Dairy Science Commons^™

Towards The Quantification Of Estrone And 17Β-Estradiol Conjugates In Dairy Cattle Urine Sorptive Stir Bar Extraction And Gas Chromatography-Mass Spectometry, S.M. Istiak Ahmed

Masters Theses & Specialist Projects

The global concern regarding the presence of compounds with estrogenic properties in the environment has grown significantly. Endocrine-disrupting compounds (EDCs) are environmental pollutants that disrupt the endocrine systems of both wildlife and humans. Estrogens, with their potent estrogenic effects, are particularly noteworthy among the various substances with endocrine-disrupting properties. They are of concern due to their prevalence in the environment, especially due to dairy waste contamination. These lipophilic compounds can accumulate in livestock fat tissues, potentially entering the human food chain. Sulfated forms of estrone and β- estriol, which exhibit a higher degree of saturation than their non-conjugated counterparts, have …

Liquid Chromatography Mass Spectrometry Method Development For The Determination Of Β–Defensins In Bovine Milk, Elisha Ogbebor

Masters Theses & Specialist Projects

Bovine mastitis is caused by a wide range of pathogens which results in a substantial economic loss for the dairy cattle livestock industry. β-defensins are a part of the innate immune system and act as the first line of defense against mastitis in bovine. β-defensins (~6- 10kDa) are antimicrobial peptides that contain about 28 to 67 amino acids, the presence of six cysteine residues results in their three disulfide bonds and a β-sheet structure. A few β- defensins have been identified in cows based on the site of occurrence and time of expression in tissue, but not in milk. A …

Liquid Chromatography With Tandem Mass Spectrometry Method Development For The Determination Of Β–Defensins In Bovine Milk, Symone T. Whalin

Masters Theses & Specialist Projects

Bovine mastitis, caused by a wide array of pathogens, results in a substantial economic loss for the dairy cattle livestock industry. β-defensins are a part of the bovine’s innate immune system and act as the first line of defense against mastitis. Only foundational research has been done on β-defensins’ ability to treat and prevent mastitis. There have been no analytical methods reported in the literature for analyzing β-defensins in bovine milk. This research aims to create an analytical approach to determine β-defensins in bovine milk. It is challenging to determine an analyte in a complex sample matrix, and milk is …

Quantification Of Tylosin Antibiotics In Cattle Waste, Appala Keerthi

Masters Theses & Specialist Projects

Antibiotics are used as prophylactic agents to promote growth and for treating infections in animals. However, the irrational use of antibiotics in livestock management is a significant cause of the development of antibioticresistant genes in the environment. Each year 2 million people suffer from the infections caused by bacteria which are resistant to antibiotics and 23,000 of these people are estimated to die because of antibiotic resistance. New drugs are continually coming into the market but are at the risk of developing resistance. Thus, there is a need for the development of analytical methods which can be used to monitor …

Distribution Of Sexual Activities Within Estrus Of Dairy Cattle, Donna Durbin

Masters Theses & Specialist Projects

Previous studies of dairy cattle have indicated that heifers and cows in hot, cold and moderate weather had different patterns of sexual activities. The purpose of this study was to compare distribution of sexual activities within estrus of dairy cattle. Three groups of lactating cows in hot, cold and moderate weather and a group of heifers in cold weather were observed. Estrus for each individual was divided into 12 equal periods. Sexual activities for 3 and 6 hours before and after estrus were also observed. The numbers of mounts and distribution of total sexual activities was analyzed. Mounts received per …

Studies On I) Dry Matter And Nitrogen Disappearance Of Six Soybean Protein Products In Situ And Ii) Contamination Of In Situ Dry Matter And Nitrogen Disappearance With Acid Detergent Fiber, James Coomer

Masters Theses & Specialist Projects

In experiment I), dry matter disappearance (DMD) and nitrogen disappearance (ND) of raw soybeans (RAW), solvent extracted soybean meal (SBM), heat treated whole soybeans (HT), mechanically extracted soybean meal (MEX), dry extruded soybeans (DEX), and wet extruded soybeans (TEX), were studied in situ for times of 3, 6, 12 and 24 h of rumen exposure. Five gram, air dry, samples were suspended in the rumen of a lactating Holstein cow fed a total mixed ration twice daily. The percent DMD for 24 h was as follows: RAW-85.9; SBM-56.6; HT-39.0; MEX-40.2; DEX-28.0; TEX-43.3. The greatest DMD was observed with RAW and …

Use Of Soybean Meal, Raw Soybeans, & Heat-Treated Soybeans As Protein Supplements With & Without Niacin For Dairy Cows In Early Lactation, Daniel Aguilar

Masters Theses & Specialist Projects

Twenty three cows with an average of 2.7 lactations were used to measure the effects of different protein sources (soybean meal, soybeans, and heat-treated soybean) and supplementation with niacin on milk production, milk components (protein, fat, somatic cell counts), 4% fat corrected milk, solid corrected milk, dry matter intake, body weight changes, and rumen volatile fatty acids (acetate, propionate, butyrate).

Diets affected performance of cows. The results indicate, in general, that feeding heat-treated soybean and soybean meal to lactating dairy cows in early lactation resulted in greater milk production, milk protein, dry matter intake and less loss of body weight …

Analysis Of The Reproductive Efficiency Of The Dairy Herd At Western Kentucky University Farm, Gregorio Lagombra

Masters Theses & Specialist Projects

A study of the reproductive performance of 179 dairy cows during the period from December 1978 through March 1984 was conducted at the Western Kentucky University Farm, Bowling Green, Kentucky. The climatic data showed seasonal variation in temperature as follows: winter 3.10C, spring 15.7°C, summer 23.8°C, and fall 12.0°C. The seasonal humidity was similar for winter (81.2%), spring (83.4%), and fall (85.3%); but for summer it was considerably higher (89.4%).

The conception rate varied through all the months but was lowest during the summer months. Seasonal data for conception rate were obtained and the results were as follows: winter 54.1%, …

Effect Of Rations On Some Selected Blood Constituents Of Dairy Heifers, Kamil Akanbi

Masters Theses & Specialist Projects

The study was conducted using nine Holstein heifers with weights ranging from 700 to 990 pounds (lb). The design was a 3 X 3 Latin Square. The three rations consisted of 26.5 lb of corn silage supplemented with 3 ounces of sodium bicarbonate, 26.5 lb of corn silage, and 26.5 lb of soybean and milo haylage per head per day. The rations were offered on a rotational basis for three experimental periods consisting of three weeks each. Blood samples were taken at weekly intervals during each period; plasma concentrations of glucose, ammonia, beta-hydroxybutyrate and volatile fatty acids were determined.

There …