Researchers tested whether replacing poor-quality alfalfa hay with corn silage could help dairy sheep produce more milk and use nutrients better. They fed 12 crossbred sheep different diet combinations and measured milk production, milk quality, and how efficiently the sheep used nitrogen (a key nutrient). The results showed that sheep eating diets with corn silage produced significantly more milk with better protein and fat content, while also wasting less nitrogen in their urine. This finding suggests that farmers in dry regions could improve their profits by switching to corn silage-based diets for lactating sheep.

The Quick Take

  • What they studied: Whether replacing low-quality alfalfa hay with corn silage in sheep feed could improve milk production and how efficiently sheep use nutrients
  • Who participated: 12 crossbred Hu sheep (a dairy breed) that were producing milk, tested at two different stages: early lactation (around 5-6 weeks after giving birth) and late lactation (around 12-13 weeks after giving birth)
  • Key finding: Sheep fed the highest amount of corn silage produced 36% more milk compared to sheep fed the traditional diet, and they also had better milk quality with more protein and fat. The sheep also wasted less nitrogen, meaning their bodies used nutrients more efficiently
  • What it means for you: If you’re a sheep farmer in dry regions, switching to corn silage could help your sheep produce more milk and make your farm more profitable. However, this study was small and done in specific conditions, so you should consult with a veterinarian or agricultural expert before making major diet changes

The Research Details

This was a controlled feeding experiment where researchers divided 12 sheep into three groups, each receiving a different diet. The control group ate the traditional diet with low-quality alfalfa hay as the main forage. The other two groups had increasing amounts of corn silage replacing some of the alfalfa hay. All diets were carefully balanced to have similar energy and protein levels so researchers could fairly compare the effects. The sheep were studied during two different milk production periods to see if the diet worked differently at different times.

The researchers measured several things: how much food the sheep ate, how much of each nutrient they digested, how much nitrogen they lost in urine and feces, how much milk they produced, and the quality of that milk (protein and fat content). They also calculated the economic value of each diet to see which was most profitable.

This research approach is important because it controls for other factors that could affect results. By keeping energy and protein levels equal across all diets, researchers could see the specific effects of swapping corn silage for alfalfa hay. Testing at two different lactation stages helps show whether the diet works equally well throughout the milk production cycle. The economic analysis makes the findings practical for real farmers who need to make profitable decisions.

This is a small study with only 12 sheep, which limits how much we can generalize the findings to all sheep farms. The study was well-controlled with careful diet formulation and multiple measurements, which strengthens the reliability of the results. However, the small sample size means results should be confirmed with larger studies before making major farming decisions. The study was published in a peer-reviewed journal, which means other scientists reviewed the work for quality.

What the Results Show

Sheep eating diets with corn silage produced significantly more milk than sheep eating the traditional alfalfa-based diet. The group with the highest corn silage amount (CS2) produced 36% more milk—a substantial increase. Beyond just quantity, the milk quality improved: both corn silage diets increased the protein and fat content of the milk, which is important for cheese and yogurt production.

The most important finding for efficiency was how the sheep used nitrogen. Sheep on corn silage diets retained more nitrogen in their bodies (meaning they used it for milk production) and lost less nitrogen in their urine. This is significant because it means the sheep’s bodies were working more efficiently—they weren’t wasting as much of the valuable protein they consumed.

The sheep also ate more digestible organic matter (the useful parts of the feed) as the proportion of corn silage increased. This suggests that corn silage is easier for sheep to digest and extract nutrients from compared to low-quality alfalfa hay.

The apparent nutrient digestibility—how much of the nutrients the sheep could actually absorb and use—was higher in all corn silage diets compared to the control diet. This means that not only were the sheep eating more, but they were also getting more value from what they ate. The nitrogen intake was highest in the diet with the most corn silage, suggesting that corn silage provides more usable protein than the low-quality alfalfa it replaced.

This research aligns with previous studies showing that corn silage is a high-quality forage that sheep can digest efficiently. The finding that replacing poor-quality hay with better-quality silage improves milk production is consistent with other dairy animal research. However, most previous studies focused on cattle rather than sheep, so this research adds valuable information specific to sheep farming. The magnitude of improvement (36% increase in milk yield) is notable and suggests that the quality difference between low-quality alfalfa and corn silage is substantial.

The study included only 12 sheep, which is a small number. Results from small studies can vary more than results from larger studies, so these findings should be confirmed with more sheep before making widespread farming changes. The study was conducted in specific conditions in northwestern China, so results might differ in other climates or with different sheep breeds. The study only lasted through two lactation periods, so we don’t know if benefits continue throughout an entire lactation cycle or over multiple years. Additionally, the study used crossbred Hu sheep specifically, so results might not apply equally to other sheep breeds used in different regions.

The Bottom Line

Based on this research, farmers in dry regions with access to corn silage may benefit from partially replacing low-quality alfalfa hay with corn silage in their dairy sheep diets. The evidence suggests this change could increase milk production by around one-third and improve milk quality. However, this recommendation comes with moderate confidence due to the small study size. Before implementing this change, consult with a veterinarian or agricultural extension specialist who understands your local conditions, because factors like feed costs, availability, and storage capacity matter for profitability.

This research is most relevant to sheep farmers in dry regions who currently use low-quality alfalfa hay and have access to corn silage. It’s particularly useful for farmers focused on milk production rather than meat production. Farmers in other regions with different forage options should consult local experts before applying these findings. This research is less relevant to sheep farmers using high-quality alfalfa hay, as the benefit comes from replacing specifically low-quality hay. Agricultural extension services and veterinarians in dryland regions should be aware of these findings when advising farmers.

Based on the study design, changes in milk production and milk quality appeared within the first few weeks of diet change. The nitrogen utilization improvements also showed up quickly. However, to see the full economic benefit, farmers should track results over at least one complete lactation cycle (several months) to account for variations in milk production and quality. Long-term sustainability should be monitored over multiple years to ensure consistent benefits.

Want to Apply This Research?

  • Track daily milk production volume (in liters or pounds) and test milk composition monthly for protein and fat percentage. Compare these metrics before and after diet changes to see if you’re achieving the 36% production increase shown in the study.
  • If using the app to manage a dairy sheep operation, set a goal to gradually introduce corn silage into your feed mix over 2-3 weeks while reducing low-quality alfalfa hay proportionally. Log the specific diet composition daily and correlate it with milk production data to find your optimal mix.
  • Create a long-term tracking system that monitors milk yield, milk quality (protein and fat %), feed costs, and overall profitability on a weekly basis. Set alerts if milk production drops unexpectedly, which could indicate a problem with feed quality or sheep health. Compare your results to baseline measurements from before the diet change to quantify actual benefits in your specific operation.

This research summary is for informational purposes only and should not replace professional veterinary or agricultural advice. The study involved only 12 sheep in specific conditions, so results may not apply to all sheep farms or breeds. Before making significant changes to your sheep’s diet, consult with a veterinarian, animal nutritionist, or agricultural extension specialist who understands your local conditions, sheep breed, and farming goals. Diet changes should be made gradually to avoid digestive upset. Individual sheep may respond differently to diet changes, and factors like feed cost, availability, and storage capacity affect the practical benefits of any diet modification. This summary does not constitute medical or veterinary advice for any specific animal or situation.