Effect of rumen degradable protein and sulfur supplementation on in vitro digestibility and ruminal fermentation

The availability of nitrogen and sulfur in the rumen should be synchronized to generate microbial protein synthesis. This study aimed to evaluate rumen degradable protein and sulfur supplementation on in vitro digestibility and ruminal fermentation. The experimental design was a 4 x 3 factorial randomized block design. Factor 1 was RDP levels (%CP) (R1= 60%; R2= 55%; R3= 50%; R4= 45%), and factor 2 was sulfur supplementation (S1= 0%; S2= 0.1%; S3= 0.2%). Data were analyzed with ANOVA followed by the Duncan test. The result showed that sulfur supplementation improved DMD and OMD without changes in rumen pH. NH3 concentration was influenced by RDP levels. Treatment R1 had the highest NH3 concentration (7.03 mM). There was an interaction of two factors on total VFA concentration. The combination of R1 and S2 resulted in the highest total VFA concentration than others. The total bacteria population increased with increasing RDP levels. Protozoa population was affected by RDP levels and sulfur supplementation. This study concluded that a combination of 60% RDP and 0.2% sulfur supplementation resulted in the best ration to improve ruminal fermentation and digestibility.

Nutritional composition, nitrate and nitrite levels of Kikuyo grass and its influence on milk production.

Objetive. Establish variations of nutritional composition and the contents of nitrates and nitrites in the Kikuyo grass (Cenchrus clandestinus (Hochst. Ex Chiov.) Morrone) from four veredas in the municipality of San Miguel de Sema: Peña Blanca, Sirigay, Sabaneca, and Quintoque, during dry and rainy seasons. were dairy production is the most significant economic activity. Material and methods. Nutritional characterization parameters, were associated a two-way ANOVA, using Tukey's as a multiple comparison test. Results. The results revealed in dry matter a high average content of total protein (TP) (23.48% +/- 3.71), neutral detergent fiber (60.86% +/- 3.03), with important DM degradability values at different time points (62.97% +/- 3.74 after 48 Hours). The report indicated decreased values of lignin (4.25% +/- 0.5), non-structural carbohydrates (11.44% +/- 2.43) and of the ratio of non-structural carbohydrates: rumen degradable protein (NSC:RDP) of 0.84 +/- 0.16. The levels of nitrates reached an average of 2977 ppm +/- 2061, which differed significantly according to the seasons and veredas, for the dry season in the different veredas the level of nitrated remained at 4728 ppm, a value 3.9 higher in comparison to the rainy season. The levels of nitrites showed average contents of 2.97 pm of DM, contents highly decreased to be potentially toxic. Conclusions. These results allowed us to establish a difference in the protein:energy relation as the limiting factor for milk production. Nitrate levels indicated as potentially toxic.

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.

Forage source (alfalfa hay vs wheat straw) and rumen undegradable to degradable protein ratio: Effects on growth performance, microbial protein yield, digestibility, blood metabolites, and behavior of Holstein dairy calves

Aim of the study: The effects of forage source (alfalfa hay; AH vs. wheat straw; WS) with rumen undegradable to degradable protein ratio [low ratio (LR) = 28:72; high ratio (HR) = 36:64] were evaluated in young dairy calves. Area of study: Arak, Iran. Material and methods: Forty-eight 3-d old female Holstein dairy calves (44.5 kg of BW) were allocated in four treatments: (1) AH with low dietary RUP:RDP ratio (AH-LR); (2) AH with high dietary RUP:RDP ratio (AH-HR); (3) WS with low dietary RUP:RDP ratio (WS-LR); and (4) WS with high dietary RUP:RDP ratio (WS-HR), being RDP and RUP rumen degradable and undegradable proteins, respectively. The calves weaned on d 53 of the experiment and remained in the study until d 73 of age. Main results: The average daily gain and feed efficiency were improved in dairy calves receiving HR diets compared to LR diets during the post-weaning period (p<0.05). The fecal score (p=0.03) and neutral detergent fiber digestibility (p=0.04) were improved when calves fed WS diets compared to AH diets. Feeding HR diets increased allantoin (p=0.04) and microbial protein yield, and reduced blood urea nitrogen concentration (p=0.03) compared to LR diets. Assessing the interaction effects of the experimental factors resulted that the greatest BW, wither height, and blood beta-hydroxybutyrate, and the lowest urinary N concentration were observed in the WS-HR treatment (p<0.05). Research highlights: Feeding WS with high RUP:RDP ratio is recommendable in dairy calves due to the improvement in gain and N efficiency.

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.