Heritability of udder morphology and colostrum quality traits in swine.

The heritability of udder quality traits, defined as morphology and colostrum IgG concentration at farrowing, was estimated together with the genetic and phenotypic correlations of these traits with other production and reproduction criteria. Udder morphology traits were recorded in 988 Meidam sows and colostrum samples were collected from 528 sows. Teat length, teat diameter (DIA), interteat distance within the same row (SAMER), and teat distance from the abdominal midline (AML) were recorded to the nearest millimeter. For each sow, a record was also made of udder development score (DEV), the proportion of teats oriented perpendicular to the udder, and the proportion of nonfunctional teats. Colostrum IgG concentration was estimated with a Brix refractometer. Heritability of udder morphology traits varied from high ( = 0.46 for teat length and = 0.56 for DIA) to moderate ( = 0.37 for SAMER, = 0.22 for AML, = 0.25 for DEV, = 0.3 for the proportion of nonfunctional teats, = 0.1 for the proportion of teats oriented perpendicular to the udder, and = 0.35 for colostrum IgG concentration). The SAMER was negatively genetically correlated with the number of stillborns (genetic correlation [] = -0.48) and positively genetically correlated with the number of piglets born alive ( = 0.69), with the opposite for the trait AML ( = -0.40 for number of piglets born alive and = 0.40 for stillborns). The highest genetic correlation with productive traits was estimated between AML and ADG during rearing ( = 0.42), although this had a negative phenotypic correlation (; -0.11). Teat length was also moderately correlated with ADG ( = 0.27). Backfat thickness at 100 kg was positively correlated with DIA and the total number of teats present in both rows ( = 0.28 and = 0.36, respectively) and negatively correlated only with DEV ( = -0.22). The same results were found for the phenotypic correlation between backfat thickness at end of test and the total number of teats present in both rows ( = 0.03). Udder quality traits can be included in the breeding goal and appropriately weighted with other important traits in the breeding objectives to enhance maternal performance.

Sources of variation in udder morphology of sows.

This experiment investigated the sources of variation in sow udder morphology. A cross-sectional study of 218 sows (109 Large White × Landrace [LWL] and 109 Meidam [Large White × Meishan {MDM}]) of different parities was conducted using a combination of scores and metric measurements. For each teat, 4 measures were taken: the inter-teat distance within the same row (SAMER), the distance from the base of the teat in the upper row to the abdominal midline (AML), the length of the teat from the tip to the base (LEN), and the diameter at the tip of the teat (DIA). Scores were adopted to define teat orientation (0 = teat not orientated perpendicular to the mammary gland and 1 = teat orientated perpendicular to the mammary gland), teat functionality (1 = milk channel not working, including teats that were blind, inverted, or very damaged; 2 = reduced availability of colostrum; and 3 = perfectly functional), and udder development (1 = not developed to 3 = fully developed). A longitudinal study on a subset of sows ( = 70) investigated how udder morphology changed in consecutive parities. Meidam had shorter teats, which were closer to the abdominal midline than LWL (LEN, < 0.001; AML, < 0.001). In both studies, first and second parity sows had smaller teats (LEN, < 0.001; DIA, < 0.001) than older multiparous sows. Teat position had a significant ( < 0.001) effect on SAMER in both breeds, with less distance between middle teat pairs. The distance from the base of the teats in the upper row to the abdominal midline was shorter in the anterior and posterior teats compared with the middle teat pairs. Teat length was greater in the anterior and middle teats than in the posterior ones, whereas DIA was greater in the middle teats. Teat pair position was associated with teat orientation ( < 0.001) and teat functionality ( < 0.001). Parity was associated with udder development ( < 0.001). Breed, parity, and teat pair position were all significant sources of variation in udder morphology in sows.

Identification of risk factors associated with poor lifetime growth performance in pigs.

During the production period from birth to slaughter there are some pigs that grow markedly slower, despite conditions that seem to support the growth of their contemporaries. This reduction in growth inevitably leads to weight variation within a group, causes difficulties with management, and results in system inefficiencies. By understanding the factors that contribute to poor growth, the performance of these slow growing pigs might be improved, thereby decreasing the overall variability at slaughter. The aim of this paper was to analyze the factors associated with poor growth performance in pigs from birth to slaughter, determine the effect of piglet birth weight (BiW) and weaning weight (WW) on lifetime growth, and investigate the capacity of small piglets to compensate for any BW deficit. Two industry databases, with individual data for approximately 40,000 and 90,000 pigs, respectively, and containing BW profiles and relevant variables, were analyzed. Body weight at birth, weaning, intermediate, and finishing stages were available as well as sex, month of birth, litter size information (number born alive and total born including still born), sow parity number, and length of gestation. Absolute and relative growth rates, based on adjusted BW for age, were calculated for each time interval and 3 types of analysis were performed: a logistic regression, a continuous linear plateau model, and a weight category analysis. For both datasets poor absolute and relative growth from birth to final BW was associated with low BiW (P < 0.001), low WW (P < 0.001), sex (P < 0.001), breed code (P < 0.001), and month of birth (P < 0.001). The linear plateau model suggested that the relationship between BiW and lifetime growth was not linear beyond 1.91 (database 1) or 1.84 (database 2) kg; the same applied to the relationship between WW at 21 d and final BW (FW) growth, which was not linear beyond 7.53 kg. Finally, the weight category analysis revealed that piglets with the lightest BiW were able to exhibit compensatory growth from BiW to FW with 74 (database 1) and 82% (database 2) moving at least 1 BW category. It is concluded that growth performance to slaughter is not solely reliant on pig BiW, with WW also playing a critical role. Additionally, piglets with BiW below the average are capable of some degree of compensatory growth; this provides the opportunity for managing them so as to improve their lifetime growth.

Unexpected new roles for heparanase in Type 1 diabetes and immune gene regulation.

Heparanase (Hpse) is an endo-ß-d-glucuronidase that degrades the glycosaminoglycan heparan sulfate (HS) in basement membranes (BMs) to facilitate leukocyte migration into tissues. Heparanase activity also releases HS-bound growth factors from the extracellular matrix (ECM), a function that aids wound healing and angiogenesis. In disease states, the degradation of HS in BMs by heparanase is well recognized as an invasive property of metastatic cancer cells. Recent studies by our group, however, have identified unexpected new roles for heparanase and HS. First, we discovered that in Type 1 diabetes (T1D) (i) HS in the pancreatic islet BM acts as a barrier to invading cells and (ii) high levels of HS within the insulin-producing islet beta cells themselves are critical for beta cell survival, protecting the cells from free radical-mediated damage. Furthermore, catalytically active heparanase produced by autoreactive T cells and other insulitis mononuclear cells was shown to degrade intra-islet HS, increasing the susceptibility of islet beta cells to free radical damage and death. This totally novel molecular explanation for the onset of T1D diabetes opens up new therapeutic approaches for preventing disease progression. Indeed, administration of the heparanase inhibitor, PI-88, dramatically reduced T1D incidence in diabetes-prone NOD mice, preserved islet beta cell HS and reduced islet inflammation. Second, in parallel studies it has been shown that heparanase and HS can be transported to the nucleus of cells where they impact directly or indirectly on gene transcription. Based on ChIP-on-chip studies heparanase was found to interact with the promoters and transcribed regions of several hundred genes and micro-RNAs in activated Jurkat T cells and up-regulate transcription, with many of the target genes/micro-RNAs being involved in T cell differentiation. At the molecular level, nuclear heparanase appears to regulate histone 3 lysine 4 (H3K4) methylation by influencing the recruitment of demethylases to transcriptionally active genes. These studies have unveiled new functions for heparanase produced by T lymphocytes, with the enzyme mediating unexpected intracellular effects on T cell differentiation and insulin-producing beta cell survival in T cell-dependent autoimmune T1D.

The cholecystokinin type A receptor g.179A>G polymorphism affects feeding rate.

A polymorphism within the 5' untranslated region of the cholecystokinin type A receptor (CCKAR) gene has been shown to affect feed intake and growth in commercial pig lines. To further investigate the phenotype of animals carrying alternative alleles at this polymorphism, we genotyped animals from a distinct segregating commercial line and an experimental cross F(2) population, both with electronically recorded feeding pattern data. The data indicate that the daily feed intake increasing effect of the DQ496228:g.179G allele is mediated through a faster rate of feed intake, without evidence for an effect on other feeding behaviour traits.

Increasing breastfeeding rates to reduce infant illness at the community level.

OBJECTIVE: Although breastfeeding is associated with lower rates of a variety of infant illnesses, skeptics have suggested that much of the association is attributable to confounding, even after appropriate statistical adjustment. This article utilizes a novel design to investigate changes in infant illness at the community level after a successful breastfeeding promotion program. METHODS: In this population-based cohort study, the medical records of all infants born in one Navajo community the year before a breastfeeding promotion program (n = 977) and the year during the intervention (n = 858) were reviewed. Outcomes assessed include changes after the intervention in: proportion breastfeeding and/or breastfeeding exclusively; incidence of common infant illnesses in the first year of life; and feeding-group specific incidence of illness. RESULTS: The proportion of women breastfeeding exclusively for any period of time increased from 16.4% to 54.6% after the intervention. The percent of children having pneumonia and gastroenteritis declined 32. 2% and 14.6%, respectively, after the intervention. Feeding-group specific rates of these illnesses were unchanged, indicating that the decline observed was attributable to the increased proportion of infants breastfeeding. In contrast, rates of croup and bronchiolitis increased after the intervention among those fed formula from birth, suggesting a viral epidemic which was limited to those never exclusively breastfed. Finally, sepsis declined in both formula-fed and breastfed infants after the intervention, suggesting that other factors affected this illness outcome after the intervention. CONCLUSIONS: Increasing the proportion of exclusively breastfed infants seems to be an effective means of reducing infant illness at the community level. The experimental design suggests that the increased incidence of illness among minimally breastfed infants is causally related to lack of breast milk, rather than being attributable to confounding.

Using cultural knowledge in health promotion: breastfeeding among the Navajo.

Although many attempts have been made to promote breastfeeding in a variety of contexts, few programs have explicitly incorporated cultural beliefs in these efforts. This article describes a breastfeeding promotion program conducted on the Navajo reservation. This program was designed to be culturally appropriate. Background information regarding beliefs and factors affecting infant feeding practices in this setting is provided, followed by a description of the intervention. The intervention, which incorporated both social marketing and community participation techniques, consisted of three components: an intervention in the health care system, a community intervention, and an individual intervention. Based on medical records review of feeding practices of all the infants born the year before (n = 988) and the year after (n = 870) the intervention, the program was extremely successful. This combination of techniques, including qualitative and quantitative research into local definitions of the problem, collaboration with local institutions and individuals, reinforcement of traditional understandings about infant feeding, and institutional change in the health care system, is an effective way of facilitating behavioral change.

Genotype analysis of human blood isolates of Campylobacter jejuni in England and Wales.

Genomic profiles were obtained for 76 strains of Campylobacter jejuni isolated from bacteraemic patients in England and Wales over the period 1981-94. Genotyping was performed by restriction fragment length polymorphism (RFLP) analysis using a random cloned DNA probe, and by ribotyping with a PCR-generated C. jejuni 16S ribosomal DNA probe. Phenotypic characterization was achieved by heat-stable (HS) and heat-labile (HL) serogrouping, and Preston phagetyping and biotyping. The blood isolates were genomically heterogenous, with 24 RFLP/16S profiles occurring within the 76 strains. Forty-four percent of isolates belonged to one of three RFLP/16S genotypes, reflecting the patterns seen in faecal isolates, except that genotypes usually associated with the HS 1 antigen were uncommon. The two most prevalent genotypes, characteristic of HS 2 and HS 4 strains, showed similarity by cluster analysis. Further evidence was seen of associations between phenotypic and genotypic characters within some HS serogroups. Chromosomal profiling by RFLP analysis does not indicate that particular genotypes have a predisposition to invade the bloodstream.

Campylobacter bacteraemia in England and Wales, 1981-91.

Routine surveillance of infection in England and Wales detected 394 cases of campylobacter bacteraemia in 11 years. This represented an average incidence of 1.5 per 1000 intestinal campylobacter infections, with a range of 0.3/1000 in children aged 1-4 years to 5.9/1000 in patients aged 65 years or more. Definitive identification of 257 isolates showed that 89% were Campylobacter jejuni or C. coli; other species were C. fetus (8.6%), C. lari (0.8%), C. upsaliensis (0.8%), Helicobacter (Campylobacter) fennelliae (0.8%), and Helicobacter (Campylobacter) cinaedi (0.4%). Most (71%) of the C. jejuni/C. coli bacteraemias were in patients with acute enteritis. Of the patients with C. fetus bacteraemia only 27% had diarrhoea; they were older than patients with C. jejuni or C. coli bacteraemia (54.1 v. 45.9 years) and proportionally more of them were male (M:F ratio 2.7:1 v. 1.9:1); 41% had endovascular pathology or cellulitis. There was a higher proportion of C. jejuni serogroup O 4 (Penner) and O 18 strains among blood than faecal isolates, which suggests that they were unusually serum resistant and/or invasive.

Campylobacter jejuni adapts to aerobic metabolism in the environment.

Campylobacter jejuni, when left on blood agar for prolonged periods, was found to survive better in air than under micro-aerobic conditions. After a period of 2-3 days in air, all strains of C. jejuni examined grew freely in air on subculture, and could be further subcultured apparently indefinitely in air. This adaptation to aerobic metabolism was accompanied by a change in colony morphology and some changes in outer-membrane protein patterns, but no change in serotyping reactions. The ability to colonise mice was unaltered as was the helical morphology of growing cells. The important survival phase of C. jejuni, when outside the animal gut, involves not only a change to coccal morphology but also fundamental changes in the metabolism of the organism. These changes are likely to be relevant to techniques required for culturing C. jejuni from foods and environmental sources.

Recovery of viable but non-culturable Campylobacter jejuni.

Suspensions of Campylobacter jejuni became non-culturable after storage in sterilized pond water at 4 degrees C for periods between 18 and 28 d, depending on the strain. Suspensions of four strains of C. jejuni that had been in water for 6 weeks, and shown to be non-culturable, were fed to suckling mice. Colonization of mice was established with two of the strains and failed with the other two strains. Examination of these suspensions under the electron microscope showed some cocci having the appearance of being viable, but most cocci and all remaining spiral forms showed extensive degeneration. The results indicate that non-culturable coccal forms of C. jejuni are capable of infecting mice but that this property may differ between strains.

Group A meningococcal disease in England associated with the Haj.

An outbreak of group A meningococcal infection amongst the Muslim population in England followed the outbreak of meningococcal disease associated with the 1987 Haj to Mecca. There were 18 primary cases amongst pilgrims returning from Mecca and 15 subsequent cases among Muslims over the following 19 months. The meningococcal strains were shown to be of the same clone as strains from the Mecca outbreak by possession of an outer membrane protein PI.9. Strains of this group A clone (A III-I) had only rarely been encountered in England before this outbreak.

Application of three typing schemes (Penner, Lior, Preston) to strains of Campylobacter spp. isolated from three outbreaks.

Campylobacters isolated from human, animal and environmental sources during the investigation of a milk-borne outbreak, an incident involving goats' milk and an outbreak associated with puppies were serotyped using the Penner and Lior schemes and biotyped using the Preston scheme. Application of these three methods to the incident strains demonstrated that heterogenicity amongst similar strains exists. This study has confirmed the need to use at least two typing methods when investigating epidemiologically-related strains and we suggest that a combination of a serotyping scheme and an extended biotyping scheme is the most useful.

Serotyping of Campylobacter species by combined use of two methods.

Five hundred strains of thermophilic Campylobacter spp. from sporadic cases of enteritis and from epidemiologically related infections connected with outbreaks were serotyped. The haemagglutination method of Penner and the slide agglutination method of Lior were used together. Greater discrimination was obtained by the use of two methods together than by either alone; 96% of sporadic strains were typed using a restricted set of typing sera. Of the sporadic strains, 50% fell within five Penner serotypes and 50% fell within four Lior serotypes, so the increased discrimination obtained by using both methods was particularly useful amongst these most common serotypes. In outbreaks associated with one serotype both methods gave consistent results, and in outbreaks due to multiple serotypes the two methods complimented each other.

Diagnosing functional visual deficits with the P300 component of the visual evoked potential.

The visual evoked potential (VEP) is routinely used to assess visual function, though it occasionally does not reflect a patient's conscious experience. Reports of normal flash or pattern VEPs obtained from blind persons are extreme examples of this problem. The difficulty in interpreting VEPs in light of such findings can be partly overcome by obtaining a cognitive component of the evoked potential, P300. We obtained traditional visual acuity measurements, pattern-reversal VEPs, and VEPs containing P300s from three patients with clinically diagnosed functional visual deficits. The P300s were obtained in response to stimuli that the patients claimed they could not see, supporting the clinical conclusions that malingering or hysteria was involved. The P300 component can be helpful in assessing the subjective visual experience of patients suspected of having functional visual loss.