Effect of including high-lipid by-product pellets in substitution for barley grain and canola meal in finishing diets for beef cattle on ruminal fermentation and nutrient digestibility

Feeding Canola, Camelina, and Carinata Meals to Ruminants

Soybean meal (SBM) is a byproduct from the oil-industry widely used as protein supplement to ruminants worldwide due to its nutritional composition, high protein concentration, and availability. However, the dependency on monocultures such as SBM is problematic due to price fluctuation, availability and, in some countries, import dependency. In this context, oilseeds from the mustard family such as rapeseed/canola (Brassica napus and Brassica campestris), camelina (Camelina sativa), and carinata (Brassica carinata) have arisen as possible alternative protein supplements for ruminants. Therefore, the objective of this comprehensive review was to summarize results from studies in which canola meal (CM), camelina meal (CMM), and carinata meal (CRM) were fed to ruminants. This review was based on published peer-reviewed articles that were obtained based on key words that included the oilseed plant in question and words such as "ruminal fermentation and metabolism, animal performance, growth, and digestion". Byproducts from oil and biofuel industries such as CM, CMM, and CRM have been evaluated as alternative protein supplements to ruminants in the past two decades. Among the three plants reviewed herein, CM has been the most studied and results have shown an overall improvement in nitrogen utilization when animals were fed CM. Camelina meal has a comparable amino acids (AA) profile and crude protein (CP) concentration to CM. It has been reported that by replacing other protein supplements with CMM in ruminant diets, similar milk and protein yields, and average daily gain have been observed. Carinata meal has protein digestibility similar to SBM and its CP is highly degraded in the rumen. Overall, we can conclude that CM is at least as good as SBM as a protein supplement; and although studies evaluating the use of CMN and CRM for ruminants are scarce, it has been demonstrated that both oilseeds may be valuable feedstuff for livestock animals. Despite the presence of erucic acid and glucosinolates in rapeseed, no negative effect on animal performance was observed when feeding CM up to 20% and feeding CMN and CRM up to 10% of the total diet.

High-fibre high-lipid by-product pellets containing calcium oxide-treated oat hulls as a partial replacement for barley grain in finishing diets for beef cattle

Two studies were conducted to evaluate the effects of treating oat hulls with calcium oxide (CaO) prior to inclusion in a high-lipid by-product pellet (HLP) on dry matter intake (DMI), ruminal fermentation, and total-tract digestibility (Study 1) and growth performance (Study 2). In Study 1, six ruminally cannulated heifers were used in a replicated 3 × 3 Latin square design. Study 2 used 210 steers in 21 pens in a 113 d finishing study. Dietary treatments for both studies included a barley-based control diet (CON), a diet where HLP partially replaced barley grain (NT-HLP), and a diet where HLP contained oat hulls treated with 7.5% CaO [dry matter (DM) basis; CaO-HLP]. For Study 1, DMI and ruminal pH were not affected. Apparent total-tract digestibility of DM and organic matter (OM) were greater (P < 0.05) for CON than NT-HLP and CaO-HLP. In Study 2, final body weight tended to be greater for NT-HLP and CaO-HLP than CON (P = 0.065). For CaO-HLP and NT-HLP, DMI was greater than CON (P < 0.01), but average daily gain (ADG) (2.0 kg d−1) and gain:feed (G:F) (0.16 kg kg−1) were not different. Thus, HLP can partially replace barley grain in finishing diets without negatively affecting ruminal fermentation or growth performance, but treatment with CaO has no effect.

Effect of dietary energy substrate and days on feed on apparent total tract digestibility, ruminal short-chain fatty acid absorption, acetate and glucose clearance, and insulin responsiveness in finishing feedlot cattle

The objective of this study was to determine the effect of dietary energy substrate and days on feed on apparent total tract digestibility, ruminal fermentation, short-chain fatty acid (SCFA) absorption, plasma glucose and acetate clearance rates, and insulin responsiveness. Eight ruminally cannulated, crossbred growing heifers were randomly allocated to 1 of 2 dietary treatments. The control (CON) diet consisted of 75.2% barley grain, 9.8% canola meal, 9% mineral and vitamin supplement, and 6% barley silage (DM basis). To evaluate the effect of energy source, a high-lipid, high-fiber byproduct pellet (HLHFP) was included in the diet by replacing 55% of the barley grain and 100% of canola meal. The study consisted of 4 consecutive 40-d periods (P1 to P4), with data and sample collection occurring in the last 12 d of each period. Dry matter intake tended ( = 0.10) to decrease by period and HLHFP-fed heifers tended to eat less ( = 0.09). The ADG of the CON was greater than that of the HLHFP during P1 and P4 (treatment × period, = 0.02). Heifers fed HLHFP tended to have greater mean ruminal pH (6.10 vs. 5.96; = 0.07) than heifers fed the CON, but pH was not affected by period. The CON heifers had a greater digestibility for DM, OM, CP, and NDF ( ≤ 0.03), and the digestibility for DM and OM linearly increased ( = 0.01) and for CP, NDF, and starch quadratically increased ( ≤ 0.04) with advancing period. Total SCFA concentration in the rumen was greater ( < 0.01) for the CON than for the HLHFP (141.6 vs. 128.1 m). The molar proportion of acetate and isobutyrate linearly increased and butyrate and valerate linearly decreased ( ≤ 0.05) with advancing periods. The rate of valerate absorption tended to increase (linear, = 0.06) and the ruminal liquid passage rate tended to decrease (linear, = 0.08) with advancing period. The arterial clearance rate of acetate tended to quadratically increase ( = 0.06) with period, whereas the clearance rate of glucose was not affected by treatment or period. Both fasting plasma insulin and the area under the insulin curve in response to glucose infusion linearly increased ( = 0.04) with period. These data suggest that partially replacing barley grain with HLHFP negatively affects total tract digestibility and performance. Moreover, with advancing days on feed, digestibility and insulin resistance increases without changes in ruminal pH and plasma metabolite clearance rates.

Effects of lipid extraction on nutritive composition of winged bean (Psophocarpus tetragonolobus), rubber seed (Hevea brasiliensis), and tropical almond (Terminalia catappa)

AIM

This experiment aimed to evaluate the nutritive composition and in vitro rumen fermentability and digestibility of intact and lipid-extracted winged bean, rubber seed, and tropical almond.

MATERIALS AND METHODS

Soybean, winged bean, rubber seed, and tropical almond were subjected to lipid extraction and chemical composition determination. Lipid extraction was performed through solvent extraction by Soxhlet procedure. Non-extracted and extracted samples of these materials were evaluated for in vitro rumen fermentation and digestibility assay using rumen: Buffer mixture. Parameters measured were gas production kinetics, total volatile fatty acid (VFA) concentration, ammonia, in vitro dry matter (IVDMD) and in vitro organic matter digestibility (IVOMD). Data were analyzed by analysis of variance and Duncan's multiple range test.

RESULTS

Soybean, winged bean, rubber seed, and tropical almond contained high amounts of ether extract, i.e., above 20% DM. Crude protein contents of soybean, winged bean, rubber seed, and tropical almond increased by 17.7, 4.7, 55.2, and 126.5% after lipid extraction, respectively. In vitro gas production of intact winged bean was the highest among other materials at various time point intervals (p<0.05), followed by soybean > rubber seed > tropical almond. Extraction of lipid increased in vitro gas production, total VFA concentration, IVDMD, and IVOMD of soybean, winged bean, rubber seed, and tropical almond (p<0.05). After lipid extraction, all feed materials had similar IVDMD and IVOMD values.

CONCLUSION

Lipid extraction improved the nutritional quality of winged bean, rubber seed, and tropical almond.

Effects of encapsulated nitrate on growth performance, carcass characteristics, nitrate residues in tissues, and enteric methane emissions in beef steers: Finishing phase

A finishing feedlot study was conducted with beef steers to determine effects of encapsulated nitrate (EN) on growth performance, carcass characteristics, methane production, and nitrate (NO) residues in tissues. The 132 crossbred steers were backgrounded in a feedlot for 91 d and transitioned for 28 days to the high-concentrate diets evaluated in the present study, maintaining the treatment and pen assignments designated at the start of the backgrounding period. The steers were initially assigned to 22 pens (6 animals per pen) in a randomized complete block design with BW (18 pens) and animals designated for methane measurement (4 pens) as blocking factors. Five animals in each pen designated for methane measurement (total of 20 animals) were monitored for methane emissions in respiratory chambers twice during the experiment. Pens received 3 dietary treatments (7 pens each): Control, a finishing diet supplemented with urea; 1.25% EN, control diet supplemented with 1.25% encapsulated NO in dietary DM that partially replaced urea; and 2.5% EN, control diet supplemented with 2.5% EN (DM basis) fully replacing urea. The final pen designated only for methane measurement received a fourth dietary treatment, 2.3% UEN, the control diet supplemented with unencapsulated NO (UEN) fully replacing urea. The cattle weighed 449 ± SD 32 kg at the start of the 150-d finishing period. The 2.5% EN diet decreased ( < 0.01) DMI compared with Control and 1.25% EN diets. Feeding EN tended to increase ( = 0.092) ADG compared with Control, and G:F was improved ( < 0.01) for EN compared with Control. No differences in methane production (g/d) and yield (g/kg DMI) were observed among treatments. Inclusion of EN in the diets increased ( ≤ 0.03) sorting in favor of large and medium particles and against small and fine particles. Plasma NO and NO concentrations were elevated ( < 0.01) with EN in a dose-response manner, but total blood methemoglobin levels for all treatments were low, below the detection limit. Feeding EN increased ( < 0.01) NO concentrations of samples from muscle, fat, liver, and kidney; NO concentrations of these tissues were similar between 1.25% EN and 2.3% UEN. In conclusion, inclusion of 2.5% EN in a finishing diet (DM basis; about 2% NO) did not cause NO toxicity or any health problems in the long term. In comparison with supplemental urea, feeding EN improved feed efficiency despite increases in sorting against dietary EN.

Evaluation of a phase-feeding strategy utilizing high-lipid high-fibre byproduct pellets in diets for feedlot steers

Two studies were conducted to evaluate the provision of high-lipid high-fibre byproduct pellets when used as a partial replacement (60% in Study 1 and 30% in Study 2; HLP) for barley grain and canola meal in finishing diets (BAR). The HLP was fed for the last 49, 98, or 147 d (HLP49, HLP98, and HLP147, respectively) in Study 1, and for the last 60 or 120 d in Study 2 (HLP60 and HLP120, respectively) or the last 60 d with additional canola oil (HLP60CO). The statistical model included the fixed effects of diet, period, and the interaction. Steers fed BAR147 had the greatest average daily gain (ADG) (P < 0.01) and G:F (P = 0.01). The HLP147 had the greatest dry matter intake (DMI) during the first 49 d but least during the last 49 d of the finishing phase (treatment × period; P < 0.01). Hot carcass weight for BAR147 and HLP49 were the heaviest (P = 0.04). In Study 2, DMI and ADG were not affected (P > 0.05), but hot carcass weight was greater for BAR120 and HLP60 than HLP120 and HLP60CO. Inclusion of high-fibre high-lipid byproduct pellets in the latter part of the finishing period may improve carcass yield grade without affecting ADG and G:F.