Production of dairy cows fed distillers dried grains with solubles in low- and high-forage diets

Exploring the cause of reduced production responses to feeding corn dried distillers' grains in lactating dairy cows

An experiment was conducted to identify the factors that cause reduced production of cows fed a diet with high corn distiller's grains with solubles (DDGS). We hypothesized that the factors could be high S content in DDGS which may directly (S toxicity) or indirectly [dietary cation-anion difference (DCAD)] cause reduced production. We also hypothesized that high polyunsaturated fatty acids (PUFA) in DDGS could be another major factor. In a randomized complete block design, 60 lactating cows (15 primiparous and 45 multiparious; average ± SD at the beginning of the trial: milk yield, 44.0 ± 6.9 kg/d; DIM, 123 ± 50; BW, 672 ± 82 kg) were blocked and cows in each block were randomly assigned to one of the following treatments: SBM [4.7% fatty acids (FA), 0.22% S, and 178 mEq/kg DM of DCAD], a diet containing soybean meal as the main protein source; DG, SBM replacing mainly soybean byproducts and supplemental fat with DG at 30% dietary DM (4.7% FA, 0.44% S, and 42 mEq/kg DM of DCAD); SBM+S, SBM with sodium bisulfate for additional dietary S (4.8% FA, 0.37% S, and 198 mEq/kg DM of DCAD); SBM+CO, SBM with corn oil (4.7% FA, 0.23%, and 165 mEq/kg DM of DCAD); and DG+DCAD, DG with increased DCAD (4.7% FA, 0.40% S, and 330 mEq/kg DM of DCAD). Due to the limited tie stalls, the blocks of 1 to 6 started the experiment first as phase 1 and the rest of the blocks as phase 2 started the experiment after phase 1. All cows were fed the SBM diet for 10 d as a covariate period followed by the experimental period for 35 d. Data were analyzed using the PROC MIXED of SAS, block and phase were random effects and treatments, repeated wk, and interaction were fixed effects. There was an interaction of wk by treatment for DMI. While milk yield did not change, milk fat concentration tended to decrease (2.78 vs. 3.34%) for DG compared with SBM. Dry matter, OM, NDF, and CP digestibilities were lower when cows were fed the DG diet compared with SBM. Additionally, cows fed DG had lower blood concentrations of HCO3-, base excess, and tCO2 compared with SBM. The SBM+S diet did not affect production, nutrient digestibility, or blood parameters when compared with SBM. The SBM+CO diet decreased milk fat concentration and yield compared with SBM. The DG+DCAD diet tended to increase milk fat yield and concentration (1.24 vs. 1.47 kg/d; 2.78 vs. 3.37%) and increased ECM (40.9 vs. 45.1 kg/d) compared with DG but did not improve nutrient digestibility. However, blood HCO3-, base excess, and tCO2 were greater for DG+DCAD compared with DG. In conclusion, the indirect role of S-, altering DCAD, along with the high PUFA content in DDGS appears to be the factors causing reduced production responses to a high DDGS diet. Increasing DCAD to 300 mEq/kg DM in a high DDGS diet can be a feeding strategy to alleviate the reduced production responses.

Modeling National Embedded Phosphorus Flows of Corn Ethanol Distillers' Grains to Elucidate Nutrient Reduction Opportunities

Freshwater quality and ecosystem impairment associated with excess phosphorus (P) loadings have led to federally mandated P reduction for certain organic waste streams. Phosphorus reduction from livestock and poultry feeds such as corn ethanol distillers' grains (DGs) presents a centralized strategy for reducing P loss from animal manurein agriculturally intensive states, but little is known about the actual distribution and geospatial P contributions of DGs as animal feed. Here, a county-level flow network for corn ethanol DGs was simulated in the United States to elucidate opportunities for P reduction and the potential for nutrient trading between centralized sources. Overall, the estimated P in DGs that was transferred to US animal feeding operations was nearly twice that present in all human waste prior to treatment. Simulation results suggest that Midwestern states account for an estimated 63% of domestic DG usage, with 72% utilized within the state of production. County-level data were also used to highlight the potential of using nutrient trading markets to incentivize P recovery from DGs at biorefineries within an agriculturally intensive watershed region in Iowa. In summary, corn ethanol biorefineries represent a key leverage point for sustainable P management at the national and local scales.

Effects of physical preparation of diets and inclusion rate of modified wet distillers grains with solubles on production and rumen measurements of lactating dairy cows

Our objective was to determine if methods for preparing total mixed ration [TMR; horizontal paddle mixer with knives (PK) vs. vertical auger (VA) mixer] would alter the physical form of the TMR and affect utilization of diets with increasing amounts of modified wet distillers grains with solubles (MWDGS). Holstein cows (n = 24 with 12 ruminally cannulated; 144 d in milk ± 31 d at start) were used in a split-plot design with mixer type as the whole plot and MWDGS concentrations as subplots in a replicated 3 × 3 Latin square arrangement with 35-d periods. Inclusion rates of MWDGS were 10, 20, and 30% of dietary dry matter, primarily replacing corn, soybean meal, soyhulls, and whole cottonseed. Feed dry matter intake (DMI) was less for PK (23.8 kg/d) than for VA (25.7 kg/d), but was unaffected by MWDGS concentration. Milk production did not differ by concentration of MWDGS or by interaction of MWDGS × mixer. Milk fat percentage declined with increasing MWDGS but the interaction between mixer and MWDGS showed that decreases were larger with VA mixing. Cows fed the diet containing 30% MWDGS mixed with PK averaged 3.45% (1.24 kg/d) milk fat, whereas cows fed the same diet mixed with VA averaged 2.81% (1.10 kg/d) fat. Concentrations of trans-10,cis-12 C18:2 in milk fat likely explain the differences observed in milk fat yield; the concentration of trans-10,cis-12 C18:2 increased as MWDGS was increased and the MWDGS × mixer interaction showed that VA had greater concentrations. Greater mean particle size and increased variation in particle size with VA may partially explain differences in milk fat via increased sorting that allowed for an altered rumen environment and favored alternative biohydrogenation pathways. Feed conversion efficiency (FCE; energy-corrected milk/DMI) decreased linearly as MWDGS increased, but FCE tended to be maintained when higher MWDGS diets were mixed using PK rather than VA. Ruminal pH and ammonia concentration decreased linearly as MWDGS increased. The PK mixer resulted in greater FCE when higher amounts of MWDGS were fed, primarily because milk fat content and yield were not as depressed and DMI was lower at similar milk yields.

Effects of Paper Mulberry Silage on the Milk Production, Apparent Digestibility, Antioxidant Capacity, and Fecal Bacteria Composition in Holstein Dairy Cows

Simple Summary

Paper mulberry (Broussonetia papyrifera; PM) is a type of roughage rich in bioactive substances, such as phenolics and flavonoids, which are beneficial for animal health. This study evaluated the apparent digestibility of PM silage in Holstein dairy cows and its effect on the milk production, antioxidant capacity, and fecal bacteria composition of the animals. The results showed that the PM silage had no significant influence on the milk yield, apparent digestibility, and fecal bacteria composition of dairy cows. However, diets with PM silage can enhance the antioxidant and immune capacity of dairy cows, mainly due to the bioactive substance in PM. Today, faced with a shortage of feedstuff resources in ruminants, PM can be a useful feed resource for ruminants. Simultaneously, with the ban on antibiotics, PM may become an important functional feed for protecting animal health.

Abstract

Paper mulberry (Broussonetia papyrifera; PM) is an excellent and extensive type of roughage in Asia. This study aimed to evaluate the effects of PM silage on the milk production, apparent digestibility, antioxidant capacity, and fecal bacteria composition in Holstein dairy cows. Forty-five lactating Holstein dairy cows with a similar milk yield and parity were selected and randomly assigned to three groups. The control group was fed a non-PM silage diet, and the PM-treated groups were fed 4.5 and 9.0% PM silage supplementary diets for 28 days. Then, treatment groups were fed diets containing 13.5 and 18.0% PM silage for the next 28 days, respectively. PM silage increased the milk urea nitrogen and decreased the somatic cell count (p < 0.05), but did not affect the dry matter intake, milk yield, apparent digestibility, and energy balance of dairy cows. PM silage can enhance the blood total antioxidant capacity, superoxide dismutase, and immune globulin content (p < 0.05). The PM silage significantly decreased the relative abundance of the genera Ruminococcaceae UCG-013 and Tyzzerella-4 (p < 0.05). In conclusion, PM silage enhanced the antioxidant capacity and immunity of dairy cows, but did not influence the milk yield, dry matter digestibility, and fecal bacteria composition.

Symposium review: Decomposing efficiency of milk production and maximizing profit

The dairy industry has focused on maximizing milk yield, as it is believed that this maximizes profit mainly through dilution of maintenance costs. Efficiency of milk production has received, until recently, considerably less attention. The most common method to determine biological efficiency of milk production is feed efficiency (FE), which is defined as the amount of milk produced relative to the amount of nutrients consumed. Economic efficiency is best measured as income over feed cost or gross margin obtained from feed investments. Feed efficiency is affected by a myriad of factors, but overall they could be clustered as follows: (1) physiological status of the cow (e.g., age, state of lactation, health, level of production, environmental conditions), (2) digestive function (e.g., feeding behavior, passage rate, rumen fermentation, rumen and hindgut microbiome), (3) metabolic partitioning (e.g., homeorhesis, insulin sensitivity, hormonal profile), (4) genetics (ultimately dictating the 2 previous aspects), and (5) nutrition (e.g., ration formulation, nutrient balance). Over the years, energy requirements for maintenance seem to have progressively increased, but efficiency of overall nutrient use for milk production has also increased due to dilution of nutrient requirements for maintenance. However, empirical evidence from the literature suggests that marginal increases in milk require progressively greater marginal increases in nutrient supply. Thus, the dilution of maintenance requirements associated with increases in production is partially overcome by a progressive diminishing marginal biological response to incremental energy and protein supplies. Because FE follows the law of diminishing returns, and because marginal feed costs increase progressively with milk production, profits associated with improving milk yield might, in some cases, be considerably lower than expected.

Effect of Harvest Time and Microbial Anaerobic Fermentation at Ruminal Degradability, In Vitro Digestibility to Milk Production and Milk Quality for Whole Plant Zhang Hybrid Millet in Dairy Cows

Simple Summary

With its drought tolerant and high productive characteristics, Zhang hybrid millet is becoming an important food source for both humans and animals. Whole plant Zhang hybrid millet has great potential in lowering feed cost while providing relatively high crude protein, vitamin, and mineral content. This study aimed to disclose whether harvest time and microbial anaerobic fermentation can improve ruminal degradability and intestinal digestibility of whole Zhang hybrid millet, and explore the effect of microbial anaerobic fermented whole Zhang hybrid millet as feedstuff on milk yield and milk quality. Results showed that the interaction effect of harvest time and microbial anaerobic fermentation had significant influence on the crude ash, Acid detergent fiber (ADF), water-soluble carbohydrate (WSC), and neutral detergent insoluble protein (NDIP) content and effective degradability of dry matter (EDDM) of whole Zhang hybrid millet. Early harvested whole Zhang hybrid millet with microbial anaerobic fermentation appeared to have a better chemical profile with lower content of crude ash, Neutral detergent fiber (NDF), ADF, and higher content of WSC, and a better ruminal degradability with lower EDDM, effective degradability of neutral crude protein EDCP, and effective degradability of neutral detergent fiber (EDNDF). Microbial anaerobic fermented whole Zhang hybrid millet as feedstuff did not significantly affect milk components, but significantly reduced somatic cell count ( SCC) compared with controls. Milk yield was numerically higher in whole Zhang hybrid millet groups. Collectively, harvest time and microbial anaerobic fermentation could further improve the nutritive value of whole Zhang hybrid millet. Microbial anaerobic fermented whole Zhang hybrid millet as an alternative feedstock for dairy diet was safe and feasible.

Abstract

This study assessed whether harvest time and microbial anaerobic fermentation could affect ruminal degradability and intestinal digestibility of whole Zhang hybrid millet, and estimate the effect of microbial anaerobic fermented whole Zhang hybrid millet as feedstuff on milk yield and milk quality. Protein degradation and intestinal digestion were determined using in situ nylon bag technique and three-step in vitro method, respectively. Results showed that harvest time, microbial anaerobic fermentation, or their interaction significantly affected EDDM, EDCP, and EDNDF (p < 0.05). In vitro fermentation was significantly influenced by harvest time. Early harvested samples appeared to have higher Total volatile fatty acid (TVFA) and lower acetate: propionate ratio than late harvested ones (p < 0.01). However, significant effect of harvest time and fermentation was failed to find in the estimation of rumen-undegradable protein (RUP) (p > 0.05). Microbial anaerobic fermented whole Zhang hybrid millet as feedstuff provided similar milk compositions compared with controls, and it significantly reduced SCC (p = 0.04). Milk yield was numerically higher in whole Zhang hybrid millet groups. In conclusion, harvest time and microbial anaerobic fermentation could further improve ruminal utilization of whole Zhang hybrid millet. Whole Zhang hybrid millet could be an alternative feedstock for dairy cows with acceptable safety profile and potential benefit in milk production.

Ruminal fermentation, kinetics, and total-tract digestibility of lactating dairy cows fed distillers dried grains with solubles in low- and high-forage diets

The objective of this study was to investigate the effects of concentrations of forages and corn distillers dried grains with solubles (DDGS) on ruminal fermentation, ruminal kinetics, and total-tract digestibility of nutrients in lactating dairy cows. Four lactating Holstein cows with ruminal cannulas were assigned to a 4 × 4 Latin square in a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain low forage [LF; 17% forage neutral detergent fiber (NDF)] or high forage (HF; 24.5% forage NDF) and DDGS at 0 or 18% (0DG or 18DG) of diet dry matter (DM). Intake of DM was not affected by the diets. Daily mean ruminal pH was affected by forage NDF × DDGS interactions, as the lowest ruminal pH was observed among cows fed LF18DG (6.02). Apparent total-tract digestibility for DM, organic matter, crude protein, NDF, acid detergent fiber, and starch was not affected by diets. Cows fed LF diets had a greater total volatile fatty acid concentration compared with cows fed HF (122 vs. 116 mM). Molar proportions of acetate were greater for HF compared with that of LF diets (62.6 vs. 57.5 mmol/100 mmol) and greater for 0DG diet compared with that of 18DG diets (61.3 vs. 58.7 mmol/100 mmol) diets. The molar proportion of propionate was affected by forage × DDGS interaction as the greatest propionate molar proportion was observed with cows fed LF18DG diet (27.7 mmol/100 mmol). Also, molar proportion of butyrate was affected by forage × DDGS interaction, as the greatest butyrate molar proportion was observed in cows fed HF18DG diet (13.5 mmol/100 mmol). Average fractional dilution rate for all diets was 11.9%/h and was not affected by diets. Fractional passage rate of the solid phase was greater for HF than for LF (4.40 vs. 3.76%/h). The ruminal retention time of solid phase was greater for LF compared with HF diets (27.3 vs. 23.3 h). Fractional passage rate of DDGS was affected by forage × DG interaction, as the highest fractional passage rate of DDGS was observed with cows fed HF18DG diet (7.72%/h). Our results demonstrated that concentrations of forage, DDGS, and their interaction influence ruminal degradation and kinetics of diets fed. Diets formulated at 17% forage NDF at 17% (DM basis) can decrease milk fat concentration compared with diets formulated at 25% forage NDF. Additionally, feeding DDGS at 18% DM basis to lactating dairy cows did not affect milk fat concentration or yield.