VTechWorks Repository :: Browsing by Author "Jones, Gerald M."

Browsing by Author "Jones, Gerald M."

Now showing 1 - 20 of 70

1991 federal regulations for drug residues in milk
Jones, Gerald M.; Bishop, J. Russell (Virginia Cooperative Extension, 1992)
Discusses federal standards and regulations for milk quality and the proper use and storage of animal drugs on dairy farms.
4-H Dairy Goat Project Record Book
McDermott, Jennifer; Natof, Maginel; Clarke, Karen; Natof, Nora; Maloid, Amelia; Clark, Mary; Harrison, William H.; Hartman, Dennis A.; Jones, Gerald M. (Virginia Cooperative Extension Service, 1981-01)
Are Liquid Protein Supplements for You?
Lanning, N. M.; Jones, Gerald M.; Murley, W. Ray (Virginia Cooperative Extension Service, 1979-08)
Assessment of dairy product quality by selective incubation and rapid techniques
Byrne, Robert Duane (Virginia Tech, 1989-12-05)
A study was conducted to investigate the use of bacterial numbers and metabolites for their Value in predicting potential shelf-life of pasteurized fluid milk. The study consisted of two phases. In the first phase, chemical inhibitors were evaluated for their ability to allow growth of gram-negative psychrotrophic bacteria while inhibiting growth of gram-positive organisms. Crystal violet, benzalkonium chloride, a mixture of crystal violet and benzalkonium chloride, and alkylaryl sulfonate were tested. These were incubated with milk samples separately inoculated with gram-negative and gram-positive bacteria, at 2l°C for 18 hours. Alkylaryl sulfonate allowed growth of gram-positive organisms. Crystal violet inhibited gram-positive organisms but was not as effective as the mixture of crystal violet and benzalkonium chloride, The inhibitor of choice was benzalkonium chloride as it inhibited growth of all gram-positive organisms tested and allowed growth of the gram-negative psychrotrophic organisms.
Capture filtration for concentration and detection of selected microorganisms in milk
Byrne, Robert Duane (Virginia Tech, 1994-05-04)
The effectiveness of an adsorption filter in retaining bacteria present in milk was examined. Skim milk and whole milk (100ml) were separately filtered through a 47mm adsorption filter. No significant change in total solids, total fat, and solids-not-fat percentages of skim and whole milk permeates was observed after filtration. Adsorption of Pseudomonas fluorescens at target concentrations of 103 , 102 , and 101 cells/ml was determined in 100ml of dairy standard methods buffer, nutrient broth, whole milk, and skim milk. The average percentage bacterial retentions were 95 ± 5.5%, 95 ± 2.6%, 28 ± 22.1%, and 62 ± 15.5%, respectively. A treatment was developed for milk to increase the bacterial retention of ~ fluorescens after filtration. The preferred treatment for 100ml of skim milk involved the following final concentrations (v/v): 0.80% disodium ethylenediamine-tetraacetic acid, 0.02% sodium dodecyl sulfate, pH to 7.5 with 1N sodium hydroxide. The average bacterial retention of ~ fluorescens using the treatment was 91 ± 7.1%. Enumeration of bacteria adsorbed to the filter was then conducted using impedance microbiology. When milk was inoculated with ~ fluorescens at target concentrations of 103 , 102 , and 101 cells/ml, an average log bacterial increase of 1.4 ± 0.1 (25x) was obtained. This method will allow for rapid detection of microorganisms in milk by increasing microbial load in the tested sample and eliminating the need for pre-enrichment.
Cleaning and Sanitizing Milking Equipment
Jones, Gerald M. (Virginia Cooperative Extension, 2009-05-01)
Inadequate or improper cleaning or sanitizing of milking equipment allows bacteria to remain on equipment surfaces and to grow and multiply. This results in elevated bacteria counts in milk.
Cleaning and sanitizing milking equipment
Jones, Gerald M. (Virginia Cooperative Extension, 1992)
All milking machine equipment that come in contact with milk, dirt or manure must be thoroughly cleaned and sanitized before the next milking.
Cow Clipping is Important for Quality Milk Production
Wagner, Philip E.; Jones, Gerald M.; Brown, Carl A. (Virginia Cooperative Extension Service, 1976-07)
Clipping cows is one management practice which could stand more attention on many dairy farms. Many dairymen delay this chore until it is practically impossible to do a good job...
Dairy Replacement Heifers: The Cost of Raising Them and Their Value
Jones, Gerald M. (Virginia Cooperative Extension Service, 1975-05)
Dietary phosphorus and water quality
Myers, Kelly; Knowlton, Katharine F.; Jones, Gerald M. (Virginia Cooperative Extension, 2000)
There is a direct relationship between phosphorus levels in dairy cattle rations and the amount of phosphorus excreted in manure. Phosphorus accumulates in surface water and can pollute ponds, streams and lakes.
Dry matter intake prediction of Holstein heifers
Hubbert, Charles J. (Virginia Tech, 1991-07-17)
Data sets from six locations containing 631 dairy heifers and 5409 observations of individual dry matter intake (DMI) were used to develop an equation to predict DMI. Data were contributed by Pennsylvania State University, University of New Hampshire, Purina Mills, Kansas State University, University of Minnesota, and Virginia Tech. Objectives varied by location and trials within locations but all contained DMI (kg/d), BW (kg), age (wk), DM, and CP, and ADF percentages of ration DM. Daily gains (g) were calculated from consecutive BW. Season was expressed as sine wave of Julian day plus 60 d times Ï divided into 180. Average daily temperature, humidity, and wind data were collected from Minnesota and Virginia and analyzed with BW to determine their effect on DMI. Sire PTA milk, protein, and fat of heifers were recorded from all sources to determine the relationship of genetics with DMI. Diet measurements (DM, CP, and ADF percent of ration DM) were analyzed with BW to determine their impact on DMI. Two equations were developed using backwards elimination techniques. The first equation was: DMI = -12.63 + .0587(BW) - .0000264(BW2) - .000 12(BWxDM) - .000477(BWxADF) + .292(DM) - .00103(DM2) - .413(CP) + .01349(CP2) + .181(ADF) - .0025(DMxCP) - .00269(DMxADF) + .00509(CPxADF) with an R2 of .90. Because body weight and diet variables were highly correlated, a smaller model could be created with one diet variable. A smaller model would also be more practical to use if accuracy was not lost. Body weight and ADF were used for second model: DMI = -1.71 + .0429(BW) - .0000246(BW2) - .00023(BWxADF) + .032(ADF) - .00068(ADF2) with an R 2 of .87. Previous DMI prediction equations from Virginia Tech were validated using all data from other locations and had R2 of .90 and .84 with this data set. Body weight raised to the .53 power most accurately described the relationship of DMI and BW. Temperature and DMI had a quadratic relationship. Higher DMI were observed at extreme temperatures between -10 to 27° C. Humidity and temperature x humidity accounted for more variation of OMI than season and other environmental measures, but were not included in the small model due to availability of these measurements and they did not change OMI by .1 kg/SO. Sire PTA milk by groups showed differences among heifer groups although no trends were found. Dry matter percent and CP percent had linear and quadratic relationships with OMI. Maximum OMI plateaued between 75 and 950/0 OM and occurred at extreme percentages for CP between 9 and 27%. Acid detergent fiber percent had a negative linear relationship with OMI between 7 and 45%.
Economics of forage testing and feeding balanced rations
Jones, Gerald M. (Virginia Cooperative Extension, 1992)
The most economical ration is a balanced ration, in which the feed requirements of the animal are met without an excess of any nutrient.
Effect of processing parameters on the detection of animal drug residues in milk
Conner, Tonya Michele (Virginia Tech, 1992-08-05)
The advent of new methods to detect animal drug residues has resulted in a need to independently validate them. The effects of processing milk on the performance of these methods was evaluated. Antibiotic-free milk samples were spiked with sulfamethazine, penicillin G, and chlortetracycline at levels of 10, 10 and 30 ppb, respectively. Spiked milk and negative control milk was heat-treated, homogenized or heat-treated and homogenized. The procedures evaluated for penicillin detection were Bacillus stearothermophilus disk assay, a HPLC described by Barker et al., Charm II microbial receptor assay, and CITE Probe and LacTek enzyme immunoassays. The procedures evaluated for sulfonamide detection were an HPLC method described by Long et al., Charm II microbial receptor assay, CITE Probe, LacTek and Signal enzyme immunoassays. The methods evaluated for tetracycline detection were a HPLC method described by Long et al., Charm II microbial receptor assay, and LacTek and CITE Probe enzyme immunoassays. The results indicate that the commercial tests and the disk assay were not adversely affected by processing treatments. Significant treatment differences were found when testing raw Charm II data by analysis of variance but these differences did not effect the overall results of the test. Results of the HPLC method were inconclusive for the three drugs tested.
The effects of a dairy cow body condition scoring system on selected production and metabolic parameters
Wildman, Edward E. (Virginia Polytechnic Institute and State University, 1979)
A dairy cow body condition scoring system was devised by the author as a practical means of determining the body condition, or fitness pertaining to the degree of body fat of dairy cows at any point during the lactation cycle. The factors considered were the thoracic and lumbar regions of the vertebral column (chine, loin and rump), spinous processes (loin), anterior coccygeal vertebrae (tailhead), tuber sacrale (hooks), and tuber ishii (pin bones). All factors in the body condition scoring system must be considered while appraising each cow. Each cow was scored on a 1 to 5 scale with 1 indicating severe undercondition and 5 indicating severe overcondition. During an 18-month period, 28 cows in each of 29 Virginia dairy herds were used for obtaining body condition scores, body weight, frame size measurements and blood samples. Herds were chosen according to rolling herd milk production average and cows were chosen at random from within five Estimated Relative Producing Ability groupings to insure a representative sample of herds across and levels of production in Virginia and of cows within each herd. Herds were sampled at 3-month intervals and complete Dairy Herd Improvement Association records were obtained for each cow in each herd. The relationships of dairy cow body weight, frame size measurements, milk production and related parameters, and blood profiles to the body condition scoring system were determined. Body condition using this method was found to be independent of frame size and only moderately correlated with body weight, the number of intercostal spaces and the ratio of body weight to wither height. Body condition was found to be relatively low during early lactation and to increase through late lactation and remain constant during the dry period. Dairy cows of greatest milk production efficiency did not increase significantly in body condition throughout lactation, had fewer days open, but had less persistency of lactation. Dairy cows that increase significantly in body condition throughout lactation were less efficient milk producers, had a greater number of days open, had relatively high body condition scores in late lactation, but had greater persistency of lactation. Blood parameters, although statistically significant in many cases, were found to be of little or no practical value when compared between body condition, stage of lactation, and dairy merit groupings. The dairy cow body condition scoring system is a practical means of quantitating body condition of dairy cows.
Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds
Grove, Tina Moler (Virginia Tech, 1990-07-05)
Bovine mastitis is the most important economic disease to the dairy industry with losses estimated at 2 billion dollars per year in the United States. Staphylococcus aureus (.Â§.. aureus) is the primary cause of contagious mastitis. Conventional culture methods (National Mastitis Council) were used as a basis for comparing the ability of the enzyme linked immunosorbent assay. ProStaph Iâ ¢, to identify s. aureus. The test had an accuracy of 96%, with a sensitivity of 90% and a specificity of 97%. Results indicated that rinsing teat-cup liners with a 25 ppm iodophor or 100 ppm chlorine solution reduced the presence of S. aureus on the liners by 97%. ProStaph I was used to rapidly screen DHIA preserved milk samples in 10 Virginia cooperator herds. Herds were classified as high (>10% infected) or low prevalence (<10% infected). There were six high prevalence herds after the first test. Average prevalence of cows scoring Ab +2 and +3 was 11.9% ± 7.9. Over the seven month study, prevalence of positive cows declined significantly (P<.OI), but somatic cell count remained relatively unchanged (P>.lO). Four herds continued to have >10% of the animals infected. Incidence of new infection averaged 3.6% ± 2.8 from the first to the last test. Chronic cows averaged 6.9% ± 4.8 over the seven month study. Analysis of variance showed significant (P<.Ol) effects of herd on ProStaph I score J milk yield, and see. Elevated ProStaph I scores were highly correlated (P <.01) with increases in lactation number. ProStaph I changed quadratically (P<.Ol) with increasing SCC. Somatic cell count increased (P<.OI) as ProStaph I score increased.
Environmental Streptococcal and Coliform Mastitis
Jones, Gerald M.; Swisher, Jerry M. (Virginia Cooperative Extension, 2009-05-01)
Today, many well-managed farms that have successfully controlled contagious mastitis and consistently produce milk with somatic cell counts (SCC) below 300,000 have problems with increased clinical mastitis.
Environmental streptococcal and coliform mastitis
Jones, Gerald M.; Swisher, Jerry M. (Virginia Cooperative Extension, 1998)
Cows in low SCC herds are most susceptible to environmental streptococci and coliform infections after drying off and just prior to calving, but which appear in early lactation.
Evaluating Body Condition Status in Dairy Cows
Jones, Gerald M.; Wildman, Edward E.; Troutt, H. F. (Virginia Cooperative Extension Service, 1981-02)
Many dairy cows appear to be over-conditioned during late lactation, especially low producers or problem breeders. A scoring system is described for determining the body condition status of dairy cows and the desired condition score is defined.
A feeding guide for milking goats
Jones, Gerald M. (Virginia Cooperative Extension, 1992)
Economical milk production, sound reproduction and herd health require that attention be given to the different nutrient requirements at different times during the lactation cycle.
A Feeding Guide for Milking Goats
Jones, Gerald M. (Virginia Cooperative Extension Service, 1981-08)

Browsing by Author "Jones, Gerald M."

Results Per Page

Sort Options