Effects of cecal oxytetracycline infusion, and dietary avidin and biotin supplementation on the biotin status of nongravid gilts.

The objective of this 49-d experiment was to test effects of cecal oxytetracycline (OTC) infusion, and dietary avidin and biotin supplementation on the biotin status of nongravid gilts. Twenty-eight crossbred gilts with an initial age of 160 d and BW of 120 kg were surgically fitted with a T-cannula in the terminal ileum, a cecal fistula, and an indwelling catheter in the anterior vena cava, and allotted to 7 dietary treatments. Treatments with the basal semipurified (SP) diet fed at 1.86 kg/d were: SP-1, negative control; SP-2, positive control with 270 µg of biotin/kg; SP-3, with spray-dried egg albumen (EA, 100 g/d) and OTC (2.56 g/d by cecal infusion); and SP-4, with EA, OTC, and 700 µg of biotin/kg. Treatments with the basal corn-soybean meal (CS) diet fed at 1.80 kg/d were: CS-1, negative control; CS-2, with EA and OTC; and CS-3, with EA, OTC, and 700 µg of biotin/kg. Response criteria were: fecal bacteria counts; plasma concentrations of biotin, glucose, and urea N (PUN); liver pyruvate carboxylase (PC) activity; kidney and epithelial tissue histology; ileal and fecal biotin concentrations; ileal and total tract N and energy utilization; daily gilt observation; and BW gain. Blood samples were collected every 7 d with serial samples collected on d 49. Total urine collections and fecal grab samples were made twice daily from d 44 to 49. Gilts were killed on d 50 and liver, kidney, and skin samples were collected. No gilts had symptoms of biotin deficiency. There were no treatment differences in BW gain, plasma glucose concentrations, liver PC activity, kidney and epithelial tissue histology, or fecal bacteria counts. Ileal and total tract N and energy digestibilities (%) did not differ among treatments within the same protein source, with greater (P ≤ 0.05) values for gilts on the SP treatments than the CS treatments. However, N retained/N absorbed and N retained/N intake (%) were less (P ≤ 0.05) and PUN concentrations were greater (P ≤ 0.05) for SP treatments with cecal OTC infusion. The overall fecal biotin concentration mean was 2.6-fold greater than the overall ileal biotin concentration mean. In conclusion, no gilts in the current experiment became biotin deficient because the biotin requirements were met primarily by microbial synthesis and absorption of biotin from the distal small intestine and large intestine, with corn and soybean meal contributing endogenous biotin. Therefore, supplementation of diets for gilts entering the breeding herd with 100% of the current NRC biotin requirement for sows is adequate.

Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: I. Growth performance and longissimus muscle fatty acid composition.

Crossbred pigs (n=288) were used to test the interactive effects of dietary fat source and slaughter weight on live performance, carcass traits, and fatty acid composition of the LM. Pigs were blocked by initial BW, and, within each of 9 blocks, pens (8 pigs/pen) were randomly assigned to either control corn-soybean meal grower and finisher diets devoid of added fat (Ctrl) or diets formulated with 5% beef tallow (BT), poultry fat (PF), or soybean oil (SBO). Immediately after treatment allotment, as well as at mean block BW of 45.5, 68.1, 90.9, and 113.6 kg, 1 pig was randomly selected from each pen, slaughtered, and allowed to chill for 48 h at 1 degrees C. Backfat was measured on the right sides, and a sample of the LM was removed for fatty acid composition analysis. Regardless of source, inclusion of fat in swine diets did not (P >or= 0.349) affect ADG, ADFI, or G:F. Furthermore, carcasses from pigs fed diets formulated with 5% fat had greater (P=0.013) average backfat depths than those from pigs fed the Ctrl diet. Body weight, carcass weight, and backfat depths increased (P<0.001) as slaughter weight increased from 28.1 to 113.6 kg. The proportion of SFA in the LM increased (P<0.001) with increasing slaughter weight from 28.1 to 68.1 kg, but SFA percentages were similar between 68.1 and 113.6 kg, and pigs fed the Ctrl diet had greater (P=0.032) proportions of SFA than pigs fed the SBO and PF diets. Moreover, the proportion of all MUFA increased (P<0.001) by 9.4 percentage units from 28.1 to 113.6 kg; however, only pigs fed the SBO diet had reduced (P=0.004) MUFA percentages than those fed the Ctrl, BT, and PF diets. Even though the proportion of PUFA in the LM decreased with increasing slaughter weight, pigs fed SBO had greater PUFA percentages, a greater PUFA-to-SFA ratio, and greater iodine values than pigs fed all other dietary treatments when slaughtered at BW of 45.5 kg or greater (fat source x slaughter weight, P < 0.001). Results of this study indicate that fat source had little to no impact on live pig performance, but feeding a polyunsaturated fat source altered the fatty acid profile of the LM within the first 17.4 kg of BW gain; more specifically, including 5% SBO in swine diets could lead to economical ramifications associated with soft pork or fat.

Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: II. Fatty acid composition of subcutaneous fat.

Crossbred pigs (n=288) were used to test the interactive effects of dietary fat source and slaughter weight on the fatty acid composition of subcutaneous fat. Pigs were blocked by initial BW (28.1 kg), and, within blocks, pens (8 pigs/pen) were randomly assigned to either grower and finisher diets devoid of added fat (Ctrl) or diets formulated with 5% beef tallow (BT), poultry fat (PF), or soybean oil (SBO). Immediately after treatment allotment, as well as at mean block BW of 45.5, 68.1, 90.9, and 113.6 kg, 1 pig was randomly selected from each pen, slaughtered, and, within 1 h postmortem, samples of backfat were removed from each carcass between the 4th and 8th thoracic vertebra and separated into the inner, middle, and outer layers for fatty acid composition analysis. During the first 17.4 kg of BW gain, percentages of all SFA increased by more than 4% in subcutaneous fat of pigs fed the Ctrl and BT diets, but decreased by 4.4 and 7.7% in pigs fed the PF and SBO diets, respectively (fat source x slaughter weight, P<0.001). Proportions of all MUFA in subcutaneous fat from BT-fed pigs increased by 6.1% during the first 17.4 kg of BW gain, but MUFA percentages in SBO-fed pigs decreased by 9.1% between 28.1 and 45.5 kg (fat source x slaughter weight, P<0.001). Conversely, percentages of all PUFA from SBO-fed pigs increased by 39.9%, whereas PUFA concentrations in BT-fed pigs decreased by 12.6% as slaughter weight increased from 28.1 to 45.5 kg (fat source x slaughter weight, P<0.001). Resultant iodine values (IV) of subcutaneous fat from SBO-fed pigs increased (P<0.05) from 73.5 to 85.2 within the first 17.4 kg of BW gain, and remained elevated above those of their contemporaries fed the Ctrl, BT, or PF diets at each subsequent slaughter weight (fat source x slaughter weight, P<0.001). The inner backfat layer had the greatest (P<0.05) proportions of all SFA and the least (P<0.05) proportions of all PUFA, whereas the outer layer had the least (P<0.05) percentages of all SFA but the greatest (P<0.05) percentages of all MUFA. Even though the middle and outer subcutaneous fat layers had similar (P>0.05) PUFA percentages, the greatest (P<0.05) and least (P<0.05) IV were in the outer and middle layers, respectively. As expected, the fat source included in swine diets was responsible for the fatty acid compositional changes in subcutaneous fat, yet the results of this study indicate that feeding 5% SBO dramatically increased the polyunsaturation of subcutaneous fat within the first 17.4 kg of BW gain, with backfat IV exceeding 80 thereafter.

Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: III. Carcass and fatty acid compositions.

Crossbred pigs (n=288) were used to test the interactive effects of dietary fat source and slaughter weight on dissected carcass composition and fatty acid composition of composite carcass samples. Pigs were blocked by initial BW, and within each of 9 blocks, pens (8 pigs/pen) were randomly assigned to either control corn-soybean meal grower and finisher diets (Ctrl) or diets formulated with 5% beef tallow (BT), poultry fat (PF), or soybean oil (SBO). Immediately after treatment allotment, as well as at mean block BW of 45.5, 68.1, 90.9, and 113.6 kg, 1 pig was randomly selected from each pen and slaughtered, and primal cuts from right carcass sides were dissected into muscle, fat, bone, and skin components. Muscle and fat tissues were then ground, and random composite samples were collected from each carcass for fatty acid composition analysis. Fat source did not alter pork primal cut yields (P >or= 0.294), nor were the percentages of carcass muscle (P=0.213), fat (P=0.502), and bone (P=0.551) affected by dietary fat source. Conversely, percentages of the whole shoulder and ham decreased linearly (P<0.001), and the percentages of loin and belly increased (P<0.001) linearly with increasing slaughter weight. Moreover, linear decreases (P<0.001) in carcass muscle, bone, and skin, as well as a linear increase (P<0.05) in carcass fat, were observed as slaughter weight increased from 28.1 to 113.6 kg. Composite samples from pigs fed the BT or Ctrl diets had greater (P<0.05) proportions of SFA, particularly oleic and stearic acids, than those from pigs fed the PF and SBO diets when slaughtered at 45.5, 68.1, and 90.9 kg (fat source x slaughter weight, P<0.001). Percentages of MUFA (including palmitoleic, oleic, and cis-vaccenic acids) decreased (P<0.05), and percentages of all PUFA, especially linoleic and linolenic acids, and iodine values increased (P<0.05) in samples from SBO-fed pigs as slaughter weight increased from 28.1 to 113.6 kg (fat source x slaughter weight, P<0.001). Dietary fat source did not affect carcass composition; however, including 5% SBO in swine diets increased the polyunsaturation of pork, which could lead to economic ramifications associated with soft pork and pork fat.

Variability in mixing efficiency and laboratory analyses of a common diet mixed at 25 experiment stations.

An experiment involving 25 experiment stations in the North Central and Southern regions (NCR-42 and S-288, respectively) was conducted to assess the degree of uniformity of diet mixing among stations and to assess the variability among station laboratories in chemical analysis of mixed diets. A fortified corn-soybean meal diet was mixed at each station using a common diet formula (except for vitamin and trace-mineral additions). The diet was calculated to contain 14% crude protein (CP), 0.65% Ca, 0.50% P, and 125 ppm Zn (based on 100 ppm added Zn). After mixing, samples were collected from the initial 5% of feed discharged from the mixer, after 25, 50, and 75% was discharged, and from the final 5% of discharged feed. The five samples were sent to the University of Kentucky, finely ground, and divided into subsamples. Each set of five subsamples from each station was distributed to three randomly selected stations for analysis of CP, Ca, P, and Zn (i.e., each station analyzed five diet sub-samples from three other stations). In addition, two commercial and two station laboratories analyzed composites of the five subsamples from each of the 25 mixed diets. Based on the laboratories that analyzed all diets, means were 13.5, 0.65, and 0.52%, and 115 ppm for CP, Ca, P, and Zn, respectively. Ranges of 11.8 to 14.6% CP, 0.52 to 0.85% Ca, 0.47 to 0.58% P, and 71 to 182 ppm of Zn were found among the 25 diet mixes. The coefficients of variation among the 25 diet samples for CP, Ca, P, and Zn were 4.3, 9.3, 4.1, and 17.4%, and among the 25 laboratories were 3.6, 12.5, 10.7, and 11.1%, respectively. Overall analyses of the five sub samples were, respectively, CP: 13.4, 13.6, 13.4, 13.5, and 13.4% (P < 0.06); Ca: 0.66, 0.67, 0.67, 0.66, and 0.67%; P: 0.50,0.51,0.51,0.50, and 0.50%; and Zn: 115, 116, 112, 113, and 120 ppm (P < 0.001). Diets were not uniformly mixed at all stations (station x sample No. was P < 0.08 for Ca and P < 0.01 for CP, P, and Zn). Among stations, the range of the five samples, expressed as a percentage of the mean and averaged for CP, Ca, P, and Zn, varied from +/- 1.1% (i.e., 98.9 to 101.0%) to +/- 12.9% (84.6 to 110.4%), with an overall average of +/- 5.2%. Neither type nor volume of mixers was related to mixing uniformity. The results suggest that uniformity of diet mixes varies among experiment stations, that some stations miss their targeted levels of nutrients (especially Zn), and that the variability among experiment station laboratories in analysis of dietary Ca, P, and Zn in mixed diets is quite large.

Impact of energy intake and pregnancy status on rate and efficiency of gain and backfat changes of sows postweaning.

A collaborative study was conducted to evaluate factors related to determining optimal feeding and management programs for increasing net returns from marketing cull sows. A total of 269 multiparous sows averaging 192 kg of body weight were weaned, moved to individual gestation crates, and assigned to one of eight treatment combinations in a 2 x 2 x 2 factorial arrangement for a 42-d postweaning feeding experiment. Factors included limited (L) (1.8 kg/sow/d) or ad libitum (AL) access to feed during wk 1 postweaning, a corn-soybean meal (corn) or barley-sunflower meal (barley) diet, and pregnant or nonpregnant status. All sows were provided ad libitum access to feed from wk 2 to 6 postweaning. Gain and feed intake (FI) data were collected weekly for each sow and used to calculate gain:feed (G/F). Ultrasonic backfat (BF) data were collected on d 0, 21, and 42 postweaning. Sows on the AL treatment had greater FI (P < 0.05) but similar gain (P = 0.80) for the 42-d postweaning period compared to sows on the L treatment. Most of this response was due to lower sow body weight loss during wk 1 postweaning (P < 0.01) when sows were provided AL (-7.2 kg) vs L (-13.2 kg) access to feed. Sows fed the corn diet had higher gain (P < 0.01), improved G/F (P < 0.01), and increased BF (P < 0.01) over the 42-d feeding period than sows fed barley. The corn diet resulted in less sow BW loss (P < 0.01) during wk 1 (-8.8 kg) than the barley diet (-11.6 kg). Pregnant sows had higher gain, FI, G/ F, and BF (P < 0.01) than nonpregnant sows over the 42-d feeding period. Most of this advantage occurred during wk 4 postweaning when FI and gain of nonpregnant sows was lower (P < 0.01) than for pregnant sows. An economic analysis indicated that, when cull sow prices are relatively high and feed prices are moderate to low, maintaining and managing cull sows for an additional 6 wk postweaning may be economically advantageous compared to 0 or 3 wk. Pregnant sows fed the corn diet produced the greatest economic return. These results suggest that mating sows as they return to estrus postweaning and providing ad libitum access to a corn-soybean meal diet improves growth performance and feed efficiency, and may thereby provide increased returns when marketing cull sows.

Variability among sources and laboratories in analyses of wheat middlings. NCR-42 Committee on Swine Nutrition.

A cooperative research study was conducted by members of a regional committee (North Central Regional Committee on Swine Nutrition [NCR-42]) to assess the variability in nutrient composition (DM, CP, Ca, P, Se, NDF, and amino acids) of 14 sources of wheat middlings from 13 states (mostly in the Midwest). A second objective was to assess the analytical variability in nutrient assays among 20 laboratories (labs; 14 experiment station labs and six commercial labs). Wheat middlings were obtained from each participating station's feed mill. The bulk density of the middlings ranged from 289 to 365 g/L. The number of labs that analyzed samples were as follows: DM and CP, 20; Ca, 16; P, 15; Se, 7; NDF, 10; and amino acids, 9. Each lab used its own analytical procedures. The middlings averaged 89.6% DM, 16.2% CP, .12% Ca, .97% P, 36.9% NDF, .53 mg/kg Se, .66% lysine, .19% tryptophan, .54% threonine, .25% methionine, .34% cystine, .50% isoleucine, and .73% valine. As expected, there was considerable variation in nutrient composition among the 14 sources (P < .01), especially for Ca (.08 to .30%) and Se (.05 to 1.07 mg/kg). "Heavy" middlings (high bulk density, >335 g/L), having a greater proportion of flour attached to the bran, were lower in CP, lysine, P, and NDF than "light" middlings (<310 g/L), having cleaner bran, resulting in negative correlations between bulk density and CP (r = -.61), lysine (r = -.59), P (r = -.54), and NDF (r = -.81). Each 1-percentage-point increase in CP in the wheat middlings was associated with .0235 (r2 = .61) and 2.1 (r2 = .39)-percentage-point increases in lysine and NDF, respectively. Lysine content was associated with NDF, CP, and bulk density of wheat middlings (r2 = .88). There was considerable variation among laboratories (P < .01) in analysis of all nutrients. The CV among sources (100 x sigmaS/mean) was greater than among labs (100 x sigmaL/mean) for CP, Ca, P, Se, and NDF, but the CV among labs was greater than that among sources for DM and all of the amino acids except lysine and phenylalanine.

Further assessment of the dietary lysine requirement of finishing gilts.

A cooperative research study involving 635 gilts was conducted at eight research stations to further estimate the lysine requirement of finishing gilts. Dietary crude protein levels of the five dietary treatments ranged from 16.0 to 24.4% with calculated lysine levels of .80, .95, 1.10, 1.25, or 1.40%. Each station contributed a minimum of two replicate pens of pigs per treatment. Average initial and final weights were 53.6 and 116.4 kg, respectively. At the end of the experimental period, pigs were killed and hot carcass weight, 10th-rib fat depth, and longissimus muscle area were measured. Carcass fat-free lean percentage and fat-free lean gain were estimated from these data. Daily lysine intakes averaged 21.8, 25.9, 30.5, 34.3, and 37.8 g/d for the five treatment groups, respectively. Increasing the dietary lysine from .80 to .95% numerically increased weight gain and gain:feed, but these increases were not maintained at higher levels of dietary lysine. Overall, rate and efficiency of gain decreased (cubic, P < .01) with increasing dietary lysine. Carcasses were leaner at the two higher levels of dietary lysine as evidenced by reduced 10th rib backfat (linear, P < .01), increased longissimus area (quadratic, P < .04), and increased percentage of estimated fat-free lean (linear, P < .01). Carcass fat-free lean gain was not influenced by dietary lysine except for a small numerical improvement (P < .11) at the .95% level of dietary lysine that paralleled the improvement in body weight gain. The results indicate that the dietary lysine requirement of finishing gilts with a mean carcass fat-free lean growth rate of 306 g/d from 54 to 116 kg body weight is probably no higher than .80% of the diet to achieve maximum rate and efficiency of body weight gain and carcass lean growth rate. The results also indicate that higher dietary lysine levels may increase carcass leanness in finishing gilts, possibly due to reduced intake of NE. Whether this response is due to the effects of lysine alone, protein (i.e., other amino acids), or soybean meal is unknown.

Variability among sources and laboratories in nutrient analyses of corn and soybean meal. NCR-42 Committee on Swine Nutrition. North Central Regional-42.

A cooperative research study involving members of a regional committee (North Central Regional Committee on Swine Nutrition [NCR-42]) was conducted to assess the variability in nutrient composition (DM, CP, Ca, P, Se, and amino acids) of corn and soybean meal from 16 sources (15 states, mostly in the Midwest) and to assess the analytical variability in nutrient assays among 22 laboratories (labs; 16 experiment station labs and six commercial labs). Corn samples were obtained from each participating station's feed mill during a 3-yr period (1989, 1990, and 1992), as were soybean meal samples during a 2-yr period (1989 and 1990). Both regular soybean meal (with hulls) and dehulled soybean meal were represented in the study. Samples were analyzed for DM and CP by all 22 labs, for Ca and P by 15 labs, for amino acids by 10 labs, and for Se by 6 labs. Each lab used its own analytical procedures. Samples of corn and soybean meal varied in their nutrient composition depending on the area of origin. The greatest variation among sources was in Se concentration, ranging from .02 to .29 mg/kg in corn and .08 to .95 mg/kg in soybean meal. Crude protein and lysine in corn were positively correlated, but the regression coefficient was low (r2 = .49). The relationship between CP and lysine for the two soybean meals combined was considerably stronger (r2 = .81). Lysine in corn increased by .018 percentage point and lysine in soybean meal (regular and dehulled combined) increased by .063 percentage point for each 1 percentage point increase in CP. Except for CP and Se, the analytical variability among labs was as great as, and in some cases greater than, the variability in nutrient composition among sources of corn and soybean meal. Within-lab analytical variability tended to be less than among-lab variability. Some labs performed certain analyses with considerably less variability and more accuracy than others.

Inversion effect for faces in split-brain monkeys.

Inverting facial stimuli disrupts recognition in human subjects more severely than does inversion of other objects normally seen upright. Furthermore, this disruption affects mechanisms in the right hemisphere, which is the hemisphere preeminent for face processing, more than mechanisms in the left. To determine the extent of these effects in monkeys we retrained each hemisphere of 20 split-brain rhesus monkeys on eight upright facial discriminations they had previously learned. As a group, the monkeys again performed better with the right hemisphere than with the left in remembering these problems, confirming the right hemispheric advantage previously found. As soon as a particular discrimination was relearned to criterion with one hemisphere, the same discrimination was presented inverted. The monkeys learned the inverted facial discriminations with each hemisphere but as a group no longer showed a right hemispheric advantage. Thus, the monkeys, like people, show a greater inversion effect for faces with the right hemisphere than with the left. This result indicates that monkeys normally process faces configurally using holistic mechanisms in the right hemisphere but, when required by the nature of the stimuli, can utilize piecemeal processing of specific features with either hemisphere.

Right-hemispheric superiority in split-brain monkeys for learning and remembering facial discriminations.

Twenty-six split-brain rhesus monkeys learned and remembered 8 go/no-go discriminations of monkey faces significantly better with the right hemisphere than with the left. Four discriminations required differentiating individual identity with expression held constant, and 4 required discriminating facial expression with identity held constant. There was no significant difference in the degree of laterality shown for these 2 types of problems. Female monkeys were more lateralized for learning to discriminate faces than were males. This sex difference in laterality was significant for learning but not for memory. Laterality for the facial discriminations was not significantly related to handedness of the monkeys. Overall, rhesus monkeys, like humans, show a right-hemispheric superiority for facial processing.

Evaluation of the feeding duration of a phase 1 nursery diet to three-week-old pigs of two weaning weights. NCR-42 Committee on Swine Nutrition.

A regional study involving a total of 618 nursery pigs with 468 continuing through the grower-finisher period evaluated the feeding duration of a Phase 1 starter diet (1, 2, or 3 wk) to 23-d old weanling pigs of two weaning weights (5.5 or 7.5 kg). The study was a 3 x 2 factorial arrangement of treatments in a randomized complete block design conducted in 19 replicates during the nursery period, with 14 replicates continuing through the grower-finisher period. Upon completion of feeding the Phase 1 diet for the experimental period, pigs were fed a Phase 2 diet (total of 5 wk for both Phases), whereupon a corn-soybean meal mixture formulated to .80% lysine was fed during the grower (to 56 kg BW) and a .65% lysine diet to a final body weight of 105 kg. Station effects were significant (P < .05) but station x treatment responses were not (P > .15). Pigs with heavier weaning weights gained faster (P < .01) and consumed more feed (P < .01) during each week of the nursery period. Nursery pig gains (P < .06) and gain: feed ratios improved (P < .01) when the Phase 1 diet had been fed for either 2 or 3 wk for both pig weight groups. There was no interaction response during the nursery period between weaning weight or duration of feeding the Phase 1 diet on daily gains or feed intake measurements; however, pigs in the heavier weight group were more efficient (P < .05) in feed utilization when fed the Phase 1 diet for 2 or 3 wk. During the grower-finisher period, gains were higher (P < .01) with the heavier pig group. When the Phase 1 diet had been fed for either 2 or 3 wk to the pigs of either weight group, gains (P < .01) and feed efficiency (P < .05) were improved. There was no evidence of compensatory growth for the lower weight pig group during the subsequent grower or finisher periods. Pigs with heavier weaning weights reached 105 kg BW approximately 8 d sooner (P < .01) and consumed less total feed (P < .05) from weaning to 105 kg than those in the lower weight group. Feeding the Phase 1 diet for 2 wk to pigs of either weight group reduced the time from weaning to 105 kg BW, but weaning heavier pigs seemed to have a greater effect on postweaning performance than the feeding duration of a Phase 1 diet.

Effects of facial identity, facial expression, and subject's sex on laterality in monkeys.

Previously we showed that rhesus monkeys processed discriminations of monkey faces significantly better with the right hemisphere of the brain than with the left. The overall effects of the type of discrimination, i.e. facial identity or expression, and the sex of the subject on laterality are examined here for seven phases of this series of experiments. Both types of discrimination produced a right hemispheric advantage, with slightly greater laterality for expression, but generally the laterality did not differ significantly for the two types. Female monkeys demonstrated more consistent and significant right hemispheric laterality than did males. Furthermore, female monkeys tended to be more lateralised for discriminations of expression, whereas males were about equally lateralised for both types. Thus, in these experiments the overall right hemispheric advantage for facial discriminations in monkeys reflects the contribution of the female subjects, especially when discriminating expression, more than that of the males.

PACE BOM chemotherapy: a 12-week regimen for advanced Hodgkin's disease.

BACKGROUND: This study was designed to evaluate the efficacy and toxicity of a 12-week alternating weekly chemotherapy regimen for advanced Hodgkin's disease. Consolidative irradiation of residual masses was used in selected cases. PATIENTS AND METHODS: Eighty-three patients with newly diagnosed advanced Hodgkin's disease (bulky stage IIA, stage IIB-IVB) or with progressive disease after extended field radiotherapy for early stage disease were included in this study. The patients were treated for 12 weeks with PACE BOM comprising oral prednisolone together with intravenous doxorubicin, cyclophosphamide and etoposide alternating weekly with intravenous bleomycin, vincristine and methotrexate. Limited field adjuvant radiotherapy was also given to 21 patients with localised persistent radiological abnormalities visible on chest X-ray after chemotherapy. The study end points were overall survival, failure free survival (FFS) and toxicity, particularly with respect to reproductive function. RESULTS: With a median post treatment follow up of 52 months the actuarial 5-year overall survival is 90% (confidence interval 81%-95%) and FFS is 64% (52%-74%). This treatment was well tolerated and fertility was maintained in a high proportion of young adults. CONCLUSIONS: The brief duration PACE BOM regimen with or without radiotherapy appears to be comparable in efficacy to other doxorubicin containing regimens, with a favourable toxicity profile. Randomised clinical trials are now needed to evaluate the role of this and comparable initial treatment approaches to advanced Hodgkin's disease.

Tryptophan needs of lactating sows fed diets supplemented with crystalline lysine.

Large White x Landrace primiparous and multiparous sows (n = 115) were used to evaluate the tryptophan needs of lactating sows fed diets supplemented with crystalline lysine to contain .75% lysine. Sows were fed 1.8 kg of their allotted diets from d 110 of gestation until parturition and then were allowed ad libitum access to diets analyzed to contain either .12 (n = 58) or .17% (n = 57) tryptophan during a 21-d lactation. Diets were created by crystalline tryptophan and lysine additions to a corn-soybean meal basal diet that contained .12% tryptophan. Tryptophan level in the lactation diet did not affect number or weight of pigs at 21 d (P > .10). Sows fed .17% tryptophan were heavier at d 21 of lactation than those fed .12% tryptophan (P = .09) due to less weight loss during the 21-d lactation (P = .09). Feed intake was greater (P < .05) for sows fed .17% tryptophan than for sows fed .12% tryptophan. A reference diet analyzed to contain .11% tryptophan and .63% lysine was fed to an additional 11 sows only as a baseline for measuring plasma urea nitrogen and amino acids. Plasma tryptophan concentrations were higher (P < .05) for sows fed .17% tryptophan than for sows not fed added L-tryptophan. Among sows fed the low-tryptophan diets, sows fed the reference diet (.60% lysine) had higher (P < .05) plasma phenylalanine and valine concentrations than sows fed .75% lysine. Diet did not affect plasma concentrations of any other essential amino acid (P > .10). Plasma urea N levels were lower (P = .11) for sows fed the diet supplemented with tryptophan. Lactating sows allowed ad libitum access to diets containing .75% lysine benefited from higher feed intake and lower weight loss when dietary tryptophan levels were increased from .12 to .17%.

Patterns of clinical metastasis in breast cancer: an analysis of 100 patients.

Many patients diagnosed with breast cancer will develop metastases and these have diverse presentations. We have reviewed 100 consecutive patients who have died with metastatic breast cancer, to determine the frequency, sites and mode of presentation of recurrent disease. The commonest site of failure was loco-regional (n = 61), this usually presented with a mass, but a minority of patients also complained of pain. Bone metastases developed in 60 patients and produced bone pain, pathological fracture (n = 6) or cord compression (n = 5). Pulmonary metastases producing shortness of breath were diagnosed in 34 patients and were asymptomatic in a further 10. Intra-abdominal metastases were found at some time in 23 patients, most commonly in the liver (n = 20) and the majority complained of epigastric pain (n = 17). Brain metastases occurred in 23 patients and produced a wide range of symptoms including those of a space-occupying lesion (n = 10), cranial nerve palsy (n = 7), diabetes insipidus (n = 3), focal limb weakness (n = 2) and meningitis (n = 1). Three patients had choroid metastases producing reduced visual acuity. Recurrent breast carcinoma can present in a variety of ways, therefore any new symptom or sign should be considered to represent recurrence until proved otherwise.

Hemispheric representation of the central retina of commissurotomized subjects.

It is controversial whether a stimulus projected within 1 to 3 degrees from the boundary between the right and left hemiretina is transmitted to only one cerebral hemisphere or to both cerebral hemispheres. In order to resolve this issue, letter- and word-stimuli were presented for 200 msec with a new type of tachistoscope, called the fundus tachistoscope, in and about the central retina, (i.e. fovea, 1.2 degrees in horizontal diameter) of the right eyes of two commissurotomized subjects (N.G. and A.A.). During stimulus presentation the subjects were attempting to fixate a fixation target. The fundus tachistoscope combined with image analysis of the fundus enables us to measure the position of the stimulus on the retina, relative to the foveal center, as well as whether or not the eye moved during stimulus presentation. The results indicate that the region of the right (temporal) hemiretina represented by both hemispheres in letter processing, if it exists, was estimated as less than 0.6 degrees from the foveal center. The two subjects frequently (27% in N.G. and 46% in A.A.) fixated the fixation target eccentrically, i.e. with a retinal point other than the foveal center, during fixation, namely stimulus presentation. Their eccentric fixations were small with magnitude almost all falling between 1.35 degrees right and 1.25 degrees left of the foveal center. It is therefore recommended that letter-stimuli be presented at least 2.0 degrees from the foveal center in ordinary tachistoscopic studies of cerebral hemispheric differences. Eye movements, which varied in 0.11 degrees and 1.43 degrees horizontally, occurred in about 8% of all the trials during fixation. On the average of the two subjects, the eye movements caused or worsened eccentric fixation in only about one third of the trials, and corrected eccentric fixation in about two thirds of the trials.

The dietary protein and(or) lysine requirements of barrows and gilts. NCR-42 Committee on Swine Nutrition.

A cooperative research study involving three experiments and 2,318 pigs was conducted at 12 research stations to evaluate the protein (lysine) requirements of barrows and gilts. The two sexes were penned separately and fed fortified corn-soybean meal diets containing protein levels ranging from 12.0 to 17.2%. Lysine levels in these diets ranged from .52 to .90%. Protein levels in Exp. 1 were 12, 14, and 16%; in Exp. 2, protein levels were 13, 14, 15, and 16%; and in Exp. 3, they were 13.2 15.2, and 17.2%. Fat (5%) was added to one-half of the diets in Exp. 3. Each station that participated contributed a minimum of two replicate pens of pigs per diet-sex combination in a given experiment. Average initial and final weights were 35 and 99 kg in Exp. 1 and 51 and 105 kg in Exp. 2 and 3, respectively. At the end of the test period, pigs were slaughtered and hot carcass weight, 10th rib fat depth, and longissimus muscle area were measured. Percentage of carcass muscle was estimated from these data. Overall, barrows gained weight faster than gilts (P < .01), but gilts required less feed per unit of gain (P < .05) and had less backfat, larger longissimus muscle areas, and a greater percentage of carcass muscle (P < .01) than did barrows. Lean growth rate was similar for barrows and gilts (332 vs 329 g/d). Increasing the dietary protein or lysine level resulted in improved rate and efficiency of gain and increased carcass leanness and lean growth rate in gilts, but the increase was less pronounced or did not occur in barrows, resulting in protein level x sex interactions. Feeding low-protein (12 or 13%) diets decreased performance and carcass leanness to a greater extent in gilts than in barrows. The pooled data from the three experiments indicated that most traits tended to reach a plateau at 13% CP (.60% lysine) in barrows, whereas in gilts, weight gains, feed/gain, carcass muscle, and lean growth rate continued to improve, but at a decreasing rate, with up to 17.2% CP (.90% lysine). The results indicate that gilts require higher concentrations of dietary amino acids to maximize lean growth rate than do barrows.

Assessment of morbidity from complete axillary dissection.

The importance of axillary dissection as part of the primary surgical procedure in the treatment of operable cases of carcinoma of the breast is established. The morbidity of this procedure, however, is less well documented. A study of 126 women who had had full axillary dissection as part of their initial surgical treatment was undertaken to assess their degree of morbidity in terms of numbness, pain, weakness, swelling, and stiffness. Seventy per cent of cases complained of numbness, 33% of pain, 25% of weakness, 24% of limb swelling, and 15% of stiffness. Objective measurements confirmed decreased sensation in 81%, weakness in 27%, swelling in 10%, and stiffness in 10%. In no case were these symptoms described as severe, though they did have an effect upon the daily lives of 39%. The side effects of full axillary dissection are common and all women should be warned of them prior to surgery; however they are usually mild and therefore should not preclude this procedure as a part of definitive surgical treatment.