Effect of nonfiber carbohydrate level and Aspergillus oryzae fermentation extract on intake, digestion, and milk production in lactating dairy cows

Abstract

Eight multiparous, ruminally cannulated Holstein cows averaging 40 d in milk and 575 kg BW at the start of trial were in a replicated 4 x 4 Latin square arrangement (28-d periods) to determine the effects of dietary nonfiber carbohydrate (NFC) level and Aspergillus oryzae fermentation extract (AO) on intake, milk production, and nutrient digestibility. Treatments were 42 or 35% NFC and 0 or 3 g of AO per day arranged as a 2 x 2 factorial. Diets formulated to contain 21% NDF from alfalfa silage (48.4% of ration DM) and 18.5% CP were fed as total mixed rations twice daily. Alteration of dietary NFC level was by partial replacement of shelled corn and soybean meal with wheat middlings and brewers dried grains. Intake of NDF was higher (1.49 vs 1.22% of BW) for 35 than for 42% NFC diets, but DMI was lower (24.1 vs 24.9 kg/d). Milkfat percentage, ruminal pH, ammonia, acetate (moles/100 moles), and total tract digestibility of fiber were higher for 35% NFC diets; however, ruminal disappearance of DM, CP, and NDF from Dacron bags containing alfalfa hay was not affected (P > .10) by NFC level. Supplementation with AO did not affect (P > .10) DMI, milk yield, or nutrient digestion. Partial replacement of corn with high-fiber byproducts to lower dietary NFC level and correspondingly increase NDF level increased NDF intake but effected only a small change in DMI. Reducing dietary NFC level improved ruminal fermentation and milkfat percentage without significantly affecting milk yield.

Effects of different forage combinations in total mixed rations on in vitro gas production kinetics, ruminal and milk fatty acid profiles of lactating cows

“…In the present study, NDF:NFC was 0.77, 1.01 and 1.07 for TMR1, 2 and 3 of different forage combinations, and lower acetate and greater propionate in the rumen were found for TMR1 with forage combinations of alfalfa hay, Chinese wild ryegrass hay and whole corn silage than those for TMR2 and TMR3 containing corn stover and rice straw, respectively. The results were consistent with a previous study which showed that lower acetate and greater propionate occurred in the rumen of ruminants fed lower NDF:NFC diet than those with greater NDF:NFC diet (Granja-Salcedo et al, 2016;Sievert & Shaver, 1993). Differences among TMR1-3 in the present study were observed in volatile fatty acid content, suggesting that TFA (total fatty acid in milk) = C8:0 + C10:0 + C12:0 + C14:0 + C14:1 cis-9 + C16:0 + C16:1 cis-9 + C18:0 + C18:1 trans-11 + C18:1 cis-9 + C18:2n-6 + C18:3n-3 + C20:0 + C20:3n-6 + C20:4n-6 + C22:0; UFA (unsaturated fatty acid) = C14:1 cis-9 + C16:1 cis-9 + C18:1 trans-11 + C18:1 cis-9 + C18:2n-6 + C18:3n-3 + C20:3n-6 + C20:4n-6; SFA (saturated fatty acid) = C8:0 + C10:0 + C12:0 + C14:0 + C16:0 + C18:0 + C20:0 + C22:0; SEM, standard error of least square means; DMI, dry matter intake.…”

“…In the present study, NDF:NFC was 0.77, 1.01 and 1.07 for TMR1, 2 and 3 of different forage combinations, and lower acetate and greater propionate in the rumen were found for TMR1 with forage combinations of alfalfa hay, Chinese wild ryegrass hay and whole corn silage than those for TMR2 and TMR3 containing corn stover and rice straw, respectively. The results were consistent with a previous study which showed that lower acetate and greater propionate occurred in the rumen of ruminants fed lower NDF:NFC diet than those with greater NDF:NFC diet (Granja‐Salcedo et al., ; Sievert & Shaver, ). Differences among TMR1–3 in the present study were observed in volatile fatty acid content, suggesting that even and odd chain volatile fatty acid contents in the rumen fluid depended on the different forage combinations under the same ratio of concentrate to forage in TMRs.…”

The Rumen Microbial Ecosystem

“…Fondevila et al (1990) found that AO stimulated the rate but not the extent of fiber digestion in the rumen. As with the increase in microbial protein synthesis, other studies have found no effect of AO on fiber degradation in the rumen (Firkins et aI., 1990;Sievert and Shaver, 1993), and Beharka and Nagaraja (1993) reported that the ability of AO to stimulate fiber degradation in vitro was dependent on the forage used. As with the increase in microbial protein synthesis, other studies have found no effect of AO on fiber degradation in the rumen (Firkins et aI., 1990;Sievert and Shaver, 1993), and Beharka and Nagaraja (1993) reported that the ability of AO to stimulate fiber degradation in vitro was dependent on the forage used.…”

Influence of sugary-Brawn2 or dent corn at two forage levels on intake, digestion, and milk production by dairy cows

“…Cows in Square 1 had previously been ruminally cannulated. The cannulation protocol was as described by Sievert and Shaver (1993). Treatments were arranged as a 2 x 2 factorial with type of corn endosperm (su-Bn2 or dent) and level of forage in ration DM (60% [high] or 45% [low] first-cut alfalfa silage) as main effects.…”

“…Volatile fatty acid concentrations were determined using GLC (Varian 2100, Sunnyvale, CA) with GP 10% SP-1200/1% H3PO4 on 80/100 Chromasorb W AW column packing (Supelco) and corrected for recovery of the internal standard (2-ethyl butyrate). Samples stored for NH3 determination were analyzed by a modification of the method of Chaney and Marbach (1962) as described by Sievert and Shaver (1993).…”