cloprostenol was tested in five partial observations: to multiparous sows at a dose of 175 micrograms on the day of weaning (experimental group no. 1), on day 1 after weaning (group no. 2), 500 micrograms on day 1 after weaning (group no.3), to primiparous sows at a dose of 500 microgram on day 1 after weaning (group no. 4). The treatment used in group no. 4 was also applied to 42 primiparous sows kept on a farm with regular occurrence of post-weaning anoestria of sows (experimental group no. 5). These parameters were evaluated: dynamics of oestrus onset within five, and/or ten, days after weaning, average length of the weaning--first insemination interval, conception rate after the first insemination in dependence on terminated deliveries and parameters of piglet litter. Cloprostenol application did not have a statistically significant effect on the evaluated reproductive parameters. The percentage of multiparous, and/or primiparous, sows in which the oestrus onset was not detected by the 10th day after weaning, did not show any large differences in the various experimental and control groups (17.09 vs. 16.55%, 23.53 vs. 32.56%, 13.66 vs. 18.13%, 29.54 vs. 30.30%; P > 0.05). On the farm with regular occurrence of post-weaning anoestria there were 73.81% of primiparous sows with oestrus onset after cloprostenol instillation and 71.43% primiparous sows without treatment.(ABSTRACT TRUNCATED AT 250 WORDS)