Showing papers in "Journal of Dairy Science in 1990"

TL;DR: The casein micelle is built of submicelles, roughly spherical aggregates of several casein molecules held together by hydrophobic bonds and salt bridges.

TL;DR: There is considerable interest in bovine DNA-level polymorphic marker loci as a means of mapping quantitative trait loci of economic importance in cattle and power to detect QTL, as a function of QTL effect, heritability of the trait, and number of animals tested was determined.

TL;DR: In this article, the degradability of starch from corn, milo, wheat, barley, and oats was determined in vitro using a 60-min incubation in a glucoamylase enzyme.

TL;DR: Anestrus cows and cows showing corpus luteum activity between d 40 and 60 obtained more energy from body reserves for milk production the first 2 wk of lactation, than cows cycling prior to d 40.

TL;DR: Significant variations in bile tolerance and ability to assimilate cholesterol were observed among 12 cultures of Lactobacillus acidophilus of human origin and the most active cholesterol-assimilating cultures also varied in the ability to produce bacteriocins.

TL;DR: It is concluded that reduced luteal activity that accompanies negative energy balance may be associated with reduced concentrations of insulin-like growth factor-I in serum, energy balance, body condition, and ovarian activity during early lactation.

TL;DR: Twenty-one quarters of seven cows were experimentally infected with Staphylococcus aureus to study the shedding pattern in quarter milk samples and consecutive samples would be advisable for accurate diagnosis of infected quarters.

TL;DR: The data for reproductive functions support the concept that high milk production is antagonistic to expression of estrous behavior but not to reactivation of ovarian function.

TL;DR: Apparent and corrected rumen digestibilities of DM, organic matter, CP, and starch were higher for diets containing barley than milo but were not affected by protein source; however, microbial N synthesis was higher in dietscontaining barley than in diets containing milo.

TL;DR: Efforts to accelerate cheese ripening by increasing amounts of active peptidases have been only partially successful, and results depended on numbers, strain, type of cheese, and condition of manufacture.

TL;DR: Cows that developed dystocia or were culled lost more condition during the dry period than those that did not develop dystice or were not culled, and overconditioned at drying off were more likely to develop cystic ovarian disease and reproductive problems.

TL;DR: Energy balance status plays an important role in determining the postpartum return of cyclic ovarian activity, and feeding excess CP as rumen degradable protein elevated plasma urea concentrations and decreased first service conception rate.

TL;DR: In this article, a total of 305 cows with known 305-d lactation yield for milk, fat, and protein were available and the effects of genetic variants of milk proteins on estimated individual Parmesan cheese yields were investigated.

TL;DR: Differences were observed in the composition of bacteria harvested from the fluid phase compared with particle-associated or mixed populations of ruminal bacteria, which translated into different estimates of bacterial N supplied to the small intestine depending on N:purine ratio used.

TL;DR: The major differences are in fatty acid composition, triacylglycerol structure, and the response of fatty acids in human milk to changes in diet.

TL;DR: Data indicated that intramammary infections and teat canal colonizations were more prevalent and SCC higher than previously realized in dairy heifers.

TL;DR: Nine well-managed dairy herds were monitored for 1 yr to determine if bulk tank SCC and rate of clinical mastitis were associated with dietary and plasma Se and vitamin E status, confirming earlier findings that Se anditamin E status of dairy cows are related to mammary gland health.

TL;DR: Intracellular lipases and esterases also occur in lactobacilli, but activity of these enzymes has been designated as "weak", and they probably contribute to flavor development in some varieties of cheese.

TL;DR: Changes in lipid composition were studied in milk obtained on postpartum d 3 (colostrum), 7, 42, and 180 from 12 Holstein cows, consistent with the theory that milk phospholipids are synthesized de novo entirely in the mammary gland.

TL;DR: Soluble calcium in the acetate-buffered rumen fluid was higher than predicted from pKa of calcium soaps, due to formation of soluble calcium acetate; however, the relative patterns were similar to their pKa values.

TL;DR: The data document an acute decline in plasma retinol, alpha-tocopherol, and Zn in the immediate periparturient period and indicate that the decline in Plasma Zn is more severe in cows with milk fever.

TL;DR: Vitamin E supplementation of diets increased intracellular kill of Staphylococcus aureus and Escherichia coli by neutrophils and ability of neutrophil to phagocytize either S. a Aureus or E. coli was independent of vitamin E and selenium.

TL;DR: Changes in composition, nitrogen fractions, fats, casein breakdown characteristics, and microbial flora were studied in Majorero cheese over a 3-mo ripening period.

TL;DR: Three experiments with 571 dairy cows indicated that significantly more primiparous cows given two prostaglandin F2 alpha injections 14 d apart conceived within 30 d of first AI than did cows given three injections 11 d apart.

TL;DR: Liquid passage rates from the rumen and the differentials between liquid and particulate dilution rates were higher in cows than in sheep for all diets at both intakes, suggesting that caution should be exercised when extrapolating results from one species to the other.

TL;DR: The pathogen grows well in liquid dairy products at 4 to 35 degrees C and achieves higher populations in chocolate than in unflavored milks and in susceptible humans (adults with a compromised immune system), pregnant women, and infants).

TL;DR: A generalized computing procedure applicable to a large set of problems in animal breeding including ordinary least squares, generalized most squares, and mixed model equations is presented using sparse storage of coefficients and iteration on data.

TL;DR: In this paper, a small amount of κ-casein was present in the reductive eluant following heat treatment at 75°C; however, a much greater amount was attached through intermolecular disulfide bonds when the mixture was heated at 85°C.

TL;DR: A protein-free synthetic diet has been shown to lower the animal-flavors of indole and skatole, eliminates 2-enals (C 3 to C 12 ), and increases branched-chain and odd carbon-numbered δ-lactones and odd-carbon-numbered fatty acids in the milk fat.

TL;DR: In this article, the effect of heat treatments between 70 and 90°C was analyzed in terms of the kinetics of whey protein unfolding and aggregation, and the results revealed that thermal denaturation of protein during industrial heating processes is predictable.