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Biomedical subjects

J F Hayes

Publications and source records attributed to J F Hayes.

52 records · Page 3Linked to original sources
PubMed1984

Association of genetic variants of casein and milk serum proteins with milk, fat, and protein production by dairy cattle.

Polyacrylamide gel electrophoresis methods were used to phenotype caseins for 2045 cows and milk serum proteins for 3870 cows distributed in 63 Quebec dairy herds. Frequencies were: alpha s1-casein A .003, alpha s1-casein B .970, alpha s1-casein C .027; beta-casein A1 .561, beta-casein A2 .421, beta-casein A3 .011, beta-casein B .007; kappa-casein A .744, kappa-casein B .256; beta-lactoglobulin A .387, beta-lactoglobulin B .613; alpha-lactalbumin B 1.00. Overall unadjusted means for 305-day production in first lactation were: 5530 +/- 26.6 kg, 197 +/- 1.0 kg, 172 +/- 1.0 kg, 3.58 +/- .009, 3.12 +/- .009 for milk yield, fat yield, protein yield, fat percentage, and protein percentage for 1687 cows for casein systems. Similar data for 2906 cows phenotyped for milk serum proteins were: 5412 +/- 20.6 kg, 193 +/- .8 kg, 170 +/- .7 kg, 3.57 +/- .007, and 3.13 +/- 007. Least squares analysis of variance showed that herd location, month of calving, age of cow at first calving, and protein variants had significant effects on production traits. alpha s1-Casein B and beta-casein A phenotypes were associated with higher milk, fat, and protein yields than other variants in the two casein systems. Milk from kappa-casein BB and beta-lactoglobulin AA phenotypes contained .13 and .05% more protein than the AA and BB phenotypes with the AB phenotype intermediate.

Animals↗
PubMed1984

Heritability of milk casein and genetic and phenotypic correlations with production traits.

Individual milk samples were obtained monthly from November 1979 to November 1981 from approximately 2,800 Holstein cows in 63 herds enrolled in the Quebec Dairy Herd Analysis Service. These milk samples were analyzed for fat, total protein, casein, and serum protein. After editing, the data comprised 2,813 lactations representing 109 sires. By approximate maximum likelihood procedures, the model included herd (absorbed), year-month, and parity fixed effects, and sire and error random effects. Lactation casein yield increased with advancing parity to parity five and then decreased slightly. Lactation casein percent and number (percent casein in protein) declined until parities four and three, respectively, and essentially remained constant thereafter. Lactation casein yield was high for lactations initiated during winter months as opposed to summer months. No seasonal trend was apparent for casein percent or number. Heritabilities for lactation casein yield, percent, and number were .11, .26, and .08. Genetic and phenotypic correlations of casein yield with milk, fat, and protein yields were large and positive. Genetic correlation of casein percent with milk yield was negative (-.76) but positive (.96) with protein percent. Genetic correlations involving casein number tended to be small.

Animals↗
PubMed1984

Effects of calving ease-calf survival on production and reproduction in Holsteins.

Data on 23,873 Holstein cows on official test of the Quebec Dairy Herd Analysis Service were analyzed for effects of calving ease-calf survival on cow productivity; data on 35,773 Holstein cows were analyzed for effects on culling and reproductive efficiency. Traits were milk, fat, and protein yields, percent fat and protein for 90-day and 305-day lactations, days from calving to first service and conception, percentage conception rate from first service, and services per conception. The effect of calving ease-calf survival on production traits was not significant in most cases except surgical calvings associated with stillbirth. For these the loss of 305-day production was approximately 300 to 500 kg milk, 8 to 17 kg fat, and 8 to 14 kg protein. Stillbirth in nonsurgical calvings was associated with lower production than when the calf survived; differences were 100 to 400 kg milk, 4 to 11.5 kg fat, and 2.5 to 13 kg protein. Age of cow and calving ease-calf survival significantly affected all measures of reproductive efficiency. Reproductive efficiency declined with advancing age. Effect of calving ease-calf survival tended to be more pronounced when calving was associated with stillbirth.

Animals↗
PubMed1984

Heritability of lactation cell count measures and their relationships with milk yield and composition in Ayrshire cows.

Lactation measures of somatic cell count were calculated from monthly test-day observations (transformed to a log scale) taken between February 1977 and February 1981 in Ayrshire cows in 115 herds enrolled in the Quebec Dairy Herd Analysis Service. Analyses were separate within three groups: 1137 first lactations, representing 37 sires; 1728 second and later lactations, representing 57 sires; and 2510 all lactations, representing 74 sires. Heritabilities of lactation measures were estimated from sire and error variances obtained by iterative minimum norm quadratic unbiased estimation. Heritabilities ranged from .09 to .16 in first lactations and averaged .09 for the group of second and later lactations and .07 for all lactations. Genetic correlations of lactation measures of cell count with milk, fat, protein yield, fat percent, and protein percent averaged .36, .68, .74, .38, and .45, in first lactations; -.97, -.27, -.56, .52, and .03 in second and later lactations; and -.50, -.54, -.73, .43, and .19 in all lactations. Respective average phenotypic correlations were low and negative for milk, fat, protein yield, and fat percent and low and positive for protein percent.

Aging↗
PubMed1983

Abdominal wall hernias as a complication of peritoneal dialysis.

Home peritoneal dialysis has recently become an important addition to the therapy of chronic renal failure. Abdominal wall hernias have become more apparent as complications of this mode of dialysis, with isolated instances of incarcerations and one fatality. Results of our review of 276 patients receiving peritoneal dialysis revealed seven with hernias, an incidence of 2.5 per cent. Six patients with hernias were receiving c.a.p.d.; one patient was receiving c.c.p.d., and none was receiving i.p.d., for incidences of 17, 5 and zero per cent, respectively. All hernias found at presentation occurred within two to 20 months after peritoneal catheter placement. Most were ventral or umbilical, and all were repaired electively without serious complications. All patients with hernias had associated problems with leaks, peritonitis or predialysis hernias. In two of four patients with predialysis hernias, herniorrhaphy without catheter removal resulted in two recurrences. Abdominal wall hernias are a more frequent complication of c.a.p.d. and c.c.p.d., modalities which require large volumes of peritoneal dialysate during ambulatory hours. Review of the literature reveals that wound tensile strength and healing are decreased in those patients having renal disease with uremia, anemia and malnutrition. However, these factors do not increase the over-all incidence of hernias. Patients should be screened for hernias, and hernias should be repaired prior to catheter placement. Hernias presenting during dialysis are best treated by herniorrhaphy and hemodialysis postoperatively or low volume peritoneal dialysis to optimize the metabolic state.

Adult↗
PubMed1982

Surgical management of renal hyperparathyroidism in the dialysis patient.

Over 12 years, 49 patients with hyperparathyroidism secondary to chronic renal failure under treatment with hemodialysis were treated with total parathyroidectomy. A portion of one gland was implanted in the sternocleidomastoid muscle. The operative indications were elevation of parathormone, serum calcium, and phosphorus, levels, pruritus, bone pain, pathologic fractures, and myalgia. Special postoperative complications discussed are hyperkalemia, hemorrhage, and respiratory obstruction. There were no operative deaths. No postoperative tetany was seen. Total parathyroidectomy should be performed in chronic renal failure patients with persistent elevation of serum calcium and parathormone levels, and who have pain, fractures, or soft tissue calcification. All postoperative parathyroidectomy patients should be observed for possible hyperkalemia.

Adult↗
PubMed1982

Effects of potassium dichromate and sample storage time on fat and protein by Milko-Scan and on protein and casein by a modified Pro-Milk Mk II method.

A rapid procedure is described for measuring casein in milk by a combination of isoelectric precipitation and amido black dye-binding. Individual milk samples from 38 cows were subsampled, preserved with potassium dichromate at a concentration of 8 mg/ml of milk, and analyzed for fat and protein by the Milko-Scan 300 and for protein and casein by the dye-binding procedure on day 1, 4, 7, and 10 after milk collection. Fat tests were not affected by sample storage time, but protein tests showed variation depending on the interval between milk sample collection and analysis. In a separate study effects of potassium dichromate used as a preservative at 0, 2, 4, 6, 8, and 12 mg/ml of milk on chemical determinations were investigated. No changes were significant in fat and protein analyzed by the infrared method for concentrations of preservative. There were no significant differences in protein determination by the two methods for nonpreserved samples. For preserved samples, the dye-binding method for protein gave determinations higher than those by the infrared method. The difference increased linearly with increasing concentration of potassium dichromate at .07% in protein for every 2 mg of potassium dichromate per milliliter of milk.

Animals↗
PubMed1982

Environmental influences on protein content and composition of bovine Milk.

A total of 24,405 individual milk samples from approximately 2,800 Holstein-Friesian cows in 63 dairy herds enrolled in the Quebec Dairy Herd Analysis Service program were analyzed monthly for protein, serum protein, casein, and somatic cell counts during 17 mo. Unadjusted means for protein, serum protein, and casein were 3.396% +/- .002, .687% +/- .001, and 2.708% +/- .002. Least squares analyses showed significant effects of calendar month of test, stage of lactation, age of cow, and somatic cell count on milk protein content and composition. Total protein, casein, and serum protein contents of milk showed a generally increasing trend from July to December. These components were highest during the first 10 days in lactation when means were 3.81%, 3.05%, and .76% and reached a minimum at 2 mo in lactation to give corresponding means of 3.08%, 2.46%, and .62%. The proportion of casein in milk protein decreased as cows became older. For every unit of increase in log somatic cell count there was an increase in protein content of 0.99%, mainly from change in the serum protein fraction. The same change in somatic cells would decrease ratio of casein to protein by 2.79%.

Age Factors↗
PubMed1980

Effect of litter size at birth on lactation in mice.

The relative influence of litter size at birth and dam body weight at parturition on lactational performance was determined with five among-line crossfostering experiments involving 17 populations of mice. Included were lines selected for postweaning growth and maternal performance, and unselected controls. Twelve-day litter weight of a crossfostered litter standardized to six or eight pups was used as the criterion of lactational performance. Litter size at birth had a small positive correlation with 12-day litter weight when pooled within lines in each crossfostering experiment (.06 to .30, with mean of .17). The correlation between dam body weight at parturition and her crossfostered 12-day litter weight was consistently higher (.13 to .51, with mean of .35). Litter size was positively correlated with dam body weight at parturition (.33 to .56, with mean of .47). The partial correlation between litter size and 12-day litter weight, with dam body weight at parturition held constant, was reduced (-.07 to .18, with mean of .02) compared to the simple correlation. Multiple regression analyses indicated that dam body weight at parturition consistently accounted for more of the variation in 12-day litter weight than litter size. The data provide no evidence to support the hypothesis that increased fetal number or mass results in a greater lactational output by the dam.

Animals↗
PubMed1980

A reparameterization of a genetic selection index to locate its sampling properties.

A transformation is proposed of the variables used for constructing genetic selection indices, such that the reparameterized phenotypic covariance matrix is identity and the genetic covariance matrix is diagonal. These diagonal elements play the role of heritabilities of the transformed variables. The reparameterization enables sampling properties of the index weights to be easily computed and formulae are given for data from half-sib families. The index is likely to be least stable when the transformed variables of low heritability have high economic weights, and the weights will have highest sampling variance when these heritabilities are nearly equal. It is suggested that the sample roots of the determinantal equation be inspected when constructing an index in order to give some guide to its accuracy.

Genetic Variation↗
PubMed1979

Direct genetic and postnatal maternal genetic effects on body composition in mice selected for body weight.

Line crossfostering techniques were used to study differences among selected and control lines of mice in direct genetic and postnatal maternal genetic influences on preweaning (day 12) body weight and composition. The lines were selected for high (H6) and low (L6) 6-week body weight and the control line (C2) was maintained by random selection. There were positive correlated responses to selection in both direct genetic and postnatal maternal genetic effects on body weight and weights of all body components (P less than 0.01) except for water and ash weight in H6. The correlated responses in postnatal maternal genetic effects were of the same order of magnitude as those in direct genetic effects. Correlated responses were greater in L6 than in H6. Correlated responses in direct genetic effects were positive (P less than 0.01) for water percent in H6 and ether extract percent in L6, and negative (P less than 0.01) for water percent and lean percent in L6. Correlated responses in postnatal maternal genetic effects were positive for ether extract percent and negative for water percent (P less than 0.01). Correlated responses were far greater in L6 than in H6 and were greater for postnatal maternal genetic effects than for direct genetic effects. Analyses of covariance results indicated line differences in the relative growth rates of the body components.

Analysis of Variance↗
PubMed1979

PTFE graft arteriovenous fistulae for hemodialysis access.

The use of expanded PTFE graft arteriovenous fistulae for hemodialysis access is becoming increasingly popular. Its low infection rate, low thrombogenicity, low body reactivity, and longevity make it an ideal vascular substitute. From May 1976 to June 2, 1978 we have placed 102 grafts in 89 patients, many of whom represent management problems of other access means. Major complications are pseudointimal proliferation at the venous anastomosis, pseudoaneurysm formation, and thrombosis, usually associated with low blood volume. These problems are, however, readily rectifiable. Other types of grafts, according to the literature, have not been successful for hemodialysis access.

Arm↗
PubMedDate not supplied

Markers within the regulatory region of the growth hormone receptor gene and their association with milk-related traits in Holsteins.

We studied sequence variations in the regulatory region of the bovine growth hormone receptor gene. A polymerase chain reaction (PCR)-based method for detecting AluI, AccI, and StuI restriction fragment length polymorphisms (RFLPs) in the 5' flanking region of the bovine growth hormone receptor gene was developed and tested for association with milk-related traits in Holstein bulls. Allele frequencies of the polymorphisms in two groups of Holstein progeny-tested bulls born from 1950 to 1970 and in the 1980s, respectively, were estimated. The allele frequency of the AluI(-) allele was 0.63 and 0.42 in the bulls from 1950 to 1970 and in the 1980s, respectively. The frequency of the StuI(-) allele was 0.14 and 0.07 in the two respective bull groups. Allele frequency for AccI(-) allele was about 0.22 in both bull groups. The differences in allele frequencies for the AluI polymorphism in the two bull groups were significantly different (P < or = .005). The AluI(+/+) bulls had a higher estimated breeding value (EBV) for fat (P < or = .016) than AluI(-/-) bulls. The average effect of allele substitution for the AluI polymorphism was +/- 8 for fat EBV. The AluI polymorphism could be further evaluated for use in marker-assisted selection in dairy cattle.

Alleles↗