Master of Science / Department of Animal Sciences and Industry / Barry J. Bradford / The transition from gestation to lactation requires numerous physiological and metabolic adaptations in order for the body to maintain relative homeostasis. For the modern dairy cow, the difficulty to meet these challenges is increased many-fold due to the large demand for energy and metabolites placed on the body by the high producing mammary gland. Milk fever or periparturient hypocalcemia can be defined as a failure of the calcium homeostatic mechanisms to maintain serum calcium around the time of calving. Though clinical cases may only arise in ≈ 5% of transition cows, subclinical rates are much higher. Animals suffering from even subclinical milk fever are much more susceptible to numerous other transition disorders. Preventing milk fever by formulation of the prepartum ration may be accomplished by decreasing the dietary cation anion difference (DCAD) which can be defined as the balance between positively and negatively charged ions in the diet. An experiment was designed to test 2 diets containing t products designed to deliver supplementary anions to the diet versus a control ration with no added anions. Total serum calcium and incidence of postpartum health disorders were not affected by prepartum dietary treatment. Though DCAD was drastically different between the control ration and the 2 anionic diets, the concentration of the strong cation potassium was low across all treatments which presumably prevented hypocalcemia with the onset of lactation. Though our diets contained low concentrations of potassium, many diets used by dairymen contain forages that are high in potassium and thus might benefit from the addition of anions. An experiment of an unrelated nature was conducted to observe the effects of 2 diets containing wet corn gluten feed (46 or 56% of DM) as the primary energy substrate and tallgrass prairie hay (14 or 20% of DM) as the sole source of physically effective fiber versus a control ration containing alfalfa and corn silage. The 20% tallgrass prairie hay diet resulted in milk components and efficiencies similar to those of the control ration, but production and income over feed cost did not match that of the control ration in this situation.

Master of Science / Department of Animal Sciences and Industry / Barry J. Bradford / Increased pressure for land use and greater demand for cereal grains have substantially increased feed costs for dairy producers. This has forced nutritionists to devise novel diet formulation strategies to help keep feed costs in check. As a result, dairymen are incorporating wet corn gluten feed (WCGF) into diets. Numerous studies have reported production responses to dietary inclusion of WCGF, but few have reported ruminal effects. Therefore an experiment was conducted to monitor production, while simultaneously measuring ruminal fermentation and total-tract digestion in 8 Holstein cows fed 0, 12, 24, and 36% WCGF (DM basis). Results from this study were consistent with recently published papers indicating that increasing dietary levels of WCGF linearly increases milk and milk component production. However, results demonstrate that this increase in production is related to an increase in feed intake, not improved digestibility. In addition to escalating grain prices, recent pressure for land and water use has led to a decrease in the availability of alfalfa. A second experiment was conducted to determine if forage fiber provided by alfalfa hay is necessary to maintain production in diets containing 31% WCGF (DM basis). Eighty primiparous and multiparous Holstein cows were utilized in two 4 × 4 Latin squares to evaluate the effects of feeding alfalfa at 0, 7, 14, and 21% of diet DM. Feeding higher proportions of alfalfa tended to increase ECM yield and decrease BW gain, suggesting that metabolizable energy supply was repartitioned from BW gain to milk production as more alfalfa was included. However, partial budget analysis determined that decreasing alfalfa inclusion rate may improve farm profitability by reducing feed costs and expenses associated with manure handling, despite small losses in productivity. Overall, these research projects suggest that large proportions of WCGF can effectively be fed to dairy cattle without sacrificing milk production, even without the use of alfalfa hay. Therefore, WCGF can be a cost-effective alternative to traditional dietary ingredients.

Master of Science / Department of Animal Sciences and Industry / Dale A. Blasi / Effects of corn processing with or without the inclusion of wet corn gluten feed (WCGF) on growth and performance were analyzed in two experiments. Treatments for both experiments were a diet including 47% whole-shelled corn (WSC) with no WCGF (WSC/0WCGF), a diet including 29% WSC with 30% WCGF (WSC/30WCGF), a diet including 47% dry-rolled corn (DRC) with no WCGF (DRC/0WCGF), and a diet with 29% DRC with 30% WCGF (DRC/30WCGF). Exp. 1 used 279 crossbred calves (230 kg) that were allocated to treatments in a 2x2 factorial completely randomized block design. No corn processing effects (all P > 0.31) were observed. Final BW was increased when WCGF was included in the diet (P = 0.03). ADG was increased for diets with WCGF (P = 0.03). Efficiency was not affected by the incorporation of WCGF in the diet. Digestibility of DM (P = 0.006) and starch (P = 0.009) was increased by the dietary inclusion of WCGF. There were no benefits observed for processing corn, but including WCGF at 30% (DM) increased gains and overall performance. Exp. 2 was a digestibility experiment using 5 ruminally cannulated Holstein heifers (248 ± 13 kg BW) in a 4 × 4 Latin square with an additional animal that was administered the same treatment sequence as another heifer on trial. No corn processing effects were observed for DM, starch, and ADF intake (all P ≥ 0.09). Dietary WCGF inclusion increased starch, non-starch and ADF intake (all P ≤ 0.01). Digestibility of DM, starch, non-starch, and ADF was not affected by corn processing, but DM, non-starch, and ADF digestibility were increased by WCGF inclusion in the diet (P ≤ 0.03). Ruminal pH was not affected by corn processing (P = 0.90) or dietary WCGF inclusion (P = 0.09). No corn × WCGF interactions were detected. There also was no difference among VFAs or total VFA concentration (all P ≥ 0.12) for corn processing effects. Passage rate (%/h) and ruminal liquid volume was not affected by corn processing or dietary WCGF inclusion (all P ≥ 0.66).

Master of Science / Department of Animal Sciences and Industry / Barry J. Bradford / Wet corn gluten feed (WCGF) is commonly included in lactation rations for dairy cattle. Research at Kansas State University has shown that increasing WCGF inclusion decreased ruminal pH. Lack of adequate particle size may result in this decrease and can impact efficiencies, animal health and longevity. A study was conducted to look at the effects of feeding WCGF while maintaining > 10% of particles > 19 mm across diets. We hypothesized that as WCGF increased, DMI and milk yield would increase while ruminal pH would be maintained. Seven ruminally-cannulated, lactating Holstein cows were used in an incomplete 4 × 4 Latin square design with treatments of 0, 12.4, 24.5 or 35.1% WCGF across 4 periods of 21 d. Alfalfa hay was used to maintain particle size. All diets met particle size goals; however, as WCGF increased, the proportion of particles > 19 mm decreased (P = 0.01) and cows changed their sorting behavior in favor of particles > 19 mm (P = 0.03) and against particles on the bottom screen (P < 0.01) and pan (P = 0.01). As WCGF increased, ruminal pH and ECM/DMI were not affected, yet DMI (P = 0.02) and milk yield (P = 0.02) increased quadratically. Milk protein, lactose and fat concentrations were not affected; however, milk protein (P = 0.004; linear) and lactose (P = 0.02; quadratic) yields increased. In a separate study, active dry yeast (ADY) products, commonly used in the dairy industry to support ruminal health, were evaluated for product guarantees and effects of storage and storage medium. Few products received through normal distribution met product guarantees (1 of 6; experiment 1) and after 3 mo of storage cell viability dropped significantly (P < 0.01). In the second experiment, products were stored in ground corn or in a vitamin-trace mineral mix (VTM). Depressions in viability caused by high-temperature storage were partially mitigated when ADY products were stored with a VTM. Although both mediums resulted in lower cell viabilities after storage at 40ºC, VTM cell viabilities were significantly (P = 0.02) higher than ground corn.