Showing papers in "Journal of Dairy Science in 1988"

TL;DR: This methodology offers a better way to simulate the rumen environment within a given feeding regimen, however, its usefulness will be dependent on the standardization of inherent variables associated with its conduct.

TL;DR: In early lactation, dietary CP and energy can profoundly affect milk yield, but current methods of assessing these nutrients are often inadequate to predict animal performance.

TL;DR: In this article, the use of buffering agents in dairy cow diets are a function of salivary buffer secretion, feedstuff buffering capacity, and feed acidity, where buffer flow from saliva is inadequate, added dietary buffers may be justified.

TL;DR: Preservation of crop quality, DM, and energy in the silo requires that plant respiration, plant proteolytic activity, clostridial activity, and aerobic microbial growth be limited, a critical mechanism for limiting these processes is quick attainment and maintenance of anaerobic conditions in thesilo.

TL;DR: Rules are presented for assigning coefficients to the genetic group portion(s) of the mixed model equations after transformation to solve directly for total genetic value (group plus animal solutions) simultaneously for sires and cows using an animal model.

TL;DR: In lactating cows, secretion of progesterone is reduced by spontaneous caloric deficit and is modulated by timing and magnitude of maximal caloric deficit, which is a potential source of infertility in lactating dairy cows.

TL;DR: Less variation in ammonia concentrations and microbial numbers suggest that ruminal fermentation was more stable in cows receiving yeast culture supplement, while rate of disappearance of cellulose in vitro was lower in cows received yeast.

TL;DR: Seasonal factors also were significant in influencing rate of gain from birth to 180 d and age of dam was a significant source of variation in calf weight gains but only for the first 35 d.

TL;DR: In this article, the first and second moments of a random vector of breeding values are derived from simple genetic assumptions and matrix expressions are derived for the first two moments of the vector.

TL;DR: Heritabilities and genetic correlations for mastitis, SCC, and milk production in first lactation were calculated using data from the Swedish disease recording system and showed a slightly unfavorable genetic correlation with mastitis and SCC.

TL;DR: Quantitative and qualitative analyses of pasteurized mastitic milk by SDS-PAGE indicated that a portion of the somatic cell proteolytic activity survived pasteurization, and 6-amino-n-hexanoic acid can be used to establish the relative contribution of somaticcell proteases and plasmin to total proteolysis activity in mastitic Milk.

TL;DR: Cows fed diets containing ammonium salts had higher serum ionized and total Ca concentrations at parturition and Calcium intake during the feeding period did not affect the incidence of parturient paresis or serum concentrations of ionized Ca at calving.

TL;DR: The sensitivity of nine strains of Listeria to nisin was determined as well as the minimum inhibitory concentration of nisin necessary to completely inhibit growth of these strains, which led to the inhibition of L. monocytogenes ATCC 7644 in TSB trypticase at different pH values.

TL;DR: Data suggest that heat stress can suppress anterior pituitary release of LH without having a measurable influence on ovarian steroid hormone secretion.

TL;DR: Methods of controlling bovine mastitis during the periparturient period is an important area that requires additional research that needs to be developed that are effective against a variety of bacteria, including environmental mastitis pathogens, if additional control is to be achieved.

TL;DR: Both fat supplements appeared inert in the rumen and did not markedly affect nutrient digestion when supplemented at 3.5% or less of the total ration DM.

TL;DR: Square times balance response differences proved nonsignificant for all parameters except blood bicarbonate and rumen isovalerate, indicating responses could be attributed to the dietary cation-anion balance itself rather than to the effects of a single ion.

TL;DR: In this article, the factors involved in depression of milk protein synthesis when whole soybeans or cottonseeds are fed were investigated in eight rumen cannulated Holstein cows in two 4×4 Latin squares.

TL;DR: In this paper, the authors used Weibull models with time-dependent covariates to estimate the genetic component of the cow's true stayability and an approximation of her functional stayability.

TL;DR: In this article, the authors analyzed the length of productive life of cows milked in 150 large herds in New York state between 1981 and 1986 by modeling their hazard, which is a measure of their probability of being culled.

TL;DR: In this article, the effects of reducing forage particle size on production, chewing, and digesta kinetic parameters in early lactation were examined in 42 Holstein cows (9 ruminally cannulated) who were assigned 14 d postpartum to one of three experimental diets with concentrate: alfalfa haylage:alfalfa pellets ratio of 60:40:0; 60:28:12; and 60:12:28 on a DM basis.

TL;DR: In this article, a multiphasic function that considers milk yield to result from an accumulation from more than one phase of lactation was used to describe a lactation curve, and the relationship between the two phases of the cycle was examined using correlations between functions of estimates for parameters within and between phases.

TL;DR: The descriptive epidemiology and risk factors were reviewed for six clinical disorders: milk fever, downer cow syndrome, hypomagnesemic tetany, udder edema, left displaced abomasum, and ketosis.

TL;DR: Proper procedures were developed for animal model evaluation of dairy cattle for milk, fat, and protein yields as well as evaluation for fat and protein percentages as a function of yield evaluations.

TL;DR: For traits controlled by a large number of loci acting additively, use of an animal model with the additive genetic relationship matrix can account for changes in genetic mean and variance due to chance or selection.

TL;DR: In this paper, the authors evaluated the effect of Ca salts of fatty acids on the digestibility and production responses of cows in early lactation, and concluded that the inclusion of ca salts in early-lactation milk and milk fat production increased milk and fat production.

TL;DR: It is concluded that most periparturient disorders occur as a complex, rather than as a single abnormality, and cows with one disorders are at increased risk for other disorders, including metabolic ones.

TL;DR: Cows managed with an intensive program for detection of estrus and for reproductive health did not show differences in reproductive efficiency when fed 13 or 20% CP rations, and there was an interaction between protein intake and lactation number.

TL;DR: An animal model can account for repeated records, multiple traits, nonadditive genetic effects, litter effects, and a number of environmental effects, both fixed and random.

TL;DR: Twenty-eight multiparous Holstein cows were utilized to determine effects of long-term administration of recombinant bovine somatotropin on lactational performance, body condition, body composition, hormones, blood constituents, and physiological parameters.