Physicochemical determinants of pH in pectoralis major of three strains of laying hens housed in conventional and furnished cages.

1. Post-mortem decline in muscle pH has traditionally been attributed to glycogenolysis-induced lactate accumulation. However, muscle pH ([H+]) is controlled by complex physicochemical relationships encapsulated in the Stewart model of acid-base chemistry and is determined by three system-independent variables - strong ion difference ([SID]), total concentration of weak acids ([Atot]) and partial pressure of CO2 (PCO2). 2. This study investigated these system-independent variables in post-mortem pectoralis major muscles of Shaver White, Lohmann Lite and Lohmann Brown laying hens housed in conventional cages (CC) or furnished cages (FC) and evaluated the model by comparing calculated [H+] with previously measured [H+] values. 3. The model accounted for 99.7% of the variation in muscle [H+]. Differences in [SID] accounted for most or all of the variations in [H+] between strains. Greater PCO2 in FC was counteracted by greater sequestration of strong base cations. The results demonstrate the accuracy and utility of the Stewart model for investigating determinants of meat [H+]. 4. The housing differences identified in this study suggested that hens housed in FC have improved muscle function and overall health due to the increased opportunity for movement. These findings support past studies showing improved animal welfare for hens housed in FC compared to CC. Therefore, the Stewart model has been identified as an accurate method to assess changes in the muscle at a cellular level that affect meat quality that also detect differences in the welfare status of the research subjects.

Effect of housing environment on laying hen meat quality: Assessing Pectoralis major pH, colour and tenderness in three strains of 80-81 week-old layers housed in conventional and furnished cages.

1. Meat quality is affected by factors such as stress, genetic strain and activity and is determined in part by measures of pH, colour and tenderness. In conventional laying hen cages (CC), lack of physical space and inability to perform highly motivated behaviours leads to stress and inactivity. Furnished cages (FCs) permit expression of highly motivated behaviours, but typically house larger group sizes than CC, thereby contributing to social stress. The objective of this study was to evaluate the effects of CC and FC laying hen housing environments and strain differences on meat quality of 80-81-week-old birds. 2. Pectoralis major meat quality was assessed for two flocks of Shaver White (SH), Lohmann Lite (LL) and Lohmann Brown (LB) hens housed in either 5-hen CC or 40-hen FC. Between 80 and 81 weeks, muscle samples were collected from randomly selected hens and analysed for muscle pH, colour and shear force (SF) using established methods. 3. In both flocks, the combined treatment body weights (BWs) were higher for CC than FC hens and the combined strain BWs were higher for LB than LL and SH hens. Flock 1 LB had lower initial and ultimate pH than SH and LL, and greater pH decline than SH. Muscle redness (a*) was higher for CC SH than FC SH in both flocks. Muscle a* was higher for LL than SH and LB in Flock 1, and higher than SH in Flock 2. Housing differences in muscle SF were absent. In CC, SF was higher for SH than LL and LB in Flock 1, and higher than LB in Flock 2. 4. Lack of housing differences suggests that environmental stressors present in both housing systems similarly affected meat quality. Strain differences for muscle pH, a* and SF indicate increased stress experienced by SH and LL hens. The absence of Flock 2 strain differences is consistent with the cannibalism outbreak that occurred in this flock and most severely impacted LB hens.

Temporal candidate gene expression in the sow placenta and embryo during early gestation and effect of maternal Progenos supplementation on embryonic and placental development.

The present study characterised gene expression associated with embryonic muscle development and placental vascularisation during early gestation in the pig and examined effects of Progenos supplementation in early pregnancy. Tissues were collected from commercial multiparous sows (n = 48) from Days 16 to 49 of gestation. In the placenta, qPCR revealed that vascular endothelial growth factor (VEGFA) expression did not change from Day 17 to 49 of gestation; however, KDR receptor and angiopoietin-1 and -2 expression were differentially regulated, with periods of high expression corresponding to two critical phases of angiogenesis in the pig. In the embryo, the pattern of myogenesis-related gene expression was consistent with available literature. A commercially available nutritional supplement Progenos (20 g day⁻¹ L-arginine) added to the diet of sows from either Day 15 to 29 (P15-29; n = 33), Day 30 to 44 (n = 29) or from Day 15 to 44 (n = 76) of gestation tended to increase (P = 0.058) embryonic growth rate compared with non-supplemented controls (n = 79) and angiogenin expression was higher (P = 0.028) at Day 30 of gestation in placentae from sows on the P15-29 Progenos treatment. These results are consistent with proposed beneficial effects of l-arginine on early embryonic development and placental vascularisation.

Restricted feed intake in lactating primiparous sows. II. Effects on subsequent litter sex ratio and embryonic gene expression.

Expression of panels of candidate genes controlling myogenesis, angiogenesis and gender-specific imprinting of development were analysed in embryonic, placental and endometrial tissues recovered at Day 30 of gestation from a subset of primiparous sows that were either feed restricted (Restrict; n=17) or fed to appetite (Control; n=15) during the last week of the previous lactation. Embryos were also sex typed to investigate gender bias in response to treatments. Average embryonic weight was lower in the subset of Restrict compared with Control litters (1.38±0.07vs 1.59±0.08g, respectively) and the male:female sex ratio was higher (P<0.05) in embryos (litters) recovered from Restrict sows. Treatment affected (P≤0.05) the expression of embryonic and placental genes involved in insulin-like growth factor (IGF) 2 signalling, including IGF2, INSR and IGF2R. Embryonic expression of ESR1 was also affected by treatment (P<0.03) and sex×treatment interactions were observed for the expression of embryonic ESR1 (P<0.05) and placental ANGPT2 (P<0.03). At the molecular level, these results support the suggestion that changes in placental function are not the primary mechanism mediating detrimental effects of previous sow catabolism on early embryonic development in the feed-restricted lactational sow model. However, perturbations in the IGF2 system are implicated as mediators of these effects.

Biological markers of boar fertility.

The semen evaluation techniques used in most commercial artificial insemination centers, which includes sperm motility and morphology measurements, provides a very conservative estimate of the relative fertility of individual boars. As well, differences in relative boar fertility are masked by the widespread use of pooled semen for commercial artificial insemination (AI) in many countries. Furthermore, the relatively high sperm numbers used in commercial AI practice usually compensate for reduced fertility, as can be seen in some boars when lower numbers of sperm are used for AI. The increased efficiency of pork production should involve enhanced use of boars with strong reproductive efficiency and the highest genetic merit for important production traits. Given that the current measures of semen quality are not always indicative of fertility and reproductive performance in boars, accurate and predictive genetic and protein markers are still needed. Recently, significant efforts have been made to identify reliable markers that allow for the identification and exclusion of sires with reduced reproductive efficiency. This paper reviews the current status of proteomic and genomic markers of fertility in boars in relation to other livestock species.

Cattle production practices and the incidence of dark cutting beef.

The effects of cattle sex, production system, growth promotant use, slaughter season, carcass phenotype, and pre-slaughter cattle management on the incidence of beef carcasses grading Canada B4 (dark cutting) were investigated using two data sets (A, n = 2009, and B, n = 86,408) containing data from cattle that produced Canada Prime, AAA, AA, A, and B4 carcasses. The probability of producing a Canada B4 carcass was greater (P < .0001) for heifers than steers in both data sets, with the likelihood of dark cutting decreasing with increased carcass weight in heifers in data set B. The incidence of dark cutting was increased (P < .0001) in Winter-born calf-fed (WC) and Fall-born calf-fed (FC) heifers. Production system and phenotype appear to interact to influence the incidence of dark cutting.

Uterine crowding in the sow affects litter sex ratio, placental development and embryonic myogenin expression in early gestation.

Uterine crowding in the pig results in intrauterine growth restriction (IUGR), and permanently affects fetal muscle fibre development, representing production losses for the commercial pig herd. The present study sought to understand how different levels of uterine crowding in sows affects muscle fibre development in the early embryo at the time of muscle fibre differentiation and proliferation. Sows either underwent surgical, unilateral oviduct ligation (LIG; n = 10) to reduce the number of embryos in the uterus, or remained as intact, relatively-crowded controls (CTR; n = 10). Embryos and placentae were collected at Day 30 of gestation, and myogenic regulatory factor (MRF) transcript abundance was determined using real-time PCR for both myogenin (MYOG) and myoblast differentiation 1 (MYOD1). Unilateral tubal ligation resulted in lower numbers of embryos in utero, higher placental weights and a higher male : female sex ratio (P < 0.05). Relative MYOD1 expression was not different, but MYOG expression was higher (P < 0.05) in the LIG group embryos; predominantly due to effects on the male embryos. Relatively modest uterine crowding therefore affects MRF expression, even at very early stages of embryonic development, and could contribute to reported differences in fetal muscle fibre development, birthweight and thus post-natal growth performance in swine.

Identifying useable semen.

The "predictors of useable semen" used in most commercial AI centers provide a very conservative estimate of the relative fertility of individual boars. Furthermore, the relatively high sperm numbers used in commercial AI practice (usually >3 x10(9) total sperm per dose of extended semen) usually compensate for reduced fertility, as can be demonstrated in some boars when lower numbers of sperm are used for AI. Differences in relative boar fertility are also masked by the widespread use of pooled semen for commercial AI in many countries. However, the need to continually improve the efficiency of pork production, suggests that commercial AI practice should involve increased use of boars with the highest genetic merit for important production traits. Necessarily, this must be linked to the use of fewer sperm per AI dose, fewer inseminations per sow bred, and hence more sows bred by these superior sires. In turn, this requires improved techniques for evaluating semen characteristics directly related to the fertilization process, such as IVM-IVF assays, analysis of seminal plasma protein markers, more discriminatory tests of sperm motility and morphology, with the goal of identifying high-index boars whose fertility is sustained when low numbers of sperm are used for AI. This paper reviews the current status of laboratory-based boar semen evaluation techniques that meet these criteria.

Ontogeny of metabolic effects on embryonic development in lactating and weaned primiparous sows.

Using an established experimental paradigm, feed restriction during the last week of lactation in primiparous sows reduces embryonic growth and development and produces female-specific embryonic mortality by Day 30 of gestation. Because this gender-specific loss of embryos at Day 30 was associated with changes in the variation of markers of epigenetic imprinting, the present study sought to establish the ontogeny of such epigenetic affects. Leucocyte DNA of restrict-fed sows exhibited decreased global methylation during the last week of lactation and during the return to oestrus (P < 0.05), but no associated changes in plasma folate and vitamin B(12). Furthermore, no changes in methylation of blastocyst DNA, embryonic sex ratios or development were evident at Day 6 of gestation that would characterise the underlying defects that reduced female embryo survival by Day 30. However, regardless of treatment, embryo recovery rates and synchrony in embryonic development were associated with the stage of development of the recovered embryos (r = 0.68; P < 0.001). The subset of sows classified as bearing litters with superior embryonic development had lower net energy balance over lactation (P < 0.01) and higher ovulation rates (P < 0.005) compared with sows classified as having poorer embryonic development. Collectively, these data suggest that a subset of litters within restrict-fed sows will be most sensitive to the latent epigenetic mechanisms that ultimately trigger gender-specific loss of embryos by Day 30 of gestation, but that these selective mechanisms are not evident by Day 6 of gestation.

Altered epigenetic variance in surviving litters from nutritionally restricted lactating primiparous sows.

Feed restriction of primiparous sows during the last week of lactation has been shown to decrease embryonic growth and female embryo survival to Day 30 of gestation. This study sought to determine whether global DNA methylation and epigenetic gene expression of the candidate genes Igf2, Igf2r, and Xist were associated with these treatment effects. Given that these epigenetic traits are expected to be important for embryo viability, changes in variance for these traits at Day 30 were predicted to be reflected in the loss of abnormal embryos at this time. Consistent with this prediction, variance in DNA methylation was reduced (P < 0.001) in Restrict male embryo, and there was a tendency for reduced variance (P < 0.06) in Restrict female embryos. Variation in DNA methylation tended to be correlated (R = 0.42, P < 0.1) with the difference in variance of embryo weights between treatments (P < 0.01), suggesting a relationship between epigenetic changes and embryonic development. Variance in Igf2r expression tended to decrease (P < 0.07) in Restrict female embryos while variance in Xist expression tended to decrease in Restrict male embryos (P < 0.08), suggesting that maternally inherited epigenetic defects may cause female embryonic loss and reduced growth before Day 30 of gestation.

Macroenvironment effects on oocytes and embryos in swine.

As in other domestic mammals, the interaction between genotype and environment in swine has profound effects on the ultimate phenotype of the individual born. Interactions within the litter in utero add an additional level of complexity in a litter-bearing species like the pig. Nutritional manipulations during the preovulatory period affect the maturity of the follicle and enclosed oocyte, and the metabolic and endocrine mechanisms potentially mediating these effects have been described. Extensive research on lactational catabolism in the first parity sow has established an association between the development of immature follicles and oocytes, and the reduced fertility of these sows when bred at the first postweaning estrus. This negative impact of lactational catabolism appears to be exaggerated in contemporary dam-lines by a minimal delay between weaning and first estrus, further limiting the maturity of the follicle and oocyte at the time of ovulation. Metabolic programming may induce gender-specific loss of embryos by Day 30 and affects embryonic development directly, without significant effects on placental size. In contrast, inadvertent crowding of embryos in utero, particularly evident in a sub-population of mature sows with high ovulation rates and moderate to high embryonic survival to Day 30, significantly limits placental development of crowded litters. However, even at Day 30, moderate crowding in utero also appears to affect myogenesis in the embryo in a gender-specific manner. In the absence of compensatory placental growth after Day 30, classic measures of IUGR are evident in surviving fetuses at Day 90 and at term.

Understanding the quality of typical and atypical dark cutting beef from heifers and steers.

Dark cutting beef with pH <6.0 may have glucidic potential approaching that of normal beef but has increased toughness that may also be influenced by cattle sex and carcass characteristics. Beef longissimus thoracis (LT) from normal (Canada AA; n=24), and typical (TB4; pH>5.9, n=20) and atypical (AB4; pH<5.9, n=20) dark cutting carcasses were analyzed to investigate relationships between beef quality, pH, glucidic potential and carcass characteristics. Results indicated that reduced lactate and glucidic potential were accompanied by increased pH and reduced L*, a* and b* values. Mean glucidic potential was lowest (P<0.0001) for TB4 whereas glucidic potentials for heifers and steers AB4 LT were sufficient to attain normal pH, substantiating the existence of atypical dark cutting. Warner-Bratzler shear force of AB4 remained higher (P<0.05) than that of Canada AA LT confirming AB4 as the toughest beef irrespective of sex and carcass characteristics.

Nutritional restriction in lactating primiparous sows selectively affects female embryo survival and overall litter development.

This study explored the possibility of sex-specific effects on embryonic survival in primiparous sows subjected to restricted feed intake during the last week of lactation and bred after weaning (Restrict; n = 16), compared with control sows fed close to ad libitum feed intakes (Control; n = 17). Restrict sows were in a substantial negative net energy balance at weaning, and lost 13% of estimated protein and 17% of fat mass during lactation, yet the weaning-to-oestrous interval and ovulation rate were not different between treatments. However, embryonic survival at Day 30 of gestation was lower (P < 0.05) in Restrict than Control sows, and selectively reduced the proportion of female embryos surviving (P < 0.01). A decrease in weight and crown-rump length of surviving female (P < 0.05) and male (P < 0.05) embryos was seen in Restrict litters. The mechanisms mediating this sex-specific effect on embryonic loss in feed-restricted sows are unclear. The data presented here indicate that feed-restriction during the last week of lactation in primiparous sows causes a selective decrease in survival of female embryos and limits the growth of all surviving embryos.

The predictive value of routine semen evaluation and IVF technology for determining relative boar fertility.

Practical techniques for assessing semen quality in order to predict male fertility are still needed. The principal objective of this experiment was to evaluate routine laboratory evaluation and in vitro fertilization (IVF) techniques as predictors of relative boar fertility using a low-dose AI protocol. Nine boars were evaluated during a 6.5+/-1 mo period, beginning at 29-32 wk of age. Ejaculates were evaluated for motility, morphology and concentration, diluted to 1.5 billion sperm in 50 mL extender, and used to breed 50+/-5 gilts over the same period. On nine occasions, a specific aliquot of the ejaculate's first sperm-rich fraction was evaluated using IVF procedures. Boars differed (P<0.001) consistently for pregnancy rate (from 73 to 98%), farrowing rate (71-98%) and total born (8.8-12.0). Routine semen evaluation and IVF parameters that presented significant differences between boars, but no differences in time and no boar by time interaction, were used to correlate in vivo fertility. A multiple regression model based on routine semen evaluation parameters accounted for up to 27 and 22% of the variation of fertility index and total piglets born, respectively, whereas male pronuclear formation rate was the IVF variable that accounted for 17 and 12% of the variation in farrowing rate and fertility index, respectively. Collectively, we inferred that the use of low sperm numbers for AI, determination of pregnancy rate at Day 30, motility of extended semen after 7 and 10d, and specific IVF parameters may be useful for identifying relatively infertile boars that are not currently excluded from use in existing commercial boar studs.

ME491 melanoma-associated glycoprotein family: antigenic identity of ME491, NKI/C-3, neuroglandular antigen (NGA), and CD63 proteins.

BACKGROUND: Numerous monoclonal antibodies (MAbs) have been produced to antigens found in human melanomas. Three of the best characterized melanoma antigens include the melanoma-associated glycoproteins (MAGs) defined by two reagent families--the ME491 family (including ME491, 8-1H, and 8-2A) and the NKI/C-3 family (including NKI/C-3 and NKI/black-13)--as well as the neuroglandular antigen (NGA) defined by MAbs LS59, LS62, and LS140. These three antigens have significant similarities in tissue distribution, biosynthesis, and structure. The ME491 MAG has been cloned, mapped, and sequenced. Numerous non-melanoma-associated proteins (Sm23, CO-029, R2, TAPA-1, CD9, CD37, CD53, and CD63) have recently been shown to have significant homology to this sequence. PURPOSE: We conducted this study to investigate the similarity between the two MAG antigens and NGA. METHODS: Several reagents defining the three different melanoma antigens were compared, using competition immunoprecipitation, immunoassay, and inhibition radioimmunoassay techniques. RESULTS: Immunoassay experiments show that MAbs defining the three melanoma antigens bind to affinity-purified ME491 antigen and inhibit each other from binding in an inhibition radioimmunoassay. Competition immunoprecipitation experiments demonstrate that the ME491 and NKI/C-3 antibodies bind to NGA. Rabbit anti-ME491 idiotype serum recognizes determinants shared by NKI/C-3 and the anti-NGA MAbs. A competition immunoprecipitation experiment also confirms the identity of CD63, as defined by MAb RUU-SP 2.28, with the three melanoma antigens. CONCLUSION: These data indicate that the MAGs defined by ME491 and NKI/C-3 as well as the anti-NGA antibodies are epitopes of the same molecule, which is identical to CD63 by both immunochemical and molecular genetic investigations. IMPLICATIONS: Our results indicate that the data obtained in studies of these three melanoma antigens may be pooled, and we propose that the molecule recognized by these reagents be classified as CD63.

Biosynthesis, glycosylation and intracellular processing of the neuroglandular antigen, a human melanoma-associated antigen.

Neuroglandular antigen (NGA) was identified as a human melanoma-associated antigen by a panel of murine monoclonal antibodies of both IgG2a (LS62, LS76, LS159) and IgG1 (LS113, LS140, LS152) subclasses, developed in this laboratory (L. Sikora, A. Pinto, D. Demetrick, W. Dixon, S. Urbanski, and L. M. Jerry, Int. J. Cancer, 39: 138-145, 1987). Monoclonal antibody LS62 was used to immunoprecipitate NGA from radiolabeled cultured melanoma cells, and it behaved as a heterogeneous glycoprotein "smear" on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis (Mr 29,000-70,000). Radioactive pulse-chase time course experiments using human melanoma cells cultured in the presence or absence of inhibitors of protein glycosylation showed that the antigen consisted of a core protein with a molecular weight of 22,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This molecule was modified by the addition of at least three N-linked oligosaccharide side chains (as revealed by limited N-glycanase digestion) to give a precursor form with a molecular weight of approximately 34,000. Subsequent processing steps yielded a heterogeneous family of glycoproteins with varying amounts of covalently attached carbohydrate. Much of this heterogeneity in both molecular weight and pI (as revealed by two-dimensional electrophoresis) could be removed by treatment of the antigen with neuraminidase, suggesting heavy sialylation of the glycoprotein. NGA could be detected on the surface of melanoma cells by fluorescence-activated cell sorter analysis, surface radioiodination, and, as previously shown, immunoperoxidase staining. However, there was a larger intracellular pool of the molecule and the antigen was rapidly released into the culture supernatant. The function of NGA remains unknown but its elevated expression in transformed melanocytes have prompted this characterization to understand its biochemical nature and relation to other melanoma-associated antigens.

Relationship between phenotype, carcass characteristics and the incidence of dark cutting in heifers.

Previous research has suggested that cattle predisposed to dark cutting can be identified from live animal or carcass characteristics. This hypothesis was tested using production and phenotype data from an existing data set collected from heifers (n=467) on study at three farms. Carcasses in the data set graded Canada AAA (n=136), AA (n=296), A (n=14), and B4 (dark cutting, n=21). Farm was identified as significant (P=0.0268) by CATMOD analysis and slaughter weight and carcass weight accounted for the variation in dark cutting frequency across the farms. Analysis of variance indicated that dark cutting heifers had reduced weight at weaning (P<0.0001) and at slaughter (P<0.0001), and produced reduced weight carcasses (P<0.0001). Results of logistic regression indicated that the probability of dark cutting was decreased in heifers slaughtered at live weight greater than 550kg and in carcasses weighing greater than 325kg.

Effects of dietary enrichment with a marine oil-based n-3 LCPUFA supplement in sows with predicted birth weight phenotypes on growth performance and carcass quality of offspring.

Effects of a marine oil-based n-3 LCPUFA supplement (mLCPUFA) fed from weaning until the end of the next lactation to sows with a predicted low litter birth weight (LBW) phenotype on growth performance and carcass quality of litters born to these sows were studied, based on the hypothesis that LBW litters would benefit most from mLCPUFA supplementation. Sows were allocated to be fed either standard corn/soybean meal-based gestation and lactation diets (CON), or the same diets enriched with 0.5% of the mLCPUFA supplement at the expense of corn. The growth performance from birth until slaughter of the litters with the lowest average birth weight in each treatment (n=24 per treatment) is reported in this paper. At weaning, each litter was split between two nursery pens with three to six pigs per pen. At the end of the 5-week nursery period, two barrows and two gilts from each litter that had individual birth weights closest to their litter average birth weight, were moved to experimental grow-finish pens (barn A), where they were housed as two pigs per pen, sorted by sex within litter. Remaining pigs in each litter were moved to another grow-finish barn (barn B) and kept in mixed-sex pens of up to 10 littermates. After 8 weeks, one of the two pigs in each pen in barn A was relocated to the pens holding their respective littermates in barn B. The remaining barrows and gilts were individually housed in the pens in barn A until slaughter. Maternal mLCPUFA supplementation increased docosahexaenoic acid (DHA) concentration in the brain, liver and Semitendinosus muscle of stillborn pigs (P<0.01), did not affect eicosapentaenoic acid and DHA concentrations in sow serum at the end of lactation, and did not affect average daily gain, average daily feed intake or feed utilization efficiency of the offspring. BW was higher (P<0.01) in the second half of the grow-finish phase in pigs from mLCPUFA sows compared with controls in barn A, where space and competition for feed was minimal, but not barn B. Carcass quality was not affected by treatment for pigs from barn A, but maternal mLCPUFA supplementation negatively affected carcass quality in pigs from barn B. Collectively, these results suggest that nutritional supplementation of sows can have lasting effects on litter development, but that feeding mLCPUFA to sows during gestation and lactation was not effective in improving growth rates or carcass quality of LBW litters.

Effects of dietary enrichment with a marine oil-based n-3 LCPUFA supplement in sows with predicted birth weight phenotypes on birth litter quality and growth performance to weaning.

The effects of a marine oil-based n-3 long-chain polyunsaturated fatty acid (mLCPUFA) supplement fed to the sow from weaning, through the rebreeding period, during gestation and until end of lactation on litter characteristics from birth until weaning were studied in sows with known litter birth weight phenotypes. It was hypothesized that low birth weight (LBW) litters would benefit more from mLCPUFA supplementation than high birth weight litters. A total of 163 sows (mean parity=4.9 ± 0.9) were rebred after weaning. Sows were pair-matched by parity and litter average birth weight of the previous three litters. Within pairs, sows were allocated to be fed either standard corn/soyabean meal-based gestation and lactation diets (CON), or the same diets enriched with 0.5% of the mLCPUFA supplement at the expense of corn. Each litter between 9 and 16 total pigs born was classified as LBW or medium/high average birth weight (MHBW) litter and there was a significant correlation (P<0.001) between litter average birth weight of the current and previous litters within sows (r=0.49). Sow serum was harvested at day 113 of gestation for determination of immunoglobulin G (IgG) concentrations. The number of pigs born total and alive were lower (P=0.01) in mLCPUFA than CON sows, whereas the number of stillborn and mummified pigs were similar between treatments. Number of stillborns (trend) and mummies (P<0.01) were higher in LBW than MHBW litters. Tissue weights and brain : tissue weight ratios were similar between treatments, but LBW litters had decreased tissue weights and increased brain : tissue weight ratios compared with MHBW litters. Placental weight was lower (P=0.01) in LBW than MHBW litters, but was not different between treatments. Average and total litter weight at day 1 was similar between treatments. mLCPUFA increased weaning weight (P=0.08) and average daily gain (P<0.05) in MHBW litters, but not in LBW litters. Pre-weaning mortality was similar between treatments, but was higher (P<0.01) in LBW than MHBW litters. IgG concentration in sow serum was similar between treatments and litter birth weight categories. In conclusion, litter birth weight phenotype was repeatable within sows and LBW litters showed the benchmarks of intra-uterine growth retardation (lower placental weight and brain sparing effects). As maternal mLCPUFA supplementation decreased litter size overall, only improved litter growth rate until weaning in MHBW litters, and did not affect pre-weaning mortality, maternal mLCPUFA supplementation was not an effective strategy in our study for mitigating negative effects of a LBW litter phenotype.

Characterization of a human melanosome-associated antigen recognized by monoclonal antibody, HMSA-2.

This study elucidates the nature of antigens recognized by monoclonal antibody (MoAb) HMSA-2, which was developed against human melanosome-associated antigen (HMSA) of malignant melanoma (Maeda and Jimbow, Cancer 59:415-423, 1987). Through flow cytometry analyses, indirect immunoprecipitation of antigen biosynthetically labeled with 35S-methionine, enzyme-linked immunosorbent assays and immunoelectron microscopy, we found that a) the antigens recognized by MoAb HMSA-2 were melanosomal matrix glycoproteins; b) these antigens were expressed mainly in the cytoplasm, although they could also be detected on the cell surface; c) the cytoplasmic expression of MoAb HMSA-2 was cell-cycle dependent; d) large amounts of these antigens were released into culture supernatants; e) MoAb HMSA-2 immunoprecipitated two major glycoproteins with molecular weights of 94 and 53 kDa from culture supernatants, and f) both components have complex N-linked oligosaccharide chains with sialic acid, suggesting that these melanosomal proteins are derived from the trans-cisternae of the Golgi. These human melanosome-associated antigens may prove useful not only for studying the immunobiology of melanogenesis, but also for the immunodiagnosis of melanocytic disorders.