A 3-yr study evaluated late winter (Feb), early spring (Apr), and late spring (Jun) calving systems in conjunction with varied weaning strategies on beef cow and calf performance from Northern Great Plains rangelands. Crossbred cows were randomly assigned to one of three calving systems (on average n= 168.calving system(-1).yr(-1)) and one of two weaning times (Wean 1, 2) within each calving system. The Feb and Apr calves were weaned at 190 and 240 d of age, whereas Jun calves were weaned at 140 and 190 d of age. Breeding by natural service occurred in a 32-d period that included estrous synchronization. Cows were managed throughout the year as appropriate for their calving season. Quantity and quality of hay and supplements were provided based on forage and weather conditions, physiological state of the cows, and available harvested feed resources within a year. After weaning, two-thirds of the early weaned steers were fed in confinement in Montana, and one-third were shipped to Oklahoma and were grazed or fed forage. One-half of the early weaned heifers grazed seeded pastures, and the other half was fed in confinement. Early weaned calves were weighed on approximately the same day as late-weaned calves. Birth weight and overall rate of gain from birth to weaning did not differ for calves from the three calving systems. Calf weaning weight differed by weaning age within calving system (P = 0.001), and calves from the Jun calving system that were weaned at 190 d of age tended (P = 0.06) to be lighter than calves of the same age from the Feb or Apr calving systems. Cow BW change and BCS dynamics were affected by calving system, but the proportion of cows pregnant in the fall was not. Cows suckled until later dates gained less or lost more BW during the 50 d between the first and second weaning than dry cows during this period. The previous year's weaning assignment did not affect production in the following year. Estimated harvested feed inputs were less for the Jun cows than for the Feb and Apr cows. We conclude that season of calving and weaning age affect outputs from rangeland-based beef cattle operations.
Our objective was to determine if serum concentrations of leptin could be used to predict carcass composition and merit in feedlot finished cattle. Two different groups of crossbred Bos taurus steers and heifers were managed under feedlot conditions near Miles City, MT. The first group consisted of 88 1/2 Red Angus, 1/4 Charolais, and 1/4 Tarentaise composite gene combination steers (CGC) harvested at the ConAgra processing facility in Greeley, CO. The second group (Lean Beef Project; LB) consisted of 91 F-2 steers and heifers born to Limousin, Hereford, or Piedmontese by CGC F-1 cows crossed to F-1 bulls of similar breed composition and harvested at a local processing facility in Miles City, MT. Blood samples were collected approximately 24 h before harvest (CGC) or approximately 3 d before and at harvest (LB). No differences in serum concentrations of leptin were detected (P > 0.10) between Hereford, Limousin, or Piedmontese F-2 calves nor between LB steers and heifers. Positive correlations (P < 0.01) existed between serum leptin and marbling score (r = 0.35 and 0.50), fat depth measured between the 12th and 13th rib (r = 0.34 and 0.46), kidney, pelvic, and heart fat (KPH) (r = 0.42 and 0.46), and quality grade (r = 0.36 and 0.49) in CGC and LB cattle, respectively. Serum leptin was also positively correlated with calculated yield grade for CGC steers (r = 0.19; P = 0.10) and LB cattle (r = 0.52; P < 0.01). Longissimus area was not correlated with serum leptin in CGC steers (r = 0.12; P > 0.10). However, a negative correlation existed between longissimus area and serum leptin in the LB cattle (r = -0.45; P < 0.01). Serum concentrations of leptin were significantly associated with carcass composition (marbling, back fat depth, and KPH fat) and quality grade in both groups of cattle studied and may provide an additional indicator of fat content in feedlot cattle.
Objectives were to determine 1) effects on traits measured from birth to slaughter in F-2 cross calves from sire breeds that differ in potential for lean tissue growth but have similar mature BW and 2) the gene action of the mutant Piedmontese myostatin allele. Hereford (normal muscling, H), Limousin (moderate increase in muscling, L), and Piedmontese (muscular hypertrophy, P) sires (20 to 25 per breed) were bred at random to crossbred cows to produce F-1 calves that were inter se-mated within sire breed to produce F-2 calves that were grown out, finished, and slaughtered. Piedmontese-cross calves were genotyped for the G-A transition mutation at the myostatin locus characteristic of P (msP). Genotypes were classified on the basis of having zero (P-0), one (P-1), or two (P-2) copies of msP (H, n = 227; L, n = 207; P-0, n = 40; P-1, n = 107; and P-2, n = 37). Limousin-cross F-2 calves had heavier birth (but dystocia was not affected) and weaning weights, gained faster, had more muscle, less fat, larger pelvic area, and more efficient feed conversion than Hereford-cross F-2 calves. Normal-muscled Piedmontese-cross F-2 calves (P-0) were similar to Hereford-cross F-2 calves except that they required less assistance at birth in heifer dams, had less fat, gained slower, were less efficient, and had larger pelvic area. Addition of msP alleles (P-1 and P-2) consistently increased muscle through hyperplasia, decreased fat, and increased adjusted efficiency, but many of those changes were not linear. Residual variances for breed were heterogeneous for most traits related to muscularity. This heterogeneity was caused by increased variances for L and P and(or) lower variances for H. Accounting for the msP alleles decreased the variance for P in most traits, but heterogeneity remained for most traits among the five genotypes because L remained high, H was low, and(or) P-2 was low. We conclude that differences in muscularity affect most traits, and when differences in muscularity include the msP allele, there is an incremental, but not equal, change in most traits with the addition of each copy of the msP allele. Advantages of L could be captured through normal crossbreeding and selection schemes but with some caution because of potential problems from increased variability. Advantages of P could be best captured through more complex breeding and selection programs that would lessen potential negative impacts and through marketing systems that do not penalize for very low fat.
ABSTRACT Consumption of pine needles tends to cause abortion in domestic cattle but not in elk. the present study was undertaken to determine whether this difference was associated with the rumen microbial population. After emptying the rumen, pregnant cattle were inoculated with either elk or cattle rumen contents. For those cows fed the pine needle diet, there was no difference in abortion rate between those inoculated with rumen contents from either elk or cattle. Protozoal concentrations and number of genera were observed to decrease markedly in all cows fed the diet containing pine needles. the cycloposthiid ciliate Parentodinium africanum was observed in rumen contents from several of the domestic cattle ( Bos taurus ). Concentrations ranged from 1.4 to 130.6 × 10 4 per ml of rumen contents, which comprised 4.6 to 80.3% of the total ciliate population. Mean dimensions of this species were: length, 33.4 μm: width, 19.7 μm: length/width ratio, 1.70. which were similar to those previously reported for this species from Bos indicus in Brazil. This is the first observation of P. africanum. originally observed and described in stomach contents of the hippopotamus, either in Bos taurus or in and host in the northern hemisphere.
Cattle of varied genetic growth potential may respond differently to management strategies because of altered nutrient demands for growth, An option for postweaning calf management is use of improved pastures for grazing. A 3-yr study (1990 to 1992) was conducted to evaluate the effects of supplemental soybean [Glycine mar (L.) Merr.] meal (SBM) on performance of Bos taurus steers (average weight 471 lb) of high-(Charolais-sired) or moderate- (Hereford-sired) genetic growth potential, Each year, 23 (Year 1 and 3) or 24 (Year 2) steers grazed pastures of a Russian wildrye [Psathyrostachys juncea (Fischer) Nevski]-wheatgrass hybrid [Elytrigia repens (L.) Neuski] x [Pseudoroegneria spicata (Pursh,) Love] complex, One-half of the steers were individually fed SBM (1 lb/d, as fed) 5 d/wk in 1990 and 7 d/wk in 1991 and 1992, Crude protein of consumed forage, as determined from esophageal masticate, averaged 15.1, 14.8, and 12.6 in mid-October and 10.5, 14.5, and 7.0% of organic matter (OM) in mid-December of 1990, 1991, and 1992, respectively, Steers of high genetic growth potential gained 1.4 lb/d compared with 1.2 lb/d for moderate growth potential steers (P < 0.05) and SBM supplemented steers had greater gains (P < 0.01) than nonsupplemented steers (1.5 vs 1.1 lb/d), Forage OM intake was affected by year (P < 0.01) and genetic potential for growth (P < 0.05), Forage OM intake averaged 8.8, 9.4, and 7.5 lb/d for 1990, 1991, and 1992, respectively, and 9.0 and 8.1 lb/d for high- and moderate-growth potential steers, Supplementation with SBM was cost effective for steers grazing regrowth in irrigated Russian wildrye-wheatgrass hybrid pastures in the fall.
Consumption of needles from Pinus ponderosa (PN) during late pregnancy causes cattle, but not sheep, to abort. This differential response may be caused by differences in ruminal microflora or postabsorptive metabolism. Pine needles were fed (2 kg.cow-1.d-1 or .4 kg.ewe-1.d-1) mixed with corn silage. In Exp. 1, cows were assigned at 250 d of pregnancy to feed treatments (T): 1) silage, 2) PN+silage, or 3) pretreated with sheep ruminal fluid and fed PN+silage. Interval to parturition was 34.3, 11.3, and 8.3 d for the T1, T2, and T3, respectively (T1 vs T2 + T3, P < .01; T2 vs T3, P > .5). Inoculation with sheep ruminal fluid did not alter activity of the abortifacient agent of PN. In Exp. 2, pregnant and nonpregnant ewes and cows were fed silage or PN mixed with silage, and plasma was analyzed for uterine vasoconstrictive activity in an in vitro placentome perfusion bioassay. Consumption of PN decreased interval to parturition in cattle (P < .01) but not in sheep (P > .5) and increased vasoconstrictive activity (P < .05) in plasma from nonpregnant and pregnant cows and ewes. The PN-fed ewes had a greater incidence of dead lambs at parturition (0/8 vs 5/8 for control vs PN-fed, P < .01). We conclude that pregnancy is not required for increased vasoconstrictive activity induced by pine needles, that sheep and cattle do not differ in ruminal metabolism of the abortifacient compounds in PN, and that species differences are subtle and due to postdigestive differences in response to the abortifacient agent.
A study was conducted over 2 years to evaluate the quality of forage selected by suckling calves compared to mature steers, Diets were collected from esophageally cannulated suckling calves or from steers that were two-years-old or older, Sampling was conducted in June, July, September, October, and November in each of 2 years, The forage portion of diets of esophageally fistulated suckling calves (beginning 115 to 136 days of age) were 21% greater (P < 0.01) in crude protein and 5% less (P < 0.06) in neutral detergent fiber relative to those consumed by mature steers in June and July, Diets of calves also contained 14% less (P < 0.01) acid detergent fiber than diets of mature steers in June, There were no differences in diet quality due to age during September, October, and November of either year, We conclude that suckling calves selected diets of higher quality than did mature steers early in the growing season, Forage quality may have allowed selective behavior at this time, low forage intakes of calves may have allowed more time for selection, or exploratory grazing by calves may have resulted in diets with increased nutrient quality in early summer.
Pregnant cows were fed pine needles (PN, 2 kg.cow-1.d-1) mixed with the diet to determine factors that affect abortion response. In Exp. 1, treatments were used to determine the effects of experimental stress and pelleting of pine needles. Pelleting needles and experimental stress delayed abortion response (P < .01). Stress-induced delay was associated with abnormal patterns of progesterone and cortisol (P < .01). In Exp. 2A and 2B, the role of the corpus luteum (CL) in abortion response to PN consumption was investigated by regressing the CL with prostaglandin F2 alpha. Regression of the CL and PN feeding reduced interval to parturition, but the effect of PN feeding was less when the CL was regressed (PN x CL, P < .01). The progesterone increase in response to experimental stress was decreased by CL regression (P < .01). In Exp. 3, melengestrol acetate (MGA) was fed (0, 2, or 4 mg.cow-1.d-1) in addition to PN. Parturition was blocked more effectively as dose of MGA increased (P = .075), but only parturition was blocked rather than the effects of PN. In Exp. 4, CL regression was blocked by feeding ketoprofen. Ketoprofen delayed response to PN, but the effect was only temporary (P < .01). Our conclusions are that 1) experimental stress delays abortion response to PN by increased concentrations of progesterone, 2) pelleting PN decreases their abortifacient activity, and 3) abortions caused by PN can be blocked by feeding a progestin or a prostaglandin inhibitor, but these compounds do not block the primary abortifacient effects of PN.
Ground beef samples (n = 302) were analyzed for DM and fat content with standard laboratory procedures. Samples were also analyzed by light spectroscopy with either a NIRSystems model 6250 or a model 6500. Samples were thawed at room temperature, packed in cups (three/sample), and scanned every 2 nm with the model 6250 in the mid wavelength (MW) region from 1,100 to 2,500 nm (MW-6250). Whirl-pak bags containing the thawed samples were also scanned every 2 nm with the model 6500 using a fiber optic attachment in the short wavelength (SW) region from 400 to 1,100 nm (SW-6500), 1,100 to 2,500 nm (MW-6500), and 400 to 2,500 nm (SW+MW-6500). Each sample was scanned at two different locations on the Whirl-pak bags. The MW-6250 produced the lowest standard errors of calibration (1.62 and 1.62%) and highest R2 values (.97 and .98) for DM and fat, respectively, during calibration. However, SW-6500 produced the lowest standard errors of performance (2.34 and 1.92%) and the highest r2 values (.86 and .95) for DM and fat, respectively, during validation. The MW-6500 and SW+MW-6500 produced intermediate results. Results with fiber optic scanning in the SW region were better than with cups and scanning in the MW region. Light spectroscopy for determining DM and fat content of ground beef samples can replace wet chemistry.
A comparison of the response of varying classes of growing beef cattle to protein supplementation was conducted on Northern Great Plains rangeland during the summer and early fall. Response was evaluated in 2 experiments, conducted in 1988 and 1989, by measuring organic matter intake and body weight gain in 13-month-old (spring-born steers) and 7-month-old steers (fall-born steers), which received either a 26% crude protein supplement or no supplement. Weight gain was also monitored in 7-month old heifers (fall-born heifers). In experiment 1, spring-born steers were fed 1.28 kg and fall-born steers and heifers 1.64 kg of protein supplement every other day. During experiment 2, spring-born steers were fed supplement at a rate of 1 kg and fall-born steers and heifers at 1.8 kg every other day. Intake of forage organic matter for steers was not affected (P > 0.10) by supplementation in either experiment. In experiment 1, total organic matter intake tended to be increased by protein supplementation in June but not in August (date X supplementation level interaction, P = 0.08). Forage organic matter digestibility was greater (P < 0.01) in June than in August during experiment 1 and in August than September in experiment 2. In experiment 1, this difference was greater for fall-born steers than spring-born steers. In experiment 1, supplementation increased (P < 0.01 average daily gain of cattle from 0.63 to 0.78 kg/day. In experiment 2, daily pin of cattle was increased (P < 0.01) from 0.62 0.82 kg/day with protein supplementation. Also, in experiment 2, cattle receiving supplement were 18 kg heavier (P < 0.05) at the end of the grazing season than unsupplemented controls. Protein supplementation increased weight pins of growing cattle in the late summer in the Northern Great Plains. The advantage was most consistent for fall-born steers with higher relative protein requirements.
Cows were fed either a control (n = 6) or pine needle (n = 12) diet beginning on day 249 of pregnancy. On day 3 and day 5 of feeding, control-fed and pine needle-fed cows were slaughtered and placentomes were collected for in vitro perfusion of the caruncular artery. Potential sensitive Ca2+ channel (PSC) activity as well as the responsiveness to phenylephrine (alpha 1-adrenergic agonist) and adrenaline (alpha 1- and alpha 2-adrenergic agonist) were determined. Selected gravid uterine tissues (endometrium and myometrium, as well as caruncular and cotyledonary tissues) and associated arteries (caruncular, intercaruncular and umbilical) were isolated, minced and portions either extracted immediately for measurement of PSC or frozen at -90 degrees C until assayed for peroxidase activity or number of alpha 2-adrenergic receptors and affinities or for both. In vitro perfused placentomes from day 5 pine needle-fed cows had greater (P < 0.05) PSC activity, as measured by the increase in perfusion pressure in response to a depolarizing dose of KCl, than day 3 pine needle-fed or control-fed cows (10.3 +/- 2.5 versus 6.1 +/- 1.2, and 4.3 +/- 0.7 kPa, respectively). Furthermore, day 5 pine needle-fed cows also exhibited greater (P < 0.05) contractile responses to adrenaline than day 3 pine needle-fed or control-fed cows. Contractile responses to phenylephrine were similar (P > 0.1) for all three treatment groups. The observed increase in PSC activity and responsiveness to adrenaline, however, was not reflected by increasing numbers or affinities of PSC or alpha 2-adrenergic receptors on caruncular arteries.(ABSTRACT TRUNCATED AT 250 WORDS)
Forty-six primiparous F1 heifers produced from mating Brahman (B), Charolais (C), Jersey (J), Longhorn (L), or Shorthorn (S) sires to crossbred cows were bred by AI to one of two Angus sires selected to produce high (H) or moderate (M) fetal growth. Dams were slaughtered at an average of 231 d of gestation. Daily blood samples were obtained from the dam on d 228 to 231 to determine serum estradiol, progesterone, and testosterone concentrations. Pelvic height was greatest (P < .05) in B, C, and L and pelvic width was greatest (P < .05) in S, C, and J dams, but pelvic areas did not differ (P > .10). Dams with greater hip height had larger pelvic areas (r = .45; P < .01). Intact fetuses from C and S dams were heaviest (P < .05), those from S dams had the greatest (P < .05) head width, and heart girth was greatest (P < .05) in fetuses from L dams. Fetuses from H sires were greater in weight (P < .01), body length (P < .01), and cannon circumference (P < .01). Dam differences were found in fetal heart weight (P < .01), trimmed placental membrane weight (P < .01), and average placentome weight (P < .05). Weights of eviscerated fetuses were greatest from C dams (P < .05). Placentome number was lowest (P < .05) in J dams, but J dams had the highest (P < .05) average placentome weight. Interactions between fetal genotype and breed of maternal environment were found for weight of eviscerated fetus (P < .05), body length, and heart weight (P < .01) and resulted from both magnitude and direction of change in the sire effect. The H sire increase in fetal weight was greatest in J dams, whereas B dams allowed expression of the fetal growth potential but at a lower level. Fetal trait interactions were also found for breed x sex and sex x sire (P < .05 to P < .01) and were due to the magnitude of differences expressed between the M and H sires. Serum testosterone concentrations were highest (P < .05) in B and L dams, dams gestating fetuses sired by the H sire (P = .08), and those with male fetuses (P < .01). We interpret these results to indicate that some maternal environments can suppress fetal growth, whereas others seem to complement the growth and allow maximum expression of the fetal genetic growth potential.(ABSTRACT TRUNCATED AT 400 WORDS)
In vitro and in vivo digestion trials with lambs were conducted to determine effects of ponderosa pine needles (PN; Pinus ponderosa Laws.) on digestibility of crested wheatgrass (CW; Agropyron desertorum [Link] Schultes) hay. Pine needles contained shikimic acid (15-28 mg/g) and several monomeric phenolics (p-hydroxy benzoid acid, caffeic acid, p-coumaric acid, ferulic acid) and flavonoids. Tannin concentration exceeded assay limits (> 10%) and terpenes were not found, probably due to the drying procedure. In the in vitro trial, needles were mixed with CW in 10% increments from 0% to 100%. In the in vivo trial, PN were fed to lambs as follows: (1) 0%, (2) 12.5%,(3) 25%, and (4) 50%, with the remainder of the diet as CW. In vitro organic matter digestibility (IVOMD) was regressed on level of PN in the substrate. As the proportion of PN increased, IVOMD declined cubicly (P < 0.01). The IVOMD values ranged from 54% for 100% CW to 24% for 100% PN. In vivo digestibility of organic matter, neutral detergent fiber and acid detergent fiber declined linearly (P < 0.01) as PN were increased from 0% to 50% of the diet. Apparent crude protein digestibility and N retention by lambs declined cubicly (P = 0.02 and P < 0.01, respectively) and urinary N increased cubicly (P < 0.01) as dietary PN increased from 0% to 50%. We concluded that PN reduce in vitro and in vivo nutrient digestibility, reduced N retention by lambs, and effects were detectable even at low levels.
Consumption of Ponderosa pine needles by late-pregnant beef cows results in the premature delivery of a viable calf. We have demonstrated the presence of a factor(s) in plasma from cows fed pine needles that specifically increased uterine arterial tone (i.e., decreased arterial diameter) in vitro. This study was designed to investigate changes in uterine blood flow and steroid secretion/uptake by the gravid uterus of cows fed pine needles to induce premature parturition. Sixteen beef cows were laparotomized on d 240 of gestation, and an electromagnetic blood-flow probe was placed around the uterine artery supplying the gravid horn. Cows were randomly assigned on d 250 of gestation to a control (n = 8; 8.2 kg/d of alfalfa hay) or pine needle (n = 8; 2.7 kg/d of pine needles + 5.5 kg/d of alfalfa hay) diet. Uterine blood flow was monitored, and systemic blood (uterine arterial and[or] jugular venous) and uterine venous blood samples were collected daily between 0630 and 0800, just before feeding. Five of eight cows fed pine needles calved prematurely (average day of gestation = 260.2 +/- .6) compared with cows fed the control diet, which calved on 287.6 +/- 3.4 d of gestation. Uterine blood flow in the control cows remained constant from d 250 through the day of parturition. In contrast, uterine blood flow of cows fed pine needles that calved early decreased progressively (P less than .01), declining to 25.2% of its original value by the day of parturition.(ABSTRACT TRUNCATED AT 250 WORDS)
Consumption of Ponderosa pine (Pinus ponderosa) needles (PN) by beef cows during late gestation results in premature delivery in association with profound constriction of the caruncular arterial bed. Further, PN extracts and plasma from PN-fed cows increase uterine arterial tone in vitro. Uterine arterial tone is a measure of the arterial resistance to stretch and controls the baseline rate of flow through the vascular bed. Uterine arterial tone results from the uptake of extracellular Ca2+ into smooth muscle cells through specific membrane channels called potential sensitive channels. Functional potential sensitive channels remain open for prolonged periods after activation, allowing a continuous uptake of Ca2+ and the maintenance of uterine arterial tone. Recent evidence from our laboratory has demonstrated that a group of estrogen metabolites produced by the placenta and(or) endometrium, called catechol estrogens, inhibits Ca2+ uptake through the potential sensitive channels. During gestation, progressive decreases in uterine arterial tone are observed, with resultant increases in uterine arterial blood flow. Thus, the continuous production of catechol estrogens may be necessary to maintain the pronounced uterine vasodilation that is required for fetal survival. Ponderosa pine needle extracts exhibit antiestrogenic activity, as evidenced by their inhibition of estrogen-induced uterine hyperemia. Data from our laboratory show that after consumption of PN by beef cows during late gestation, uterine arterial blood flow progressively decreased to less than 50% of prefeeding rates before premature delivery of a live calf.(ABSTRACT TRUNCATED AT 250 WORDS)
Consumption of Ponderosa pine needles by cows during late pregnancy results in the premature delivery of viable calves. Previous observations made at necropsy suggested that vascular insufficiency in the caruncular bed was associated with this induced parturition. The present studies used the perfused caruncular arterial bed of an isolated bovine placentome to determine whether blood plasma collected from cows fed pine needles contained a vasoactive factor(s). Changes in caruncular arterial tone (i.e., long-term changes in vessel diameter) and phasic contractility (i.e., transient reductions in vessel diameter) were evaluated. Tone was quantified as the pressure exerted against a constant intraluminal flow and as the force of contraction during K(+)-stimulated depolarization of membranes. Phenylephrine, an alpha 1-adrenergic agonist, was used to stimulate a phasic contractile response. Jugular blood was collected from beef cows fed pine needles (n = 4) or a control diet (n = 4), during the last 3 d of gestation, and plasma was used for two studies. In Study 1, placentomes were perfused with decreasing dilutions (1:150 to 1:40) of plasma pooled over the last 3 d of pregnancy from cows fed pine needle or control diets. Caruncular arterial perfusion pressures and responses to K+ progressively increased (P less than .05) with decreasing dilutions of plasma from cows fed pine needles, and responses to phenylephrine remained constant. Caruncular arterial perfusion pressures and responses to K+ and phenylephrine remained constant during perfusion of plasma from cows fed the control diet. In Study 2, the changes in vasoactivity of plasma (1:60 dilution) from cows fed pine needles was evaluated during the last 3 d of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)
Esophageal fistulae were established in five 34-day-old suckling calves by a modified surgical procedure used previously for sheep and goats. After skin incision, the esophagus was exposed by separating the brachiocephalicus and sternocephalicus muscles. A cannula was inserted into the esophagus after a longitudinal incision was made into the lumen of the esophagus. Sutures were not used in the esophagus. The calves recovered quickly with moderate post-operative swelling. We concluded that the surgical procedure was satisfactory and that diets were collected readily and without fistulae shrinkage.