Álvaro García
In modern livestock production, feed quality is key for farm success and profitability. Optimal nutrition directly impacts animal health, productivity, and farm revenue. Adequate feed sampling is essential for informed feed management decisions, allowing producers to fine-tune diets for maximum performance and returns on investment. Because of their variability, three feed groups—silage, hay, and concentrates—play particularly important roles in meeting dietary requirements. Precise sampling enables accurate assessment of their nutritional content, facilitating tailored diet formulations to meet animals’ specific needs. Let us explore the critical sampling aspects across these feed groups.
Potential losses due to unanalyzed feed
Consider a dairy farm with one thousand milking cows that are on average at 150 days in milk, exhibit good genetics, and consume a well-balanced diet, however not corrected by actual corn silage analytical values. Assume that 50% of the cows’ dry matter intake comes from corn silage, and the producer assumes this silage contains 9% CP. However, upon analysis, it was determined that the actual CP content of the corn silage is 8%. Let us calculate the potential economic losses incurred by not analyzing the corn silage.
The “milk response factor” represents the daily milk production change per unit change in crude protein (CP) intake. For instance, if cows consume feed with 1% less CP, resulting in a reduction of 0.3 kilograms of milk per day, the milk response factor would be 0.3 kilograms per day per 1% CP difference.
Calculations:
- Milk response factor: 0.3 kilograms per day per 1% CP difference.
- Daily loss per cow: 0.3 kilograms/day * 1% CP difference = 0.3 kilograms/day
- Daily loss for 1000 cows: 0.3 kilograms/day * 1000 cows = 300 kilograms/day
- Daily revenue loss for the entire herd: 300 kilograms/day * $15/cwt = $45/day
Annual Loss:
Multiplying the daily loss by 365 days, the potential annual revenue loss amounts to:
$45/day * 365 days = $16,200
This loss underscores the importance of accurately analyzing feed to optimize herd nutrition and maximize profitability in dairy operations.
Sampling essentials: silage, hay, and concentrates
Silage serves as a vital feed for livestock, offering crucial nutrients essential for their health and productivity. Due to the significant variations in its nutritional composition, precise sampling techniques are essential for accurate assessment. Proper sampling involves collecting samples from various depths within the silage pile to capture differences in fermentation and nutrient distribution. This meticulous approach allows producers to formulate tailored diets that meet their animals’ specific needs, promoting optimal performance and overall herd health.
When collecting samples for silage analysis, using appropriate equipment such as clean, stainless steel silage probes or augers is crucial to ensure accuracy and reliability. With manual sampling, careful handling is necessary to prevent contamination. Obtain multiple sub-samples from separate locations within the pile to account for variability in nutrient distribution, then composite them into one. While freezing samples is not typically necessary, it can be beneficial for preventing further fermentation and nutrient degradation during prolonged delays or long-distance transportation. Proper labeling and packaging are essential to prevent leakage or contamination during storage and transportation. Additionally, consulting with the laboratory regarding specific requirements and recommendations for sample preservation is advisable.
Sampling from various depths within the silage pile ensures a representative sample that reflects the entire pile’s composition. Adequate sample size, typically ranging from 1 to 2 kilograms, and regular sampling frequency are crucial for reliable analysis. Regular sampling allows for monitoring fluctuations in nutrient composition over time, facilitating prompt adjustments to feed formulations to maintain optimal herd nutrition.
Sampling hay
Proper sampling techniques are equally vital for hay, given its significant role in most cattle diets. When sampling rectangular bales, it is essential to select bales randomly from various parts of the stack to ensure representativeness. This ensures that the sample reflects the variability present within the entire batch. For round bales, collecting cores from multiple bales distributed throughout the storage area is crucial. Take core samples from various parts of each bale, including the core and outer layers, to account for potential differences in nutrient composition. Aim to sample at least 10% of the total bales or baleages to obtain a representative sample, which provides a more accurate assessment of the overall quality of the hay. If a core sampler is not available, then unrolling bakes to sample from them is a viable alternative. However, it is essential to note that unrolling bales exposes them to moisture and other environmental factors, potentially affecting their quality. When unrolling bales for sampling, make sure you feed them within a couple of days to minimize any further deterioration.
In addition to random selection, consider variations in cutting times, weather conditions, and storage methods during hay sampling to ensure accurate nutrient analysis. For example, hay harvested at various stages of maturity may have different nutrient profiles. Weather conditions during harvesting and storage can also affect hay quality, with factors such as rain or high humidity potentially leading to mold growth and nutrient loss. Provide around 200-500 grams of hay per sample and place them in clean, airtight containers, labeled properly with sample identification information. To preserve the nutrient content of the samples, consider freezing them before shipping or storing them in a cool, dry place away from direct sunlight.
By following these guidelines for sampling, handling, and shipping hay samples to the lab, livestock producers can ensure that their samples arrive in optimal condition for accurate analysis, enabling informed decision-making regarding feed management and diet formulation for their cattle.
Sampling concentrates
Sampling concentrates is a critical aspect of livestock management, ensuring the provision of essential nutrients to supplement their diets effectively. When sampling from bags or piles try to guarantee representativeness and accuracy. When sampling from bags, it is essential to take subsamples from multiple bags across the batch to address potential variations in nutrient composition. Given that concentrates may settle during storage, collect samples from different depths within each bag to capture variability. A core sampler is ideal to collect representative samples from each bag. Introduce the sampler in depth with the groove(s) facing down, once inside the bag turn it around to collect the sample from all the sampler length. Similarly, when sampling from piles, collect subsamples from various locations within the pile and depths to ensure a representative sample. Aim to collect at least ten subsamples to create a composite sample that accurately reflects the entire batch’s composition.
Following the collection of samples, proper handling and storage are crucial before sending them to the laboratory for analysis. Package concentrate samples in clean, airtight containers, such as plastic bags or labeled containers, to maintain sample integrity. Adequate sample quantity, typically ranging from 200 to 500 grams per sample, should be enough for analysis, depending on the laboratory’s requirements and the tests to run. To preserve the nutrient content of the samples, store them in a cool, dry place away from direct sunlight. If feasible, freezing the samples before shipping can help prevent nutrient degradation. When shipping concentrate samples to the laboratory, it is essential to use a reliable courier service or postal service to ensure timely delivery. Additionally, including a completed sample submission form with each shipment is crucial, providing details such as sample identification, desired analyses, and any special instructions for handling or analysis.
Adhering to these guidelines for sampling, handling, and shipping concentrate samples to the laboratory enables dairy farmers to ensure that their samples arrive in optimal condition for accurate analysis. This facilitates informed decision-making regarding feed management and diet formulation, contributing to the overall health and productivity of their dairy herd.
In today’s livestock farming success relies on maximizing production while ensuring optimal herd nutrition. By employing adequate sampling techniques across various feedstuffs, farmers and/or their nutritionists can make informed decisions, fine-tune diet formulations, and enhance both the productivity and profitability of their operations. Adequate feed sampling is the prerequisite upon which livestock production success rests. Following proper sampling protocols, including selecting appropriate sampling equipment, sampling locations, sample handling, transportation, laboratory analysis, and interpretation of results, is essential to ensure the accuracy and reliability of feed analysis.
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