Effect of flaxseed physical form on digestibility of lactation diets fed to Holstein steers.

Four multicannulated (rumen, duodenum, and ileum) Holstein steers (459.7±46.4kg of initial body weight) were used in a 4×4 Latin square design to determine the effect of flaxseed processing method on ruminal fermentation and digestibility. Treatments were based on inclusion of (1) 7.5% linseed meal (control), (2) 10% whole flaxseed, (3) 10% rolled flaxseed, or (4) 10% ground flaxseed on a dry matter (DM) basis, and were formulated to mimic typical high-producing dairy cow lactation diets. The control diet contained linseed meal in a proportion to provide crude protein (CP) equal to the amount of CP contributed by the flaxseed in the other treatments. Diets were fed for ad libitum intake and contained 30% corn silage, 17% chopped alfalfa hay, 6% sugar beet pulp, and 47% concentrate (comprising ground corn, supplemental protein, trace minerals and vitamins, and either flaxseed or linseed meal (DM basis). Diets were formulated to contain 17% CP, 34% neutral detergent fiber, 21% acid detergent fiber, and 4% fatty acid (DM basis). Periods were 14 d long and consisted of 7 d of adaptation and 7 d of sample collection. Dry matter intake (as a % of body weight) was similar (2.41±0.17) for all treatments. The inclusion of flaxseed, regardless of processing method, tended to decrease total-tract organic matter digestibility relative to the linseed control, but no differences in CP intake, duodenal CP flow (bacterial, apparent feed, or total), ileal CP flow, fecal CP output, microbial efficiency, or CP digestibility (apparent ruminal, true ruminal, small intestine, large intestine, or total tract) were observed between treatments. Method of processing did not alter ruminal pH, ammonia, or volatile fatty acids production. The ground flaxseed treatment had the fastest rate of in situ DM degradation (11.25%/h), followed by the control (7.46%/h), rolled flaxseed (4.53%/h), and whole flaxseed (0.57%/h) treatments. Degradability of CP and fat followed the same pattern as DM degradability for processed flaxseed. In situ degradation rates of alfalfa hay neutral detergent fiber and acid detergent fiber tended to be fastest for the ground flaxseed treatment. Taken together, the digestibility, fermentation, and in situ data indicate that rolling and grinding are both acceptable methods of processing flaxseed. The in situ data strongly support the need for processing flaxseed before inclusion in lactation diets.

Density functional theory based screening of ternary alkali-transition metal borohydrides: a computational material design project.

We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. We investigate the stability and decomposition of alloys containing 1 alkali metal atom, Li, Na, or K (M(1)); and 1 alkali, alkaline earth or 3d/4d transition metal atom (M(2)) plus two to five (BH(4))(-) groups, i.e., M(1)M(2)(BH(4))(2-5), using a number of model structures with trigonal, tetrahedral, octahedral, and free coordination of the metal borohydride complexes. Of the over 700 investigated structures, about 20 were predicted to form potentially stable alloys with promising decomposition energies. The M(1)(Al/Mn/Fe)(BH(4))(4), (Li/Na)Zn(BH(4))(3), and (Na/K)(Ni/Co)(BH(4))(3) alloys are found to be the most promising, followed by selected M(1)(Nb/Rh)(BH(4))(4) alloys.

Effect of feeding rolled flaxseed on milk fatty acid profiles and reproductive performance of dairy cows.

The objectives were to study the effects of feeding rolled flaxseed (FLX) to early-lactation dairy cows on milk yield, milk components, and milk fatty acid profiles as well as on measures of cow reproduction. Lactating Holstein cows, on 3 commercial dairies, were fed either an early-lactation ration (CON) or a ration that was similar in protein, energy, and fat content but that included FLX (0.85 kg of DM/cow per day). Within each dairy, cows were allocated alternately to breeding pens upon leaving the fresh pen (approximately 10 ± 5 d postpartum). Pens (n = 4 to 5 pens/dairy) were randomized to treatment (n = 2 to 3 pens/treatment per dairy). Pen (CON, n = 6; FLX, n = 7) was considered the experimental unit and data were analyzed as a split plot with pen as the whole-plot error term. Cows fed FLX had greater (P ≤ 0.06) proportions of cis-9, trans-11 C18:2, C18:3n-3, and C20:0 fatty acids in milk fat and a lesser (P = 0.03) proportion of C20:3n-6 fatty acid when compared with cows fed the CON diet. Treatment did not affect (P ≥ 0.24) milk yield, milk protein, protein yield, milk fat, or milk fat yield. No interactions (P ≥ 0.52) were found between treatment and season of the year or parity, or between treatment and days open, pregnancies per AI at first or second service, or pregnancy loss. In conclusion, feeding FLX at 0.85 kg/cow per day (DM basis) altered the fatty acid profile of milk, but milk yield, milk composition, and reproductive performance of dairy cows were not affected.