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Evaluating the Energy Potential of Corn Silage for Dairy Cows /

Record Type:	Electronic resources : Monograph/item
Title/Author:	Evaluating the Energy Potential of Corn Silage for Dairy Cows // Evan Cole Diepersloot.
Author:	Diepersloot, Evan Cole,
Description:	1 electronic resource (245 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 86-11, Section: B.
Contained By:	Dissertations Abstracts International86-11B.
Subject:	Animal sciences. -
Online resource:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=32039755
ISBN:	9798314886182

Evaluating the Energy Potential of Corn Silage for Dairy Cows /
Diepersloot, Evan Cole,

Evaluating the Energy Potential of Corn Silage for Dairy Cows /Evan Cole Diepersloot. - 1 electronic resource (245 pages)

Source: Dissertations Abstracts International, Volume: 86-11, Section: B.

Corn silage is an important part of the diets of dairy cattle, providing energy to support milk production and physically effective fiber to support gut health. However, the quality of corn silage varies widely and there are many management strategies that can affect the nutritive value of corn silage and ultimately affect dairy cow productivity. Despite many studies evaluating the effect of management strategies on the nutritive value of corn silage, in some cases there is a lack of quantitative evaluations. In other cases, the continual adaptation and improvement of management strategies may warrant continued evaluations with more recent data. Furthermore, evaluating corn silage quality and nutritive value can be difficult for producers and popular tools, such as MILK2006, may require updating to incorporate more recent predictions and concepts into their equations. Thus, a series of 4 studies was conducted to evaluate the effect of different management strategies on the nutritive value of whole-plant corn forage or silage and to compare the recently released MILK2024 with previous MILK indexes. In the first study, a meta-analysis was conducted to evaluate the overall effect of cutting height during harvest on the nutritive value, fermentation profile, and dry matter (DM) yield of whole-plant corn forage and silage. Furthermore, the effects of cutting height on these variables were evaluated in different DM categories at harvest (LO, ≤ 32% DM; AVG, 32 to 37% DM; HI, ≥ 37% DM). Overall, increasing cutting height improved nutritive value by increasing starch concentration and neutral detergent fiber (NDF) digestibility, while decreasing fiber fractions. However, increasing cutting height also decreased DM yield. Starch concentration and NDF digestibility followed different patterns for different DM categories at harvest. Briefly, starch concentration increased the most for LO, while NDF digestibility increased the most for HI DM at harvest. However, no effects of increasing cutting height overall or for any DM at harvest category were observed on the fermentation profile of whole-plant corn silage. Thus, increasing cutting height during harvest can improve the nutritive value of whole-plant corn forage or silage at the expense of DM yield, but some effects may depend on DM at harvest. In the second study, a meta-analysis was conducted to evaluate the effect of storage length on starch digestibility (starchD) and nutritive value of whole-plant corn silage as well as the relationships between starchD and ammonia or soluble crude protein concentrations. As storage length increased, starchD increased, although the most rapid increase in starchD came during early storage lengths. As storage length increased, the concentrations of ammonia and soluble crude protein also increased and there were linear relationships between starchD and ammonia as well as soluble crude protein. However, there were little to no differences between storage lengths on the rest of the nutrient composition of whole-plant corn silage. Thus, increasing storage length can be used to improve the energy density of whole-plant corn silage by increasing starchD with minor changes in nutrient composition. The third study evaluated the effect of hybrid type (brown midrib: BMR or conventional: CON) and region (upper Midwest: UM, Mideast: ME, Northeast: NE, and California: CA) on the nutritive value, DM yield, and NDF digestibility kinetics of whole-plant corn forage grown during multiple years. Ruminal NDF digestibility (rNDFD) was predicted with 2- or 3-pool mechanistic models based on rates of degradation calculated with single NDF digestibility timepoints or different combinations of timepoints. This experiment was conducted as a completely randomized design with a 2 (hybrid type) x 4 (region) factorial arrangement of treatments. Interactions between hybrid type and region were observed for all NDF digestibility timepoints and rNDFD calculations, where BMR hybrids were greater than CON and there were small differences among regions within hybrid types. An interaction was also observed for starch concentration, which was greater for CON hybrids within each region, except for CA. Additionally, DM yield was lower for BMR hybrids compared to CON hybrids. Thus, BMR hybrids improved NDF digestibility and predicted rNDFD at the expense of starch concentration and DM yield. Differences in patterns between different NDFD timepoints and different predictions of rNDFD suggest that the same NDFD timepoint or rNDFD calculations should be used for comparisons of digestibility in whole-plant corn silage. In the last study, the predicted milk yield of the recently released MILK2024 was compared with previous versions of the MILK index, including MILK2000 and MILK2006. A large dataset of corn silage nutrient composition was compiled from commercial labs and used to predict milk per Mg of corn silage with MILK2024, MILK2006 (with DM and 7h starchD calculations), and MILK2000. Additionally, the dataset was ranked by NDF concentration, NDF digestibility, starch concentration, and 7h starchD and the top and bottom 10 or 25% of samples were assigned as high- or low-quality. The percentage of overlap in predicted milk yield of high-and low-quality samples was also calculated. The predicted milk yield of MILK2024 was lower than other MILK indexes, except for MILK2006 calculated with 7h starchD. Likewise, the range and standard deviation of MILK2024 was lower than all other MILK indexes. The MILK2024 had a lower overlap than other MILK indexes for samples ranked by NDF and a similar overlap to MILK2000 for samples ranked by NDF digestibility and starch concentration. However, MILK2006 had the lowest overlap for samples ranked by 7h starchD. Thus, it appears that MILK2024 performed better than other MILK models overall, although the lower range and standard deviation suggests that smaller differences in predicted milk yield should be considered compared to other MILK indexes. Overall, our results demonstrate that the nutritive value of whole-plant corn silage can be improved by increasing cutting height (at the expense of DM yield) or by increasing storage length to improve starchD. Additionally, BMR hybrids can increase NDF digestibility and predicted rNDFD if producers can cope with lower DM yields and starch concentration. Lastly, the MILK2024 appears to perform better than other MILK indexes and can separate samples with different nutrient compositions better than MILK2006. Thus, management practices can be used to improve the nutritive value of whole-plant corn silage and nutritive value can be evaluated by using the recently released MILK2024.

English

ISBN: 9798314886182Subjects--Topical Terms:

3174829
Animal sciences.
Subjects--Index Terms:

BMR

Evaluating the Energy Potential of Corn Silage for Dairy Cows /
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500 $a Advisors: Ferraretto, Luiz F. Committee members: Dorea, Joao R.; White, Heather M.; Kaur, Harkirat.
502 $b Ph.D. $c The University of Wisconsin - Madison $d 2025.
520 $a Corn silage is an important part of the diets of dairy cattle, providing energy to support milk production and physically effective fiber to support gut health. However, the quality of corn silage varies widely and there are many management strategies that can affect the nutritive value of corn silage and ultimately affect dairy cow productivity. Despite many studies evaluating the effect of management strategies on the nutritive value of corn silage, in some cases there is a lack of quantitative evaluations. In other cases, the continual adaptation and improvement of management strategies may warrant continued evaluations with more recent data. Furthermore, evaluating corn silage quality and nutritive value can be difficult for producers and popular tools, such as MILK2006, may require updating to incorporate more recent predictions and concepts into their equations. Thus, a series of 4 studies was conducted to evaluate the effect of different management strategies on the nutritive value of whole-plant corn forage or silage and to compare the recently released MILK2024 with previous MILK indexes. In the first study, a meta-analysis was conducted to evaluate the overall effect of cutting height during harvest on the nutritive value, fermentation profile, and dry matter (DM) yield of whole-plant corn forage and silage. Furthermore, the effects of cutting height on these variables were evaluated in different DM categories at harvest (LO, ≤ 32% DM; AVG, 32 to 37% DM; HI, ≥ 37% DM). Overall, increasing cutting height improved nutritive value by increasing starch concentration and neutral detergent fiber (NDF) digestibility, while decreasing fiber fractions. However, increasing cutting height also decreased DM yield. Starch concentration and NDF digestibility followed different patterns for different DM categories at harvest. Briefly, starch concentration increased the most for LO, while NDF digestibility increased the most for HI DM at harvest. However, no effects of increasing cutting height overall or for any DM at harvest category were observed on the fermentation profile of whole-plant corn silage. Thus, increasing cutting height during harvest can improve the nutritive value of whole-plant corn forage or silage at the expense of DM yield, but some effects may depend on DM at harvest. In the second study, a meta-analysis was conducted to evaluate the effect of storage length on starch digestibility (starchD) and nutritive value of whole-plant corn silage as well as the relationships between starchD and ammonia or soluble crude protein concentrations. As storage length increased, starchD increased, although the most rapid increase in starchD came during early storage lengths. As storage length increased, the concentrations of ammonia and soluble crude protein also increased and there were linear relationships between starchD and ammonia as well as soluble crude protein. However, there were little to no differences between storage lengths on the rest of the nutrient composition of whole-plant corn silage. Thus, increasing storage length can be used to improve the energy density of whole-plant corn silage by increasing starchD with minor changes in nutrient composition. The third study evaluated the effect of hybrid type (brown midrib: BMR or conventional: CON) and region (upper Midwest: UM, Mideast: ME, Northeast: NE, and California: CA) on the nutritive value, DM yield, and NDF digestibility kinetics of whole-plant corn forage grown during multiple years. Ruminal NDF digestibility (rNDFD) was predicted with 2- or 3-pool mechanistic models based on rates of degradation calculated with single NDF digestibility timepoints or different combinations of timepoints. This experiment was conducted as a completely randomized design with a 2 (hybrid type) x 4 (region) factorial arrangement of treatments. Interactions between hybrid type and region were observed for all NDF digestibility timepoints and rNDFD calculations, where BMR hybrids were greater than CON and there were small differences among regions within hybrid types. An interaction was also observed for starch concentration, which was greater for CON hybrids within each region, except for CA. Additionally, DM yield was lower for BMR hybrids compared to CON hybrids. Thus, BMR hybrids improved NDF digestibility and predicted rNDFD at the expense of starch concentration and DM yield. Differences in patterns between different NDFD timepoints and different predictions of rNDFD suggest that the same NDFD timepoint or rNDFD calculations should be used for comparisons of digestibility in whole-plant corn silage. In the last study, the predicted milk yield of the recently released MILK2024 was compared with previous versions of the MILK index, including MILK2000 and MILK2006. A large dataset of corn silage nutrient composition was compiled from commercial labs and used to predict milk per Mg of corn silage with MILK2024, MILK2006 (with DM and 7h starchD calculations), and MILK2000. Additionally, the dataset was ranked by NDF concentration, NDF digestibility, starch concentration, and 7h starchD and the top and bottom 10 or 25% of samples were assigned as high- or low-quality. The percentage of overlap in predicted milk yield of high-and low-quality samples was also calculated. The predicted milk yield of MILK2024 was lower than other MILK indexes, except for MILK2006 calculated with 7h starchD. Likewise, the range and standard deviation of MILK2024 was lower than all other MILK indexes. The MILK2024 had a lower overlap than other MILK indexes for samples ranked by NDF and a similar overlap to MILK2000 for samples ranked by NDF digestibility and starch concentration. However, MILK2006 had the lowest overlap for samples ranked by 7h starchD. Thus, it appears that MILK2024 performed better than other MILK models overall, although the lower range and standard deviation suggests that smaller differences in predicted milk yield should be considered compared to other MILK indexes. Overall, our results demonstrate that the nutritive value of whole-plant corn silage can be improved by increasing cutting height (at the expense of DM yield) or by increasing storage length to improve starchD. Additionally, BMR hybrids can increase NDF digestibility and predicted rNDFD if producers can cope with lower DM yields and starch concentration. Lastly, the MILK2024 appears to perform better than other MILK indexes and can separate samples with different nutrient compositions better than MILK2006. Thus, management practices can be used to improve the nutritive value of whole-plant corn silage and nutritive value can be evaluated by using the recently released MILK2024.
546 $a English
590 $a School code: 0262
650 4 $a Animal sciences. $3 3174829
650 4 $a Agriculture. $3 518588
650 4 $a Agronomy. $3 2122783
650 4 $a Nutrition. $3 517777
653 $a BMR
653 $a Corn silage
653 $a Cutting height
653 $a MILK2024
653 $a NDFD
653 $a Storage length
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690 $a 0473
690 $a 0285
690 $a 0570
710 2 $a The University of Wisconsin - Madison. $b Animal and Dairy Sciences. $e degree granting institution. $3 3826317
720 1 $a Ferraretto, Luiz F. $e degree supervisor.
773 0 $t Dissertations Abstracts International $g 86-11B.
790 $a 0262
791 $a Ph.D.
792 $a 2025
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