Showing papers in "Journal of Dairy Science in 1972"

TL;DR: Lignin concentration in fiber influences the extent of in vivo ruminant digestion, but increasing lignin content during digestion does not slow rate of digestion.

TL;DR: Forage fiber digestion followed first-order reaction kinetics even though individual forages differed widely in maturity, composition, and rate of fiber digestion as mentioned in this paper, and linearity of individual semilog plots of remaining digestible cell walls on time and their individually high r 2 (mean.978) for each of 112 different samples representing 15 species support this general model.

TL;DR: In this article, the authors summarized 543 energy balance trials with lactating cows to partition the energy required by cows into maintenance and production components and to determine the influence of energy source on the efficiency with which dietary energy is used for milk production.

TL;DR: Alfalfa, orchard grass, native grass, and mixtures of 31 hay and 16 silage heat damaged samples on which in vivo digestibility had been determined, were assembled to relate laboratory estimates to nitrogen digestibility as discussed by the authors.

TL;DR: Holstein lactation records from the Dairy Herd Improvement test day files of the New York Dairy Records Processing Laboratory of Cornell University were used to study genetic and environmental relationships of days dry and days open with milk production.

TL;DR: In this paper, a pseudo-normal distribution was used to test the heritability of parent-offspring correlation and paternal sib correlation, and the results showed that the adjustment from theory was quite satisfactory for the paternal Sib correlation but would lead to substantial overestimates of heritability on the normal scale when p is small and normal heritability is actually large.

TL;DR: Spermatozoa diluted in zwitter ionic buffer were more motile but released more GOT than sperm diluted in phosphate or citrate, and N-Tris (hydroxymethyl) methyl-2-amino ethane sulfonic acid (TES) with Tris as the titration base was the most satisfactory buffering system for diluting bull spermatozoA for freezing.

TL;DR: Activity of ejaculated dead sperm is only slightly less than freshly killed sperm, and inhibition of toxicity by EDTA is by protection of sperm against deleterious effects of peroxide and not by inhibition of the enzyme.

TL;DR: In this paper, a few reasonable estimates and assumptions with what statistics are available are used to make an estimate that will adequately serve the purpose of this discussion can be made by combining with what is available.

TL;DR: The mean daily dry matter intake 28 days prepartum did not differ significantly and Digestible energy consumed during the 28 days before calving averaged 155, 138, 159, and 173% of National Research Council's maintenance requirements for the four treatment groups, respectively.

TL;DR: Energy intake, milk yield, milk fat and rectal temperature of 36 Holstein cows representing three stages of lactation, were examined in relation to air temperature, relative humidity, indices combining these two variables (THI and THC) and wind velocity occurring June to August.

TL;DR: Reduction in milk production was most severe when infections began during early lactation, however, infections that lasted less than 40 weeks caused a greater decrease in milkProduction than those lasting longer.

TL;DR: Ruminal volatile fatty acid production rates and blood glucose entry rate were measured in two cows, nonlactating and again lactating, with a constant infusion isotope dilution technique, suggesting propionate contributed to not more than 60% of the glucose formed during the lactating phase.

TL;DR: Both the magnitude of the cortisol response and the interval to maximum response to ACTH varied among cows (P) and both the magnitude and timing of the response ranged from low to high levels.

TL;DR: Among treated cows S. agalactiae infection, new infection rate, and cases of clinical mastitis were reduced from controls, and there was no increase in coliform infections.

TL;DR: In this article, the initial rates and extents of β-casein were determined for 1,440min reaction of whole, α-, β-, and κ-caseins by crystallized rennin, crystallized pepsin and purified M. pusillus protease.

TL;DR: Energy balance measurements related the amount of metabolizable energy required by the pregnant cow to the stage of pregnancy, which was 75% above that of a nonpregnant animal of equal weight.

TL;DR: Year-season and stage of lactation effects were statistically significant for several criteria of infection in first, second, and later lactation groups but did not explain much of the variation in any infection criterion.

TL;DR: The extent of butyrate conversion was affected by pH and by concentration of volatile fatty acid in the ruminoreticulum and was negatively correlated to the rate of Butyrate absorption, and about three-fourths of the portal-arterial differences in ketone bodies were accounted for by β -hydroxybutyrate.

TL;DR: Differences in the lipids of human and cow's milk were evidenced: these concerned mainly the degree of unsaturation, the positional distribution of fatty acids, cholesterol and 7-dehydrocholesterol content, the amount and type of phospholipids as well as their fatty acid distribution.

TL;DR: High genetic correlations between first lactation production and lifetime performance support the utility of selection on first lactations, and all appraisal traits combined were as effective as production variables in predicting number of lactations.

TL;DR: Milk fat with increased polyunsaturated fatty acids was produced by feeding cows a diet containing a formaldehyde-treated safflower oil-casein particle, and the linoleic acid content of the milk increased from 3% to 35% of the total fatty acids.

TL;DR: In this paper, corn silage and either 30 or 60% of the dry matter from concentrate were fed to Holstein cows in amounts calculated to minimize body tissue change, and complete energy balance measurements were made at 6-week intervals throughout the lactation cycle.

TL;DR: Lactoferrin decreased during the first two weeks, paralleling a decrease in total and in whey protein nitrogen, and then the curve sloped more gradually.

TL;DR: The occurrence of these immunoglobulin units helps to explain the complicated immunoelectrophoretic patterns often observed in bovine body fluids and also the multiple ring phenomena obtained during radial diffusion assay for Immunoglobulins in the cow.

TL;DR: Heat detection was a problem in several herds due to inadequate observation and failure to recognize some heat signs, and many operators need additional training to detect heat and on maintaining complete, individual-cow, health records.

TL;DR: A quadratic regression analysis revealed a loss in milk yield per quarter when somatic cell counts were elevated, and found that clinical mastitis had not been observed, regardless of presence of bacteria.

TL;DR: Radioimmunoassay procedures have sufficient sensitivity and specificity for assaying minute quantities of peptide hormones in biological fluids and it is suggested that secretin and pancreozymin are involved in bringing about the rise in plasma insulin in cattle within 1 hr after feeding and that glucose and, possibly, short-chain fatty acids produced in the rumen are involvement in maintaining elevated plasma insulin for about 6 hrs after feeding.