Journal of Dairy Science back issues from May 2008:
NEWS AND ANNOUNCEMENTS
May 01, 2008; ... ADSA Member News ... Coming Soon - Dairy News Watch your inbox in late April for the spring ADSA newsletter, Dairy News. The newsletter replaces Animal and Dairy News and will be e-mailed to members and published on the ADSA web site twice a year. Please take a few minutes to read ...
Supramolecular Structure of the Casein Micelle
May 01, 2008; ... ABSTRACT The supramolecular structure of colloidal casein micelles in milk was investigated by using a sample preparation protocol based on adsorption of proteins onto a poly-L-lysine and parlodion-coated copper grid, staining of proteins and calcium phosphate by uranyl oxalate, ...
Influence of Lamb Rennet Paste Containing Probiotic on Proteolysis and Rheological Properties of Pecorino Cheese
May 01, 2008; ... ABSTRACT Pecorino cheeses made from heat-treated ewes' milk using traditional lamb rennet paste (RP), lamb rennet paste containing Lactobacillus acidophilus (LA-5; RPL), and lamb rennet paste containing a mix ofBifidobacterium lactis (BB-12) and Bifidobacterium Iongum (BB-46; RPB) were ...
Modeling of the Effect of Freezer Conditions on the Principal Constituent Parameters of Ice Cream by Using Response Surface Methodology
May 01, 2008; ... ABSTRACT A systematic analysis was carried out by using response surface methodology to create a quantitative model of the synergistic effects of conditions in a continuous freezer [mix flow rate (L/h), overrun (%), cylinder pressure (kPa), drawing temperature (°C), and dasher speed ...
Microbial and Sensory Changes Throughout the Ripening of Prato Cheese Made from Milk with Different Levels of Somatic Cells
May 01, 2008; ... ABSTRACT The objective of this research was to evaluate the effects of 2 levels of raw milk somatic cell count (SCC) on the composition of Prato cheese and on the microbiological and sensory changes of Prato cheese throughout ripening. Two groups of dairy cows were selected to obtain ...
Production, Purification, and Characterization of a Potential Thermostable Galactosidase for Milk Lactose Hydrolysis from Bacillus stearothermophilus
May 01, 2008; ... ABSTRACT β-Galactosidase, commonly named lactase, is one of the most important enzymes used in dairy processing; it catalyzes the hydrolysis of lactose to its constituent monosaccharides glucose and galactose. Here, a thermostable β-galactosidase gene bgaB from Bacillus ...
Enhancing the Lethal Effect of High-Intensity Pulsed Electric Field in Milk by Antimicrobial Compounds as Combined Hurdles
May 01, 2008; ... ABSTRACT High-intensity pulsed electric field (HIPEF) is a non-thermal treatment studied for its wide antimicrobial spectrum on liquid food, including milk and dairy products. Moreover, the antimicrobial effect of HIPEF may be enhanced by combining HIPEF with other treatments as hurdles ....
The Effect of Pasteurization Temperature on Consumer Acceptability, Sensory Characteristics, Volatile Compound Composition, and Shelf-Life of Fluid Milk
May 01, 2008; ... ABSTRACT The relationship among consumer acceptability, descriptive sensory attributes, and shelf-life was determined for 2% milk pasteurized at 77, 79, 82, and 85°C. Sensory descriptive attributes and volatile compound composition were monitored over the shelf-life of the products to ...
Effect of Sex-Sorted Sperm Dosage on Conception Rates in Holstein Heifers and Lactating Cows
May 01, 2008; ... ABSTRACT Ejaculates were collected by artificial vagina from 3 Holstein sires and sorted to 90% purity for X-chromosome-bearing spermatozoa (range 88 to 93%) using flow cytometry. Sorted sperm were diluted to 2.1, 3.5, or 5.0 × 10^sup 6^ sperm per dose in an egg yolk (20%), Tris, ...
Quality of Embryos Produced From Dairy Cows Fed Whole Flaxseed and the Success of Embryo Transfer1
May 01, 2008; ... ABSTRACT The objective of the experiment was to determine the effects of fat supplementation on embryo quality of dairy cows and the subsequent success of embryo transfer into recipient heifers fed the same sources of fat. A total of 30 lactating Holstein cows were allotted on d 18 ...
Continuous Lactation in Dairy Cows: Effect on Milk Production and Mammary Nutrient Supply and Extraction
May 01, 2008; ... ABSTRACT Reports over the past decade have indicated that normal lactational performance can be achieved in genetically superior and high-producing dairy cows, even when the dry period between 2 lactations is omitted. The hypothesis tested in this experiment was that normal lactogenesis ...
Growth Hormone Receptor, Insulin-Like Growth Factor (IGF)-1, and IGF-Binding Protein-2 Expression in the Reproductive Tissues of Early Postpartum Dairy Cows
May 01, 2008; ... ABSTRACT The growth hormone/insulin-like growth factor (IGF) system plays a critical endocrine role controlling nutrient metabolism in dairy cattle. In liver, growth hormone receptor (GHR) and IGF-1 are dynamically regulated by lactation and energy balance. Less is known about the ...
Variation in Plasma Concentrations of Insulin-Like Growth Factor-I in Pasture-Fed Holstein Cows
May 01, 2008; ... ABSTRACT The objective of this 5-wk study was to determine dietary effects on plasma concentrations of insulin-like growth factor-I (IGF-I), as well as milk production and milk components in pasture-fed dairy cows. Thirty-two Holstein cows 4 to 5 wk postpartum were randomly assigned to 4 ...
Effect of Restricted Feeding and Monopropylene Glycol Postpartum on Metabolic Hormones and Postpartum Anestrus in Grazing Dairy Heifers
May 01, 2008; ... ABSTRACT This study was designed to determine the effects of feed restriction and monopropylene glycol (MPG) supplementation on the reproductive, milk production, and somatotropic axes in dairy heifers postpartum. At calving, 49 Holstein-Friesian heifers were allowed either unrestricted ...
Evaluation of Serotonin as a Feedback Inhibitor of Lactation in the Bovine
May 01, 2008; ... ABSTRACT Serotonin (5-HT), a neurotransmitter synthesized from tryptophan, has been proposed as a feedback inhibitor of lactation. We determined that the gene coding for tryptophan hydroxylase 1, the rate-limiting enzyme for 5-HT synthesis, is expressed in bovine mammary epithelial cells ...
Production and Health of Cows Given Monensin Prepartum and a High-Energy Diet Postpartum
May 01, 2008; ... ABSTRACT The object of this study was to evaluate the impact of monensin administration on the early lactation performance of cows maintained on a high-energy diet, and on health traits during the transition period. Cows (n = 168; parity 3.3 ± 1.4, initial body condition score 3.1 ± ...
Activation of Immune Cells in Bovine Mammary Gland Secretions by Zymosan-Treated Bovine Serum1
May 01, 2008; ... ABSTRACT Mastitis, caused by bacterial infection of the mammary gland, is a major disease of dairy cattle. The greatest risks of intramammary infection occur at the end of lactation and at the initiation of the next lactation when the cow calves. Treating serum with zymosan (yeast cell ...
Relationship Between Milk Lactoferrin and Etiological Agent in the Mastitic Bovine Mammary Gland
May 01, 2008; ... ABSTRACT Bovine mastitis is one of the most deleterious diseases for dairy herds and is mainly caused by contagious and environmental bacterial pathogens. Among contagious bacteria, Staphylococcus aureus is the most prevalent, whereas the main environmental mastitis pathogens are ...
Effect of Different Flooring Systems on Weight and Pressure Distribution on Claws of Dairy Cows
May 01, 2008; ... ABSTRACT Weight and pressure distribution on the claw were studied in Swedish Holsteins housed in different flooring systems. A total of 127 cows housed in different sections of the experimental barn were used. Each section had different flooring in the walking and standing areas. There ...
Evaluation of Free-Stall Mattress Bedding Treatments to Reduce Mastitis Bacterial Growth
May 01, 2008; ... ABSTRACT Bacterial counts were compared in free-stall mattresses and teat ends exposed to 5 treatments in a factorial study design on 1 dairy farm. Mattresses in five 30-cow groups were subjected to 1 of 5 bedding treatments every other day: 0.5 kg of hydrated limestone, 120 mL of ...
A Longitudinal Field Study to Evaluate the Diagnostic Properties of a Quantitative Real-Time Polymerase Chain Reaction-Based Assay to Detect Staphylococcus aureus in Milk
May 01, 2008; ... ABSTRACT Bacteriological culture as a diagnostic tool for chronic infections with Staphylococcus aureus intramammary infection is not completely satisfactory. The cyclical shedding pattern of Staph. aureus with intervals of low excretion is considered to be the main reason. We recently ...
Short Communication: Effect of Stocking Density on Indices of Cow Comfort
May 01, 2008; ... ABSTRACT The objective of this study was to evaluate the effects of increasing stocking density on indices of cow comfort measured over a 24-h period, during peak lying time (0000 to 0400 h), and 1 h after the afternoon milking. Holstein cows (n = 136) were assigned to 1 of 4 pens, and ...
Technical Note: Immunomagnetic Procedure for Positive Selection of Macrophages in Ovine Milk
May 01, 2008; ... ABSTRACT A simple immunomagnetic procedure was developed to select macrophages from ovine milk by using a non-specific magnetic positive separation technique. Samples of ewe bulk milk were collected during early, mid, and late lactation; milk samples were centrifuged at 2,000 × g for 30 ...
Effects of Feeding Prepubertal Heifers a High-Energy Diet for Three, Six, or Twelve Weeks on Mammary Growth and Composition
May 01, 2008; ... ABSTRACT The experimental objective was to determine the effects of feeding prepubertal dairy heifers a high-energy diet for 3,6, or 12 wk on mammary growth and composition. Holstein heifers (age = 11 wk; body weight = 107 ± 1 kg) were assigned to 1 of 4 treatments (n = 16/ treatment) ....
Effects of Feeding Prepubertal Heifers a High-Energy Diet for Three, Six, or Twelve Weeks on Feed Intake, Body Growth, and Fat Deposition
May 01, 2008; ... ABSTRACT The objective was to determine the effects of feeding prepubertal dairy heifers a high-energy diet for a duration of 0, 3, 6, or 12 wk on feed intake, growth, and fat deposition. We also used feed composition, daily intake, and body growth data to evaluate the nutritional model ...
Effect of Feeding Corn, Hull-Less or Hulled Barley on Fermentation by Mixed Cultures of Ruminal Microorganisms
May 01, 2008; ... ABSTRACT Increased demands for corn grain warrant the evaluation of alternative grain types for ruminant production systems. This study was conducted to determine the effects of hulled and hull-less barley (Hordeum vulgare L.) cultivars compared with corn (Zea mays L.) as an alternative ...
Effects of the Chop Lengths of Alfalfa Silage and Oat Silage on Feed Intake, Milk Production, Feeding Behavior, and Rumen Fermentation of Dairy Cows
May 01, 2008; ... ABSTRACT Effects of chop length (shorter: 6 mm, or longer: 19 mm) of alfalfa silage and oat silage were determined in 16 mid-lactation Holstein cows, 4 of which were rumen cannulated, using a replicated 4 × 4 Latin square design with a 2 × 2 arrangement of treatments. Experimental ...
Timothy Hay with a Low Dietary Cation-Anion Difference Improves Calcium Homeostasis in Periparturient Holstein Cows
May 01, 2008; ... ABSTRACT The current study was undertaken to evaluate the effects of feeding timothy (Phleum pratense L.) hay differing in dietary cation-anion difference (DCAD) on the capability of cows to maintain calcium homeostasis around parturition. We hypothesized that feeding lowDCAD timothy hay ...
Efficacy of Liquid Feeds Varying in Concentration and Composition of Fat, Nonprotein Nitrogen, and Nonfiber Carbohydrates for Lactating Dairy Cows1
May 01, 2008; ... ABSTRACT In trial 1, we evaluated the efficacy of a liquid feed (LF) containing cane molasses and corn steep liquor as carriers of suspended white grease (WG) without or with urea (U) or with soybean lipid (SL; a byproduct of soybean processing) compared with roasted soybeans plus tallow ...
Effect of Trace Mineral Source on Lactation Performance, Claw Integrity, and Fertility of Dairy Cattle
May 01, 2008; ... ABSTRACT Two hundred fifty multiparous and primiparous cows were assigned to a study at approximately 70 d prepartum to determine the effect of trace mineral source on lactation performance, claw integrity, and fertility. Cows received treatments from 3 wk prepartum through wk 35 ...
Extent of Methionine Limitation in Peak-, Early-, and Mid-Lactation Dairy Cows1,2
May 01, 2008; ... ABSTRACT Five multiparous, ruminally and duodenally cannulated Holstein cows were assigned to 5 × 5 Latin squares at wk 2 (experiment 1), wk 11 to 13 (experiment 2), and wk 17 to 19 postpartum (experiment 3) to determine extent of Met limitation. Treatments were duodenally infused and ...
Metabolism of Dairy Cows as Affected by Prepartum Dietary Carbohydrate Source and Supplementation with Chromium Throughout the Periparturient Period1
May 01, 2008; ... ABSTRACT Holstein cows (n = 72) entering second or later lactation were used to determine whether metabolic indices and hepatic capacities for oxidation and gluconeogenesis from propionate are affected by source of carbohydrate in the prepartum diet and chromium-L-methionine (Cr-Met) ...
A Model of Phosphorus Digestion and Metabolism in the Lactating Dairy Cow
May 01, 2008; ... ABSTRACT A dynamic, mechanistic, compartmental model of phosphorus (P) digestion and metabolism was constructed in the Advanced Continuous Simulation Language using conservation of mass principles and mass action kinetics. Phosphorus was assumed to exist in 3 forms: inorganic (Pi), ...
Frequent Allocation of Rotationally Grazed Dairy Cows Changes Grazing Behavior and Improves Productivity
May 01, 2008; ... ABSTRACT Twenty Holstein cows were blocked in 2 groups according to milk yield to evaluate the effect of frequency of allocation to new grazing plots on pasture intake, grazing behavior, rumen characteristics, and milk yield. The 2 treatments, daily allocation to 0.125-ha plots (1D) or ...
Modeling the Adequacy of Dietary Fiber in Dairy Cows Based on the Responses of Ruminal pH and Milk Fat Production to Composition of the Diet
May 01, 2008; ... ABSTRACT The main objective of this study was to develop practical models to assess and predict the adequacy of dietary fiber in high-yielding dairy cows. We used quantitative methods to analyze relevant research data and critically evaluate and determine the responses of ruminal pH and ...
Chitotriosidase Activity in Goat Blood and Colostrum
May 01, 2008; ... ABSTRACT Chitotriosidase (ChT) activity has not been investigated in ruminants, and therefore, we studied this activity in blood and colostrum of 25 pregnant goats and 60 goat kids. Blood samples were taken from pregnant goats at 3, 2, and 1 d prepartum; at partum; and at 1, 2, 3, and 4 ...
Technical Note: A Near-Infrared Reflectance Spectroscopy Technique to Predict Particle Size of Starch Within Corn Silage
May 01, 2008; ... ABSTRACT Starch particle size characteristics of 81 diverse corn silage samples, which included 27 combinations of hybrid, planting dates, and harvest dates subjected to 3 different degrees of kernel processing, were determined via vertical shaking through 9 screens with nominal square ...
Short Communication: Salivary Secretion During Meals in Lactating Dairy Cattle
May 01, 2008; ... ABSTRACT Four multiparous Holstein cows in midlactation were used in a 4 × 4 Latin square to evaluate whether source of forage influenced salivary secretion during eating in lactating dairy cows. The forages were allocated separately from the pelleted concentrates. Cows were offered 1 of ...
Short Communication: Turbidity as an Indicator of Escherichia coli Presence in Water Troughs on Cattle Farms
May 01, 2008; ... ABSTRACT Studies have shown that water-drinking troughs are an important source of Escherichia coli infection on cattle farms, and a study was designed to provide farmers with an easy-to-use tool to monitor trough contamination and help determine when to empty and clean water troughs. A ...
Short Communication: Apoptosis Regulates Passive Immune Transfer in Newborn Kids
May 01, 2008; ... ABSTRACT Ten newborn kids were used to evaluate the relationship between apoptosis and passive immune transfer in neonatal enterocytes. Kids were slaughtered in groups of 2 at birth, 1, 2, 3, or 60 d postpartum, and samples of duodenal epithelium collected from each animal. Samples were ...
Conformation of Hind Legs and Lameness in Danish Holstein Heifers
May 01, 2008; ... ABSTRACT Lameness causes major financial losses and welfare problems in dairy herds. Prevention of foot lesions may suffice in the majority of lameness cases. The objectives of this longitudinal study were to describe the dynamics and associations between abnormal hind leg conformation, ...
Quantitative Trait Loci Affecting Calving Traits in Danish Holstein Cattle
May 01, 2008; ... ABSTRACT The objectives of this study were 1) to detect quantitative trait loci (QTL) affecting direct and maternal calving traits at first calving in the Danish Holstein population, 2) to distinguish between pleiotropic and linked QTL for chromosome regions affecting more than one ...
Extent of Linkage Disequilibrium in Holstein Cattle in North America
May 01, 2008; ... ABSTRACT The success of fine-scale mapping and genomic selection depends mainly on the strength of linkage disequilibrium (LD) between markers and causal mutations. With Lewontin's measure of LD (known as D'), high levels of LD that extend over several million base pairs have been ...
Genetic Parameters for Tunisian Holsteins Using a Test-Day Random Regression Model
May 01, 2008; ... ABSTRACT Genetic parameters of milk, fat, and protein yields were estimated in the first 3 lactations for registered Tunisian Holsteins. Data included 140,187; 97,404; and 62,221 test-day production records collected on 22,538; 15,257; and 9,722 first-, second-, and third-parity cows, ...
Frequency and Effect of the Bovine Acyl-CoA:Diacylglycerol Acyltransferase 1 (DGAT1) K232A Polymorphism in Swedish Dairy Cattle
May 01, 2008; ... ABSTRACT Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in triacylglycerol synthesis in the mammary gland, and the corresponding gene has emerged as a strong candidate for the variation in milk fat percentage. In this study, the allele frequencies and effects of the ...
Erratum
May 01, 2008; ... A Survey of Bovine Colostrum Composition and Colostrum Management Practices on Pennsylvania Dairy Farms S. I. Kehoe, B. M. Jayarao, and A. J ....
Economic Impact of Milk Production in the State of New Mexico1
May 01, 2008; ... ABSTRACT The goal of this study was to quantify the economic role of dairy farming in New Mexico and to identify its linkages with allied industries in terms of income, value added, and employment impacts. An input-output model was used to estimate the direct, indirect, and induced ...
Effect of Stocking Rate on Pasture Production, Milk Production, and Reproduction of Dairy Cows in Pasture-Based Systems
May 01, 2008; ... ABSTRACT Ninety-four cows were randomly allocated to 1 of 5 stocking rates (2.2, 2.7, 3.1, 3.7, and 4.3 cows/ha) in a completely randomized design for 3 years. Herds were seasonal calving, with only minor differences in grazing management to optimize the profitability of each stocking ...
Milk Fatty Acid Unsaturation: Genetic Parameters and Effects of Stearoyl-CoA Desaturase (SCD1) and Acyl CoA: Diacylglycerol Acyltransferase 1 (DGAT1)
May 01, 2008; ... ABSTRACT With regard to human health aspects of milk fat, increasing the amount of unsaturated fatty acids in milk is an important selection objective. The cow's diet has an influence on the degree of unsaturation, but literature suggests that genetics also plays a role. To estimate ...