Compost bedded pack (CBP) barn design and pack maintenance procedures vary considerably, making advising and problem-solving challenging. One objective of this research was to characterize herd performance and management practices employed by Kentucky CBP managers (42 farms and 47 CBP facilities). Producer satisfaction, changes in historical bulk-tank somatic cell count, and improvement in herd performance parameters after transitioning to a CBP barn support reported CBP barn system benefits. Daily milk production increased from before moving into the CBP barn to the second year after (29.3 ± 0.3 vs. 30.7 ± 0.3 kg, respectively; P < 0.05) for farms using the CBP barn as the primary housing facility (n = 8). Increasing stirring frequency, stirring depth, and ambient temperatures increased pack temperature. Increased drying rate decreased CBP moisture. Increased 20.3 cm depth CBP temperature and ambient temperatures improved cow hygiene. Mastitis-causing bacteria thrive in conditions similar to optimal composting bacteria conditions, making reduction of these bacteria difficult in an active composting environment. Producers must pay attention to other management areas where preventive measures can be employed. The New Dairy Housing Investment Analysis Dashboard provides users an interactive and flexible decision tool to make more informed facility investment decisions.

The objectives of this research were to compare lying time, milk yield, rumination time, hock score, stall cleanliness, and stall temperature for 97 cows (Holsteins (n = 71), Jerseys (n = 10), and crossbreds (n = 16)) housed on Dual Chamber Cow Waterbeds™ (DCCW, Advanced Comfort Technology, Reedsburg, WI) or conventional rubber mattresses (MAT). This study was conducted at the University of Kentucky Coldstream Research Dairy Farm from January 18, 2012 to May 3, 2013. Lying times were longer (P < 0.01) for cows housed on the DCCW (10:32 ± 0:13) compared to cows housed on the MAT (9:47 ± 0:15). Milk yield was not different (P ≥ 0.05) between cows housed on the DCCW or MAT. Rumination times were greater (P = 0.03) for cows housed on MAT (6:44 ± 0:08) compared to cows housed on DCCW (6:29 ± 0:08). Hock scores were lesser (P = 0.02) for cows housed on DCCW (1.86 ± 0.03) compared to cows housed on MAT (1.97 ± 0.04). Stall cleanliness was not different (P ≥ 0.05) between the DCCW and the MAT. The DCCW stall temperature was warmer (P < 0.01) (13.29 ± 0.21 ⁰C) than the MAT (10.52 ± 0.21 ⁰C).

Lameness and mastitis are the two most costly diseases in the dairy industry. Reduction of these diseases through housing and management is beneficial. Compost bedded pack (CBP) and sand freestall barns were compared in a long-term, on-farm study to assess the effect of housing on each disease. Another research objective was to evaluate the effects of ambient weather conditions on moisture and 20 cm internal temperature of CBP. Compost bedded pack moisture, C:N ratio, and internal temperature effects on cleanliness, mastitis, and bedding bacterial counts were also considered. The last research objective was to evaluate the economics of bedding material decisions in CBP and provide a user-friendly decision support tool to predict bedding costs and usefulness.

The objective of the first study was to quantify the effects of feeding Schizochytrium sp. microalgae (SP-1, Alltech, Inc., Nicholasville, KY) on milk fat and DHA content. Eight cows were fed: 0, 100, 300, or 600 g of algae per day. Fat percentage was greater (P < 0.05) for cows on treatments 0 g and 100 g than for cows on treatments 300 g and 600 g (P < 0.05). Docosahexaenoic acid in milk was greater for cows on treatment 300 and 600 than for cows on treatment 0 and 100 (P < 0.05). The objective of the second study was to assess yeast supplementation effects on high and low forage dairy cow diets. Four cows were assigned to 1 of 4 treatments: 1) low forage (LF), 2) low forage with 10 g/d yeast (Yea-Sacc®; Alltech Inc., Nicholasville, KY; LFY), 3) high forage (HF), or 4) high forage with 10 g/d yeast (HFY). Only rumination time and DMI were influenced by treatment (P < 0.01). Dry matter intake was 17.05, 13.41, 19.44, and 20.29 ± 1.40 kg/d and rumination time was 442.88, 323.09, 433.34, and 475.50 ± 21.93 min/d for cows on the LF, LFY, HF, and HFY treatments, respectively.

The objective of this study was to determine dairy cattle preference amongst four species of cool-season forage grasses: eight orchardgrasses (Dactylis glomerata L.), five tall fescues [Schedonorus arundinaceus (Schreb.) Dumort.], five perennial ryegrasses (Lolium perenne L.), and six festuloliums [xFestulolium braunii (K. Richt.) A. Camus.]; 24 cultivars in total. Each grazing trial utilized four Holstein-Friesian heifers over six hours. Maturity differences were eliminated by having animals graze only vegetative material. After six grazing trials (three each in 2014 and 2015), consistent results in animal preference were not found; three of the six trials did show preference (P

In vitro produced bovine embryos are critical to the cattle industry. However, these embryos have altered morphology, epigenetics, and metabolism when compared to their in vivo counterparts. The aim of this thesis was to alter maturation and culture media to improve the developmental competence of in vitro bovine embryos. This thesis is comprised of three experiments and one proof of concept study. Each experiment followed the same general layout: oocyte aspiration from Jersey or Holstein ovaries, oocyte maturation for 24 hours, fertilization with bull semen for 24 hours, then embryo culture for 7-8 days in 38.5 °C in 5% O2, 5% CO2 and 90% N2. A proportion of stage 7 grade 1 blastocysts were fixed and stained with Nile Red to evaluate lipid content, Mitotracker Red CMX-Rosamine to measure mitochondrial activity, or Cell Rox Green to assess reactive oxygen species (ROS). Using a confocal microscope, images were taken of each stained embryo to detect and measure fluorescence. Any stage 7 embryos that were not imaged were slow frozen and evaluated for re-expansion when thawed. Experiment 1 was a one-way treatment designed to compare the conventional maturation media (control) containing fetal bovine serum (FBS), to an alternative media replacing FBS with a human platelet lysate serum substitute (SS). Both abattoir and ovum pick up (OPU) oocytes were used. The results suggested that maturing in vitro and OPU oocytes with serum substitute maintained developmental competence, including a similar yield of embryos and re-expansion rate. Resulting in vitro SS embryos had lower lipid content (p<0.05) and ROS levels compared (p<0.05) to the FBS control. Experiment 2 was a 2x2 factorial design testing how the addition of FGF2, LIF, and IGF1 cytokines to maturation and culture media affected in vitro embryo development. The first factor was maturation media (Mcon: industry standard and Mcyt: added cytokines) and the second factor was culture media (Ccon: industry standard and Ccyt: added cytokines). The two maturation media crossed with the two culture media equated to four treatments, including a control. The results suggested that cytokine addition had no effect on blastocyst rate or re-expansion rate. The combination of MCyt x CCyt media produced the lowest lipid levels (p<0.05) while the MCon x CCon treatment led to the highest mitochondrial activity (p<0.05). Experiment 3 was a 2x2 factorial design testing how the addition of melatonin to cytokine supplemented maturation media affected embryo developmental competence. The maturation factor had two levels: no supplementation (NoM) and melatonin with cytokine supplementation (MM). The culture factor had two levels: no supplementation (NoC) and cytokine supplementation (CC). We found no difference in blastocyst or re-expansion rate between any treatments. NoM showed higher mitochondrial activity than MM (p<0.05). NoC showed higher mitochondrial activity than CC (p<0.05). The NoM x NoC treatment showed the highest lipid levels of any treatment (p<0.05). The NoM x NoC treatment showed the highest mitochondrial activity of any treatment (p<0.05). The final part to this thesis focused on the preliminary use of phasor-fluorescence lifetime imaging microscopy (FLIM) and deep imaging via emission recovery (DIVER) technologies to autofluoresce endogenous compounds and predict the viability of an embryo without the use of invasive labels. In conjunction with the University of California Irvine, we tested the technologies on morula and blastocyst stage embryos to see if developmental competence was altered. Results suggested FLIM successfully captured NADH levels and DIVER successfully captured ROS and lipid content. Future studies are planned to fully investigate the effects of the microscopes on development and to accurately predict bovine embryo viability for transfer. Overall, human platelet lysate was a successful replacement for FBS, likely due to its similar content of protein and growth factors. Neither cytokine nor melatonin supplementation had conclusive results, further trials are needed to fully determine effectiveness.

Twenty four cattle, six each of healthy cows and calves, and cows and calves with brisket disease, were obtained, examined and slaughtered, The concentrations of calcium, chloride, cobalt, copper, iron, magnesium, molybdenum, phosphorus, potassium, sodium and zinc; and percent absolute dry matter and percent ash were determined in tissues selected from the following: cardiac, hepatic, renal, osseous, whole blood and blood serum. In addition, certain physical and biological parameters were recorded for each animal. The results were analyzed as a 2 x 2 factorial, segregating the effects of age and brisket disease, and the age-disease interaction. The following statistically significant (P<0.05) differences were attributed to the effect of brisket disease: reduction in the percent dry matter and percent ash in all soft tissues studied; increase in cardiac, hepatic and renal calcium and sodium; decrease in serum total calcium; marked decrease in hepatic copper and increase in hepatic iron; decreased blood iron, hematocrit and hemoglobin; decreased hepatic potassium, magnesium and phosphorus; and increased hepatic zinc. The effects of brisket disease are superimposed upon these marked differences in the cattle in the present study as compared to those in a previous study of well nourished cattle of similar breeding from a similar environment: reduced cardiac, hepatic, serum and osseous calcium; reduced hepatic, osseous and serum magnesium and increased renal magnesium; reduced hepatic phosphorus and increased renal phosphorus; reduced hepatic, serum and osseous potassium and increased cardiac potassium; and reduced cardiac, osseous and serum sodium and zinc. The effects of age must be evaluated in view of the fact that half of the animals were diseased; moreover, some age effects occurred almost exclusively in the diseased animals. Statistically significant (P<0.05 ) differences attributed to the effect of age were: decreased phosphorus concentrations in hepatic and renal tissue and serum; increased percent dry matter in hepatic and osseous tissue; increased osseous percent ash; decreased hepatic and osseous potassium; increased serum ionic calcium; and decreased hepatic calcium, magnesium and sodium, all in cows as compared to calves. The interaction of increased age and brisket disease produced the following statistically significant (P<0.05) results: hepatic percent dry matter and iron concentration were increased; hepatic magnesium, potassium and sodium were decreased; and cardiac zinc was increased. Hypotheses regarding possible reasons for these results are formulated and discussed.

The intensity of the pressure of population on an area may be increased on three occasions. Economic and social opportunities may contract; population may increase; or both these factors may combine to increase the intensity of pressure. This pressure, naturally can be diminished either by an increase of opportunity or an dimunition of population.

Two factors that are important in the production of the typical body and texture of cheddar cheese are acid development and milk fat content. When either of these is absent or present in less-than-normal amounts, the resulting cheese shows marked defects of curdiness and firmness.

Properly dried sweet cream buttermilk, because of its high fat and lecithin contents, should make superior ice cream. Its use as a source of serum solids in ice cream. Its use as a source of serum solids in ice cream mix would open an outlet for this butter by-product and would serve the needs of ice cream manufacturers during nonfat dry milk solids shortage and it may make a higher score ice cream. The demand for milk solids shortage and it may make a higher score ice cream. The demand for milk solids has been increasing so rapidly that today the by-products of the dairy industry are being utilized as sources of human food to a much greater extent than before. In past years the greater bulk of creamery buttermilk has been utilized as animal feeds. Attempts are being made to convert more of this by-product into channels of human consumption. As the manufacture of sweet cream butter is increasing at a rapid pace, a larger supply of buttermilk product of high quality which is fit for human consumption is available in the market. Many previous investigators have used buttermilk products as a source of serum solids in ice cream mix with favorable results. The advantage claimed has been that it tends to improve the whipping ability of ice cream mixes and to impart richer flavor to the product. These beneficial qualities have been attributed to the butterfat and the phospholipids, of which lecithin is predominant. The work of Chapman and Supplee shows that buttermilk and cream contins several times as much licithin as skimmilk. The amounts of total phospholipids reported by Holm et al and Wright et al are approximately 1.77 per cent in dry buttermilk and 1.06 per cent in dry skim milk.