Sources Of Variation In Corn Silage Quality And Feeding Value For Lactating Dairy Cows
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Sources Of Variation In Corn Silage Quality And Feeding Value For Lactating Dairy Cows
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Author : Carla Sjostrom Kuehn
language : en
Publisher:
Release Date : 1999
Sources Of Variation In Corn Silage Quality And Feeding Value For Lactating Dairy Cows written by Carla Sjostrom Kuehn and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1999 with categories.
Corn Silage Contributions To Energy Supply And Milk Fat Synthesis Of Dairy Cows
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Author : Celso Heinzen Junior
language : en
Publisher:
Release Date : 2024
Corn Silage Contributions To Energy Supply And Milk Fat Synthesis Of Dairy Cows written by Celso Heinzen Junior and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024 with categories.
Adequate energy supply to lactating dairy cows is essential to maximize genetic potential of milk production and efficiency. Corn silage often accounts for more than 50% of diets and therefore, corn starch is one of the main sources of energy fed to lactating dairy cows. However, the energy supply found in form of starch is dependent on its availability to the animal. Several strategies exist to improve starch digestibility in corn silages, including hybrid selection, kernel processing and prolonged storage. However, different ways to assess starch digestibility are used in the dairy industry and research, while ruminal disappearance is the most common procedure, it differs among laboratories, and much is unknown about how the analytical results of starch digestibility assays relates to in vivo digestibility and energy supply. Moreover, high inclusion of corn, in general, in dairy cattle diets are often related to milk fat depression, due to a highly fermentable carbohydrate source and unsaturated fatty acids profile that corn provides. Therefore, a series of experiments were conducted to evaluate a novel technology of corn silage hybrids effects on silage fermentation and starch digestibility, to better understand the sources of variation on starch digestibility assays to improve sample comparison, and to assess the risks of feeding starch and fatty acids from corn silage in milk fat depression.Two experiments were conducted to evaluate the effects of a genetically-modified corn hybrid with alpha-amylase expressed in the kernel (AMY) on fermentation profile, aerobic stability, nutrient composition, and starch disappearance of whole-plant corn silage (WPCS) and earlage. Both hybrids, AMY and its isogenic counterpart (ISO), were grown in 10 replicated plots (5 for WPCS and 5 for earlage). Samples of each plot were collected at harvest, homogenized, and divided into 5 subsamples which were randomly assigned to 5 storage lengths (0, 30, 60, 90 and 120 d). Minor differences on fermentation profile were observed between AMY and ISO for WPCS and earlage. Starch concentration was greater for AMY than ISO in WPCS and earlage and greater starch disappearances at 0 h and 6 h were observed for ISO in WPCS and earlage. Minor effects on fermentation profile, microbial counts, aerobic stability, and nutrient composition suggests that AMY can be ensiled for prolonged periods with no concerns for undesirable fermentation or nutrient losses. However, in situ starch disappearance was lower for AMY compared to ISO. A series of experiments was conducted to investigate variation across time-points, sample grinding size procedures and bag pore sizes used in ruminal starch digestibility assays. Experiment 1: samples of different starch sources submitted three times to multiple laboratories to evaluate variability of starch digestibility assays and the use of different incubation time-points on feedstuff ranking. Greater variation was observed for shorter incubation time-points, while different submission of samples did not influence starch digestibility for corn forage and corn grain samples. Moreover, different incubation time-points can change the ranking of samples. Experiment 2: samples of different starch sources were used to investigate how different grinding sizes and incubation time-point procedures affect starch digestibility assays variation and ranking of samples. Longer incubation time-points and finely ground samples reduced variation of in vitro starch digestibility assays; however, smaller grinding size increased starch digestibility in all starch sources and affected sample ranking. Experiment 3: samples from different starch sources were incubated in situ at 0 h to investigate the loss of particles and their influence on ruminal kinetics. Our results suggest that secondary loss of particles on ruminal incubations at 0 h might be a problem that limits the relationship between bag disappearance and degradation in forage and corn grain samples. Experiment 4: dry ground corn and pure starch samples were washed in water at different temperatures and using different filter types (Dacron polyester in situ bags, Ankom Technology; DPB, F57 bags, Ankom Technology; F57 or filter papers Whatman G3; WG3) to understand their effects on DM recovery. Samples incubated in room temperature water had greater DM recovery when compared to samples incubated in water at 39℗ð C. Pure starch had greater DM recovery in F57 and WG3 when compared to DPB, however, dry ground corn samples DM recovery was similar across all filter types. Experiment 5: dry ground corn and pure starch samples were incubated in rumen fluid at 0 h, using different filter bags (F57 and DPB) to investigate the effect of sample type and filter bags on DM and starch recovery. F57 bags were able to retain 100% of the starch incubated in pure starch, however, no difference between bags were found for dry ground corn samples for DM or starch recovery. These experiments highlighted the importance of the consideration of specific procedures in starch digestibility assays when ranking samples or generating information for ration formulation. The objective of the last study was to investigate the effects of dietary fatty acids and starch on milk fat secretion, the fatty acid profile changes in whole-plant corn silage (WPCS) and high-moisture corn (HMC) with different silage management practices as well as the contributions of these nutrients derived from WPCS and HMC to milk fat secretion. Twenty-three published studies that evaluated lipids supplementation to dairy cows were included in the dataset and meta-regressions analysis were conducted to model the effects of: 1) dietary fatty acids, starch and forage concentrations (expressed as % of DM) on milk fatty acids concentration (expressed as g/100g); 2) dietary fatty acids, starch and forage concentrations (expressed as % of DM) on milk fatty acids yield (expressed as g/d); 3) intake of fatty acids (expressed as g/d), starch, and forage (expressed as kg/d) on milk fatty acids concentration (expressed as g/100g); and 4) intake of fatty acids (expressed as g/d), starch and forage (expressed as kg/d) on milk fatty acids yield (expressed as g/d). While predictions of milk fatty acids concentrations are useful, models that predict milk fatty acids yield had greater performance. In general, starch concentration and starch intake had a positive effect on de novo and total milk fatty acids yield, while unsaturated fatty acids had a negative effect. Samples of WPCS and HMC from previous studies from our laboratory were analyzed for fatty acids profile to evaluate the effects of cutting height and storage length on fatty acids profile of WPCS and the effects of DM concentration and storage length on fatty acids profile of HMC. Increasing cutting height increased unsaturated fatty acids in WPCS, however, storage length and DM concentration effects did not follow a clear pattern of changes in fatty acids profile of WPCS and HMC. Simulations using the generated models were conducted to visualize the contributions of different inclusions of WPCS and HMC in the diet as well as different WPCS and HMC management practices to milk fat secretion. Our results suggest that energy contributions from starch and saturated fatty acids are important in milk fat synthesis predictions, while supporting the general role of unsaturated fatty acids on milk fat depression described in the literature. Management practices like cutting height, dry matter concentration and storage length affect fatty acids profile of WPCS and HMC and it may affect rumen bacteria metabolism and milk fat secretion.
Effects Of Forage Quality And Management Decisions On Feed Intake Of Lactating Dairy Cows
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Author : Michael Devin Miller
language : en
Publisher:
Release Date : 2020
Effects Of Forage Quality And Management Decisions On Feed Intake Of Lactating Dairy Cows written by Michael Devin Miller and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with Dairy cattle categories.
Dry matter intake (DMI) is one of the most important factors affecting lactational performance and health of dairy cows. Control of DMI in dairy cattle is complicated and multifactorial, but we have chosen to prioritize the two main components that primarily drive farm profitability: forage quality and cow comfort. Brown midrib-3 (BM3) genetics in corn silage typically result in greater fiber digestibility and less indigestible fiber, which result in greater DMI and milk production compared to conventional, non-BM (CON) corn silage. Trace minerals may negatively affect fiber digestion by solubilizing in the rumen. Importantly, hydroxy trace minerals (HTM) are less soluble in the rumen compared to sulfate sources (STM). Still, to-date, no models have inputs that reflect social environment factors such as stocking density and feeding frequency. The objectives of this dissertation were to: 1) evaluate the effect of source of corn silage and trace mineral on lactational performance, total tract digestibility (TTD) of nutrients, and rumen fermentation, and 2) create a model that accurately quantifies the effect of management decisions on DMI. The study addressing the first objective (Chapters 2 and 3) investigated the effects of source of corn silage (CON or BM3) and trace minerals (STM or HTM) on lactational performance, TTD of nutrients, and particle passage rates. Sixteen Holstein cows averaging 82 (SE = 3) days in milk were used in a replicated 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. The dietary treatments were: 1) CON-STM, 2) CON-HTM, 3) BM3-STM, and 4) BM3-HTM. There was no significant interaction between corn silage and trace mineral for DMI and milk yield. Cows fed the BM3 diets had greater DMI and milk yield compared to the cows fed the CON diets. The cows fed the HTM diets had greater DMI than cows fed STM diets. The cows fed the BM3 diets had greater TTD of dry matter (DM) and organic matter (OM) than cows fed the CON diets. Cows fed the HTM diets had a tendency for greater TTD of neutral detergent fiber (NDF) than the cows fed STM diets. Cows fed the BM3 diets had a faster passage rate of small- and medium-sized corn silage NDF particles than cows fed the CON diets. The study addressing the second objective (Chapter 4) created a model that accurately quantifies the effects of stocking density and feeding frequency on behavior and performance of lactating dairy cattle. The foundation of the management model was a time budget. The eating time was predicted using common on-farm measures (NDF content, physically effective NDF, body weight, and milk yield) and had a good predictive ability with a mean absolute error of 39 min/d regardless of parity. Stocking density affected lying time, which accounted for 76% of the variance in lying time. The adjusted lying time was then used to predict a milk yield, which accounted for 36% of the variance in milk yield. The peuNDF240 accounted for 60% of the variance in DMI. Brown midrib-3 corn silage enhanced DMI, milk yield, TTD of OM, and greater passage rate of corn silage particles. Hydroxy trace minerals improved DMI, tended to improve TTD of NDF. The management model appeared to be a useful tool, although more data and research are needed to validate the model. In the future, hopefully, both forage quality and management decisions will be included in the same nutritional model to predict feed intake more accurately.
Effect Of Feeding Corn Silage Based Diets Predicted To Be Deficient In Either Ruminal Nitrogen Or Metabolizable Protein On Nitrogen Utilization And Efficiency Of Use In Lactating Cows
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Author : Erin Beth Recktenwald
language : en
Publisher:
Release Date : 2007
Effect Of Feeding Corn Silage Based Diets Predicted To Be Deficient In Either Ruminal Nitrogen Or Metabolizable Protein On Nitrogen Utilization And Efficiency Of Use In Lactating Cows written by Erin Beth Recktenwald and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007 with categories.
Due to concern over nitrogen (N) emissions, this study attempted to evaluate dietary approaches to reduce N excretion by dairy cattle. Knowledge about potential N sources that were either unaccounted for or under-predicted by CPM Dairy and the Dairy NRC (2001) was used to formulate rations that were much lower in crude protein (CP) than typically fed to dairy cattle but would potentially not decrease production. Specifically, the three diets fed were predicted to have: (1) positive rumen N and metabolizable protein (MP) balances (Diet P) (2) negative MP balance and positive rumen N balance (Diet N), or (3) negative rumen N balance but positive MP balance (Diet T) as predicted by CPM Dairy version 3. The objective of this experiment was to determine whether, and to what extent, the decrease in predicted ruminally available N and MP supply would affect milk production. Eighty-eight multiparous lactating Holstein cows (83 ± 20 DIM), were blocked by average daily milk yield to 50 DIM and parity and assigned to three diets differing in N content or predicted rumen degradability of the feed N. The diets were formulated with CPM Dairy V3 using library values for all feeds except corn silage where actual chemical, digestibility, and degradation rate values were determined and used. The diets (DM basis) consisted of approximately 50% corn silage, 2% wheat straw and 48% of a diet specific ingredient mix and were formulated for 22.2 of kg DMI. Actual diet CP levels were 16.7, 14.2 and 14.3% for Diets P, N and T, respectively. The predicted CPM Dairy rumen N balance at the formulated DMI was 29 and 27 g for Diets P and N and negative 39 g/d for Diet T, whereas the predicted MP balance was 263 and negative 145 and 91 g/d for Diets P, N and T, respectively. Monensin was included in the diets at a formulated intake of approximately 300 mg per cow per d and somatotropin was administered per label. Actual DMI for cattle fed these treatments were 25.7, 25.5 and 24.2 kg/d for Diets P, N and T, respectively and were significantly lower for Diet T. Actual milk yield was 45.0, 42.6 and 43.3 kg/d and 3.5% FCM was 38.1, 36.5, and 36.4 kg/d for cows fed Diets P, N and T, respectively and was significantly lower for cows fed Diets N and T. Milk protein percent was not affected by diet; however, milk protein yield was significantly greater for cows fed Diet P due to the difference in milk yield. Plasma urea N concentrations were 11.31, 8.40 and 7.13 mg/dl for cows fed diets P, N and T, respectively and were different and paralleled the rumen ammonia levels of 8.32, 6.58 and 5.84 mg/dl. Milk fat depression (MFD) was observed in all cows and was not affected by treatment, and the average milk fat levels were 2.67, 2.68 and 2.54% for diets P, N and T, respectively. To determine if monensin was partially responsible for the MFD, monensin was removed from the diets of approximately half of the cows on treatment once they had finished the experimental period. Removal of monensin resulted in a 30% increase in milk fat percent, and milk protein content was not affected. Calculated milk N:intake N ratios for the three treatments were 0.31, 0.33 and 0.36 for Diets P, N and T respectively. The results of this study suggest that more productive N is available than currently predicted by either CPM Dairy and the Dairy NRC (2001). Understanding where these differences exist would allow for feeding less CP to dairy cattle and decreasing N emissions to the environment. It may also be a profitable strategy for dairy farmers, as they would be able to reduce their purchase of costly protein feeds, but that was not demonstrated in this study - primarily due to the severe milk fat depression that decreased the economic value of milk. However, ration cost was not a concern for this experiment, and that aspect can be considered when implementing feeding strategies stemming from this research. (Abstract).
Designing Foods
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Author : National Research Council
language : en
Publisher: National Academies Press
Release Date : 1988-02-01
Designing Foods written by National Research Council and has been published by National Academies Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 1988-02-01 with Medical categories.
This lively book examines recent trends in animal product consumption and diet; reviews industry efforts, policies, and programs aimed at improving the nutritional attributes of animal products; and offers suggestions for further research. In addition, the volume reviews dietary and health recommendations from major health organizations and notes specific target levels for nutrients.
High Energy Corn Silage For Lactating Dairy Cattle
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Author : Randall Richard Uschold
language : en
Publisher:
Release Date : 1966
High Energy Corn Silage For Lactating Dairy Cattle written by Randall Richard Uschold and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1966 with Dairy cattle categories.
Effects Of Forage Quality Variation On Lactating Dairy Cows
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Author : Peter Samuel Yoder
language : en
Publisher:
Release Date : 2012
Effects Of Forage Quality Variation On Lactating Dairy Cows written by Peter Samuel Yoder and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with categories.
Abstract: Day to day variation in forage quality, e.g. neutral detergent fiber (NDF) concentration, is substantial on dairy farms, potentially costly, and presents challenges for sampling the forage accurately. We hypothesized that variation in forage NDF concentration (FNDF) and diet variation caused by sampling error will result in decreased milk production over time, affect partitioning of nutrients, and decrease feed efficiency. Twenty-four Holstein cows averaging 73 days in milk were used in 8 concurrent replicated 3x3 Latin squares with 21 d periods. The treatments were 1) Control, 2) Variable, and 3) Overreacting. All 3 treatments were fed similar diets on average, being 24.8% FNDF, 48.2% total forage, and the forage containing 67% alfalfa silage (45% NDF) and 33% grass silage (64% NDF). Control was consistent in total forage, FNDF, and proportion of alfalfa and grass silages fed from day to day. Variable changed daily (random pattern) in proportion of alfalfa and grass silages fed which resulted in a FNDF standard deviation of 2.4 and range of 6.4 over the 21 d period. Overreacting varied in a 5 day cyclic pattern in total forage concentration resulting in a FNDF standard deviation of 2.6 and range of 7.1 over the 21 d period. Overreacting (25.1 kg/d) had higher dry matter intakes (DMI) compared to the Control (24.5 kg/d) and Variable (24.3 kg/d). Milk production (42.8 kg/d) and gross feed efficiency were not affected by treatment. Milk production, diet sorting, DMI, milk urea nitrogen, and milk fatty acid concentrations were affected by treatment by day interactions. Milk fat (3.49%) and protein (2.80%) concentrations were not affected by treatment or treatment by day interactions. Lipolytic and lipogenic enzymes mRNA abundance in subcutaneous adipose tissue were unaffected by treatment, but were generally higher for Variable and Overreacting. Milk fatty acid markers for cellulolytic bacteria (iso-14:0, iso-15:0, iso-16:0), ruminal propionate (15:0) and lipolysis (18:0, long chain fatty acids) were affected by treatment by day interactions and generally followed the expected response to individual day rations and/or DMI changes. Variable had lower DMI and milk production than Control on 4 and 1 d during the 21 d period. In contrast, Variable had higher daily DMI on 1 d and milk production on 3 d compared to Control. Daily DMI for Overreacting was never lower than Control but milk yield was lower on 1 d of the 21 d period. Daily DMI and milk yields were higher on 5 d and 6 d for Overreacting compared to Control. Daily decreases for milk yields by Variable and Overreacting followed sustained 4 and 5 d of feeding a higher FNDF diet compared to Control. In contrast, increased daily milk yields versus Control for Variable and Overreacting were more frequent (3 and 6 d) and responsive to sustained diet changes (3 and 2 d). Cows in peak lactation showed no cumulative negative effects of variable FNDF for DMI, milk production, and gross feed efficiency. Changes of lipolysis indicators suggested the ability was present to buffer short term diet aberrations and/or changing DMI.
High Energy Corn Silage For Lactating Dairy Cattle
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Author :
language : en
Publisher:
Release Date : 1969
High Energy Corn Silage For Lactating Dairy Cattle written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1969 with Corn categories.
Effects Of Corn Silage Hybrids And Dietary Nonforage Fiber Sources On Productive Performance In Early Lactating Dairy Cows Fed High Forage Diets
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Author : Michael Shane Holt
language : en
Publisher:
Release Date : 2010
Effects Of Corn Silage Hybrids And Dietary Nonforage Fiber Sources On Productive Performance In Early Lactating Dairy Cows Fed High Forage Diets written by Michael Shane Holt and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
This experiment was conducted to determine the effects of corn silage hybrids and nonforage fiber sources (NFFS) in high forage diets formulated with high dietary proportion of alfalfa hay (AH) and corn silage (CS) on ruminal fermentation and productive performance by early lactating dairy cows. Eight multiparous Holstein cows (4 ruminally fistulated) averaging 36 " 6.2 d in milk were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Cows were fed 1 of 4 dietary treatments during each of the four 21-d periods. Treatments were: 1) conventional corn silage (CCS)-based diet without NFFS, 2) CCS-based diet with NFFS, 3) brown midrib corn silage (BMRCS)-based diet without NFFS, and 4) BMRCS-based diet with NFFS. Diets were isonitrogenous and isocaloric. Sources of NFFS consisted of ground soyhulls and pelleted beet pulp to replace a portion of AH and CS in the diets. In vitro 30-h NDF degradability was greater for BRMCS than CCS (42.3 vs. 31.2%). Neither CS hybrids nor NFFS affected intake of DM and nutrients. Digestibility of N, NDF, and ADF tended to be greater for cows consuming CCS-based diets. Milk yield was not influenced by CS hybrids and NFFS. However, a tendency for an interaction between CS hybrids and NFFS occurred with increasing milk yield due to feeding NFFS with the BMRCS-based diets. Yields of milk fat and 3.5% FCM decreased when feeding the BMRCS-based diet, and there was a tendency for an interaction between CS hybrids and NFFS by further decreased milk fat concentration because of feeding NFFS with BMRCS-based diet. Although feed efficiency (milk/DM intake) was not affected by corn silage hybrids and NFFS, there was an interaction between CS hybrids and NFFS because feed efficiency increased when NFFS was fed only with BMRCS-based diet. Total VFA production and individual molar proportion were not affected by diets. Dietary treatments did not influence ruminal pH profiles except that duration (h/d) of pH
Efficiency Of Dairy Rations Containing Various Quantities Of Grain
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Author : Kenneth Maxwell Autrey
language : en
Publisher:
Release Date : 1942
Efficiency Of Dairy Rations Containing Various Quantities Of Grain written by Kenneth Maxwell Autrey and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1942 with Dairy cattle categories.