Unlocking the Secrets of Concentrate Feed for Enhanced Dairy Cow Efficiency

One of the main things that helps dairy cows produce more milk is proper nutrition, and concentrated feed makes a big difference in this respect. In modern times, where there are increasing demands for better herd health and higher milk production, the importance of understanding how efficient and beneficial concentrated feeding can be cannot be overemphasized, especially among livestock nutritionists and dairy farmers. This write-up explains the science and tactics surrounding concentrate feed, examining how targeted nutrient content can increase the quantity of milk produced, support general health, and encourage economical farm practices. Whether you are trying to maximize the performance of your group or want to add refinement to your way of feeding, this manual contains some tips that will help you put actions on the ground in order to improve your farming business using tested methods.

What is Concentrate Feed, and How Does it Benefit Dairy Science?

Feed concentrations are combinations of high-energy and nutrient-dense materials meant to supplement forage in the rations of dairy cows. Usually, it incorporates grains, protein meals, vitamins, and minerals, which provide a balanced supply of essential nutrients. In terms of dairy science, concentrate feed is beneficial due to its capacity to increase milk output by meeting the energy and protein requirements needed by lactating cows. This also contributes to herd health by ensuring consistent or reliable nutrition that can improve reproduction rates as well as reduce disease incidences among these herds. For farmers, concentrate feed offers a cost-effective way of managing their livestock’s diet, resulting in optimal performance and production levels.

Understanding Concentrate Feed Components

Energy sources, protein supplements, vitamins, and minerals are the main ingredients of concentrate feed. Grains and other by-products serve as energy sources that supply calories for maintenance and production. Protein supplements such as soybean meal or canola meal contain essential amino acids which enhance milk production and general health. Vitamins and minerals are added to meet dietary requirements needed for sustained metabolic function and health immunity. Proper herd performance depends on how well these components are balanced with one another in order to achieve optimal productivity.

The Role of Concentrates in Dairy Science

Energy-dense nutrition is a key role played by concentrates in enhancing dairy cow efficiency and productivity; as these are when forage alone cannot meet the nutritional requirements of lactating cows, which often require more energy and protein. Amidst these, concentrates usually account for about 30-50% of the total diet, depending on the growth stage and quality of forages .

The formulation of feedstuff is aimed at optimizing energy from sources such as corn, barley, or wheat while ensuring that enough protein levels are present through the inclusion of soybean meal, cottonseed meal, or other proteinaceous materials. In terms of ingredient quality, modern approaches have shifted to precise nutrient balancing supported by tools like near-infrared spectroscopy (NIR). Specifically designed concentrate mixes are recommended because they could boost milk production by as much as 15-20%, thus enhancing economic and nutritional factors for dairy farmers (Douglas et al., 1995).

More fertility, immunity and metabolic health are contributed by trace minerals as well as vitamin in feeds. For instance, vitamins E and selenium improve the antioxidant defense mechanisms, while calcium and phosphorus ensure strong bones and milk synthesis respectively. Additionally, it is important to formulate feeds with no anti-nutritional factors like non-protein nitrogen that may cause acidosis or reduce feed efficiency.

Through accurate feed composition data and sophisticated nutritional models, the sector is moving towards precision agriculture practices. The aim of this approach is not only to maximize yields but also minimize wastage of feeds and their environmental impact thus aligning with sustainability objectives in dairy science.

Comparing Concentrate with Roughage in Animal Feed

Animal feed is divided into two main categories: concentrates and roughages. These two types of feeds have their unique advantages for animal nutrition and serve specific roles in animal nutrition. Grains, oilseeds such as soybean meal and by-products are some examples of concentrates rich in protein and energy but lacking fiber. Concentrates are normally used to fulfill the nutritional requirements of high-producing animals, including dairy cows, during the lactation stage and, therefore, usually consist of TDN values ranging from 70-90%, meaning that they provide highly concentrated energy sources.

On the other hand, roughages include hays, silage, crop residues, and grasses, which are characterized by high fiber content but less energy density. They play a major role in maintaining good rumen health for ruminants among others. Roughages can however vary between 50-65 % depending on the quality of forage being used as indicated by its TDN value. In addition, these foods enhance rumination, thereby reducing the chances of metabolic disorders like acidosis, which may result from excessive reliance on concentrate-based diets.

Recent researches have stated that it is imperative to maintain a suitable ratio of concentrates to roughages in dairy cow diets for milk productivity and animal wellbeing. A typical diet for high-producing dairy cows may consist of 50-60% roughage, on a dry-matter basis, and 40-50% concentrate; however, this can vary based on the stage of lactation, quality of the forage and production goals. In addition, research shows that including high-quality roughages with improved digestibility reduces feed costs while maintaining production efficiency.

One major problem faced by concentrates is the cost factor as well as their ability to increase environmental impacts when grains and oilseeds are grown. However, sole reliance on roughages might not ensure optimal production rates. When combined evidence-based, the two feeds not only lead to optimal animal performance but also ensure sustainable agriculture by minimizing feed wastage and nutrient losses.

How Does Concentrate Feed Improve Animal Feed Efficiency?

Optimizing Nutrient Intake for Dairy Cows

Concentrated feed enhances the nutritional efficiency of dairy cattle by offering rich energy, proteins, and vitamins as well as minerals, which are usually deficient in roughage diets. This ensures that cows’ nutrients are provided in a manner that is suited for optimum milk production, growth, and good health. Farmers, while observing sustainable feeding practices, may achieve the aforementioned goals by combining concentrate feed to roughage, thus satisfying the nutrient needs of dairy cows and preventing overbalance deficits.

Impact on Milk Production and Lactation

Balanced concentrate feeding combined with roughage is of great importance for maximizing milk yield and ensuring appropriate lactation. Energy intake is important for supporting the metabolic requirements of lactating cows, especially in early lactation when there is a peak in milk production. High-starch, high-fat compound feeds are known to have a direct effect on milk volume and composition which sometimes increases the butterfat and protein content.

Recently published studies indicate that feeding well-balanced concentrate feed rations can increase milk production by up to 25% as opposed to diets dependent solely on roughage. Furthermore, balancing of key nutrients like calcium and phosphorus reduces the risk of metabolic disorders such as milk fever and supports overall cow health under the intensive lactation phase. In addition, fine-tuned nutrition strategies based on the specific stage of lactation also enhance feed efficiency, thus promoting a sustainable, cost-effective dairy industry with little or no compromise on productivity.

Enhancing Rumen Fermentation and Dairy Cow Health

To make optimal rumen fermentation and safeguard the well-being of dairy cows, a blend of methods and measures must be employed. The following outlines critical components and evidence-supported steps to improve rumen function and promote overall cow health:

Effective Fiber Levels

• Sufficient quantities of physically effective fiber (PEF) in the diet are vital for stimulating chewing as well as saliva secretion this helps buffer the pH of the rumen thus reducing chances of acidosis. Reports show that it is ideal to have 28-34% neutral detergent fiber (NDF) in total diet with not less than 19% coming from forages so as to reduce metabolic disorders.

Balanced Carbohydrate Sources

• To avoid too much acid accumulation in the rumen, there must be an appropriate ratio between fast fermenting carbohydrates like starch and structural carbs. To optimize microbial efficiency without compromising the functioning of the rumen, studies suggest that non-fiber carbohydrate (NFC) levels in total mixed ration (TMR) should range between 32-38%.

Use of Rumen-Protected Fats

• Supplementing these fats into rations allows increased energy density while maintaining fiber digestion and microbial activity. Research has shown that supplementing dairy diets with rumen-protected fats at a rate of 2-5% improves energy balance and milk yield.

Buffer as well as added supplements

• Stabilization of rumen pH can be achieved by using buffering agents like sodium bicarbonate and magnesium oxide. The use of yeast based products and live microbial additives such as Saccharomyces cerevisiae increases fermentation activity by microorganisms hence enhancing fiber digestibility and feed efficiency.

Consistent Feed Intake

• Regular consistent feed delivery with no sorting of the feed prevents the inconsistencies in the diets that would disturb rumen fermentation. Available data shows that feeding multiple times daily significantly increases daily dry matter intake (DMI), leading to better ruminal behavior.

Proper Protein Supplementation

• The balance between DIP (degradable intake protein) and UIP (undegradable intake protein) is important to optimize nitrogen use in the rumen. Crude protein values for diet are usually recommended at around 16-18% depending on lactation category as well as milk yield targets, respectively.

Water Availability

• Rumen microbes and digestion thrive on clean, quality water provided continuously. It has been suggested that a lactating dairy cow should consume three to four pounds of water per pound of milk produced which emphasizes its importance in hydration.

Measurement of Rumen pH

• Administrative assessment of rumen pH, ideally by means of puncturing the rumen or inserting a permanent pH meter, facilitates the early identification of subclinical acidosis. It is generally accepted that microbial fermentation efficiency tends to be optimal when rumen pH lies within 6 and 7.

Implementing such strategies while at the same time consistently monitoring them will improve rumen health hence increasing productivity, lowering risks related to animal health as well as improving dairy farming sustainability. Furthermore, these advancements in contemporary dairy management practices are reinforced by integrating precision technology and data-driven decision-making processes.

What are the Essential Nutrients Found in Concentrate Feeds?

Key Nutrient Groups: Crude Protein, Fatty Acids, and More

Concentrate feeds are formulated to give essential nutrients that help in the health, productivity and efficiency of livestock. Below is a comprehensive breakdown of the main nutrient groups present in concentrate feeds:

Crude Protein

• Crude protein serves as a critical source of amino acids essential for growth, reproduction, and milk production in dairy cattle. Normally, concentrate feeds contain 12-20% crude protein depending on the dietary needs of the livestock. Soybean, canola, and cottonseed are common sources of protein.

Fatty Acids (Fats and Oils)

• Concentrate feeds also contain fats that serve as concentrated energy sources which support reproductive performance and milk quality while improving feed efficiency. The fat content normally ranges from between 2-8%, with sources such as tallow, soybean oil and protected fat supplements being used.

Carbohydrates

• Rapid energy production is made possible by carbohydrates, largely through starches or sugars. Carbohydrates are an important part of concentrate feeds derived mostly from grains like corn, barley, and wheat, which ensures a constant supply of energy.

Fiber

• Although concentrate feeds have lower fiber contents compared to roughage; additions have been made to support digestion using insoluble fiber components. Commonly included fibrous materials such as beet pulp or soy hulls are meant for enhancing rumen function.

Vitamins and Minerals

• Bone development, immune health and metabolic functioning are affected by the presence of essential vitamins such as A, D, E and trace minerals which include calcium, phosphorous, zinc and selenium. These compounds are included in exact quantities to keep animal feed balanced according to their needs.

Energy

• The Total Digestible Nutrients (TDN) is used to measure the energy content in concentrate feeds. High-energy feeds support lactation, weight gain, and physical activity. Cornmeal and molasses are some examples of energy-dense ingredients.

Additives and Supplements

• Concentrate feeds could have probiotics or prebiotics; enzymes; buffers that aid in digestion thereby enhancing nutrient utilization while preventing rumen acidosis.

Every nutrient group has a unique role in supporting the overall health as well as productivity of animals hence; feeding should take into consideration specific dietary goals of a given farming operation.

Importance of Dry Matter and Energy Sources

Dry matter (DM) after detaching the moisture is a feed component that has all the essential nutrient components such as proteins, fibers, fats, vitamins and minerals. Dry matter percentage in feeds is key to making accurate rations which ensure livestock are supplied with the right amount of nutrients in their correct proportions for good health and high production levels. For instance, dairy cows typically require diets constituting 40-60% of dry matter content from forage to maintain milk yield and digestive efficiency.

Energy, on the other hand, is equally essential as it forms the basis for all growth, reproduction, and production processes, such as lactation or body weight gain. Total Digestible Nutrients (TDN) are used to determine the energy content in feeds. High-producing dairy cows ought to be fed at about 70-75% TDN level to meet their energy demands. Energy imbalances, usually resulting in underweight or overweighting, can cause diseases like ketosis or obesity, reducing productivity by a significant margin.

Optimum dry matter contents in feed are of importance in recent research. For instance, incorporating high energy foods such as cereals (maize and barley) has been found to enhance the energy density and still keep the ruminal function good in forage-based diets. More specifically, technological feeding allows reconciling these ingredients which increases the effectiveness of feeding thus improving feed conversion ratio and economic gain.

The Role of Vitamins like Vitamin E in Dairy Nutrition

On the whole, Vitamin E is a key component of dairy cows’ health as it acts primarily as an antioxidant that supports their immune system and reproductive ability. It also helps reduce oxidative stress that can damage overall animal health and productivity, especially during metabolic stress, such as calving. Satisfactory levels of vitamin E also play a role in reducing mastitis infection rates, thus promoting udder health. Since forage-based diets cannot always provide enough, proper supplementation must be maintained at all times. On the other hand, making sure that there is constant availability of vitamin E by using feeds or supplements improves milk quality, herd health, and production efficiency.

How to Balance Concentrate Ratios for Optimal Animal Nutrition?

Strategies for Feed Intake Management

Feed Quality and Consistency

• Make sure the feeds are new, flavourful and devoid of any impurities. Wholesomeness in the feeds composition helps with regulated intake and digestive complications.

Fostering Feeding Regularity 

• Feeding at certain times should also ensure that there is adequate feeding to ensure lower wastage and feeding gaps. Long intervals could lead to gluttony hence causing serious health issues that could have been avoided.

Feed Adjustment for Environmental Conditions

• Ensure weather related situations like heat strain and lack of water are well catered for by adjusting and re-formulating feeds for maximum effectiveness.

Feed Bunk Management and Maintenance 

• Tend to the cleanliness of feed bunks and the amount of feed given to ensure that there is minimal leavings leading to more wastage and or spoilage and ensuring more consistent feeding habits.

Animal Needs in the Diets 

• Rations should be designed to meet the particular energy, protein, and fiber needs of different kinds of animals during their various stages of production.

Adjusting Concentrate Levels for Different Stages of Lactate

First, I would assess the animal’s energy needs, which are determined by body condition, milk production, and overall health, in order to adjust concentrate levels depending on stages of lactation. In general, early lactation requires a higher level of concentrates for the increased energy demand, while mid and late lactation may necessitate gradual alterations to reduce excessive weight gain. I would ensure that the ratio between forage and concentrates is balanced well enough to promote ideal digestion as well as productivity while keeping track of performance and then tweaking it accordingly.

Incorporating Supplements for Better Dairy Cow Performance

The use of food supplements in the rations of dairy cows can go a long way to increasing milk production, health and reproductive efficiency. Commonly used supplements are vitamins, minerals as well as feed additives that target specific physiological needs.

Vitamins and Minerals

• It is critical to ensure adequate intake of vitamins and minerals for optimal performance in dairy cows. For example, calcium and phosphorus are important for bone formation and milk synthesis whereas magnesium supports muscle function. Zinc, manganese, selenium among other trace elements play critical roles in immunity and reproduction. Selenium deficiency can be overcome by supplementing diets with 0.3 ppm (total dry matter ration) Se with improved fertility rates while reducing retained placenta problems among dairy cows.

Rumen-Protected Amino Acids

• Methionine and lysine amino acids are generally limiting in ruminant diets. Milk protein synthesis can be enhanced through inclusion of rumen-protected amino acids resulting into more protein content in milk produced. Methionine supplementation has been shown via research to increase milk yield up to 1.5 pounds per day per cow while improving overall nitrogen efficiency.

Probiotics and Yeast Cultures

• To stabilize the rumen pH, increase fiber digestion and improve feed efficiency, live yeast cultures including probiotics are applied. The dry matter intake of high-producing cows in an early lactation period can be increased by using live yeasts like Saccharomyces cerevisiae. The milk output could be raised by 2-3% due to improved digestibility of fiber.

Fatty Acids

• Inflammation may be reduced while reproductive performance improved by adding specific types of fatty acids such as omega-3 or omega-6. Omega-3 fatty acids enriched diets have been linked to a decline in days open (the number of days between calving and conception) which in turn support better fertility.

Buffers and Neutralizing Agents

• Diets for dairy cows mostly contain sodium bicarbonate as a buffer to stabilise rumen pH hence prevent acidosis mainly on high rapidly fermentable carbohydrate diets. Ruminal function stabilization and increase in milk fat content has been reported where buffers were employed at a rate of 0.75% of total ration.

Choline and Betaine

• Diets that include rumen-protected choline and betaine may help improve liver function and energy metabolism in transition cows. Choline aids in lowering the incidence of fatty liver and ketosis, resulting in an increased milk yield after calving.

Developing improved milk quality, cow health, and overall productivity necessitates meticulous selection and proportioning of supplements based on herd-specific needs. Regular monitoring and consultation with nutritionists will ensure the effectiveness and safety of supplementation strategies.

Are there Challenges in Using Concentrate Feeds for Lactating Dairy Cows?

Addressing Rumen pH and Acidosis Risks

To prevent acidosis in a lactating dairy cow, it is very important to hold the rumen pH at optimum. Feeding high levels of rapidly fermentable carbohydrates in the diet may lower the rumen pH thereby leading to subacute or acute acidosis. It interferes with digestion and lowers intake of feed and production of milk negatively by a ruminant. Therefore, enough roughages should be included in feeding programs as they enhance chewing action and stimulate saliva flow, thus buffering the acidity level within the rumen. Use of dietary buffers like sodium bicarbonate can help stabilize ruminal pH so that it can support large populations of beneficial microorganisms. Early detection and effective management of potential issues are only possible if there is constant monitoring of feed composition and cow behavior.

Managing Protozoon and Microbial Balance

A good microbial ecosystem balance in the rumen is essential for maximizing feed digestion and fermentation in lactating dairy cows. Rumen protozoa are very important in stabilizing rumen fermentation by breaking down excess starch thus, they check the uncontrolled growth of some types of bacteria such as those that cause lactic acid which prevent the overproduction of lactic acid-producing bacteria. Such a state of affairs minimizes the risk of acidosis while enhancing overall ruminal health.

The latest development in rumen microbiology has underscored the importance particular bacterial groups i.e. Fibrobacter succinogenes and Ruminococcus albus on cellulose degradation leading to maximal fiber breakdown and nutrient uptake. Conversely, excessive amounts of amylolytic bacteria can lead to immoderate fermentation of starch thus excessively high levels of lactic acid with disruption of rumen pH levels.

Microbial balance should be maintained through feeding strategies that contain appropriate quantities of structural carbohydrates like NDF (neutral detergent fiber) that foster cellulolytic microorganisms’ multiplication. Additionally, including fermentable carbohydrates slowly ensures that fermentable energy is gradually released, preventing rapid changes in microbial populations. The feeding schedule may also be supplemented with certain components such as yeast cultures or live probiotic strains like Saccharomyces cerevisiae to improve cellulase activity, stabilize fermentation, and promote the proliferation of beneficial bacteria.

The data in numbers show that cows fed live yeast recorded an increase of between 15-20% in fiber digestion efficiency and a decreased prevalence of subacute ruminal acidosis (SARA) by more than 30%. The findings thus highlight the necessity for appropriate formulation of diets to maintain a balanced microbial community within the rumen environment, which is vital for milk production and animal health. Regular sampling and analysis of the rumen contents coupled with precise ration adjustments give valuable information about the changes occurring within microbial populations, thereby ensuring top performance in the rumen.

Evaluating Concentrate Impact on Milk Fat Content

When excessive concentration is present in dairy cow diets, it may have a negative impact on the milk fat portion. Excessive concentrate feeding results in reduced fiber consumption, which lowers rumination and, therefore, saliva production that decreases the buffering capacity of the rumen, leading to a fall in rumen pH and alteration of microbial fermentation patterns involving reduced acetate formation and increased propionate levels. The decrease in acetate caused by this directly influences the synthesis of milk fats. To address the decline, an optimal forage-to-concentrate ratio should be maintained while ensuring that there is an effective fiber source available in the diet to ensure healthy milk fat production.

Frequently Asked Questions (FAQs)

Q: What are concentrate feeds, and how are they different from complete dairy cow feeds?

A: Concentrate feeds are high-nutrient feeds that complement forages in dairy cows’ diets. Unlike a complete feed that meets nutrient requirements in one blend, concentrate feeds are designed to increase energy, protein, and other necessary nutrients. Usually, it comprises grains, protein, and other supplements meant to enhance forage intake and milk yield in a dairy cow.

Q: What is the influence of total feed intake and net energy utilization in dairy cows with the use of concentrate feeds?

A: Focused dairy concentrate has the potential to affect total feed intake and net energy utilization in dairy cows. If the relationship between forage and concentrate is maintained it usually elevates the energy density of the diet therefore improving feed conversion ratio. This consequently leads to increased net energy possible for milk production and maintenance of the individual. However, a careful monitoring of the concentrate and forage ratio is important to maintain proper rumen health and digestive health of the animal.

Q: What is the importance of volatile fatty acids to the nutrition of dairy cows, and what is the role of concentrate feed in their synthesis?

A: Notably, volatile fatty acids such as acetic, butyric, and propionic are produced during carbohydrate fermentation in the rumen space. The use of concentrates high in starch, like maize, has been known to alter the VFA profile towards increased production of propionic acid, which can potentially increase energy efficiency and milk output. It is worth noting, however, that excessive use of concentrates has the potential to indiscriminately lower fiber digestion efficiency, ruminal acidosis being one of the possible causes.

Q: Comment on the effect of concentrate feed on microbial protein synthesis in goats and dairy cattle rumen culture.

A: Concentrate feed serves as a primary factor that stimulates the synthesis of microbial protein in the rumen environment. It tends to include fermentable carbohydrates and protein which favors the growth of microbes hence increasing’s the amount of microbial protein synthesized, this protein is especially useful in milk production as well as aiding the cow in cellular functioning. On the other hand, as previously mentioned, tight regulation of protein and energy in the concentrate is important, as excess protein will lead to excess ammonia in the rumen.

Q: What is the impact of different feed additives usually included in dairy cow concentrate feeds?

A: Among the feed supplements that fit within the category mentioned above are vitamins A and E supplements, which are useful in enhancing the immune system and reproductive functions. These include dicalcium phosphate, ferrous sulfate, zinc oxide, zinc sulfate, manganese sulfate, and copper sulfate; these supplements are important for numerous physiological activities. Provided that they are properly redistributed in the concentrate before supplementation, such additives may be beneficial through improvement of health status, feed conversion efficiency, and increase of milk yield.

Q: What is the effect of supplementing dairy cow concentrate feeds with maize on their performance?

A: Maize grain is one of the high-energy supplement ingredients fed to dairy cows in concentrate rations and diets. This could especially raise the overall energy concentration of the diet, resulting in enhanced milk production and body condition. Maize starch is easily fermentable, providing starch that can increase the amount of propionic acid produced in the rumen, which in turn is favorable for glucose synthesis and used for lactose production in milk. It should be anticipated, however, that there need to be enough fiber sources provided to complement the maize so as to maintain the health of the rumen.

Q: What factors are to be kept in mind while preparing the Holstein Cow concentrates feeds?

A: The feed composition of Concentrates for Holstein Cows is influenced by numerous factors. They consist of the level of lactation, level of milk production, body condition, and quality of forage. Since Holstein cows are known for their high milk yield, they would require a higher energy and protein content in their concentrates than other types of cattle. Alongside the right amino acid balance, adequate levels of NFCs, minerals, and vitamins are required for the optimization of performance in the said breed of cattle.

Reference Sources

1. Kholif et al. (2022) (Kholif et al., 2022)

• Key Findings:
• Replacing 20-40% of the concentrate mixture with a mixture of Moringa oleifera silage and Chlorella vulgaris microalgae improved nutrient digestibility, ruminal fermentation characteristics, milk production, composition, and fatty acid profile in Damascus goats.
• Including mixed Moringa oleifera and microalgae feedstuff as partial substitutes for concentrates may improve milk production performance and milk quality without reducing animal health status.
• Methodology:
• A 3 × 3 Latin square design was used with 15 lactating Damascus goats divided into three groups.
• The control treatment’s concentrate mixture received a substitution of Moringa oleifera silage plus Chlorella vulgaris microalgae at either 20% (MA20) or 40% (MA40).
• Feed intake, nutrient digestibility, ruminal fermentation, serum metabolites, milk production and composition, and fatty acid profile were measured.

2. Schilde et al. (2021) (Schilde et al., 2021, pp. 79–104)

• Key Findings:
• Methane emissions per kg of dry matter intake (DMI) and per kg of energy-corrected milk were mitigated by 3-nitrooxypropanol (3-NOP) and high concentrate feed proportion (CFP).
• Supplementing the high-forage diet over time resulted in a declining methane-mitigating effect of 3-NOP.
• High CFP and 3-NOP enhanced feed efficiency while decreasing body weight loss in periparturient dairy cows.
• Methodology:
• A 2 × 2 factorial design was used with 55 Holstein cows: low and high CFP, either without (CONLC, CONHC) or with 3-NOP (NOPLC, NOPHC).
• Digestibility of the diet, methane emissions, and rumen fermentation were measured.

3. Liu et al. (2021) (Liu et al., 2021)

• Key Findings:
• Rumen-protected methionine and lysine and/or supplementary concentrate feed affected the volatile fatty acid (VFA) profiles and composition of rumen microbiota in grazing lactating yaks.
• The proportions Firmicutes to Bacteroidetes in the rumen were higher in the animals that received both concentrate feed and protected amino acids in contrast to those which got only protected amino acids.
• Concentrate feed increased VFA concentrations, including total VFAs, acetate, and butyrate in the rumen.
• Methodology:
• Twenty four lactating yaks were randomly assigned to four groups: control, concentrate feed (C), rumen-protected amino acids (RPA), or both RPA and C.
• Samples of rumen content were taken for analysis by means of sequencing of 16S rRNA gene fragments.
• Also, we determined accumulations of VFA in the rumen.

4. Heymann et al. (2021) (Heymann et al., 2021, p. e0246679)

• Key Findings:
• The liver-related blood parameters, gene expression, and liver histology were not affected by the Glyphosate (GLY) residues in dairy cow diets, even with a different concentrate feed proportion.
• In the group fed high-concentrate rations with GLY-contaminated feed, there was a temporal increase in total bilirubin blood concentration, but its significance was unknown.
• Methodology:
• 61 German Holstein cows were either provided with GLY-contaminated total mixed ration (TMR) or control TMR and divided into low/high concentrate feed proportion groups.
• The study thus assessed blood parameters, gene expression, and liver histology.

5. Patyal et al. (2021) (Patyal et al., 2021, pp. 37705–37715)

• Key Findings:
• Dairy animal concentrates from Punjab, India, were contaminated with aflatoxin.
• When aflatoxin B1 carry over to milk is assumed theoretically (aflatoxin M1), then this can result in contamination of milk by 50-100% above EU tolerance level.
• Methodology:
• Aflatoxin contamination in concentrate feed samples from dairy farms in Punjab, India, was analyzed.
• Potential carry-over of aflatoxin B1 from feed to milk (aflatoxin M1) through theoretical calculations.

6. Animal feed

7. Nutrient

8. Fat