Factors Affecting Forage Quality and the Subsequent Response in Production and Energy Metabolism in Lactating Jersey Cows

Forage quality is the potential of a forage to produce a production response in animals. Because of how essential they are in dairy cattle rations, forages can have major influence on the behavior and production of dairy cattle. In experiment 1, the effect of forage fragility on the rumen environment and digestibility was evaluated. Increasing the inclusion of a less fragile forage led to greater rumen retention time, which resulted in lower rumen pH and greater NDF digestibility. Experiment 2 evaluated the effects of diets high in either corn silage or alfalfa haylage supplemented with either corn- or soybased protein on the production, energy, and N utilization. Supplementing corn-based protein did not affect milk production or components in both corn silage and alfalfa haylage diets. Corn silage diets had the greatest N intake and urinary N but the lowest fecal N. The effects of lower-lignin (LoL) and conventional (CON) alfalfa on energy and N utilization was evaluated in experiment 3. No difference was observed in DMI, but methane production was lowest in the diet with a 50:50 blend of LL and CON alfalfa. Intake of N linearly decreased while urinary N increased with increasing LL alfalfa inclusion. In experiment 4, the effect of forage quality on feed preference of lactating dairy cattle was examined. Cows most preferred hay with a higher forage quality. Surprisingly, low quality hay was the next most preferred followed by moderate quality hay. Experiment 5 continued the comparison of LL and CON alfalfa with evaluating NDF content and digestibility across a growing season. Overall NDF content was affected by variety and cutting, but no difference was observed in NDF digestibility. No difference was observed in NDF for the first, third, and fourth cuttings between LL and CON alfalfa, but NDF was greatest in the second cutting. Results suggest that differences in forage quality can have diverse effects on production and energy metabolism in dairy cattle

Factors Affecting Forage Quality and the Subsequent Response in Production and Energy Metabolism in Lactating Jersey Cows

Forage quality is the potential of a forage to produce a production response in animals. Because of how essential they are in dairy cattle rations, forages can have major influence on the behavior and production of dairy cattle. In experiment 1, the effect of forage fragility on the rumen environment and digestibility was evaluated. Increasing the inclusion of a less fragile forage led to greater rumen retention time, which resulted in lower rumen pH and greater NDF digestibility. Experiment 2 evaluated the effects of diets high in either corn silage or alfalfa haylage supplemented with either corn- or soybased protein on the production, energy, and N utilization. Supplementing corn-based protein did not affect milk production or components in both corn silage and alfalfa haylage diets. Corn silage diets had the greatest N intake and urinary N but the lowest fecal N. The effects of lower-lignin (LoL) and conventional (CON) alfalfa on energy and N utilization was evaluated in experiment 3. No difference was observed in DMI, but methane production was lowest in the diet with a 50:50 blend of LoL and CON alfalfa. Intake of N linearly decreased while urinary N increased with increasing LoL alfalfa inclusion. In experiment 4, the effect of forage quality on feed preference of lactating dairy cattle was examined. Cows most preferred hay with a higher forage quality. Surprisingly, low quality hay was the next most preferred followed by moderate quality hay. Experiment 5 continued the comparison of LoL and CON alfalfa with evaluating NDF content and digestibility across a growing season. Overall NDF content was affected by variety and cutting, but no difference was observed in NDF digestibility. No difference was observed in NDF for the first, third, and fourth cuttings between LoL and CON alfalfa, but NDF was greatest in the second cutting. Results suggest that differences in forage quality can have diverse effects on production and energy metabolism in dairy cattle. Advisor: Paul J. Kononof

Comparison of methods to estimate ruminal degradation and intestinal digestibility of protein in hydrolyzed feather meal with or without blood

Hydrolyzed feather meal (HFM) is a feedstuff high in rumen undegraded protein (RUP) that can be used as an effective source of metabolizable protein for dairy cattle. Because the production process may vary, the rumen degradability and intestinal digestibility of HFM may also vary. Additionally, some processes may incorporate additional blood into the final product to result in feather meal with poultry blood. To determine the rumen degradability and intestinal digestibility of these products, several laboratory assays can be used; the common assays are the mobile bag (MOB), modified three-step (MTS), and Ross (ROS) assays. Although all 3 assays determine RUP digestibility, they vary in whether they are performed in situ, in vitro, or both. The objective of this study was to evaluate the ruminal degradability and intestinal digestibility of HFM originating from processes that differ in their inclusion of blood, and to compare the MOB, MTS, and ROS assays. Ten samples of HFM, which were identified by the suppliers as HFM with little blood (n = 5) and with more blood (n = 5), were spot-sampled, collected from 10 production plants across the United States, and subjected to all 3 assays. Assay type had an effect on RUP, total-tract crude protein (CP) digestibility, and the amount of RUP digested. A significant effect was observed on RDP and RUP concentrations for blood inclusion; no effect was detected for total-tract CP digestibility. We found no difference in RUP digestibility for assay or blood inclusion. There was also no interaction of the effect of assay or blood inclusion. Results suggest that even though there are differences in chemical composition in HFM associated with the inclusion of blood, such as ash and crude fat, few if any differences are observed in intestinal digestion of protein. Although the assays varied in their estimates of rumen undegraded protein, MOB and MTS yielded the most similar values. However, all 3 assays resulted in similar estimates of RUP digestibility

Effect of Alga Bio 1.0 on Reducing Enteric Methane Emission from Cattle

An experiment was conducted to determine the effect of Alga Bio 1.0 inclusion on methane and carbon dioxide emissions along with diet digestibility. Three treatments were evaluated with 0, 69, and 103 grams per day Alga Bio 1.0 fed as a top dress in a corn-based diet. Indirect calorimetry headboxes were utilized to evaluate gas production with 12 cows in 4 replicated 3x3 Latin squares. There was a 39% reduction in methane per lb of dry matter intake for cattle fed 69 g of Alga Bio 1.0 and 63% reduction when cattle were fed 103 g of Alga Bio 1.0 daily compared to the control treatment. Both dry matter intake and organic matter intake were reduced by 13% with Alga Bio 1.0 inclusion, but the treatments did not affect the digestibility of dry matter or organic matter. Gross and digestible energy were not affected by Alga Bio 1.0 inclusion. Although this strain of algae is not FDA approved for feeding to cattle, the research shows great potential of Alga Bio 1.0 as a methane mitigation strategy

Characterization of protein and fat in dairy feeds and implications on digestibility and milk composition

A variety of feedstuffs are used to comprise dairy rations, each with their own nutritional contributions. In order to best utilize these feedstuffs to maximize production, characterization of their chemical composition is needed. Through the use of both in vitro and in situ methods, not only can the composition of the feed be determined, but also its digestibility. Also, because of the important role they play in human health, omega 3 fatty acids have received increasing attention. Most individuals consuming Western diets do not meet the recommended requirement for omega 3 fatty acids, and one way to improve that is through the enrichment of dairy products by selective feeding high fatty acid feedstuffs to dairy cows. In the first experiment, three assays were used to determine RUP digestibility, the Mobile Bag (MOB), Modified Three Step (MTS), and Ross (ROS) assays, were compared. Also with this experiment, 10 samples of feather meal from different plants across the United States, five with blood (FMB) and five without blood (FM), were evaluated. Each of the ten samples were subjected to all three assays. The results indicate that while the average initial compositions were different between FM and FMB samples, very little difference was observed in the ruminal or intestinal digestibility of the protein. However, there was differences in values among assays. Assay had a significant effect on rumen dry matter digestibility, RDP, RUP, total tract dry matter digestibility, and total tract crude protein digestibility with MOB and MTS being the most similar in values. Nonetheless, RUP digestibility did not differ among assay or blood inclusion. Overall, even though values between samples and assays varied, there was no difference in RUP digestibility among blood inclusion and assay. The second study’s goal was to evaluate the effect of the novel fatty acid supplement, Perfect Omega 3 (PO3), on the milk fatty acid profile and energy utilization. Diets ranging in 0 to 20% PO3 inclusion were fed to four multiparous Jersey cows in a 4 × 4 Latin square, and headbox-style indirect calorimeters were used to determine the effect of increasing inclusion on energy utilization. Results show that increasing inclusion of PO3 not only increased the milk fat concentration but also increased the concentration of α-linolenic acid in the milk while decreasing linoleic acid with no difference in milk yield. Gross energy increased with increasing inclusion, but DE and ME did not differ among treatments. Increasing inclusion also had no effect on NDF and energy digestibility. Through this study, increasing inclusion of PO3 not only maintained milk production, but also increased milk fat concentration with favor towards omega 3 fatty acids. Advisor: Paul J. Kononof

Factors Affecting Forage Quality and the Subsequent Response in Production and Energy Metabolism in Lactating Jersey Cows

Forage quality is the potential of a forage to produce a production response in animals. Because of how essential they are in dairy cattle rations, forages can have major influence on the behavior and production of dairy cattle. In experiment 1, the effect of forage fragility on the rumen environment and digestibility was evaluated. Increasing the inclusion of a less fragile forage led to greater rumen retention time, which resulted in lower rumen pH and greater NDF digestibility. Experiment 2 evaluated the effects of diets high in either corn silage or alfalfa haylage supplemented with either corn- or soybased protein on the production, energy, and N utilization. Supplementing corn-based protein did not affect milk production or components in both corn silage and alfalfa haylage diets. Corn silage diets had the greatest N intake and urinary N but the lowest fecal N. The effects of lower-lignin (LoL) and conventional (CON) alfalfa on energy and N utilization was evaluated in experiment 3. No difference was observed in DMI, but methane production was lowest in the diet with a 50:50 blend of LL and CON alfalfa. Intake of N linearly decreased while urinary N increased with increasing LL alfalfa inclusion. In experiment 4, the effect of forage quality on feed preference of lactating dairy cattle was examined. Cows most preferred hay with a higher forage quality. Surprisingly, low quality hay was the next most preferred followed by moderate quality hay. Experiment 5 continued the comparison of LL and CON alfalfa with evaluating NDF content and digestibility across a growing season. Overall NDF content was affected by variety and cutting, but no difference was observed in NDF digestibility. No difference was observed in NDF for the first, third, and fourth cuttings between LL and CON alfalfa, but NDF was greatest in the second cutting. Results suggest that differences in forage quality can have diverse effects on production and energy metabolism in dairy cattle