Large White Female Pigs Research Articles

Radiation Nephropathy in Mature Pigs Following the Irradiation of Both Kidneys

Both kidneys in mature female Large White pigs, ca. 45 weeks old were irradiated with single doses of 7.8-14.0 Gy of 60Co gamma-rays. Radiation-induced changes in renal function were assessed on the basis of sequential individual measurements of kidney glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) for up to 24 weeks after irradiation. At the same time intervals blood samples were taken to determine plasma renin levels and the haematological status of each animal. Two weeks after irradiation the ERPF and in particular the GFR was increased. This was followed by a pronounced, dose-dependent, decline in renal haemodynamics. Minimal functional levels were observed 8-12 weeks after irradiation. Function then somewhat recovered. There was a significant (r greater than or equal to 0.98; p less than 0.001) inverse relationship between the mean values of GFR and ERPF, determined at 4-24 weeks after irradiation, and the radiation dose. After a dose of 7.8 Gy the reduction in ERPF was greater than that for GFR. However, at higher doses both parameters were reduced to an equal extent. The resulting slope of the dose-effect curve for impaired renal function versus dose was significantly steeper for GFR than that for ERPF (p less than 0.001). There was a significant reduction (p less than 0.002) in the erythrocyte count, the haematocrit and haemoglobin levels within 6-8 weeks of irradiation; this anaemia was characterized as a normochromic normocytic anaemia. There were no marked changes in plasma renin levels as a result of renal irradiation. The pathogenesis of late radiation-induced damage to the kidney is discussed in the light of these findings.

The response of the pig kidney to the combined effects of cisplatin and unilateral renal irradiation

Seven mature Large White female pigs, approximately 10 months of age received a single dose of cis-dichlorodiammineplatinum(II), c-DDP (2.5 mg/kg body weight). Prior to, and 4 weeks after c-DDP administration, individual kidney glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured by [ 99mTc]DTPA and [ 131I]hippuran renography. Of the 5 pigs surviving the c-DDP treatment most exhibited a reduction in both GFR and ERPF; the mean reduction in GFR (36.2 ± 18.9%) was more pronounced than that for ERPF (12.6 ± 19.4%). However, the difference in the severity of the impairment in these two parameters was not significant ( p > 0.55). Haematocrit, haemoglobin and red blood cell counts were markedly reduced 14 days after c-DDP infusion, and despite some recovery evident 21 days after treatment, all three haematological parameters were still reduced 28 days after c-DDP administration. The right kidneys of these 5 animals, plus 5 pigs which did not receive c-DDP, were irradiated with a single dose of 11.9 Gy of 60Co γ-rays. Individual kidney GFR and ERPF was routinely measured up to 24 weeks after irradiation. Pigs in which only the right kidney was irradiated showed a marked increase in both GFR and ERPF values 2 weeks after irradiation. This was followed by a decline in function with a reduction of 50% in terms of ERPF 16 weeks after irradiation. Values then showed some evidence of a recovery in function. There was a concomitant compensatory response by the contralateral unirradiated kidney. Animals that received c-DDP prior to irradiation failed to exhibit the hyperaemic response 2 weeks after irradiation. Moreover, the degree of reduction in renal function was greater than that observed in the irradiated kidneys of pigs receiving radiation alone. Prior treatment with c-DDP did not prevent a compensatory hypertrophie response by the contralateral unirradiated kidney; indeed the GFR in the unirradiated kidneys of c-DDP treated pigs increased at a greater rate than in those pigs which did not receive c-DDP. Thus prior treatment with c-DDP enhances the radiation-induced reduction in individual kidney GFR and ERPF.

Effect of protein and lysine levels in the diet on body gain composition and energy utilization in growing pigs.

Eight replicates of four Large White littermate female pigs were used to evaluate the effect of protein and lysine levels in the diet on the efficiency of protein and energy utilization. In each replicate, one pig was slaughtered at about 20 kg live weight and the others received three diets that contained (per Mcal digestible energy) 37.5 and 2.00 g (diet pl), 37.5 and 2.35 g (diet pL) or 45.0 and 2.35 g (diet PL) of digestible protein and lysine, respectively. Pigs were slaughtered after a 7-wk period. Tissue and chemical composition of the gain and energy and nitrogen gain were determined by using the comparative slaughter technique. Metabolizable energy (ME) intakes were similar in the treatments. Pigs fed the pl diet had a smaller body weight and muscle gain and retained less nitrogen and more lipids than pigs fed pL and PL diets. The decrease in the level of nonessential nitrogen in the diet (pL vs PL) did not affect body weight and muscle gain and the amount of nitrogen retained in muscle tissues. However, pigs given the PL diet had a higher total nitrogen retention and a lower fat deposition and exhibited a higher heat production. For each gram of additional protein catabolized for energy purposes (PL vs pL), heat production was increased by 1.8 kcal. The amount of lysine per unit of muscle gain (38 g/kg) or protein deposited (120 g/kg) was independent of protein and lysine levels in the diet. Estimates of energy (indirect calorimetry) and nitrogen (balance technique) retention were also obtained on the same animals; results were comparable with data obtained by direct measurements.

Breed and sex effects on the development and proportions of muscle, fat and bone in pigs

SummaryThe development and proportions of muscle, fat and bone were studied in 341 entire male and female Iron Age (European Wild Pig × Tamworth), Pietrain and Large White pigs ranging in live weight from 12 to 370 kg. The number of pigs was: Large White, 138 entire males and 112 females; Pietrain, 41 entire males and 31 females; Iron Age, eight entire males and 11 females. The breeds and sexes were compared in terms of the allometric growth coefficients of tissues (b) and of tissue weights at constant side weight and constant weight of total side bone.At the geometric mean for side weight (26·5 kg), Pietrain carcasses had the most muscle (16 kg), followed by Large White (15kg) and Iron Age (11 kg), but the least fat (6 kg). Large White and Iron Age carcasses had 7 and 12 kg of fat, respectively. Relative to side weight, the earliest maturing tissue, bone, was particularly slow growing in Iron Age pigs (b = 0·627) and relatively fast growing in Large Whites (b = 0·801). The opposite was true for fat, the latest maturing tissue, and consequently Iron Age (b = 1·345) and Large White (b = 1·164) pigs were identified as early and late maturing, respectively. Pietrains had a higher growth coefficient for fat relative to side weight (b = 1·249) and lower growth coefficient for bone (b = 0·713) than Large Whites. The difference in percentage fat between Pietrains and Large Whites decreased slightly between 65 and 120 kg live weight. In terms of tissue growth patterns, Pietrains therefore demonstrated early maturing characteristics compared with Large Whites, and it is possible that a low voluntary feed intake under ad libitum feeding conditions prevents them from expressing these characteristics in terms of percentage of fat in the side. Pietrains had a particularly high muscle:bone ratio (6·2 at the mean side weight) compared with Large White (5·2) and Iron Age pigs (5·3).The difference in carcass composition between entire males and females was breeddependent. Entire male carcasses were slightly leaner overall and had a lower muscle: bone ratio than those of females, but tissue allometric growth patterns were similar in the two sexes.

Body composition and feed intake of young pigs postweaning

AbstractThirty‐five female Large White pigs were weaned at 14 days of age, penned individually, given a single diet and slaughtered serially at 25, 40, 55 and 70 days of age. A control group was fed to appetite throughout while three groups were subjected to feed restriction at various ages postweaning. For the periods 25 to 40, 40 to 55, 55 to 70 days of age pigs fed to appetite gained 321 (±19.9), 532 (±35.4) and 601 (±35.5) g liveweight day−1. Pigs restricted between 25 and 55 days, followed by refeeding from 55 to 70 days, gained 192 (±14.0), 169 (±44.8) and 508 (±81.0) g liveweight day−1; pigs restricted between 40 and 55 days, followed by refeeding from 55 to 70 days, gained 425 (±42.8), 409 (±49.6) and 480 (±70.1) g liveweight day−1. A group given 200 g feed day−1 gained 42 (±4.2) g liveweight daily between 25 and 70 days. Refed groups did not differ significantly from controls in their feed intakes for the period 55 to 70 days, either in absolute intakes or in feed intake kg−1 mean liveweight. Refed pigs grew no faster, and made no greater protein gains than controls of equivalent weight; however, lipid gains were elevated.

Functional recovery in the irradiated kidney following removal of the contralateral unirradiated kidney

The right kidneys of seven Large White female pigs, approximately 14 weeks of age, were irradiated with single doses of 7-12.6 Gy of 250 kV X-rays. Sequential measurements of individual kidney glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were carried out using 99mTc-DTPA and [131I]hippuran renography for time periods up to 24 weeks after irradiation. From this data, kidneys receiving a dose of 7 Gy were found to be functioning (F), while kidneys which received greater than or equal to 8.8 Gy were assessed as having no significant function (NF). When the pigs were approximately 10 months of age the contralateral unirradiated kidney was removed; the left kidney of three age-matched unirradiated pigs was also removed. The response of the right kidney to unilateral nephrectomy (UN) in these animals was assessed in terms of changes in haemodynamics (i.e. GFR and ERPF) for periods up to 24 weeks after UN. At post-mortem, the length and weight of the remaining kidney was measured. A marked increase in renal length was observed in irradiated kidneys following UN. In addition, the weights of irradiated kidneys following UN were greater than those of irradiated kidneys in age-matched pigs where the unirradiated kidney had not been removed. Four weeks after UN there was a pronounced increase in GFR and, in particular, ERPF in previously NF irradiated kidneys. The mean increase in these parameters, measured at the end of the follow-up period, when compared with the pre-surgery values, was 350.1 +/- 84.3 and 781.8 +/- 151.0% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Post-natal changes in some histochemical and enzymatic characteristics of three pig muscles

Post-natal changes in histoenzymatic and enzymatic characteristics were studied in porcine longissimus, psoas major and tibialis cranialis muscles. The experiment was carried out on thirty-five female large White pigs: fifteen were slaughtered between birth and 120 kg body weight (BW) and twenty at the market liveweight of 100 kg. The relative growth of each of the three muscles in relation to BW appeared to be monophasic, the allometric growth rates differed significantly between muscles: 1·21, 1·08 and 0·97, respectively. Myofibers were classified according to their contractile and metabolic properties as βR, αR and αW fibers. In the three muscles, the percentage of β fibers increased from birth up to 2 months of age and little change occurred thereafter. Glycolytic fibers were detectable only from about one month onwards. Their percentage then increased rapidly up to 30–50 kg BW to reach 60%, 30% and 12% in longissimus, psoas major and tibialis cranialis muscles, respectively. Thereafter, these values only changed slightly. This histoenzymatic differentiation led to the typical type grouping found in pigs. Throughout the period studied, the cross-sectional area of the myofibers increased with some differences according to fiber type and muscle. Lactate dehydrogenase (LDH) specific activity was similar in the three muscles at birth and then increased rapidly up to 4–5kg BW (15–20 days of age), although to a greater extent in the future glycolytic muscle ( longissimus) This increase then abruptly slowed down. The period between 15 and 20 days of age corresponds to a critical stage already known in the rearing of pigs, i.e. growth rate, body composition and food intake. Changes in isocitrate dehydrogenase (ICDH) specific activity were much slighter and differed according to the muscle. There were close correlations between percentages of αW fibers and enzymatic kinetic measurements from one month onwards.

Effects of single doses of X-rays on renal function in unilaterally irradiated pigs

The right kidney of 13 Large White female pigs was irradiated with single doses of 250 kV X-rays in the range 7-12.6 Gy. Sequential measurements of individual kidney glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were carried out by means of 99mTc-DTPA and 131I-hippuran renography for periods up to 24 weeks after irradiation. GFR levels increased in irradiated and unirradiated contralateral kidneys 2 weeks after treatment compared with age-matched controls. ERPF values exhibited a small increase in a proportion of animals. Renal function then declined in irradiated kidneys in a dose-dependent manner. A dose of 7 Gy resulted in a decline followed by subsequent recovery. After doses of greater than or equal to 8.8 Gy GFR and ERPF declined rapidly, reaching minimal levels by 6-12 weeks, the time depending on the dose. The reduction in ERPF was quantitatively greater than that for GFR. In animals receiving greater than 8.8 Gy the irradiated kidney contributed in the order of only 10% of the total ERPF. The reduction in GFR resulted in a prompt functional compensatory response in GFR in the unirradiated contralateral kidney. In terms of ERPF, a compensatory response was not evident until weeks 20-24. The results indicated that the radiation tolerance dose of the pig kidney following unilateral irradiation with single doses of X-rays was approximately 8 Gy.

Techniques for the quantitative measurement of individual kidney function in the pig

A prerequisite for elucidating the effect of radiation on porcine renal function is the development of non-invasive methods for accurate quantification of unilateral glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). The techniques presented here are (a) measurement of unilateral kidney filtration fraction (FF) determined by analysis of the early rise of the kidney's time-activity curves following the injection of tubular ([ 131I]hippuran) and glomerular ([ 99mTc]DTPA) tracers, and (b) deconvolution of the respective renogram. Unilateral FF values are obtained by calculating the ratio of glomerular to tubular clearances. Results for 23 female large white pigs indicate a highly significant correlation ( r=0.91, P<0.001) between computed FF values and those obtained from the plasma disappearance curves of [ 99mTc]DTPA and [ 131I]hippuran. Deconvolution of the renogram allows estimation of the mean transit time (MTT) for [ 99mTc]DTPA and [ 131I]hippuran, these are 6.94±1.87 and 6.86±1.44 min respectively. In addition, FF values calculated from the H 0 values are significantly correlated ( r=0.7, P<0.05) with estimates from plasma disappearance curves of the tracers. Therefore these techniques appear to provide accurate non-invasive methods for determing individual porcine kidney function.

Single injection techniques in determining age-related changes in porcine renal function

Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined in 32 anaesthetised female Large White pigs, aged 4–24 months, from the plasma disappearance curves of [ 99m Tc] DTPA and [ 131I]hippuran respectively. Clearance was also monitored by external counting over the heart. GFR and ERPF increased markedly with age in pigs up to 12 months old, reaching mean values of 242.06 ± 5.89 and 919.39 ± 79.01 mL/min. In pigs aged 12–24 months ERPF increased slightly, but renal function remained essentially unchanged after 1 yr of age. These results for renal function were similar to previous estimates, using continuous infusion techniques inferring that GFR and ERPF could be accurately monitored using single injection procedures.

Some comparative aspects of the energy and nitrogen metabolism of Large White and Duroc female pigs during growth

Abstract The energy and nitrogen metabolism of Duroc and Large White female pigs offered 2 levels of feeding were compared in open-circuit calorimeters at 30 and 80 kg liveweight. Fasting heat production was measured after the final energy balances. The digestibilities of energy and nitrogen were lower for the Duroc than the Large White pigs, but only nitrogen digestibility was significantly different (P<0.05). Metabolisability of gross energy, fasting heat production, and the regression of energy retention on metabolisable energy intake did not differ significantly between the breeds (P>O.05). During this experiment (in which the pigs increased from 20 to 90kg liveweight) the 2 genotypes had similar growth rates and feed conversion ratios.

Degeneration and regeneration of the olfactory epithelium after olfactory bulb ablation in the pig: a morphological and electrophysiological study.

The olfactory bulbs were removed surgically from Large White male and female pigs, 10--12 weeks of age. At intervals of 3, 7, 14, 42 and 84 d after bulbectomy, the pigs were sacrificed and portions of olfactory mucosa were removed from the ethmoturbinate and septum regions of the nasal cavity; olfactory mucosa was also removed from unoperated pigs. A piece of each tissue sample was processed for light microscopy. The remaining tissue was placed in Ringer-Locke solution, saturated with O2/CO2 at room temperature, and the electrical activity of the olfactory epithelium was investigated in vitro by passing a stimulus of butyl acetate vapour over the epithelium. Slow negative potential changes (electro-olfactogram, e.o.g.) induced by butyl acetate were recorded. During the first two weeks after bulbectomy there was a rapid decrease in the height of the olfactory epithelium associated with the disappearance of the e.o.g. response. However by 42 and 84 d after bulbectomy, partial recovery of the height and some electrical activity of the olfactory mucosa had occurred. In some pigs, the insertion of a stainless steel lining over the cribriform plate to prevent any association of regenerating axons with forebrain tissue had no effect on the regenerative characteristics studied.

Genetic parameters of Large White and French Landrace progeny testing female pigs over the 1970-1978 period

Genetic parameters of Large White and French Landrace progeny testing female pigs over the 1970-1978 period

Very low density lipoprotein metabolism in domestic pigs

Patterns of triacylglycerol (TG) turnover in plasma and liver, and the hepatic secretion of very low density lipoprotein triacylglycerol (VLDL TG) into the circulation, have been studied in young Large White female pigs, using i.v. tracer [1,3- 14C]- and [2- 3]glycerol. Serial measurements were made of plasma [ 14C]glycerol and [ 14C]glucose and of liver TG and plasma VLDL TG specific activities. In other studies VLDL TG obtained from a donor pig was reinjected into recipient animals to measure the early disappearance (dilution) of VLDL TG. Multicompartmental analysis revealed a mean rate of hepatic TG turnover somewhat slower than the rate of VLDL TG turnover, suggesting that almost all of the hepatic TG turnover was due to secretion of VLDL TG, and that the intestine probably contributed an appreciable part of the newly synthesized plasma VLDL TG. The t 1 2 of reinjected VLDL TG, whether prepared by the most rapid possible techniques and reinjected immediately or stored for several days, was approximately 10 min. This was much faster than the t 1 2 of the falling limb of the plasma VLDL TG curve seen after injection of labelled glycerol ( t 1 2 approximately 2 h). Thus, in these respects, the pig resembled all other species studied rather than human subjects as described by Farquhar et al.

The plasma and tissue turnover and distribution of two radio-iodine-labelled pig plasma low density lipoproteins

Two classes of pig plasma low density lipoprotein (LDL 1 and LDL 2) with different densities and molecular sizes were isolated by zonal ultracentrifugation and were further purified by flotation. The peptide component was iodinated with 125I, and the labelled lipoprotein was injected intravenously. 125I-LDL 1 turnover studies were performed on 22 3–4 month old female Large White pigs, and 125I-LDL 2 turnover studies on 4 similar pigs. A biological screening experiment confirmed that the shape of the plasma activity curve was not a function of protein denaturation. The pattern of radioactivity decline in plasma was not affected by the degree of LDL iodination. 125 I-LDL 1 turnover The curve of plasma radioactivity plotted against time over the first 5 days after injection could be resolved into two exponentials. The plasma biological half-life ( T 1 2 ) was calculated from the slower exponential predominant from the second day. The mean T 1 2 over 2–5 days was 22.9 hr (range 17.2 – 28.5 hr). Multicompartmental analysis of the plasma decay curve using an open mammillary model gave a mean fractional catabolic rate per day for LDL 1 of 1.4 (range 0.9 – 1.9). The mean T 1 2 was 0.26 – 0.31 times and the fractional catabolic rate 3.0 – 3.9 times those values found in two studies on adult humans. The tissue distribution of 125I was analysed in a series of 20 animals killed from 1.0 to 33.8 days after 125I-LDL 1 injection. Most tissue 125I (86–89%) was protein bound. An appropriate correction was made to the 125I counts for retained plasma in liver and spleen (using 131I-albumin); retained plasma in other tissues was negligible. Highest 125I tissue levels were found in the liver, supporting other evidence that the liver may be the major site of LDL 1 catabolism. After 2.06 and 4.06 days the livers in two animals contained 1.6% and 0.7% respectively of the total injected 125I, equal to 33% and 54% of the total plasma 125I at those times. The skin contained about one-third to one-ninth the 125I in the liver at various times. Distribution in other organs was quantitatively minimal. Higher levels of radioactivity were found in the intima and inner media of the aorta than in the outer media. These results suggest that plasma LDL in the pig diffuses through the endothelial surface into the arterial wall. These findings are confirmed by autoradiography. 125 I-LDL 2 turnover Parallel studies of plasma 125I-LDL 2 turnover and tissue distribution were performed. The plasma biological decay curve was multi-exponential, suggesting that LDL 2 metabolism is complex, and possibly more rapid than that of LDL 1 (LDL 2 is smaller and denser than LDL 1). The tissue distribution of 125I-LDL 2 in these pigs was very similar to that of 125I-LDL 1. As LDL 1 and LDL 2 differ in the amount of lipid they contain, they may have different roles to play in lipid transport, and there may be interconversion of one into the other at different sites. This hypothesis remains conjectural.

A comparison of tissue development in Pietrain and Large White pigs from birth to 64 kg live weight. 3. Growth changes in bone distribution

SUMMARYHalf carcasses of 18 Pietrain and 18 Large White female pigs were dissected into 10 bone units. An allometric analysis of the weights of these units relative to total bone revealed increasing craniocaudal and distoproximal growth gradients. No differences in bone distribution were observed between the two breeds. Because of a difference in muscle distribution, the muscle: bone ratio in the femoral region of the Pietrain was greater than that of the Large White breed.

A comparison of tissue development in Pietrain and Large White pigs from birth to 64 kg live weight 2. Growth changes in muscle distribution

SUMMARYHalf carcasses of 18 Pietrain and 18 Large White female pigs were each dissected into 93 muscle units. An allometric analysis of the weight of these units relative to total muscle revealed increasing craniocaudal and distoproximal growth gradients, which were more pronounced in the Pietrain.The greater total weight of muscle, shown previously for the Pietrain at any given body weight over the range studied, was not due to higher muscle weights in any particular region at birth, but at 60 kg body weight was due to heavier high impetus muscles. Heart weight relative to total muscle weight was higher for the Large White over the entire range.It is concluded that for the animals studied the changes in muscle distribution are related to the functional demands of an increase in body size, and that the muscle distribution of pigs can differ between breeds.

A note on meat production from pigs slaughtered after first weaning a litter

SUMMARYFourteen Large White female pigs were mated at about 6 months of age and 90 kg live weight. Three of them gave birth to very small litters and were slaughtered a week after parturition at an average live weight of 166 kg. From the other 11 females 6-week-old litters with average an of 8-8 piglets were weaned. Twenty-four days after weaning the mothers, averaging 152 kg live weight, were slaughtered. Performance was compared with that of unmated females slaughtered at 90 or 130 kg live weight. After subtracting the amount of feed used normally for the production of weaned litters from the total feed consumption of the 14 females which farrowed, the feed intake per 1 kg live-weight gain was 3·67 kg, as compared with 3·43 kg and 4·46 kg in the groups slaughtered at 90 or 130 kg live weight, respectively. The average daily protein deposition in the 14 females together with their litters was 119·6 g, compared with 104·1 and 81·4 g in the control groups.

Studies of the toxicity of copper to pigs. 1. Effects of oral supplements of zinc and iron salts on the development of copper toxicosis.

1. Six groups of four litter-mate female Large White pigs of about 17 kg live weight were allocated according to a 2×2 factorial design in each of two experiments in which rations containing 0 or 750 ppm copper were offered with either 0 and 500 ppm zinc, or 0 and 750 ppm iron. 2. Severity of toxicosis was assessed by determining aspartate transaminase activity in serum, observing the incidence of jaundice and determining the hemoglobin concentration in whole blood and Cu concentration in serum and liver. 3. Addition of 750 ppm Cu to the diet caused toxicity in nine out of twelve animals; it was most severe after about 4 weeks when two-to five-fold increases in serum Cu and aspartate transaminase levels were found and seven pigs were jaundiced. Serum Cu and aspartate transaminase concentrations and degrees of jaundice were apparently interrelated and returned to normal levels after 6 weeks, suggesting adaptation to the high Cu intake. Growth depression and a microcytic hypochromic anaemia persisted. 4. Addition of 500 ppm Zn or 750 ppm Fe in the presence of 750 ppm Cu eliminated jaundice and produced serum Cu and aspartate transaminase concentrations similar to control values after 4 weeks. Only supplementary Fe afforded protection against anaemia. 5. Variability in the response of the pig to Cu supplements could be partly due to variations in the intake of Fe and Zn. The addition of Fe and Zn supplements to pig diets supplemented with Cu would probably reduce the small risk of causing Cu poisoning.