Reformulation of dairy cow diets based on rumen degradable protein and total digestible nutrient with varying levels on in vitro fermentability and digestibility

Rumen degradable protein (RDP) needs to be balanced with the adequacy of rumen undegradable protein (RUP) and energy for optimal microbial growth. Therefore, this study aimed to determine the optimal level of the RDP:RUP ratio and the energy level of dairy cattle rations using the in vitro method. The rumen inoculum used to carry out this research, was obtained from two bull rumen fistulated of Friesian Holstein. The treatments consisted of 3 levels of RDP:RUP ratio, namely 50:50, 55:45 and 60:40, while the energy levels consisted of total digestible nutrient (TDN) levels of 65.6% and 68.6%. The experimental design was a factorial randomized block, while data were analyzed using ANOVA and Duncan multi range’s test. The result showed the ratio of RDP:RUP had an effect on DMD, OMD, NH3, and rumen microbe. Furthermore, the higher TDN content increased significantly DMD, OMD, total VFA, and partial VFA. The increase in the microbial population was associated with a rise in total VFA and NH3 concentrations. This research concluded, the rations with RDP:RUP (60:40) ratio increased the population of bacteria and protozoa, while the availability of ammonia in the rumen, and the high level of TDN provided a higher supply of VFA, DMD, and OMD.

Impacts of Rumen Degradable or Undegradable Protein Supplementation with or without Salt on Nutrient Digestion, and VFA Concentrations

The objectives of this study were to evaluate the effect of differences in protein type and delivery method on rumen dynamics and nutrient digestion. Cows were allotted to rumen degradable protein (RDP) or rumen undegradable protein (RUP) and self-fed (SF) salt-limited pressed blocks or hand-fed (HF) loose supplement, resulting in four dietary treatments. There was a delivery effect (p = 0.04) on neutral detergent fiber (NDF) intake, as the SF animals consumed more NDF than HF animals. The RDP-SF animals had greater NDF digestibility (p = 0.04) and water intake (p = 0.03) than the three other treatments. Supplement intake displayed a protein type effect (p = 0.03), as RDP-supplemented animals consumed more supplement on a g·kg body weight (BW)−1 d−1 basis than RUP animals. There was an effect of protein type (p = 0.02) and delivery method (p = 0.03) on fluid flow rate, with RUP and HF cows having greater liquid flow rates. Ruminal pH was lower (p < 0.01) in RDP-HF cows than RDP-SF cows at all hours, except 4-h post-feeding. RDP-SF animals had the greatest (p < 0.01) concentrations of ruminal ammonia. Valerate ruminal concentrations were greater (p = 0.04) in RDP supplemented animals compared to RUP supplemented animals. In conclusion, self-fed supplements containing RDP may enhance the use of low-quality forages and increase ruminal ammonia concentrations.

Estimation rumen degradable protein of local feeds in dairy cattle using in sacco method

There is a lack of nutrition information on local feeds protein in Indonesia, especially to determine protein fraction of dairy feed. The objective of this study was to determine rumen degradable protein (RDP) of local feeds in dairy cattle using in sacco method. The local feeds are copra meal, palm kernel meal, coffee husk, tofu waste, soy-sauce waste, brewer waste, and habbatussauda waste. Two ruminal fistulated male Frisian Holstein were used to determine rumen degradable protein using in sacco method. The parameters observed include the estimated kinetic parameters, effective degradability (ED), and RDP. The parameters were evaluated with analysis of variance using SAS University software. The result showed that tofu waste and habbatussauda waste had high potential rapid degradation of CP following by brewer waste, palm kernel waste, soy-sauce waste, copra meal, and coffee husk. Habbatussauda waste had higher RDP followed by brewer waste, tofu waste, copra meal, palm kernel meal, soy-sauce waste, and coffee husk. There was a positive correlation between RDP and crude protein content, and a negative correlation between RDP and crude fiber. It is concluded that local feeds have various characteristics of quality feed protein, which is shown by rumen degradable protein and rumen undegradable protein.

Effects of rumen undegradable protein sources on nitrous oxide, methane and ammonia emission from the manure of feedlot-finished cattle

Here, the effects of sources of rumen undegradable protein (RUP) in diets on methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from the manure of feedlot-finished cattle were evaluated. We hypothesized that the use of different RUP sources in diets would reduce N loss via urine and contribute to reduced N2O, CH4 and NH3 emissions to the environment. Nellore cattle received different diets (18 animals/treatment), including soybean meal (SM, RDP source), by-pass soybean meal (BSM, RUP source) and corn gluten meal (CGM, RUP source). The protein source did not affect the N and C concentration in urine, C concentration in feces, and N balance (P > 0.05). The RUP sources resulted in a higher N2O emission than the RDP source (P = 0.030), while BSM resulted in a higher N2O emission than CGM (P = 0.038) (SM = 633, BSM = 2521, and CGM = 1153 g ha− 2 N-N2O); however, there were no differences in CH4 and NH3 emission (P > 0.05). In conclusion, the use of RUP in diets did not affect N excretion of beef cattle or CH4 and NH3 emission from manure, but increased N2O emission from the manure.

Advances in Pasture Management and Animal Nutrition to Optimize Beef Cattle Production in Grazing Systems

The increasing demand of meat requires the adoption of sustainable intensification livestock systems, applying nutritional strategies to reduce any negative contribution from beef cattle to global warming and, at the same time, to increase animal performance and productive efficiency. The pasture management practices and feed supplementation, mainly using non-edible feed with less costs, could minimize environmental and social impacts, resulting in higher productivity with less inputs utilization. Tropical grass submitted to grazing management according to plant height present high soluble protein and low levels of indigestible neutral detergent fiber contents. Energy or rumen undegradable protein supplementation, associated to alternative additives to antibiotics effects, such as probiotics, tannin, essential oils and saponin, can help to fully exploit the animal genetic potential and nutrient utilization efficiency, which decreases greenhouse gases emissions and improves animal performance. Hence, more information about these tools can make the livestock systems in tropical pasture more efficient and eco-friendlier.

252 Effects of Increasing Urea in Corn Silage Diets and Duration of Ensiling on the Rumen Undegradable Protein Content of Corn Silage

Two experiments were conducted to evaluate the effects of increasing urea in a corn silage cattle diet and ensiling time (ET) impact on rumen undegradable crude protein (RUP) content of corn silage. In Exp. 1, ten ruminally- and duodenally cannulated heifers (body weight 265 ± 16 kg) were utilized in a 4 × 4 Latin square design and treatments were urea included at 0, 0.5, 1, or 1.5% of dietary dry matter (DM). In Exp. 2, corn silage samples were collected during feedout at 32-d intervals from the time of ensiling (d 0) to 160 d post-ensiling followed by separation in water to forage and grain components. Forage and grain samples were ruminally incubated in two steers to calculate RUP content of corn silage. In Exp. 1, DM intake increased linearly from 5.7 to 6.8 kg/d as urea inclusion increased (P &lt; 0.001). Apparent total tract digestibility of DM and organic matter increased linearly from 55.8% to 60.8%, and 60.1% to 64.9%, respectively (P &lt; 0.001). Total tract digestibility of neutral and acid detergent fiber increased linearly with increasing urea inclusion (P ≤ 0.004). In Exp. 2, the RUP content of the corn grain component decreased from 43.7% of CP at day 0 to 15.8% and 10.0% of CP after 32 and 96 d of ensiling, respectively (quadratic, P &lt; 0.01). The RUP content of the forage averaged 19.3% of CP across ET ranging from 21.5 to 17.8% of CP (P ≥ 0.28). Estimated from the individual components, the RUP content of whole corn silage decreased from 32% to 17.1% of CP after 160 d in storage, a portion of which is digestible. Urea supplementation improved digestibility of corn silage diets and RUP content of corn silage decreased with storage time, primarily driven by changes in the corn grain component.

157 Effects of Monensin and Protein Type on Performance of Yearling Steers Grazing Smooth Brome

A two-yr study was conducted to evaluate the effects of monensin on sparing ruminal degradable protein in yearling steers grazing smooth bromegrass pastures (n = 288, initial BW = 332 kg, SD = 7). Treatment design was a 2 x 3 factorial with the following factors: 1) 0 or 200 mg monensin/steer daily; 2) no protein supplement, 1.25 kg soybean meal (SBM) as a source of RDP, or 1.31 kg non-enzymatically browned SBM as a source of RUP. Steers receiving supplemental protein were provided isonitrogenous amounts equivalent to dried distillers grains plus solubles at 0.50% BW. Steers were weighed approximately every 34 d to adjusted the amount of protein supplement. There was no interaction (P &gt; 0.41) of monensin by protein type for average daily gain (ADG). Rate of gain for steers supplemented monensin was not different (P = 0.26) from steers not supplemented monensin. However, monensin supplemented steers numerically gained 7.9% more than steers not provided monensin when no supplemental protein was provided. Compared to steers supplemented with no protein, supplementing RDP increased ADG by 0.19 kg/steer (P &lt; 0.001). Likewise, RUP supplementation increased ADG by 0.24 kg/steer (P &lt; 0.001) compared to steers supplemented no protein. Supplementing RUP increased ADG by 0.05 kg/steer (P &lt; 0.001) compared to steers supplemented RDP. Supplementing protein, especially rumen undegradable protein, improved yearling steer rate of gain on smooth bromegrass pastures. Monensin supplementation did not improve rate of gain. These data do not support the protein-sparing effects of monensin for steers supplemented with RDP.

Effect of extrusion on the rumen undegradable protein fraction of lupins

Lupins are highly degradable in the rumen, and do not provide enough bypass protein for high-producing ruminant animals. The effects of extrusion on dry matter (DM) and crude protein (CP) rumen degradability of Lupinus albus and Lupinus angustifolius were determined in situ. Samples of both types of lupin were extruded at maximum temperature, which reached 116 °C. Six Dohne Merino wethers fitted with rumen cannulas were used in this trial. Samples were incubated in the rumen at intervals of 0, 2, 4, 12, 36, and 48 hours. This procedure was repeated in two sheep per treatment and in three periods, giving a total of six observations for each variable. Extrusion lowered the soluble fraction of CP and increased the potential degradable fraction without affecting its rate of degradation. It also lowered the effective degradability of CP of both types of lupin by 28% at an outflow rate of 0.08% per hour. No differences were observed between types. Extrusion modified the ruminal degradation parameters and decreased effective rumen degradation, especially at faster outflow rates. Thus, the rumen undegradable protein (RUP) fraction of lupins was increased by extrusion and lupins could be used more efficiently in ruminant diets. This study showed that the benefits of extrusion could be reached at a relatively low temperature of 116 °C to reduce the possibility of heat damage.