Semen quality and fertility after heat stress in boars

Sperm morphology and the fertilizing capacity of ejaculated spermatozoa were examined in 6 Swedish Landrace boars before and after heat stress. The boars were exposed to 35° C during 100 h in a climatic room. Fertility was measured by insemination of gilts before and at various times after heat stress. Each gilt (n = 44) was inseminated with a total of 5×10⁹ spermatozoa diluted to 10O ml with EDTA-glucose diluent and fertilization was assessed by examining recovered ova 2 days after insemination.Changes in semen quality varied among the boars from a very weak response in 2 boars to pronounced semen alterations occurring 2–6 weeks after heat stress in the other boars. A close relationship was found between seminal changes and fertilization rates, all ejaculates which had high fertilization rates being of the same quality as the pre-exposure ejaculates. The ejaculates that had poor fertility were characterized by lowered sperm motility and increased numbers of spermatozoa with abnormal heads, proximal cytoplasmic droplets and nuclear pouch formations.     

玉米赤霉烯酮对后备母猪子宫和卵巢抗氧化和炎症指标及相关基因表达的影响

试验旨在研究玉米赤霉烯酮（zearalenone,ZEA）对后备母猪子宫和卵巢抗氧化和炎症指标及相关基因表达的影响。选择胎次和体重（（23.20±0.68）kg）相近的长×大二元后备母猪48头,随机分为4组,每组设12个重复,每个重复1头母猪。对照组（CON组）饲喂基础饲粮,试验组（T1、T2、T3组）饲喂在基础饲粮中分别添加200、800、1600 μg·kg^-1ZEA的试验饲粮。预试期7 d,正试期40 d。结果如下：1）与CON组相比,T3组血清T-AOC和SOD活性显著降低（P<0.05）,MDA水平显著升高（P<0.05）。2）与CON组相比,子宫组织中,T2和T3组T-AOC活性显著降低（P<0.05）,T3组SOD活性极显著降低（P<0.01）,卵巢组织中,T3组T-AOC活性、T2组GSH-Px和SOD活性显著降低（P<0.05）,T3组MDA水平显著升高（P<0.05）。3）与CON组相比,T2组血清TNF-α和IL-4水平显著升高（P<0.05）,T1~T3组血清IL-10水平显著降低（P<0.05）。4）与CON组相比,子宫组织中,T2组IL-1β水平显著升高（P<0.05）,T1和T3组IL-10水平显著降低（P<0.05）。卵巢组织中,T2组TNF-α水平显著升高（P<0.05）,T1~T3组IL-4水平显著升高（P<0.05）。5）子宫组织中,T3组Cu/Zn-SOD mRNA的相对表达显著低于CON组（P<0.05）,T2组IL-1β mRNA的相对表达显著高于CON组（P<0.05）。6）卵巢组织中,T3组GSH-Px mRNA的相对表达显著低于CON组（P<0.05）,T2组IL-1β mRNA的相对表达显著高于CON组（P<0.05）。综上所述,ZEA能通过抑制SOD和GSH-Px的表达与合成,降低后备母猪子宫和卵巢的抗氧化性能,并引起氧化应激。ZEA能通过促进TNF-α和IL-1β表达与合成引起子宫和卵巢的炎症反应,抑制IL-10的表达与合成从而抑制两组织的抗炎反应。     

貉早期胚胎发育内环境的研究

为研究貉早期胚胎发育体内微环境变化,试验选用年龄相同、体重相似的成年健康母貉23只,在繁殖季节自然交配,并受配1～2次,以第1次交配为零点开始计时,分别于初配后29～99h(n=7)、100～126h(n=7)、169～268h(n=9)随机处死貉,用免疫组化、透射及扫描电镜的方法研究貉早期胚胎发育过程中输卵管和子宫的形态学和超微结构变化;用X射线能谱技术对貉输卵管液和子宫液中的钾、钙、铁、锌等9种元素进行测定。结果显示:①随着貉早期胚胎的发育,其后期输卵管长度、黏膜厚度、皱襞高度和上皮高度均显著减小(P<0.05),输卵管直径有所降低,但差异不显著(P>0.05);子宫黏膜厚度、皱襞高度及子宫腺密度均显著增加(P<0.05),子宫的直径和长度有所增加,但差异不显著(P>0.05)。②随着貉早期胚胎的发育,貉子宫黏膜上皮微绒毛、脂滴和溶酶体含量增多。③随着貉早期胚胎的发育,其后期输卵管液中硫、钙、铁、铜和锌元素含量均显著升高(P<0.05),磷含量显著降低(P<0.05),而钾、氯和钠含量呈波动性变化;子宫液中硫、氯、钾的相对含量逐渐降低(P>0.05),锌的相对含量显著降低(P<0.05),磷、钙、铁和铜的含量呈波动性变化。本试验初步揭示了貉早期胚胎发育内环境的变化,为貉胚胎体外培养体系的建立提供参考。     

玉米赤霉烯酮对青年母猪子宫发育、生长激素分泌及其受体分布与表达的影响

本试验旨在研究玉米赤霉烯酮(ZEA)对青年母猪子宫发育、生长激素(GH)分泌及其受体(GHR)分布与表达的影响.选择胎次和体重[(23.20±0.68)kg]相近的长×大二元青年母猪48头,将其随机分为4组,每组12个重复,每个重复1头.对照组(CON组)饲喂基础饲粮,试验组(T1、T2、T3组)饲喂在基础饲粮中分别添...     

Serum profile of metabolites and hormones in obese (Iberian) and lean (Landrace) growing gilts fed balanced or lysine deficient diets

Serum hormones and metabolites of lean and obese gilts were determined. Fifteen Iberian and fifteen Landrace gilts, of approximately 20 kg body weight, were fed isoenergetic (13.6 kJ ME/g DM, semisynthetic diets either with equilibrated amino acid profile at two crude protein (CP) levels (12% (0.81% lysine (Lys)) and 16% CP (1.08% Lys) as-fed basis) or lysine deficient (12% (0.30% Lys) or 16% CP (0.36% Lys) as-fed basis for Iberian and Landrace, respectively). Lysine deficient diets were offered only at the optimal protein level for maximum protein accretion for each breed. Each dietary treatment was assayed in 5 animals. Gilts were allocated in metabolic cages at 21 ± 1.5 °C with free access to water and fed four times daily at 90% ad libitum during 10 days. On day 11th blood samples were taken 5–5.5 h postprandial and serum obtained and frozen at − 20 °C. Growth hormone (GH), insulin like growth factor I (IGF-1), insulin, leptin, glucose, urea, creatinine, cholesterol and triglycerides were determined. Landrace gilts had higher serum glucose (P < 0.05) and creatinine (P < 0.001) than Iberian while no differences (P = 0.122–0.494) were found for the rest of the biochemical variables. Higher serum levels of insulin, IGF-1 and leptin (60, P < 0.05; 79, P < 0.05 and 189%, P < 0.001, respectively) and no differences in GH (P = 0.512) were encountered in Iberian gilts compared to Landrace. Dietary crude protein did not alter the serum hormonal profile (P = 0.110–0.454). Serum cholesterol (total, P < 0.01; HDL, P < 0.05; LDL, P < 0.05) decreased and triglycerides and urea increased (P < 0.05 and P < 0.001, respectively) as dietary crude protein increased. When lysine deficient diets were used, serum glucose decreased (P < 0.05) and urea increased (P < 0.001) compared to equilibrated diets. Serum insulin (P = 0.052), IGF-1 (P < 0.05) and leptin (P = 0.051) concentration decreased when lysine deficient diets were fed to the animals while GH remained unaffected (P = 0.214).These data suggest that Iberian and Landrace growing gilts have distinct hormone and metabolite serum profiles which are altered by a severe dietary lysine deficiency.     

The uterus and early pregnancy failure in the mare

The environment the equine conceptus finds itself in when it arrives in the uterus some 6 days after ovulation will determine if it will thrive or die. The uterus will be its home for approximately the next 11 months and as such it needs to both coordinate the growth of the placenta and ensure there is enough nourishment passing to this organ for the fetus to develop normally. The trophoblast, endometrium, maternal ovaries and, later in pregnancy, the fetal gonads, all play roles in the hormonal changes that orchestrate these events. Although failures of these processes later in pregnancy can have catastrophic effects for the fetus, it is in early gestation that the foundations for a successful pregnancy are laid. This paper therefore concentrates on some of the noninfectious influences the uterus may have on survival of the young conceptus.     

Monitoring changes in back fat thickness and its effect on the restoration of ovarian activity and fertility in Bos indicus cows

With the objective of testing the hypothesis if animals with a stable layer of body fat (FAT) during the peripartum have a better chance of becoming pregnant after calving, fifty‐nine multiparous Brahman cows in their last trimester of pregnancy were used. Animals averaged four parturitions and were stocked at a rate of 1.25 animal units per hectare and divided into two groups depending on the time postpartum (dpp) that the intravaginal releasing device CIDR was inserted; Group 1 (<30 dpp; n = 30) received the implant at 25.2 ± 4.21 and withdrawn 9 days later. Group 2 (≥30 dpp; n = 29) received the CIDR at 38.41 ± 5.8. Animals were AI at detected oestrus until 170 dpp and calculated as pregnant at first service or requiring more than one service (1s and >1s), not pregnant but cycling (not pregnant) and those not cycling at all (anestrus). The FAT measurements were taken twice each month from the last trimester of gestation until 96 dpp. The onset of ovarian activity was monitored through blood levels of progesterone (P4) at days 14 and 9 prior to CIDR insertion and days 10, 13, 30 and 33 after CIDR withdrawal. Animals pregnant did not have any major changes in their fat thickness. In contrast, cows pregnant in the group ≥30 dpp had changes in their FAT homoeostasis, and pregnant animals in the 1s and >1s groups did not show differences in dorsal back fat in the last trimester of pregnancy and early postpartum. In contrast, animals not pregnant and in anestrus FAT values decreased considerably after parturition. Overall, fertility was 49%, but 18% of all the animals remained anestrus losing FAT. Thus, animals with adequate metabolic conditions will have a better chance of pregnancy regardless of the time postpartum when the reproductive programme starts.     

Aurora A inhibition disrupts chromosome condensation and spindle assembly during the first embryonic division in pigs

As common overexpression of Aurora A in various tumours, much attention has focused on its function in inducing cancer, and its value in cancer therapeutics, considerably less is known regarding its role in the first cleavage division of mammalian embryos. Here, we highlight an indispensable role of Aurora A during the first mitotic division progression of pig embryos just after meiosis. The expression and spatiotemporal localization of Aurora A were initially assessed in pig embryos during the first mitotic division by Western blot analysis and indirect immunofluorescent staining. Then, the potential role of Aurora A was further evaluated using a highly selective Aurora A inhibitor, MLN8054, during this mitotic progression in pig embryos. Aurora A was found to express and exhibit a specific dynamic intracellular localization pattern during the first mitotic division in pig embryos. Aurora A was diffused in the cytoplasm at the prophase stage, and then exhibited a dynamic intracellular localization which was tightly associated with the chromosome and spindle dynamics throughout subsequent mitotic phases. Inhibition of Aurora A by MLN8054 treatment led to the failure of the first cleavage, with the majority of embryos being arrested in prophase of the mitotic division. Further subcellular structure examination showed that Aurora A inhibition not only led to the failure of spindle microtubule assembly, but also resulted in severe defects in chromosome condensation, accompanied by an obvious decrease in p-TACC3(S558) expression during the prophase of the first mitosis. Together, these results illustrated that Aurora A is crucial for both spindle assembly and chromosome condensation during the first mitotic division in pig embryos, and that the regulation of Aurora A may be associated with its effects on p-TACC3(S558) expression.     

Transrectal Doppler sonography of uterine blood flow during the first two weeks after parturition in Simmenthal heifers

Transrectal Doppler sonography was used to evaluate uterine blood flow during the first two weeks after parturition in six primiparous Simmental cows. The uterine blood flow was evaluated on the day of parturition (Day 0), once daily from Days 1 to 8 and then every other day until Day 14. Blood flow was quantified by determining the diameter (D), the time-averaged maximum velocity (TAMV), the pulsatility index (PI) and the blood flow volume (BFV) of the uterine arteries ipsilateral and contralateral to the formerly pregnant uterine horn. During the first four days after calving D, TAMV and BFV declined (ipsilateral: TAMV 70%, BFV 87%, contralateral: D 47%, BFV 84%; p < 0.05), while PI increased (ipsilateral 158%, contralateral 100%; p < 0.05) distinctly. Between Days 4 and 14 only the ipsilateral D (12%) and the BFV of both arteries (ipsilateral 5%, contralateral 8%) decreased (p < 0.05). Blood flow variables were very strongly correlated with each other (r > ±0.75, p < 0.05), with negative correlations with PI and positive correlations with all other investigated factors. Overall, this study revealed characteristic changes in uterine perfusion during the first two weeks after parturition in cows that were pronounced during the first four days postpartum.     

Effect of feeding guanidinoacetic acid and L‐arginine on the fertility rate and sperm penetration in the perivitelline layer of aged broiler breeder hens

Two experiments were conducted to evaluate the effects of feeding guanidinoacetic acid (GAA) and L‐arginine (ARG) on fertility and sperm penetration (SP) rate of broiler breeder hens. In the first experiment, a total of 200 broiler breeder hens (Ross 308) aged 53 week were randomly allotted to four dietary treatments (0, 0.6, 1.2 and 1.8 g GAA/kg diet) with five replicates of 10 birds each. In the second experiment, 320 broiler breeder hens (Ross 308) were used from 53 to 62 weeks of age in a 2 × 4 factorial arrangement (0 or 1.2 g GAA/kg diet along with 0, 3, 6 or 9 g ARG/kg diet). The hens received a diet containing 2800 kcal ME/kg and 14% CP. Sixteen sexually mature Ross 308 breeder roosters (34 weeks old) were used to artificially inseminate the hens. Fertility of the hens was determined in 61 and 62 weeks of age. The sperm penetration holes in the inner perivitelline layer (IPL) overlying the germinal disc were enumerated on days 3 and 7 following each insemination. Adding GAA to the breeder diet increased the number of SPs in the IPL and fertility in both experiments (p < 0.01). The interactive effect of ARG and GAA on the SP and fertility was significant. Supplementary ARG increased the SP rate in the IPL (p < 0.01). In conclusion, dietary supplementation of GAA and ARG might be potentially used to improve the fertility of broiler breeder hens at the later phase of the egg production period.     

Morphometric and ultrastructural changes in ciliated cells of the oviductal epithelium in prolific Chinese Meishan and Large White pigs during the oestrous cycle.

There are some differences in reproductive features between the Chinese Meishan (CM) pig and Large White (LW) pig. The aim of the present study was to investigate the quantitative changes and ultrastructural features of ciliated cells in the various regions of the CM and LW pig oviduct during the follicular and luteal phases of the oestrous cycle. In the fimbrial and ampullar epithelia at the follicular phase, the ciliated cells were more plentiful than in the isthmic region in both pigs. In the CM pigs, there was a striking decrease in the percentage and cell height of ciliated cells in the luteal phase compared with the follicular phase. Although similar quantitative changes were observed in the LW pig oviduct, these changes were less dramatic than that in the CM pig oviduct. In both pigs, the percentage and cell height of ciliated cells in the isthmus were unchanged between the follicular and luteal phases. The ultrastructure of ciliogenic and ciliated cells was observed. In the fimbrial and ampullar epithelia during the follicular phase, most of the ciliated cells showed normal morphology, having many elongated cilia and mitochondria, but in the CM pig oviduct during the luteal phase many of the ciliated cells possessed immature cilia and swollen mitochondria. Cells undergoing ciliogenesis were frequently observed in the fimbriae and ampulla, and occasionally in the isthmus. Cytoplasmic protrusions containing variable numbers of ciliary axonemal complexes occurred in the fimbrial and ampullar epithelium in the CM pigs at the luteal phase, suggesting that deciliation of cells occurs by membrane-bound cilia packets forming at the apices of cells and pinching off. These results demonstrate that there are regional variations in the cyclic changes associated with the oviductal ciliated cells of the pigs, while there are marked morphometrical and ultrastructural changes in oviductal ciliated cells of the CM pigs compared with that of the LW pigs.     

克隆种公猪生长状况和繁殖性能评价

体细胞核移植技术可以成功用于克隆性能优良的种用家畜,理论上克隆个体与供体在遗传上是完全相同的。为验证该理论,本试验检测了克隆种公猪自身在出生后的生长发育指标以及克隆种公猪与供核种公猪精液品质各项指标、情期受孕率、窝产仔数、产活仔数、断奶活仔数、仔猪初生重、仔猪断奶重和平均日增重等指标,探讨了克隆种公猪与供核种公猪在繁殖性能以及遗传性能之间的关系。结果显示,克隆种公猪与供核种公猪在各检测指标之间均不存在显著差异(P>0.05),提示克隆种公猪与供核种公猪在繁殖性能和遗传性能上无显著差异,可以作为种公猪用于扩繁。     

Evaluation of cervical and uterine size,at 4 weeks postpartum,as a predictor of subsequent fertility in Jersey cattle

Uterine and cervical size of Holstein dairy cows is reported among reasons for a decline in dairy cow fertility. Therefore, the objectives of this study were to (a) determine whether size of the cervix and uterus at 4 weeks postpartum impacted subsequent fertility at first service in Jersey cattle, (b) determine whether progesterone level at 4 weeks postpartum impacted cyclicity and (c) the association of the presence of corpus luteum and uterus and cervix size. Body condition scores at calving, presence of postpartum diseases, parity number and milk weights were taken from lactating Jersey dairy cows (N = 147) for 28 days postpartum. During the fourth week postpartum, a blood sample was obtained for progesterone concentration, and transrectal ultrasonography was performed by a high-resolution ultrasound machine to determine cervical and uterine horn diameter, as well as ovarian structures measurements. Correcting for parity number, BCS at calving, presence of diseases and milk yield, cows with a cervix >2.54 ± 0.63 cm and uterine horn >2.25 ± 0.59 cm were less likely to become pregnant at first service (p = .04 and p = .003, respectively). The cows with larger cervix had a trend to be less likely to have a corpus luteum present at the 4th week of lactation (p = .067). Cows with larger uterine horn size were less likely to have a corpus luteum present at the 4th week of lactation (p = .015). It is concluded that a larger cervix and/or uterus during the postpartum was associated negatively with fertility and cyclicity in Jersey cows.     

Association between embryonic loss and damage to the zona pellucida by invasive micromanipulation during oviductal transfer of early-stage embryos in pigs

The aim of this study was to examine the impact of zona pellucida damage, which might arise during somatic cell nuclear transfer (SCNT), on the development and survival of transferred embryos. The zonae pellucidae of in vitro matured oocytes were either punctured with 8- to 10-microm square-ended nuclear injection pipettes and piezo pulses or slit with 35- to 40-microm enucleation pipettes. Intact oocytes were used as controls. These oocytes were electroactivated to induce parthenogenesis and transferred to the oviducts of estrus-synchronized recipient gilts. After 5 to 7 days, the recipient uteri were flushed to collect embryos, and embryonic development (morula-blastocyst stage embryos/collected embryos) and survival (viable embryos/collected embryos) were determined. In total, 221 zona-punctured, 129 zona-slitted and 57 intact embryos were transplanted into four, two and two gilts, respectively. The efficiency of embryo recovery was similar in all groups (64.3 to 79.1%). However, the zona-penetrated and incised embryos exhibited unstable development and survival compared with the controls; development and survival of the control embryos were 94.7 and 87.7%, whereas those of the zona-punctured embryos were 69.0 and 47.9% (P<0.01) and those of the zona-slit embryos were 64.7 and 50.0% (P<0.01). Cells with large foci that appeared to be macrophage giant cells were observed at the surface or inside the degenerated zona-damaged embryos. These results indicate that the recipient's immune response to damage to the zona pellucida may impair embryonic development after transplantation to the oviduct. This may be one of the factors causing the reduced efficiency of live progeny production by SCNT.     

Effects of feeding l-carnitine to gilts through day 70 of gestation on litter traits and the expression of insulin-like growth factor system components and l-carnitine concentration in foetal tissues

We investigated the influence of supplemental l -carnitine on foetal blood metabolites, litter characteristics, l -carnitine concentration in skeletal muscle and insulin-like growth factor (IGF) axis components in foetal hepatic and skeletal muscle tissues at day 40, 55 and 70 of gestating gilts. A total of 59 gilts (body weight = 137.7 kg) received a constant feed allowance of 1.75 kg/day and a top-dress containing either 0 or 50 ppm of l -carnitine starting on the first day of breeding through the allotted gestation length. Foetuses from the gilts fed diets with l -carnitine tended to be heavier (p = 0.06) and the circulating IGF-II tended to be lower (p = 0.09) at day 70, compared with the foetuses from the control gilts. Insulin-like growth factor-I messenger RNA (mRNA) was lower (p = 0.05) in hepatic tissue in the foetuses collected from gilts fed l -carnitine. Free and total carnitine concentration increased (p < 0.05) in the skeletal muscle from the foetuses collected from gilts fed supplemental l -carnitine. This study showed that l -carnitine had beneficial effects on the average foetal weight at day 70 of gestation, associated with changes in the foetal IGF system.     

The Effect of Transport Stress on Plasma Levels of Catecholamines,Cortisol, Corticosteroid-Binding Globulin,Blood Cell Count,and Lymphocyte Proliferation in Pigs

The effect of transport stress on the plasma levels of catecholamines, Cortisol, and corticosteroid-binding globulin were studied in 6 gilts. To assess the effect on immune status, white blood cells were also counted and the cell-mediated immunity was estimated. The adrenaline level increased significantly during transport, from a basal mean level of 0.03 ng/ml to a plateau level of 0.11 to 0.12 ng/ml. The noradrenaline level fluctuated, but not constantly, during transport. The mean plasma Cortisol level before loading was approximately 40 nmol/1 and rose immediately after the start of transport to 70 nmol/1 (p< 0.05) and to 87 nmol/1 (p< 0.01) within 10 and 30 min, respectively. After unloading the Cortisol level rapidly decreased and a minimum level was seen 4 h after the transport, whereafter the diurnal rhythm was resumed. The plasma corticosteroid-binding globulin level increased nonsignificantly during the day of transport, from 25 nmol/1 to a level of 34 nmol/1, and it continued to increase until a plateau level was reached on the second day after transportation. The total white blood cell number increased significantly (from 13.7 to 15.5 × 10⁹ cells/1), the number of lymphocytes decreased significantly (from 8.4 to 7.0 × 10⁹ cells/1), and the number of polymorphonuclear neutrophils increased significantly (from 4.3 to 7.2 × 10⁹ cells/1) during transport. No significant variation in the proliferation response was seen in the whole blood cell cultures. The main results were the significant signs of simultaneous activity of both the adrenal cortex and the adrenal medulla during transport.     

Appearance of interferon-alpha in serum and signs of reduced immune function in pigs after transport and installation in a fattening farm

Pigs were transported from several breeding facilities at the age of 10-12 weeks and regrouped in a fattening farm, specialized in breeding pigs for subsequent slaughter. Blood samples were obtained from the animals just before transport and daily for 17 days after installation in the fattening farm. On each occasion a group of ten animals (170 animals in total) was sampled. The levels of interferon-alpha (IFN-alpha) in serum were measured as antiviral activity in a cytopathic effect inhibition assay. Beginning at day 4 after installation, a significant proportion of sera contained IFN-alpha, with the highest incidence of IFN-alpha positive animals (25%) and IFN-alpha titers on days 5-10. This indicates a high frequency of viral infections in the animals. The in vitro ability of peripheral blood mononuclear leukocytes (PBMCs) to produce IFN-alpha after stimulation by glutaraldehyde-fixed pseudorabies virus-infected PK15 cells and their proliferative response to the T-cell mitogen leukoagglutinin (LA) was also monitored. There was a significant, but moderate decrease in the ability of PBMCs to produce IFN-alpha during the observation period. In contrast, the response to the mitogen LA decreased markedly during the first 5 days, and thereafter remained at the same low level. The proliferative response to LA was significantly lower for PBMCs from serum of IFN-alpha-positive than from IFN-alpha-negative animals. These impaired PBMC responses could indicate a stress-induced immune depression, possibly contributing to the high incidence of viral infections.     

Carcass quality and technological and sensory meat quality of once-bred gilts in a seasonal outdoor rearing system

Seasonal application of once-bred gilts for piglet and meat production outdoors could be a worthwhile alternative rearing form to normal commercial production. Compared with growing/finishing pigs, payment for sow carcasses is considerably reduced because of an assumed decrease in meat quality and processing properties. The purpose of this study was to compare maiden and once-bred gilts for carcass quality, and technological and sensory meat quality. The control group of 14 gilts (LW*L and LW*D) was reared indoors and slaughtered unmated at an average live weight of 145 kg. In contrast, 38 once-bred gilts of the same breeds were initially reared like the maiden control, inseminated and then housed outdoors from one month before farrowing until slaughter. Carcass traits, technological meat quality (pH, internal and surface reflectance, water holding capacity, commercial processing yield (total yield) and laboratory processing yield (Napole yield), WB shear force and chemical composition of M. longissimus dorsi were measured. Sensory meat quality (taste panel) of oven-baked M. longissimus dorsi and cured and smoked M. semimembranosus et adductor was investigated. Carcass quality traits such as higher lean meat content and lower backfat thickness were preferable with the once-bred gilts. For technological meat quality characteristics, once-bred gilts had lower thawing loss, Napole yield, dry matter and higher total work of WB shear force and intramuscular fat, compared to maiden gilts. In general, sensory meat quality was comparable between the two groups. In processed meat only, once-bred gilts had higher juiciness and salinity and unfavourable increased stringiness, compared to maiden gilts. Thus, once-bred gilts produce valuable carcasses and are suitable for an outdoor seasonal rearing system.     

Assessment of reproduction and growth performance of offspring derived from somatic cell cloned pigs

Since cloned pig was successfully produced, a new opportunity for porcine breeding industry to conserve genetic resources has been opened. However, there has been no report to investigate whether both somatic cell nuclear transfer (SCNT) pigs and their offspring have the characteristics of the donor breed. In this study, we compared the reproductive and growth performance of American Large White boars cloned by SCNT with the donor boar, and analyzed the test parameters, including semen quality, re‐service rate, rate of parturition, and average daily gain. The results showed that these cloned boars and the donor boar had no significant differences in the tests (P > 0.05) and the growth performance of their offspring was similar to the naturally bred American Large White pigs. In summary, the reproductive and growth performance of cloned pigs are similar to the donor pig and within the normal range. This suggests that pigs cloned by SCNT have the potential to be used in reproduction and breeding.