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PubMed1969

Factors affecting the persistence of Staphylococcus aureus on fabrics.

The persistence of Staphylococcus aureus (Smith) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. The fabrics were exposed to bacterial populations by three methods: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. The contaminated fabrics were held in 35 or 78% relative humidities at 25 C. In general, the persistence time of S. aureus populations on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by exposure to aerosolized cultures or to dust containing bacteria than when contaminated by direct contact. In a 78% relative humidity, bacterial populations on the fabrics persisted for substantially shorter periods of time regardless of the mode of contamination or fabric type. Cotton wash-and-wear fabric (treated with a modified triazone resin) was the material on which populations of S. aureus persisted for the shortest time. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 4 weeks in 35% relative humidity and 6 weeks in 78% relative humidity.

Animals↗

PubMed1971

Quantitative studies on fabrics as disseminators of viruses. V. Effect of laundering on poliovirus-contaminated fabrics.

The effects of laundering with both anionic and nonionic detergents in cold, warm, and hot water on poliovirus-contaminated cotton sheeting, cotton terry cloth, washable wool shirting, wool blanketing, dull nylon jersey, and dacron/cotton shirting were determined. The fabrics were exposed to virus by aerosolization and direct contact (pipette) in separate studies. Although the results varied with each factor used in the study, virus titers on all the fabrics were generally reduced considerably by the laundering process. When the fabrics were dried for 20 hr after laundering, an additional decline in virus titers was seen, often to below detectable levels. The type of detergent used made little difference in effect on virus titer reduction, but the hot wash water markedly reduced the detectable virus. Fabric type was not a major factor in the majority of the experiments, although virus tended to be eliminated more readily from the nylon jersey, and in warm water the virus persisted longer on wool blanketing material laundered in anionic detergent. Sterile fabrics of each type laundered with similar fabrics which contained virus often became contaminated by the virus during the laundering process. Virus titers ranging from undetectable to 10(3.9) cell culture 50% infectious doses/ml were obtained from samples of the rinse water after warm- and cold-water laundering.

Animals↗

PubMed2000

Factors affecting the effectiveness of head-only electrical stunning in sheep.

The effects of factors such as the position of the tongs, the presence of wool, and the wetness of the skin on the efficiency of the head-only stunning procedure, and the duration of the periods of unconsciousness and analgesia were studied in lambs. The degree of insensibility was determined from the evaluation of physiological responses and electroencephalograms. The proportion of successfully stunned animals was significantly higher (P<0.05) in the animals stunned with the tongs in a frontal position than in those stunned with them in a caudal position, in the animals stunned with wet electrodes than in those stunned with dry electrodes and also in the animals without wool than in those with wool. The interval between stunning and sensibility to pain was affected significantly (P<0.01) only by the position of the tongs, being longer in animals with them in a frontal position than in those with them in a caudal position.

Abattoirs↗

PubMed1984

Central effects of photoperiod on reproduction in the ram revealed by the use of a testosterone clamp.

Over a 3-year period eight adult Soay rams were exposed to an artificial lighting regimen of alternating 16-week periods of long days (16 h light: 8 h darkness; 16L : 8D) and short days (8L : 16D) to induce a seasonal cycle in reproduction and wool growth every 32 weeks. Early in the study the rams were castrated (four during long days and four during short days) and 48 weeks later the castrated animals were each given an s.c. implant of testosterone to increase the blood plasma concentration of testosterone to 14-20 nmol/l. The changes in the concentrations of LH, FSH and testosterone were measured in blood samples collected once or twice weekly while records were made of the changes in the size of the testes (before castration), the intensity of the sexual skin flush, the expression of aggressive and sexual behaviour and the rate of wool growth. The results showed that in the castrated rams there were only minor changes in the blood levels of LH, FSH and the expression of aggressive behaviour related to the 32-week light cycle, while the sexual skin flush was permanently absent. However, after the commencement of the constant testosterone therapy, there were major changes in all the reproductive parameters related to the lighting regimen with a similar temporal relationship as observed in the rams before castration. Cyclic variation in wool growth occurred throughout the study related to the changes in photoperiod but this was not markedly affected by castration and testosterone replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Aggression↗

PubMed1995

Cortisol secretion and growth in ewe lambs chronically exposed to electric and magnetic fields of a 60-Hertz 500-kilovolt AC transmission line.

A study was conducted to determine whether chronic exposure of ewe lambs to the electric and magnetic fields (EMF) of a high-voltage ac transmission line affected cortisol secretion and growth. Twenty Suffolk ewe lambs were assigned randomly in equal numbers to a control and treatment group. Treatment from 2 to 10 mo of age consisted of continuous exposure within the electrical environment of a 60-Hz, 500-kV transmission line (mean electric field 6 kV/m, mean magnetic field 40 mG). Treated lambs were confined directly beneath the transmission line; control lambs were maintained in a pen of similar construction 229 m from the line where the EMF were at ambient levels (mean electric field < 10 V/m, mean magnetic field < .3 mG). Cortisol was analyzed by RIA in serum of blood samples collected at .5- to 3-h intervals over eight 48-h periods. All ewe lambs were weighed weekly and side-patch wool growth was measured biweekly. Cortisol secretion occurred in a circadian rhythm; daytime serum concentrations were greater (P < .05) than nighttime concentrations for both groups. Concentrations of cortisol did not differ between the control and exposed ewe lambs. Weight gain and wool fiber length and diameter also were not affected by treatment. These data suggest that chronic exposure of developing ewe lambs to 60-Hz environmental EMF does not affect concentrations of cortisol secretion, body weight gain, and wool growth.

Animals↗

PubMed2004

The effects of cadmium in feed, and its amelioration with zinc, on element balances in sheep.

The effects of feeding Cd to sheep at a level that is typical of polluted regions were investigated, as well as possible amelioration by adding Zn to the diet. Welsh Mountain ewes (n = 24) were fed herb-age and concentrate in metabolism crates, with four supplement treatments in a two-factor factorial design: no supplement, Cd supplement only, Zn supplement only, and a combination of both the Cd and Zn supplement. Cadmium (286 microg/kg of feed DMI) and Zn (8.6 mg/kg feed DMI) were added as sulfates. Food and water intakes and element balances were recorded over 20 d after 7 d dietary adaptation, and element concentrations were determined in wool samples. Neither metal affected DMI or digestibility (P > 0.15), but water intake (P = 0.001) and urine output (P = 0.03) were decreased when only the Zn supplement was added. Water retention was increased by the Cd supplement (P = 0.04). In wool, the Cd supplement greatly increased the K concentration if no Zn supplement was fed (P = 0.02), and the Zn supplement decreased Mn concentration (P = 0.02). Cadmium in feed increased the Cd balance and produced several mineral disturbances, in particular a decrease in Na balance that is typical of renal tubular disorders. Adding Zn as well as Cd to feed returned the Cd balance to a level similar to that of sheep receiving neither Cd nor Zn, which suggests that Zn status is critical in determining whether Cd in feed increases the Cd balance in sheep. Feeding Cd also increased urinary K, Fe, Mo, Cr, B, and Ca concentrations, even when supplementary Zn was fed. It is concluded that low levels of Cd in sheep feed can increase the Cd balance if adequate Zn is not provided, which can lead to subclinical mineral disturbances and changes in the mineral concentrations in wool.

Adaptation, Physiological↗

PubMed1985

Lifetime (seven years) production of 1/4 and 1/2 Finnish Landrace ewes from Rambouillet, Targhee and Columbia dams under range conditions.

Lifetime lamb and wool production of 1/4 and 1/2 Finnish Landrace (Finn) crossbred ewes in comparison with local purebred controls was evaluated under range conditions. A total of 1,234 ewe lambs, representing nine breed groups, were first exposed to breeding at 7 mo of age and subsequently retained with no artificial culling, except for debilitating unsoundness, through 7 yr of production. Mating was to Suffolk sires. Differences among pooled breed groups (1/4 Finns, 1/2 Finns and purebreds) generally were not significant for ewe viability to lambing, percentage of lambs born alive and lamb viability to weaning; nor were differences significant for fertility except among yearlings (12 mo at lambing) where 1/4 and 1/2 Finn fertility exceeded that of purebreds by 217 and 278%, respectively. However, for prolificacy, Finn-crosses were consistently superior to purebreds at all seven ages; 1/4 and 1/2 Finns averaged 24 and 48% higher, respectively, than purebreds. Further, Finn-cross ewes clearly excelled purebreds (P less than .05) in the two overall measures of reproduction--net reproductive rate and weight of lamb weaned. The superiority was sustained through all ages and averaged (over ages 2 through 7 yr) 29 and 49% for net reproductive rate and 24 and 41% for weight weaned, for 1/4 and 1/2 Finns, respectively. Conversely, for wool weight, purebreds were consistently superior at all ages; the lifetime averages of 1/4 and 1/2 Finn fleeces were only 90 and 77% as high, respectively, as those of purebreds. It was concluded, however, that the loss in value of wool production associated with Finn breeding was economically of much less importance than the gains made in weight of lamb weaned. The use of 1/4 and 1/2 Finn-crosses involving the above adapted domestic breeds increased the net value of lifetime production by approximately 18 and 29%, respectively.

Animals↗

PubMedDate not supplied

Effect of different types of textiles on male sexual activity.

The effect of different types of textile underpants on sexual activity was studied in 50 men. All the subjects were potent and sexually active. They were divided into 5 equal groups: 4 test and 1 control. Each of the 4 test groups were dressed in one type of textile underpants made of either 100% polyester, 50/50% polyester/cotton mix, 100% cotton, or 100% wool. Sexual behavior was assessed before and after 6 and 12 months of wearing the pants, and 6 months after their removal. Behavioral response was rated as potent if the subject's penis became erect, entered the vagina, and ejaculated. The rate of potent intromission (I) to mounts (M) (I/M ratio) was determined. The electrostatic potentials (EP) generated on the penis and scrotum were measured by an electrostatic kilovoltmeter. The I/M ratio at 6 and 12 months of wearing the polyester and polyester/cotton mix pants was significantly reduced compared to the pretest levels and the controls (p < .001). The reduction was more manifest in the pure polyester than in the polyester/cotton mix group, and at the 12-month than at the 6-month examination. The I/M ratio of the cotton and wool groups showed insignificant changes during the study period. Six months after removal of the underpants, the I/M ratio had returned to the pretest levels in the two groups that had worn polyester-containing pants. The polyester-containing pants generated EP, which may induce electrostatic fields in the intrapenile structures and could explain the diminished sexual activity. The cotton and wool textiles did not generate EP. Thus, polyester underpants could have an injurious effect on human sexual activity.

Animals↗

PubMed1992

Pulmonary function studies in 15 to 18 years age workers exposed to dust in industry.

Pulmonary function tests (VC, FEV1% and FEF25-75%) were evaluated in 15 to 18 years age workers employed in slate pencil industry exposed to silica dust, in wool carpet industry exposed to wool dust and in diamond cutting and polishing exposed to carbon dust. These values were compared with the values obtained in clinically healthy non-smokers of the same age group. The results revealed significant impairment of VC in diamond workers, and FEF25-75% in slate pencil workers. When the values were observed according to smoking habits in diamond workers, VC, FEV1 and FEF25-75% were all significantly reduced in smokers whereas in non-smokers only VC was lowered significantly. Among slate pencil workers FEF25-75% was significantly reduced in both smokers and non-smokers. Wool dust exposed workers showed reduced values than normal subjects. The detailed results including the prevalence of various pulmonary impairments were presented.

Adolescent↗

PubMed1979

[Resistance of the Aujeszky's disease virus to gamma ray irradiation].

Investigations on the resistance of Aujeszky's disease virus to gamma irradiation from a 60Co source were performed. The resistance of the virus was tested in vitro in a fluid medium of 50% Henk's balanced saline solution, 50% Eagle's medium MEM and a supplement of 10% normal calf serum as well as its resistance on artificially virus infected pig skin and greasy wool of sheep. It is established that virus inactivation in the fluid medium occurs following 1.6 Mrad gamma irradiation. The irradiated with lower than 1.6 Mrad gamma doses live virus particles form smaller than and with irregular oval shape and dentated plates as compared to the non-irradiated control virus. 1.5 Mrad gamma rays are needed to inactivate the virus on pig skin and greasy wheep's wool. The presence of lanoline in greasy sheep's wool, due to the alkaline pH (9--13) it produces, has an effect on the vitality of the virus both in the control and in the experimental samples.

Animals↗

PubMed1985

Effects of deficient and adequate dietary magnesium concentrations on body magnesium concentrations in wethers.

Effects of 2 dietary Mg concentrations (deficient and adequate: 0.04 and 0.12 g of Mg/100 g of dry matter, respectively) on body fluid and tissue Mg concentrations and performance of wether lambs were evaluated in a 28-day trial. Nine blood and 6 urine samples were collected from each wether. After 28 days, CSF and wool samples were collected, and diet, body fluids, and tissues were analyzed for mineral concentration. Diet effects on serum and urine Mg concentrations were noticed after day 3 (P less than 0.01; P less than 0.05, respectively). Mean serum and urine Mg concentrations for 6 sampling periods were correlated (r = 0.83, P less than 0.001; No. of samples = 12). The effect of dietary Mg on CSF Mg concentrations approached significance (P less than 0.10). Effects of diet on cardiac muscle, liver, and 3rd metatarsal bone Mg contents or hematologic criteria were not observed. Diet affected wool and kidney cortex Mg contents (P less than 0.02). Individual mean 28-day serum Mg concentration was correlated with wool Mg content (r = 0.73, P less than 0.05; n = 8) and with kidney cortex Mg content (r = 0.75, P less than 0.05; n = 8). Wethers fed low Mg diet excreted less urine Ca (P less than 0.001) and had slightly lower serum Ca and K values (P less than 0.10) than did wethers fed high Mg. Significant differences in cardiac muscle, liver, spleen, or kidney cortex Ca contents were not observed. Wethers fed low Mg diet consumed less dry matter and gained less weight (P less than 0.001) than did wethers fed high Mg diet. Body fluid and tissue macromineral concentrations of 1 wether with hypomagnesemic tetany are presented for prognostic and diagnostic purposes.

Animals↗

PubMed1993

Sequence, expression, and evolutionary conservation of a gene encoding a glycine/tyrosine-rich keratin-associated protein of hair.

In hair differentiation several families of keratin proteins with distinctive amino acid compositions are produced. To study the role and regulation of one of these families, the glycine/tyrosine-rich keratin-associated proteins encoded by the KAP6 gene family, a partial wool follicle cDNA clone encoding a sheep KAP6 protein was sequenced and the corresponding gene isolated from a sheep cosmid library. The KAP6.1 gene encodes a basic protein of 82 amino acids (M(r) = 8,296) with a combined glycine and tyrosine content of approximately 60 mol%. There are several KAP6 genes in the sheep genome, all located within a 1,050-kilobase SfiI fragment. Northern blot analysis demonstrated that at least one member of the KAP6 family is expressed in the wool follicle. A rabbit KAP6 gene was isolated and its sequence and expression patterns were compared with the sheep gene. The sheep and rabbit genes have a nucleotide sequence identity of 89%, suggesting that they are equivalent genes and indicating strong selection pressure during evolution. Both genes contain several conserved sequence motifs of 7-9 nucleotides in their 5'-flanking regions that may be involved in the regulation of their expression. Localization of KAP6 mRNAs in sheep wool and rabbit hair follicles by in situ hybridization suggests that the genes are expressed in the cells of the hair shaft cortex in varying expression patterns. KAP6 expression starts relatively late in hair follicle differentiation, and the proportion of hair cortical cells that express it may change from follicle to follicle.

Amino Acid Sequence↗

PubMed1977

Sulphur-selenium studies in sheep. I. The effects of varying dietary sulphate and selenomethionine on sulphur, nitrogen and selenium metabolism in sheep.

Sulphur, selenium and nitrogen metabolism were studied in Merino wethers fed for 35-day periods on semipurified diets in which the sulphur content was increased to either 0-07 or 0-20% by the addition of sodium sulphate. At both levels of sulphur, additions of selenium as DL-selenomethionine increased the basal level of selenium (0-02 microgram/g) to 0-06, 0-09 and 0-67 microgram/g. Both levels of dietary sulphur supported positive sulphur balances but a reduction in sulphur intake per se resulted in a significant depression in dry matter digestibility (P less than 0-05), apparent nitrogen digestibility (P less than 0-05), nitrogen balance (P less than 0-01), sulphur balance (P less than 0-05) and plasma sulphate-sulphur (P less than 0-05) and wool (P less than 0-01) selenium levels. Selenium balance was not affected by differences in sulphate-sulphur intake. Selenium balances (P less than 0-001), plus the selenium levels in plasma (P less than 0-001), and wool (P less than 0-001) were significantly different at the different levels of selenium supplementation. A positive selenium balance was achieved when the selenium intake was approximately 37 microgram/day, regardless of sulphur treatment. The validity of using plasma and/or wool selenium levels as indices of the selenium status of sheep is questioned.

Animals↗

PubMed1990

Overberg Research Projects. VIII. The productivity of Merino ewes subjected to different internal parasite control programmes in the winter rainfall region of South Africa.

Suckling Merino lambs on lucerne pasture, demonstrated no appreciable mass gain when compared with untreated controls, despite regular treatment with anthelmintics. This was ascribed to severe parasitic challenge. After weaning and transfer to wheat stubble fields with no parasitic challenge, however, the live mass of the untreated lambs, still harbouring a residual burden of nematodes, was depressed. Control sheep produced 1.2 kg less wool than regularly-treated sheep, but produced finer wool which had a higher market value. Regularly-treated ewes (F1) produced 12.1% more lambs, but their mean live mass was 2.6 kg lower than that of ewes treated less frequently. The overall financial benefit was in favour of the group which received fewer anthelmintic treatments and was due mainly to the higher market value of the finer wool produced by these apparently stressed animals.

Animals↗

PubMed2004

Risks of progression of retinopathy and vision loss related to tight blood pressure control in type 2 diabetes mellitus: UKPDS 69.

OBJECTIVE: To determine the relationship between tight blood pressure (BP) control and the different aspects of diabetic retinopathy in patients with type 2 diabetes mellitus (DM). SETTING: Nineteen hospital-based clinics in England, Scotland, and Northern Ireland. DESIGN: Outcome of retinopathy status assessed by 4-field retinal photography related to allocation within a randomized controlled trial comparing a tight BP control policy aiming for a BP less than 150/85 mm Hg with a less tight BP control policy aiming for a BP less than 180/105 mm Hg. SUBJECTS: One thousand one hundred forty-eight hypertensive patients with type 2 DM were studied. These patients had type 2 DM for a mean duration of 2.6 years at the inception of the Hypertension in Diabetes Study, had a mean age of 56 years; and had a mean BP of 160/94 mm Hg. Seven hundred fifty-eight patients were allocated to a tight BP control policy with angiotensin-converting enzyme inhibitor or beta-blockers as the main therapy; 390 were allocated to a less tight BP control policy. MAIN OUTCOME MEASURES: Deterioration of retinopathy (>/=2-step change on a modified Early Treatment Diabetic Retinopathy Study [ETDRS] final scale), together with end points (photocoagulation, vitreous hemorrhage, and cataract extraction) and analysis of specific lesions (microaneurysms, hard exudates, and cotton-wool spots). Visual acuity was assessed at 3-year intervals using ETDRS logarithm of the minimum angle of resolution charts. Blindness was monitored as an end point with the criterion of Snellen chart assessment at 6/60 or worse. RESULTS: By 4.5 years after randomization, there was a highly significant difference in microaneurysm count with 23.3% in the tight BP control group and 33.5% in the less tight BP control group having 5 or more microaneurysms (relative risk [RR], 0.70; P = .003). The effect continued to 7.5 years (RR, 0.66; P<.001). Hard exudates increased from a prevalence of 11.2% to 18.3% at 7.5 years after randomization with fewer lesions found in the tight BP control group (RR, 0.53; P<.001). Cotton-wool spots increased in both groups but less so in the tight BP control group which had fewer cotton-wool spots at 7.5 years (RR, 0.53; P<.001). A 2-step or more deterioration on the ETDRS scale was significantly different at 4.5 years with fewer people in the tight BP control group progressing 2 steps or more (RR, 0.75; P = .02). Patients allocated to tight BP control were less likely to undergo photocoagulation (RR, 0.65; P = .03). This difference was driven by a difference in photocoagulation due to maculopathy (RR, 0.58; P = .02). The cumulative incidence of the end point of blindness (Snellen visual acuity, >/=6/60) in 1 eye was 18/758 for the tight BP control group compared with 12/390 for less tight BP control group. These equate to absolute risks of 3.1 to 4.1 per 1000 patient-years, respectively (P = .046; RR, 0.76; 99% confidence interval, 0.29-1.99). There was no detectable difference in outcome between the 2 randomized therapies of angiotensin-converting enzyme inhibition and beta-blockade. CONCLUSIONS: High BP is detrimental to each aspect of diabetic retinopathy; a tight BP control policy reduces the risk of clinical complications from diabetic eye disease.

Adrenergic beta-Antagonists↗

PubMed2000

Laryngeal and hypopharyngeal cancer and occupational exposure to asbestos and man-made vitreous fibers: results of a case-control study.

BACKGROUND: The data from a case-control study performed in France between 1989 and 1991 were used to test whether exposure to either asbestos or to man-made vitreous fibers (MMVF) is a risk factor for cancer of the larynx or the hypopharynx. METHODS: This study involved 315 incident cases of laryngeal cancer, 206 cases of hypopharyngeal cancer, and 305 hospital-based controls with other types of cancer, all recruited in 15 hospitals in six French cities. The subjects' past occupational exposure to asbestos and to four types of MMVF (mineral wool, refractory ceramic fibers, glass filaments, and microfibers) was evaluated based on their job history, with the aid of a job-exposure matrix. Odds ratios were calculated with unconditional logistic regression, with adjustment for smoking and drinking levels. RESULTS: Exposure to asbestos resulted in a significant increase in the risk of hypopharyngeal cancer (OR = 1.80, 95% CI: 1.08-2.99) and a nonsignificant increase in the risk of laryngeal cancer (OR = 1.24, 95% CI: 0.83-1.90). Risk was highest for the epilarynx (highest cumulative level of exposure: OR = 2.22, 95% CI: 1.05-4.71). Exposure to mineral wools was of borderline significance for the risk of hypopharyngeal cancer (OR = 1.55, 95% CI: 0.99-2.41), and nonsignificantly associated with the risk of laryngeal cancer (OR-1.33, 95% CI: 0.91-1.95). The risk was again highest for the epilarynx (OR = 1.85, 95% CI: 1.08-3.17). No significant results were observed for the other MMVF. CONCLUSIONS: These results suggest that asbestos exposure increases the risk of epilaryngeal and hypopharyngeal cancers. It is difficult to reach a conclusion about the effects of mineral wools, because nearly all the exposed subjects were also exposed to asbestos. The possible effects of other MMVF were difficult to assess in this study, because of the paucity of exposed subjects.

Adult↗

PubMed2002

Respiratory cancer and exposure to man-made vitreous fibers: a systematic review.

BACKGROUND: Man-made vitreous fibers (MMVF's) have some structural features similar to those found in asbestos. This has lead to concern that exposure to MMVF's could increase the risk of respiratory cancer. METHODS: Bibliographic resources were used to identify 10 case-control and 10 cohort studies, which analyzed the relationship between exposure to MMVF's and cancer of the respiratory system. Standardized mortality ratio's (SMR's) were extracted from the cohort studies for a meta-analysis. RESULTS: A significant increase in SMR was observed for workers exposed to rock and glass wool, but not in workers exposed to glass filament. Meta-analysis of SMR's after stratification by fiber type resulted in aggregate estimates of risk of 1.23 (95% CI = 1.10-1.38), 1.08 (95% CI = 0.93-1.26), and 1.32 (95% CI = 1.15-1.52) for exposure to glass wool, glass filament, and rock wool, respectively. Some or all of the increased mortality could be attributed to tobacco use. CONCLUSIONS: The results highlight the difficulty of assessing small increases in risk of respiratory cancer potentially caused by occupational exposure in populations with high prevalence of tobacco use.

Air Pollutants, Occupational↗

PubMed1983

[Development and testing of protein mixtures based on blood and collagen].

Using the results of the chemical amino acid analyses of the unconventional proteins blood, collagen and wool and the conventional proteins soya, maize and casein, protein mixtures were developed. The quality of the protein mixtures was estimated in feeding experiments with growing male Sprague-Dawley rats and expressed as protein efficiency ratio (PER). Different blood parameters and the weight of some organs were also recorded. Blood, collagen and wool protein are very poor in different essential amino acids, therefore their quality is very low, it can however be significantly improved when they are fed in mixtures with other animal or plant proteins of higher quality. In mixtures of three components only containing blood (10--40%), collagen (10--25%) and casein (50 to 70%) the deficit in the content of essential amino acids cannot be compensated. Rats fed with such diets showed, however, decreased food intake and depressed growth. The relative PER values of those mixtures were 44--69% of that of casein. The best supplementing effect on the imbalanced amino acid patterns was achieved when the protein mixture was developed from 4 or 5 different proteins. The quality of these five-component-mixtures amounted to 94--100% of that of casein. In these mixtures the percentage of casein in the protein mixture amounted to only 35% and soya or maize to 15%. Exactly 50% of the protein supply could be derived from hydrolysates of the unconventional proteins blood, collagen and wool.

Amino Acids↗