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Our aim was to determine whether the method used to estimate truly digestible neutral detergent fiber (tdNDF) affects calculated concentrations of total digestible nutrients (TDN 1x ) and net energy of lactation (NE L3x ) of canola meal (CM). Samples were collected from 12 CM processing plants in Canada over 4 yr (2011 to 2014, n = 47) and analyzed for dry matter (DM), crude protein (CP), ether extract (EE), ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (ADL), and neutral detergent insoluble CP (NDICP). Ruminal in situ incubation of CM samples was performed at 0, 24, 48, 96, and 288 h to determine NDF fractions (A, B, and C), effective ruminal NDF digestibility (ERNDFD), and indigestible NDF (iNDF) of CM. Three tdNDF-estimation methods were evaluated: 1) National Research Council (NRC) = 0.75 × (NDF − NDICP − ADL) × {1− [ADL/ (NDF − NDICP)]0.667}; 2) iNDF = 0.75 × (NDF − NDICP − NDF remaining after 288 h in situ); and 3) ERNDFD estimated from in situ NDF digestion kinetics. Resulting tdNDF values were used for calculation of TDN1x and NEL3x according to NRC (2001) equations. Data were analyzed with MIXED procedure of SAS 9.4 to determine the effect of processing plant on chemical composition, NDF degradation kinetics and NEL3x of CM. Effect of tdNDF estimation method on calculated TDN1x and NEL3x of CM was also evaluated. Model for analysis of processing plant included the fixed effect of plant and the random effect of year (plant) as replication, while analysis of tdNDF methods included the fixed effect of tdNDF estimation method and the random effects of processing plant and of year(plant) as replication. There was an effect of processing plant on DM (P = 0.03), CP (P < 0.01), EE (P < 0.01), and NDF (P < 0.01) of CM. Processing plant also had an effect on NDF fractions A (P < 0.01) and B (P = 0.02) but did not affect fraction C and ERNDFD. The tdNDF estimation method had an effect on tdNDF (P < 0.01), TDN1x (P < 0.01), and NEL3x (P < 0.01) of CM, yielding average NEL3x values of 1.72, 1.87, and 2.07 Mcal/kg for NRC, iNDF, and ERNDFD, respectively. Our results indicate that calculated energy concentration of CM according to NRC (2001) equations varies depending on the method used for estimation of tdNDF. Further research will be needed to determine the most accurate estimation method. [ABSTRACT FROM AUTHOR]

Climate change may have an adverse effect on feed production. Hydroponic fodders produced in controlled environments are alternative feeds that may be used for dairy cattle. The objective of this study was to evaluate in-situ dry matter ruminal degradability of hydroponic fodders and corn silage. Two rumen-canulated lactating Holstein cows were used in a complete randomized block design with four treatments and 9 times (0, 2, 4, 8, 12, 24, 48, 72, and 240 h). Treatments were corn silage (CS), hydroponic sprouts of barley, wheat, and triticale. Quadruplicate samples were placed in Dacron bags (10 x 20 cm, 50 μm porosity) and incubated in the rumen. After incubation, samples were washed and dried in an air-forced oven set at 60°C for 48 h and DM recovery was weighted. Ingredients nutrient composition were CS (32.3% NDF, 8.4% CP, and 41.6% starch, 1.3% WSC; % of DM), barley (34.3% NDF, 17.1% CP, and 4.2% starch, 32.9% WSC; % of DM), wheat (23.7% NDF, 23.3% CP, and 8.5% starch, 32.7% WSC; % of DM), triticale (20.0% NDF, 16.2% CP, and 21.7% starch, 33.2% WSC; % of DM). Model included fixed effects of treatment and random effects of cow and replicate(cow). Data were analyzed using PROC MIXED of SAS. Degradation fractions were calculated based on DM disappearance. There were treatment effects (P < 0.01) on fraction A (degradable), fraction B (potentially degradable), fraction C (undegradable), effective ruminal degradability (ERD), and rate of degradation (kd: %/h). Fraction A was greater for triticale (74.1%) compared with wheat (70.2%), CS (63.1%), and barley (55.0%). Fraction B was greater for barley (28.5%) compared with CS (23.2%), wheat (19.1%), and triticale (13.9%). Fraction C was less for wheat (10.6%) than triticale (12.0%), CS (13.7%), and barley (16.4%). The ERD was greater for wheat (90.8%) compared with triticale (89.0%), CS (88.0%), and barley (85.6%). The kd for barley (2.4%) was less than triticale (4.9%). The kd for CS (1.8%) was less than triticale (4.9%). Overall, triticale had the greatest fraction A, barley had the greatest fraction B, and wheat had the least fraction C and the greatest ERD and kd. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate the effects of partially replacing soybean meal (SBM) with black soldier fly larvae frass (BSFL) on nutrient digestibility, growth performance, and blood profile of ewes consuming diets with approximately 10% SBM on a DM basis. Six yearling Florida native ewes, averaging (mean ± SD) 44 ± 3 kg BW were enrolled in a replicated 3 x 3 Latin square design with 3 experimental periods of 21 d each (14 d adaptation + 4 d samples collection + 3 d washout). First 14 d of each period, ewes were housed in 7.4 x 1.8 m individual pens with rubber mats, one automatic waterer and two plastic feeders. During collection, ewes were moved to 1.4 x 0.7 m metabolic crates equipped with an individual waterer and feeder and two trays for the collection of feces and urine. Animals were fed TMR ad libitum twice daily at 0730 and 1530 h consisting of different levels of SBM replacement with BSFL, as follows: no replacement (CON), partial replacement of SBM with 25% BSFL (BSFL25) and 50% BSFL (BSFL50) on a DM basis. Data on DM and nutrient intake, excretion, and apparent digestibility, and also plasma concentrations of glucose and blood urea nitrogen (BUN), and urine concentrations of allantoin, urine blood nitrogen, and uric acid, were collected. Data were analyzed with SAS 9.4 evaluating orthogonal polynomial contrasts to determine linear and quadratic effects of SBM replacement with BSFL for each response variable. The intakes of DM, NDF, ADF, EE, and starch were greater for BSFL25 compared with control (Quadratic effect; P < 0.01) while no differences were observed between BSFL25 and BSFL50. Similarly apparent digestibilities of DM, NDF, ADF and starch was less for BSFL25 than CON (Quadratic effect; P ≤ 0.01). Intake of CP linearly increased (P < 0.01) with BSFL, while apparent digestibility of CP linearly decreased and that of EE increased, with inclusion of BSFL. There was a quadratic effect of BSFL on total feces excretion (P < 0.01) and water consumption (P < 0.01) being greater in BSFL25 compared with CON. Urine BUN (P < 0.01) and urine nitrogen (P < 0.01) linearly increased with BSFL inclusion. Results indicate that partial replacement of SBM with BSFL in the diet of yearling Florida native ewes may quadratically increase feed intake and decrease nutrient apparent digestibility. Further research is needed to explore the long-term implications of incorporating BSFL into animal diets, considering their impact on overall growth and performance. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of different sources of cobalt in a lactating dairy cow diet on in vitro ruminal fermentation. All diets provided the same amount of supplemental Co (1 mg per kg of diet DM) included in a premix with a targeted inclusion level of 2.5% of diet DM. Treatments were cobalt carbonate (CON), and three alternative Co sources; alternative source 1 (AS1), alternative source 2 (AS2), and alternative source 3 (AS3). Eight dual-flow continuous culture fermenters were used in a replicated 4 × 4 Latin square. Experimental periods were 10 d (7 d adaptation and 3 d sample collection). Composite samples of daily effluents were collected and analyzed for NH3-N, lactate, and VFA concentration as well as for nutrient digestibility. Samples of ruminal content were collected from each fermenter at 0, 1, 2, 4, 6, and 8 h after feeding to determine lactate, NH3-N, and pH kinetics. All data were analyzed using PROC MIXED of SAS and the repeated variable of time was included for pH, lactate, and NH3-N. There were neither treatment effects nor interactions between treatment and time for pH, NH3-N, and lactate concentrations, indicating a similar Co kinetics across treatments. With regards to lactate pool, we did not observe treatment effects for L-lactate; however, we observed treatment effects for D-lactate and total-lactate as seen in Table 1. Analyses of total and individual VFA, N utilization, and nutrient degradation are still undergoing, hence, it is possible that Co sources have effects on ruminal fermentation. [ABSTRACT FROM AUTHOR]