U.Y. Anele

Effect of Supplementing Diets of Anglo-Nubian Goats with Soybean and Flaxseed Oils on Lactational Performance

We studied the effect of soybean or flaxseed oil feeding in the diets of lactating Anglo-Nubian goats. A total of 20 goats (33.6 ± 0.6 kg) were divided into four treatments and fed a basal diet of berseem clover and concentrates (40:60 DM basis; control) or the control diet supplemented with either 20 mL/day of flaxseed oil or soybean oil or 10 mL of soybean oil plus 10 mL of flaxseed oil per day for 12 weeks (i.e., 22 to 23 g per kg of DM intake). Oil inclusion decreased ruminal pH (P < 0.05), and acetate but increased (P < 0.05) total volatile fatty acids and molar proportion of propionate and blood glucose (P < 0.01). In addition, increased milk yield and decreased milk-fat contents were evident (P < 0.05) with oil supplementation. Diets containing oil increased (P < 0.05) unsaturated fatty acids (FA), conjugated linoleic acid, and the athrogenicity index of milk fat but decreased saturated FA concentrations. It is concluded that soybean-oil or flaxseed-oil supplementation of goats at 20 mL/day increased feed utilization and milk production.

Effects of bulk density of steam-flaked corn in diets containing wet corn gluten feed on feedlot cattle performance, carcass characteristics, apparent total tract digestibility, and ruminal fermentation

The effects of varying bulk density of steam-flaked corn (SFC) in diets containing wet corn gluten feed (WCGF; Sweet Bran; Cargill Corn Milling, Blair, NE) have not been defined. In Exp. 1, yearling steers (n = 108; initial BW = 367 ± 1.18 kg) were housed in 27 pens (4 steers/pen) and received 1 of 3 different SFC bulk density treatments in a randomized complete block design. Bulk density treatments were 283, 335, or 386 g/L SFC in diets containing 25% WCGF (% of DM). Steers were fed once daily to provide ad libitum access to feed for an average of 163 d. For a 5-d period before d 70 of the experiment, DMI was measured, and fecal samples were collected from each pen for measurement of nutrient digestibility using dietary acid insoluble ash as a marker. Varying bulk densities of SFC did not affect (P ≥ 0.233) overall DMI, ADG, or G:F on a live- or carcass-adjusted basis. Dressing percent and LM area increased linearly (P ≤ 0.05) as bulk density increased, but other carcass traits were not affected by treatments. Intake of DM, OM, and CP during the 5-d digestion phase did not differ among bulk densities; however, starch intake increased linearly (P = 0.004) as bulk density of SFC increased. Digestibility of DM, OM, and CP tended (P ≤ 0.065) to decrease and starch digestibility decreased (P = 0.002) linearly as bulk density of SFC increased. In Exp. 2, a 3 × 3 Latin square design was used for collection of ruminal fluid from 3 ruminally cannulated Jersey steers adapted to the same diets used in Exp. 1. Bulk density did not affect NH3 concentrations, VFA molar proportions, ruminal fluid osmolality, and IVDMD of the diets. Total gas production increased linearly (P = 0.003) as bulk density of SFC increased from 283 to 335 g/L, but it decreased (P = 0.002) at 386 g/L. Present data suggest that bulk density can be increased up to 386 g/L in finishing diets containing 25% (DM basis) WCGF without affecting cattle performance and with limited effects on ruminal fermentation; however, digestibility of starch seemed to be affected negatively by increased bulk density in these diets.

Ruminal in vitro gas production, dry matter digestibility, methane abatement potential, and fatty acid biohydrogenation of six species of microalgae

Abstract: This study evaluated the composition, digestibility [dry matter digestibility (DMD)], CH4 abatement potential, and fatty acid biohydrogenation of six species of microalgae. Lipid content ranged from 115 g kg-1 dry matter (DM) (Scenedesmus sp. AMDD) to 361 g kg-1 DM (Tetracystis sp.), while Scenedesmus sp. AMDD had the highest carbohydrate (364 g kg-1 DM) and fibre content (277 g kg-1 DM). Gas production was highest (P < 0.001) for Micractinium reisseri and Chlorella vulgaris. In vitro DMD ranged from 654 g kg-1 for Scenedesmus sp. AMDD to 797 g kg-1 for Nannochloris bacillaris. Total CH4 differed (P < 0.001) among microalgae, ranging from 1.76 mL g-1 DM for Tetracystis sp. to 4.07 mL g-1 DM for M. reisseri. Nannochloropsis granulata (marine) had higher myristic, palmitoleic, and eicosapentaenoic acid levels than freshwater microalgae. Levels of a-linolenic acid were higher in Scenedesmus sp. AMDD than all other microalgae. CH4 production negatively correlated (P < 0.05) with levels of total carbohydrate, oleic, and a-linolenic acid. Despite having a lower lipid content, CH4 reductions with Scenedesmus sp. AMDD were comparable to Tetracystis sp. and N. bacillaris. Reductions in CH4 with Tetracystis sp. and N. bacillaris occurred without a decline in DMD, suggesting that overall microbial activity was not inhibited.

Predicting dry matter intake by growing and finishing beef cattle: evaluation of current methods and equation development.

The NRC (1996) equation for predicting DMI by growing-finishing beef cattle, which is based on dietary NEm concentration and average BW(0.75), has been reported to over- and underpredict DMI depending on dietary and animal conditions. Our objectives were to 1) develop broadly applicable equations for predicting DMI from BW and dietary NEm concentration and 2) evaluate the predictive value of using NE requirements and dietary NE concentrations to determine the DMI required (DMIR) by feedlot cattle. Two new DMI prediction equations were developed from a literature data set, which represented treatment means from published experiments from 1980 to 2011 that covered a wide range of dietary NEm concentrations. Dry matter intake predicted from the 2 new equations, which were based on NEm concentration and either the ending BW for a feeding period or the DMI per unit of average BW (End BW and DMI/BW, respectively), accounted for 61 and 58% of the variation in observed DMI, respectively, vs. 48% for the 1996 NRC equation. When validated with 4 independent data sets that included 7,751 pen and individual observations of DMI by animals of varying BW and feeding periods of varying length, DMI predicted by the 1996 NRC equation, the End BW and DMI/BW equations, and the DMIR method accounted for 13.1 to 82.9% of the variation in observed DMI, with higher r(2) values for 2 feedlot pen data sets and lower values for pen and individual data sets that included animals on lower-energy, growing diets as well as those in feedlot settings. The DMIR method yielded the greatest r(2) values and least prediction errors across the 4 data sets; however, mean biases (P < 0.01) were evident for all the equations across the data sets, ranging from as high as 1.01 kg for the DMIR method to -1.03 kg for the 1996 NRC equation. Negative linear bias was evident in virtually all cases, suggesting that prediction errors changed as DMI increased. Despite the expanded literature database for equation development, other than a trend for lower standard errors of prediction with the DMI/BW equation, the 2 new equations did not offer major advantages over the 1996 NRC equation when applied to the validation data sets. Because the DMIR approach accounted for the greatest percentage of variation in observed DMI and had the least root mean square error values in all data sets evaluated, this approach should be considered as a means of predicting DMI by growing-finishing beef cattle.

Enhancing lactational performance of Holstein dairy cows under commercial production: malic acid as an option: Malic acid in the diet of Holstein cows

BACKGROUND In Experiment 1 we studied the effect of malic acid addition at 0, 1, 2 and 3 mg g-1 dry matter (DM) feed on in vitro ruminal fermentation. In Experiment 2, the effect of supplementing malic acid on feed intake, digestion and milk production and composition of lactating cows was studied. 200 multiparous lactating Holstein dairy cows were randomly assigned to two treatments: a basal diet containing concentrate and roughage at 58:42, respectively, with no additive (control treatment) or supplemented with malic acid at 30 g per cow daily (malic treatment). RESULTS In Experiment 1, malic acid inclusion at 3 mg g-1 DM decreased in vitro methane production by 33%. In Experiment 2, malic acid decreased (P < 0.01) nutrient intake and increased nutrient digestibility. Greater (P < 0.05) milk yields, energy-corrected milk yields and milk component yields were observed in cows supplemented with malic acid. Greater milk (feed) efficiency was observed with malic acid treatment compared with the control treatment. CONCLUSION The results show that the inclusion of malic acid at 30 g daily in the diet of lactating cows enhanced the nutrient digestibility and increased the milk production as well as feed efficiency.

Interactive effects of bulk density of steam-flaked corn and concentration of Sweet Bran on feedlot cattle performance, carcass characteristics, and apparent total tract nutrient digestibility

Two hundred twenty-four steers (initial BW = 363 ± 1.57 kg) were used in a 2 × 3 + 1 factorial arrangement of treatments to evaluate the interactive effects of concentration of wet corn gluten feed (WCGF) and bulk density (BD) of steam-flaked corn (SFC) on feedlot performance, carcass characteristics, and apparent total tract digestibility. Diets consisted of 0, 15, or 30% WCGF (DM basis) with a BD of SFC at 283 or 360 g/L. The additional treatment consisted of 15% WCGF, SFC at 283 g/L, and a 6% inclusion of alfalfa hay vs. 9% for all other treatments. Steers were fed once daily for an average of 163 d. During a 5-d digestion period, DMI was measured, and fecal samples were collected for measurement of nutrient digestibility using dietary acid insoluble ash as a marker. There were few WCGF × BD interactions for feedlot performance, carcass characteristics, and digestibility. Similarly, contrasts between the treatment containing 15% WCGF/360 g/L SFC and 15% WCGF/360 g/L with 6% hay yielded few differences for performance and carcass data. Final BW responded quadratically (P ≤ 0.02) to WCGF inclusion and showed increased (P ≤ 0.007) BW for greater BD. As WCGF inclusion increased, G:F and calculated NE values (P ≤ 0.03) decreased quadratically. Steers consuming 360 g/L SFC had greater (P < 0.05) G:F than those fed 283 g/L SFC. Marbling score, HCW, 12th-rib fat thickness, and calculated yield grade increased quadratically (P ≤ 0.04) with increased inclusion of WCGF. Percentage of cattle grading premium Choice or greater responded quadratically (P = 0.04) to WCGF concentration. Increasing BD increased (P ≤ 0.01) HCW, dressing percent, marbling score, and 12th-rib fat thickness and decreased calculated yield grade and percentage of cattle grading Select; however, lower BD tended (P = 0.09) to increase LM area. Intake of DM, OM, CP, and NDF and fecal output during the digestibility period increased linearly (P ≤ 0.01) with increasing WCGF, and greater BD increased (P ≤ 0.04) intake of DM, OM, starch, and CP. Starch digestibility decreased quadratically (P = 0.008) as WCGF increased; however, digestibility of CP and NDF increased (P ≤ 0.02) linearly as WCGF increased. The 283 g/L BD increased (P ≤ 0.02) starch and CP digestibility compared with 360 g/L. These data suggest that increasing WCGF in feedlot diets with a greater BD of SFC can increase performance and carcass characteristic, but it might not be ideal for starch digestibility.

Evaluation of in vitro models for predicting acidosis risk of barley grain in finishing beef cattle

Our objective was to develop a model to predict the acidosis potential of barley based on the in vitro batch culture incubation of 50 samples varying in bulk density, starch content, processing method, growing location, and agronomic practices. The model was an adaptation of the acidosis index (calculated from a combination of in situ and in vitro analyses and from several components of grain chemical composition) developed in Australia for use in the feed industry to estimate the potential for grains to increase the risk of ruminal acidosis. Of the independent variables considered, DM disappearance at 6 h of incubation (DMD6) using reduced-strength (20%) buffer in the batch culture accounted for 90.5% of the variation in the acidosis index with a root mean square error (RMSE) of 4.46%. To evaluate our model using independent datasets (derived from previous batch culture studies using full-strength [100%] buffer), we performed another batch culture study using full-strength buffer. The full-strength buffer model using in vitro DMD6 (DMD6-FS) accounted for 66.5% of the variation in the acidosis index with an RMSE of 8.30%. When the new full-strength buffer model was applied to 3 independent datasets to predict acidosis, it accounted for 20.1, 28.5, and 30.2% of the variation in the calculated acidosis index. Significant ( < 0.001) mean bias was evident in 2 of the datasets, for which the DMD6 model underpredicted the acidosis index by 46.9 and 5.73%. Ranking of samples from the most diverse independent dataset using the DMD6-FS model and the Black (2008) model (calculated using in situ starch degradation) indicated the relationship between the rankings using Spearmans rank correlation was negative (ρ = -0.30; = 0.059). When the reduced-strength buffer model was used, however, there were similarities in the acidosis index ranking of barley samples by the models as shown by the result of a correlation analysis between calculated (using the Australian model) and predicted (using the reduced-strength buffer DMD6 model) acidosis index (ρ = 0.67; < 0.001). Results suggest that our model, which is based on a reduced-strength buffer in vitro DMD6, has the potential to predict acidosis risk and can rank barley samples based on their acidotic risk. Nonetheless, the model would benefit from further refinement by expanding the database.