Supplementation effect with slow-release urea in feed blocks for Thai beef cattle—nitrogen utilization, blood biochemistry, and hematology

Effects of rumen-bypass protein supplement on growth performance, hepatic mitochondrial protein complexes, and hepatic immune gene expression of beef steers with divergent residual feed intake

We investigated the impact of a rumen-bypass protein (RBP) supplement on growth performance, plasma and urinary N (UN) concentration, hepatic mitochondrial protein complexes, and hepatic mRNA expression of immune genes of beef steers with negative or positive residual feed intake (RFI) phenotype. Forty crossbred beef steers with an average body weight (BW) of 492 ± 36 kg were subjected to a generalized randomized block design over a 42-day experimental period. This study followed a 2 × 2 factorial arrangement of treatments. The factors evaluated were: 1) RFI classification (low-RFI (-2.12 kg/d) vs. high-RFI (2.02 kg/d), and 2) rumen-bypass protein supplement: RBP supplement (RBP; 227 g/steer/d) vs. control diet (CON; 0 g/d), resulting in four distinct treatments: LRFI-CON (n = 10), LRFI-RBP (n = 10), HRFI-CON (n = 10), and HRFI-RBP (n = 10). The RBP supplement (84% crude protein) is a mixture of hydrolyzed feather meal, porcine blood meal, and DL-methionine hydroxy analogue. The beef steers were stratified by BW, randomly assigned to treatments, and housed in four pens (1 treatment/pen) equipped with two GrowSafe feed bunks each to measure individual dry mater intake (DMI). Body weight was measured every 7 d. Liver tissue samples were collected on d 42 from all the beef steers. These samples were used for mRNA expression analysis of 16 immune-related genes and for evaluating the mitochondrial protein complexes I - V. No significant effects due to RBP supplementation or RFI × RBP interactions (P > 0.05) were observed for average daily gain (ADG) and DMI. However, compared to high-RFI steers, low-RFI steers showed a trend towards reduced DMI (12.9 vs. 13.6 kg/d; P = 0.07) but ADG was similar for the two RFI groups. Regardless of RFI status, supplemental RBP increased blood urea nitrogen (BUN) (P = 0.01), with a lower BUN concentration in low-RFI steers compared to high-RFI ones. A tendency for interaction (P = 0.07) between RFI and RBP was detected for the UN concentrations; feeding the dietary RBP increased the UN concentration in high-RFI beef steers (209 vs. 124 mM), whereas the concentration was lower than that of the CON group for low-RFI beef steers (86 vs. 131 mM). Interactions of RBP and RFI were observed (P ≤ 0.05) for mitochondrial activities of complexes IV, V, and mRNA expressions of some immune genes such as TLR2, TLR3, and IL23A. In conclusion, while RBP supplementation did not alter growth performance, its observed effects on hepatic immune gene expression, mitochondrial protein complexes, BUN, and UN depended on the beef steers' RFI phenotype. Therefore, the RFI status of beef steers should be considered in future studies evaluating the effects of dietary protein supplements.

Effects of substituting agro-industrial by-products for soybean meal on beef cattle feed utilization and rumen fermentation

The purpose of the present investigation was to detect the effect of replacement of soybean meal (SBM) with citric waste fermented yeast waste (CWYW) as an alternative protein source of portentous substances in a concentrate mixture diet of beef cattle on intake, digestibility, ruminal fermentation, plasma urea-nitrogen, energy partitioning, and nitrogen balance. Four Thai-native beef bulls (170 ± 10.0 kg of initial body weight) were randomly allocated to a 4 × 4 Latin square design. The dietary treatments were four levels of CWYW replacing SBM in a concentrated diet at ratios of 0, 33, 67, and 100%. SBM was added to the concentrate diet at a dose of 150 g/kg DM. All cattle were offered ad libitum rice straw and the concentrate diet at 5 g/kg of body weight. The study was composed of four periods, each lasting for 21 days. The findings demonstrated that there was no difference in total dry matter intake, nutritional intake, or digestibility between treatments (p > 0.05). When CWYW replaced SBM at 100% after 4 h of feeding, ruminal pH, ammonia nitrogen, plasma urea nitrogen, and bacterial population were highest (p < 0.05). Volatile fatty acids and energy partitioning were not different (p > 0.05) among dietary treatments. Urinary nitrogen excretion was greatest (p < 0.05) for cattle fed CWYW to replace SBM at 100% of the concentrate. However, nitrogen absorption and retention for Thai-native cattle were similar (p > 0.05) among treatments. In conclusion, CWYW may be utilized as a substitute for SBM as a source of protein in Thai-native beef cattle without having an adverse impact on feed utilization, rumen fermentation characteristics, or blood metabolites.

Bioconversion of agro-industrial residues as a protein source supplementation for multiparous Holstein Thai crossbreed cows

The purpose of this field study was to compare the effects of top-dressing tropical lactating cows with soybean meal (SBM) or citric waste fermented yeast waste (CWYW) on intake, digestibility, ruminal fermentation, blood metabolites, purine derivatives, milk production, and economic return. Sixteen mid-lactation Thai crossbreeds, Holstein Friesian (16.7 ± 0.30 kg/day milk yield and 490 ± 40.0 kg of initial body weight) were randomly allocated to two treatments in a completed randomized design: SBM as control (n = 8) or CWYW (n = 8). The feeding trial lasted for 60 days plus 21 days for treatment adaptation. The results showed that total dry matter intake, nutrient intake, and digestibility did not (p>0.05) differ between SBM and CWYW top-dressing. Ruminal pH and the protozoal population did not (p>0.05) differ between SBM and CWYW top-dressing. After 4 hours of feeding, CWYW top-dressing showed greater ammonia nitrogen, plasma urea nitrogen, and bacterial population compared with the top-dressing of SBM. Volatile fatty acids and purine derivatives were not different (p>0.05) between SBM and CWYW top-dressing. For milk urea nitrogen, there was a greater (p<0.05) and somatic cell count was lower (p<0.05) for cows fed the CWYW top-dress compared to cows fed the SBM top-dress. The cost of the top-dress and total feed cost were less (p<0.05) for CWYW compared to SBM top-dressing, at 0.59 vs 1.16 US dollars/cow/day and 4.14 vs 4.75 US dollars/cow/day, respectively. In conclusion, CWYW could be used as an alternative protein source to SBM without having a negative impact on tropical lactating cows.

Ruminal Fermentation, Milk Production Efficiency, and Nutrient Digestibility of Lactating Dairy Cows Receiving Fresh Cassava Root and Solid Feed-Block Containing High Sulfur

This study evaluates the effects of fresh cassava root (CR) and a solid feed-block containing sulfur (S-FB) on fermentation in the rumen, feed utilization, milk yield, and milk composition in lactating dairy cows. Four Holstein-Friesian cows with 470 ± 50.0 kg body weight (BW), 10 ± 2 kg day−1 average milk yield, and 112 ± 15 days-in-milk were studied. A 2 × 2 factorial combination was arranged in a 4 × 4 Latin square design to evaluate the treatment-related effects. The treatments were obtained from a combination of two factors: (1) levels of CR at 10 g kg−1 BW (CR-1) and 15 g kg−1 (CR-1.5) and (2) levels of sulfur supplementation in solid feed-block at 20 g kg−1 (S-FB-2) and 40 g kg−1 (S-FB-4). The results showed that CR and S-FB had no interaction effect on feed intake, digestibility, fermentation, blood metabolites, milk yield, or its composition. Feeding CR up to 15 g kg−1 of the BW significantly increased (p < 0.05) the milk fat concentration while it decreased (p < 0.05) the somatic cell count. The S-FB-4 of the sulfur significantly (p < 0.05) increased the acid detergent fiber when compared with the S-FB-2 of the sulfur. CR could be fed up to 15 g kg−1 of BW with S-FB containing high sulfur (40 g kg−1) in dairy cows without a negative impact.

Effect of phytol in forage on phytanic acid content in cow's milk

Objective

Bioactive compounds in the ruminant products are related to functional compounds in diets. Therefore, this study aimed to explore the effect of forage sources, Italian ryegrass (IR) silage vs corn silage (CS) in the total mixed ration (TMR), on milk production, milk composition, and phytanic acid content in milk, as well as on the extent of conversion of dietary phytol to milk phytanic acid.

Methods

Phytanic acid content in milk was investigated for cows fed a TMR containing either IR silage or corn silage using 17 cows over three periods of 21 days each. In periods 1 and 3, cows were fed corn silage-based TMR (30% corn silage), while in period 2, cows were fed IR silage-based TMR (20% IR silage and10% corn silage).

Results

The results showed that there were no differences in fat, protein, lactose, solids-not-fat, somatic cell count, and fatty acid composition of milk among the three experimental periods. There were no differences in the plasma concentration of glucose, triglycerides, total cholesterol, and nonesterified fatty acids among the three experimental periods, while the blood urea nitrogen was higher (p<0.05) in period 2. The milk phytanic acid content was higher (p<0.05) in period 2 (13.9 mg/kg) compared with period 1 (9.30 mg/kg) and 3 (8.80 mg/kg). Also, the phytanic acid content in the feces was higher (p<0.05) in period 2 (1.65 mg/kg DM) compared with period1 (1.15 mg/kg DM) and 3 (1.17 mg/kg DM). Although the phytol contents in feces did not differ among the three feeding periods, the conversion ratio from dietary phytol to milk phytanic acid was estimated to be only 2.6%.

Conclusion

Phytanic acid content in cow's milk increases with increasing phytol content in diets. However, phytol might not be completely metabolized in the rumen and phytanic acid, in turn, might not be completely recovered into cow's milk. The change of phytanic acid content in milk may be positively correlated with the change of phytol in the diet within a short time.

In vitro rumen gas production kinetics, hydrocyanic acid concentration and fermentation characteristics of fresh cassava root and feed block sulfur concentration

Context Feeding ruminants with fresh cassava roots (FCR) is limited because they have a high concentration of hydrocyanic acid (HCN). Thus, it was hypothesised that receiving a feed block containing high sulfur (FBS) would reduce hydrocyanic acid (HCN) in FCR and improve rumen fermentation and nutrient digestibility in animals. Aims The goal of the present work was to study the influence of the ratio of FCR to rice straw (RS) together with FBS on kinetics of gas production, HCN concentration, fermentation characteristics and nutrient digestibility, using in vitro technique. Methods The experimental design was a 4 × 2 factorial arrangement in a completely randomised design, with three replications per treatment. Factor A was the FCR to RS ratio, which was 100:0, 60:40, 40:60 or 0:100. Factor B was sulfur, which was provided as two concentrations in FBS (2% and 4% DM). Gas production was recorded after incubation, at 0, 0.5, 1, 2, 4, 6, 8, 12, 18, 24, 48, 72 and 96 h. Fermentation liquor was collected and determined for kinetics of gas production, HCN concentration, fermentation characteristics and nutrient digestibility. Key results Cassava root to RS ratio influenced the cumulative gas production after 96 h. Inclusion of sulfur in the FBS at 4% increased the cumulative gas production, when compared with inclusion at 2%. The gas production from degradable fraction (b) and the rate of gas production (c) were significantly different among the treatments with different FCR:RS ratios, whereas there was no difference between using 2% and 4% sulfur in the FBS. The HCN concentration in fermentation liquor increased with an increasing proportion of FCR. Furthermore, inclusion of sulfur in the feed block at 4% reduced HCN concentration by 42.8%, when compared with inclusion at 2% (P &lt; 0.05). Ammonia-nitrogen concentration was significantly different among the FCR:RS-ratio treatments and was reduced when the proportion of FCR was decreased (P &lt; 0.05). In vitro digestibility was significantly increased with an increasing proportion of FCR. Increasing the proportion of FCR with 4% of sulfur in the FBS significantly increased in vitro DM digestibility, compared with 2% sulfur. Increasing the FCR:RS ratio with 4% of sulfur in the FBS increased the proportion of propionic acid (P &lt; 0.05). Conclusions Using a high FCR:RS ratio (100:0 or 60:40) with 4% sulfur in the FBS enhanced kinetics of gas production, propionic molar proportion, nutrient digestibility, and HCN detoxification by rumen microbes in an in vitro trial. Implications An in vivo study should be encouraged to verify the results and obtain more data.

Effect of tree foliage supplementation of tropical grass diet on in vitro digestibility and fermentation, microbial biomass synthesis and enteric methane production in ruminants

The objective of this study was to evaluate the influence of tree foliage species supplemented in ruminant diets based on Pennisetum purpureum on the in vitro digestibility and fermentation, microbial biomass synthesis and enteric methane production. Seven experimental diets were evaluated, including a control treatment based on P. purpureum (PT) grass, and six additional treatments supplemented with 30.0% foliage from Neomillspaughia emargiata (NE), Tabernaemontana amygdalifolia (TA), Caesalpinia gaumeri (CG), Piscidia piscipula (PP), Leucaena leucocephala (LL) and Havardia albicans (HA). A randomised complete block design repeated in two periods (block) was used. The highest gas production (P < 0.05) was recorded in treatments TA and PT (237 and 228 mL g-1, respectively). The highest in vitro digestibility of dry matter (IVDMD) and organic matter (IVOMD) (P < 0.05) was recorded in the control treatment PT (57.9% and 66.1%, respectively). Treatments LL, NE, TA and PP promoted greater microbial biomass synthesis (290, 223, 220 and 213 mg g-1, respectively) (P < 0.05). The proportion of propionic acid also increased in these latter treatments and in treatments CG and HA (P < 0.05). Additionally, treatments LL, PP, NE and TA decreased methane production (25.8, 29.5, 30.6 and 31.8 L kg-1 of digested dry matter, respectively). In conclusion, supplementation with L. leucocephala, P. piscipula, N. emargiata and T. amygdalifolia in ruminant diets based on P. purpureum is one feed alternative that can promote greater efficiency and synthesis of microbial biomass, increase the proportions of propionic and butyric acid and decrease the production of enteric methane by 15.6 to 31.6%.

Effects of Supplementation of Piper sarmentosum Leaf Powder on Feed Efficiency, Rumen Ecology and Rumen Protozoal Concentration in Thai Native Beef Cattle

Methane (CH₄) is an end-product of enteric fermentation in cattle [...].

Effect of urea-supplemented diets on the ruminal bacterial and archaeal community composition of finishing bulls

In this study, we evaluated the effects of urea-supplemented diets on the ruminal bacterial and archaeal communities of finishing bulls using sequencing technology. Eighteen bulls were fed a total mixed ration based on maize silage and concentrate (40:60) and randomly allocated to one of three experimental diets: a basal diet with no urea (UC, 0%), a basal diet supplemented with low urea levels (UL, 0.8% dry matter (DM) basis), and a basal diet supplemented with high urea levels (UH, 2% DM basis). All treatments were iso-nitrogenous (14% crude protein, DM basis) and iso-metabolic energetic (ME = 11.3 MJ/kg, DM basis). After a 12-week feeding trial, DNA was isolated from ruminal samples and used for 16S rRNA gene amplicon sequencing. For bacteria, the most abundant phyla were Firmicutes (44.47%) and Bacteroidetes (41.83%), and the dominant genera were Prevotella (13.17%), Succiniclasticum (4.24%), Butyrivibrio (2.36%), and Ruminococcus (1.93%). Urea supplementation had no effect on most phyla (P > 0.05), while there was a decreasing tendency in phylum TM7 with increasing urea levels (P = 0.0914). Compared to UC, UH had lower abundance of genera Butyrivibrio and Coprococcus (P = 0.0092 and P = 0.0222, respectively). For archaea, the most abundant phylum was Euryarchaeota (99.81% of the sequence reads), and the most abundant genus was Methanobrevibacter (90.87% of the sequence reads). UH increased the abundance of genus Methanobrevibacter and Methanobacterium (P = 0.0299 and P = 0.0007, respectively) and decreased the abundance of vadinCA11 (P = 0.0151). These findings suggest that urea-supplemented diets were associated with a shift in archaeal biodiversity and changes in the bacterial community in the rumen.

Improving rumen ecology and microbial population by dried rumen digesta in beef cattle

Four Thai native beef cattle with initial body weight (BW) of 91.8 ± 4.75 kg were randomly assigned according to a 4 × 4 Latin square design to receive four concentrates replacement levels of soybean meal (SBM) by dried rumen digesta (DRD) at 0, 33, 67, and 100 % on dry matter (DM) basis. All cattle were fed rice straw ad libitum while additional concentrate was fed at 0.5 % BW daily. The experiment was conducted for four periods of 21 days. Rumen fluid was analyzed for predominant cellulolytic bacterial population by using real-time PCR technique. Increasing levels of DRD did not alter total feed intake, ruminal pH and temperature, and plasma urea nitrogen (P > 0.05). Protozoa and fungal population were not differed by DRD supplementation while population of bacteria at 4 h post feeding was increased when SBM was replaced with DRD at 66 and 100 % DM. Population of total bacteria and R. flavefaciens at 4 h post feeding were significantly highest with inclusion of 100 % of DRD in the ration. The experimental diets has no effect on excretion and absorption of purine derivatives (P > 0.05), while microbial crude protein and efficiency of microbial N synthesis were significantly increased with DRD inclusion in the diet and highest with 100 % DRD replacement (P > 0.05). Replacement of SBM by DRD at 100 % DM improved the rumen ecology and microbial population in beef cattle fed on rice straw.

Nutrient utilisation and methane emissions in Sahiwal calves differing in residual feed intake

The presented study aimed at investigating the residual feed intake (RFI) of Sahiwal calves, nutrient utilisation as affected by RFI and its relationship with methane (CH4) emissions and some blood metabolites. Eighteen male Sahiwal calves (10-18 months of age; mean body weight 133 kg) were fed ad libitum with a total mixed ration. After calculating RFI for individual calves (-0.40 to +0.34 kg DM/d), they were divided into three groups with low, medium and high RFI, respectively. Dry matter intake (DMI) was higher (p < 0.05) in Group High RFI, whereas digestibility of all nutrients except crude protein and ether extract was significantly higher in Group Low RFI. Nitrogen balance was also significantly higher in Group Low RFI (20.2 g/d) than in Group High RFI (17.0 g/d). Average daily gain and feed conversion ratio were similar among the groups. With exception of glucose, concentrations of all measured blood metabolites were higher in Group High RFI (p < 0.05). Compared with Group High RFI, the CH4 emission of Group Low RFI was significantly lower (on the basis g/d and g/kg DMI by 11% and 19%, respectively). Furthermore, the CH4 emission [g/d] was significantly correlated with RFI (r = 0.77). Because higher feed efficiency and less CH4 production were observed in Group Low RFI, it was concluded that RFI can be used as a measure of feed efficiency, which has a potential to select Sahiwal calves for lowered CH4 emissions.