Compensatory growth and nitrogen balance in grower-finisher pigs.

Sixteen castrated male pigs (averaging 21.2 +/- 4.9 kg) were used in two trials to investigate the effect of dietary amino acid content during the grower phase on growth performance and N balance. In each trial, pigs were assigned randomly to corn-soybean meal grower diets formulated to contain 5.0 or 11.0 g lysine/kg (as-fed basis). Common Finisher 1 and 2 diets were offered when pigs reached 51.2 +/- 3.3 and 79.5 +/- 3.4 kg, respectively. Pigs were placed in metabolism crates for a 9-d period during each of the grower, Finisher 1, and Finisher 2 phases when they weighed 43.3 +/- 3.9, 70.4 +/- 4.9, and 90.5 +/- 3.8 kg, respectively, to determine N balance. Blood samples were taken from each pig periodically after an overnight fast. Pigs were allowed ad libitum access to feed and water, except during the three adaptation/collection periods. There were no diet x trial interactions; thus, the data were combined. Pigs fed the low-amino acid grower diet grew more slowly and less efficiently (P < 0.001) during the grower phase and had more ultrasound backfat (P = 0.010) at the end of the grower phase than those fed the high-amino acid grower diet. During the Finisher 1 phase, however, pigs fed the low-amino acid diet grew more efficiently (P = 0.012) than those fed the high-amino acid diet, and the grower diet had no effect on overall weight gain, carcass traits, lean accretion, or meat quality scores. Although pigs fed the low-amino acid diet had less serum urea N (P < 0.001) and more glucose (P = 0.009) at 43.3 kg, there seemed to be no clear, long-term effect of the grower diet on serum metabolites. During the grower phase, pigs fed the high-amino acid diet consumed more N (P < 0.001), had higher apparent N digestibility (P = 0.041), N utilization (P = 0.027), and N retention (P < 0.001), and excreted more fecal (P = 0.034) and urinary (P < 0.001) N than those fed the low-amino acid diet. Pigs fed the low-amino acid grower diet, however, had a higher N utilization (P = 0.024) during the Finisher 1 phase, and excreted less urinary N during both the Finisher 1 (P = 0.029) and 2 (P = 0.027) phases than those fed the high-amino acid grower diet. These results indicate that pigs subjected to early dietary amino acid restrictions compensated completely and decreased N excretion during both the restriction and realimentation phases. Compensatory growth can, therefore, have a positive effect not only on the overall efficiency of pig production but also on environment.

Tumour necrosis factor alpha inhibitor treatment for sarcoidosis refractory to conventional treatments: a report of five patients.

OBJECTIVE: To study the effectiveness of tumour necrosis factor alpha (TNFalpha) inhibitor treatment for sarcoidosis refractory to conventional treatments. METHODS: Five patients (two men, three women) were treated with infliximab. All patients received a loading dose of 3 mg/kg at 0, 2, and 6 weeks and then maintenance infusions every 4-8 weeks. Patients had their dose increased or the dosing interval reduced when the disease relapsed. These patients had active disease despite treatment with corticosteroids and other immunomodulatory agents. All patients had a negative tuberculin skin test. RESULTS: Sarcoidosis in all patients improved significantly without any serious adverse reactions. CONCLUSION: This study suggests that TNFalpha is effective in patients for whom conventional treatment fails.

Mapping of porcine genetic markers generated by representational difference analysis.

Representational difference analysis (RDA) was performed using pig genomic DNA from a Landrace non-selected control population and a Landrace population selected for increased loin muscle area (LMA) for five generations. Pigs used for the analysis differed phenotypically for various carcass traits and were divergent in genotype at the skeletal muscle ryanodine receptor 1 locus. Two RDA experiments were performed using BamHI and BglII. Fourteen BamHI and 37 BglII difference products were cloned and sequenced. Oligonucleotide primers were designed to amplify RDA difference products and sequence-tagged sites (STS) were developed for 16 RDA fragments (two BamHI and 14 BglII). These 16 STS were mapped using the INRA-Minnesota porcine Radiation Hybrid panel. Polymorphisms identified in nine of the STS were used to place these markers on the PiGMaP genetic linkage map. Sequence-tagged sites were localized to 11 different chromosomes including three markers on chromosome 11 and four markers on chromosome 14. Development of RDA markers increases the resolution of the pig genome maps and markers located within putative quantitative trait locus (QTL) regions can be used to refine QTL positions.

Growth performance, dry matter and nitrogen digestibilities, serum profile, and carcass and meat quality of pigs with distinct genotypes.

We investigated the effect of distinct genotypes on growth performance, DM and N digestibilities, serum metabolite and hormonal profiles, and carcass and meat quality of pigs. Eight control-line and eight select-line pigs with an equal number of gilts and castrated males per genotype were chosen from the group of pigs subjected to selection for lean growth efficiency. Pigs were housed individually and allowed ad libitum access to common grower, finisher 1, and finisher 2 diets when they reached approximately 20, 50, and 80 kg, respectively, and water throughout the study. Although genotype had no effect on growth performance during the finisher 2 phase and overall, select-line pigs grew faster and more efficiently (P < 0.05) during the grower and finisher 1 phases than did control-line pigs. Dry matter and N digestibilities during the grower phase were lower (P < 0.05) in select-line pigs compared with control-line pigs. Select-line pigs had less ultrasound backfat (P < 0.05) at the end of the grower and finisher 2 phases. Serum urea N (P < 0.05) and leptin concentrations were lower in select-line pigs than in control-line pigs, but the effect of genotype on serum glucose, triglyceride, or insulin concentration was rather inconsistent. Select-line pigs had heavier heart (P < 0.05), liver (P = 0.08), and kidneys (P < 0.01), implying a higher metabolic activity. Less 10th-rib carcass backfat (P < 0.01) and a trend for larger carcass longissimus muscle area (P = 0.10) were reflected in the greater (P < 0.01) rate and efficiency of lean accretion in select-line pigs. Select-line pigs had lower subjective meat color (P < 0.01), marbling (P < 0.05), and firmness (P < 0.01) scores. Final serum leptin concentration was correlated positively with carcass backfat thickness (r = 0.73; P < 0.01) and negatively with overall feed intake (r = -0.77; P < 0.01). These results indicate that pigs with distinct genotypes exhibited differences in the growth rate, metabolite and hormonal profiles, and body composition. Further research is necessary to determine whether pigs with distinct genotypes respond differently to dietary manipulations, which would have an effect on developing optimal feeding strategies for efficient and sustainable pig production.

Degree of amino acid restrictions during the grower phase and compensatory growth in pigs selected for lean growth efficiency.

A total of 32 select line (SL) and 32 control line (CL) Duroc pigs were used in two trials to determine the effect of dietary amino acid contents during the grower (G) phase and selection for lean growth efficiency on growth performance, carcass traits, and meat quality. In each trial, pigs weighing 20 kg were assigned to 16 pens with two gilts or two castrated males per pen, and pens were randomly assigned within the genetic line to corn-soybean meal G diets formulated to contain 5.0, 7.0, 9.0, or 11.0 g lysine/kg. After 50 kg, all pigs were fed common finisher 1 (F1) and finisher 2 (F2) diets. Pigs were allowed ad libitum access to feed and water. After the initial statistical analyses, the data sets from the two trials were combined. During the G phase, pigs consumed less feed [linear (Ln), P < 0.001] and more lysine (Ln, P < 0.001), grew faster (Ln, P < 0.05) but utilized feed more and lysine less efficiently (Ln, P < 0.001) for weight gain as the amino acid content of G diets increased. Increasing dietary amino acids resulted in less ultrasound backfat (Ln, P < 0.001) and more serum urea nitrogen [Ln, P < 0.001; quadratic (Qd), P < 0.01] at the end of the G phase. Pigs grew more slowly during the F1 (Ln, P < 0.01 and Qd, P = 0.05) and F2 (Ln, P = 0.07) phases and utilized feed and lysine less efficiently (Ln, P < 0.05) for weight gain during the F1 phase as the amino acid content of G diets increased. The grower diet had no effect on overall weight gain and feed efficiency, carcass traits, or meat quality scores. The efficiency of lysine utilization for overall weight gain (Ln, P < 0.001) and lean accretion (Ln, P < 0.05) improved as the amino acid content of G diets decreased. The SL pigs grew faster (P < 0.05) and had less (P < 0.001) ultrasound backfat throughout the study compared with the CL pigs. The SL pigs had less 10th rib backfat (P < 0.001) and tended to have larger longissimus muscle area (P = 0.09) than the CL pigs, which were reflected in greater rate (P < 0.001) and efficiency (P < 0.05) of lean accretion. Marbling (P < 0.05) and meat color (P = 0.07) scores were lower in the SL pigs. No grower diet x genotype interactions were observed in response criteria of interest. The results indicate that pigs subjected to dietary amino acid restrictions during the G phase (as low as 5.0 g lysine/kg) compensated completely in terms of growth rate and body composition regardless of the genotype. Compensatory growth can have a positive impact not only on the overall efficiency of pig production but also on the environment by reducing excretion of unused nutrients.

Genetics of growth, feed intake, and milk yield in Holstein cattle.

Heritabilities, genetic and phenotypic correlations among growth, forage consumption, and BW changes of heifers and feed consumption, BW changes, and yields of first lactation cows were estimated. Data were from 1266 Holstein progeny of 74 sires born from 1972 to 1985 at three Agriculture Canada research herds. Heavier heifers at 26 wk consumed more feed from 26 to 34 wk than smaller heifers but gained the same BW. The BW gain and feed consumption heritabilities were .17 and .23, respectively; genetic correlation was .44, and phenotypic correlation was .27. During first lactation, feed intake from 8 to 16 wk and measures of milk yield are very tightly intercorrelated both phenotypically and genetically (.78 to .98). Precalving BW gain and BW at calving were genetically uncorrelated with measures of milk yield (-.09 to +.05). Loss of BW during the first 8 wk of first lactation was moderately heritable (.29) and correlated genetically and phenotypically with measures of milk yield in early lactation (.32 to .39) and feed consumption (.26). From 8 to 16 wk, average BW changes were small and had low heritability and weak phenotypic correlations with measures of milk yield or feed intake. The BW at 26 wk and BW gain from 26 to 34 wk were very poor indicators of early first lactation milk yield. Heifer feed intake was weakly correlated phenotypically (-.07 to .16) but moderately genetically correlated (.17 to .23) with early first lactation milk yield and feed consumption.

Relationship of bull fertility with daughter fertility and production traits in Holstein dairy cattle.

The phenotypic and genetic correlations between fertility ratings of AI bulls for conception rate and their estimated breeding values for daughters' fertility and production traits were calculated. Genetic correlations between fertility ratings of bulls for conception and heifer fertility traits (age at first breeding, age at last breeding, and number of insemination per conception) were negative and ranged from -.04 to -.23, indicating daughters of bulls with high fertility ratings were younger at first breeding and required fewer services to conceive. In general, genetic correlations between fertility ratings of bulls for conception rate and cow fertility traits (days from calving to first breeding, days open, and number of inseminations per conception) and production traits (breed class average milk and fat and fat percentage) in the first two lactations were also moderate to high and in the favorable direction. Although heritability of both male and female fertility is low, these data indicate that heavy use of sires with high fertility ratings could have a mild positive effect on both male and female fertility. Evidence is also found to indicate that in this breed, selection for increased milk yield should not impair genetic ability of cows to reproduce.

Genetic parameters for fertility of dairy bulls.

Genetic parameters for male fertility and fertility ratings of AI bulls were obtained by analyzing 298,013 service records of cows with successive calving records. Cows were mated to 746 service bulls, which were progeny of 126 sires. The model for variance component estimation accounted for fixed effects of herd-year-seasons, sire of the service bull, age of mates, and random effects of service bull and residual error. Estimates of variances of service bulls and residual error components for bull fertility indicated almost 10% of the phenotypic variation for fertility is among AI bulls. Best linear unbiased prediction of fertility ratings of individual bulls with inclusion of sire and maternal grandsire relationships on these data permitted the evaluation of 886 AI bulls for bull fertility. Heritability for bull fertility computed as twice the regression of son on sire was .158. Differences in fertility ratings of AI bulls ranged from -.29 to .19. Prediction of fertility of young AI bulls and more accurate rating of proven bulls might be useful to the industry.

Evaluation of phenotypic and genetic trends in weaning weight in Angus and Hereford populations in Virginia.

Weaning weight records of 27,774 Angus calves in 13 herds and 14,738 Hereford calves in 11 herds born during 1953 through 1983 in Virginia were analyzed using regression techniques and maximum likelihood (ML) procedures to estimate phenotypic and genetic trends for adjusted weaning weight (AWWT), weaning weight ratio (WWR) and deviations of AWWT from the mean AWWT of the contemporary group (DEV). Phenotypic trends for AWWT in the Angus and Herefords were .96 plus or minus .02 and .82 plus or minus .03 kg/yr, respectively. In the Angus breed, estimates of one-half of the sire genetic trend obtained from the ML procedure for WWR and DEV were .40 plus or minus .04 ratio units/yr and .72 plus or minus .07 kg/yr, respectively; corresponding values for Herefords were .25 plus or minus .06 ratio units/yr and .45 plus or minus .12 kg/yr. Estimates of one-half of the dam trends for the respective traits were .32 plus or minus .02 ratio units/yr and .55 plus or minus .04 kg/yr for Angus and .21 plus or minus .03 ratio units/yr and .30 plus or minus .07 kg/yr for Herefords. Estimates of sire and dam genetic trends from the regression analyses were slightly higher than estimates from the ML procedure, but adjustments to eliminate bias due to non-random mating and culling from the regression analyses increased the similarity of the results from the two procedures. Average annual genetic trends over the entire study period from the ML procedure for AWWT were 1.27 kg/yr for Angus and .75 kg/yr for Herefords. Genetic trends were not linear over the entire period. Total genetic trends in AWWT for Angus and Hereford, respectively, were .30 and -.61 kg/yr before 1971 and 2.18 and 1.98 kg/yr after 1970.

Catamenial pneumothorax.

Catamenial or menses related pneumothorax is a rare clinical manifestation of pulmonary endometriosis. We document a case where the clinical history was the key to diagnosis, and evidence of endometriosis elsewhere was scanty. Prolonged medical therapy was not preferred in our patient in view of her age and parity. Surgical pleural ablation was carried out to prevent further episodes of life threatening pneumothoraces. The investigations that may be useful in such a patient are discussed and the clinical profile of our patient is compared with those of the few cases reported in the literature.

Growth patterns of cows sired by British and Continental beef and American dairy bulls and out of Hereford dams.

Growth patterns from birth to maturity were compared for 92 straightbred Herefords (H) and 299 Hereford crossbred (XB) cows. Crossbred cows were out of Hereford dams and were sired by bulls of two British [Angus (A) and Shorthorn (Sh)], two Continental [Charolais (C) and Simmental (S)] and two American dairy breeds [Brown Swiss (B) and Holstein (F)]. British XB and H cows differed only slightly in weight but both weighed less than Continental and dairy XB cows. Body condition also differed significantly among breed types; dairy XB were thinnest. Among XB individuals SH calves were heaviest (34 kg) and AH calves were lightest (30 kg) at birth. Birth weights of Continental XB were 2.6 kg more than those of British XB and 1.7 kg more than those of dairy XB. At weaning, all XB calves were heavier than straightbred H calves, but differences among XB types were not significant. However, on the average, Continental XB and dairy XB calves were heavier (28 kg) than British XB at 19 mo. At 32 mo, Continental and dairy XB weighed 41 and 23 kg more, respectively, than British XB. Although differences between the British XB and the Continental and dairy XB at some ages were not significant, no case existed where the latter two groups weighed less than British XB. Adjusting weight to a common condition score reduced phenotypic variance at all ages and changed the ranking of some breed types for weight, primarily by increasing predicted weights of dairy XB. Differences in growth curves were reflected by differences in mature weight and maturing rate. Asymptotic weights of Continental XB were highest, followed by those of dairy XB. British XB and H weighed least at maturity (average of 509 kg). The CH cows matured more slowly but grew to a heavier mature weight (592 kg) than SH cows (552 kg). Generally animals reached 95% of their mature weight between 68 and 80 mo of age.

Growth patterns of Angus, Charolais, Charolais X Angus and Holstein X Angus cows from birth to maturity.

Growth patterns of 182 cows [73 Angus (AA), 31 Charolais (CC), 38 Charolais X Angus (CA) and 40 Holstein X Angus (FA)] were studied from birth to maturity. Breed type significantly affected weight and condition at all ages. Crossbred cows were heavier than AA and lighter in weight than CC cows (P less than .01) at all periods. Differences between CA and FA cows were small. The CA cows were somewhat heavier than FA cows, but when weight was adjusted for condition, these two groups reversed rank at 56 and 68 mo. Differences in weight among breed types increased from birth to 44 mo and stabilized thereafter. Weights at early ages were influenced more by environmental effects than were weights at later ages. Adjustment for condition significantly reduced phenotypic variation in weight at all ages. Two growth models (Brody and Richards) were fitted to the weight-age data for each breed type. Differences in growth were expressed in terms of differences in mature weight and maturing rate. The AA cows were smallest at maturity and matured most rapidly; CC cows were largest and matured least rapidly. The FA and CA cows were intermediate and similar in mature size and maturing rate. Crossbreeding may have increased maturing rate somewhat when weights were not adjusted for condition. The four-parameter Richards model did not provide an appreciably better fit to the data than the three-parameter Brody model, and both models described early growth less adequately than later growth.