Unlock Better Lamb Nutrition: How Protein and Supplement Timing Impact Forage Digestion

Ruminally degradable protein (RDP) is crucial because it's broken down in the rumen, providing ammonia necessary for microbial growth. Without adequate RDP, the microbes in the rumen can't efficiently digest forage, especially low-quality forage like mature crested wheatgrass hay. Supplementing with RDP ensures these microbes have the building blocks they need to break down fiber and release nutrients, which directly impacts the lamb's overall health and growth. If RDP is deficient, lambs may not be able to extract sufficient energy and protein from their diet, leading to reduced performance.

The research focused on the effects of ruminally degradable protein (RDP) and ruminally undegradable protein (RUP) supplementation, along with the frequency of supplementation, on digestive processes in lambs. It measured parameters such as forage intake, ruminal pH, ammonia concentrations, and nutrient flow through the digestive tract. The digestibility of organic matter (OM), nitrogen, neutral detergent fiber (NDF), and acid detergent fiber (ADF) was also analyzed to understand how different protein types and feeding schedules impacted digestion and fermentation in lambs.

Mature crested wheatgrass hay, a low-quality forage, was used as the basal diet in the study. This choice reflects the reality that many grazing animals, especially in certain regions or during specific seasons, rely on such forages. Low-quality forages are typically characterized by high fiber content and low digestibility. Supplementation strategies, such as those involving ruminally degradable protein (RDP) and ruminally undegradable protein (RUP), become crucial in maximizing the nutritional value that lambs can derive from these forages. Without appropriate supplementation, lambs may struggle to meet their nutritional needs on mature crested wheatgrass hay alone.

The study indicated that incorporating both ruminally degradable protein (RDP) and ruminally undegradable protein (RUP) in the diet, particularly when delivered on alternate days, can improve nutrient utilization. The MIX-A strategy (a 50:50 mixture of RDP and RUP supplements, provided on alternate days) aimed to strike a balance between providing readily available nitrogen for rumen microbes (RDP) and supplying protein that can be digested in the small intestine (RUP). This approach potentially optimizes both ruminal fermentation and post-ruminal digestion, leading to more efficient use of forage. Additionally, alternate-day feeding schedules can reduce the frequency of supplementation, potentially lowering costs for farmers.

Ruminally undegradable protein (RUP) is important because it bypasses the rumen and is digested in the small intestine. This provides lambs with amino acids directly, supplementing the protein produced by microbial digestion in the rumen. RUP is especially valuable when the supply of ruminally degradable protein (RDP) is sufficient to meet the needs of rumen microbes, but the lamb requires additional protein for growth or production. Balancing RDP and RUP in the diet ensures that both the microbes and the lamb's own tissues receive the necessary protein building blocks. An ideal RUP level helps to promote better overall health and more efficient forage utilization.