Effects of the inclusion of dried molassed sugar beet pulp in a low-forage diet on the digestive process and blood biochemical parameters of Holstein steers

Rumen fermentation of meal-fed sheep in response to diets formulated to vary in fiber and protein degradability

The concentration of volatile fatty acid (VFA) provides an imprecise view of VFA dynamics due to the confounding effects of fluid pool size and dynamics. Determination of VFA flux using isotope is expensive and a complex methodology. Therefore, a rapid and affordable approach to explore VFA dynamics may allow comprehensive characterization of VFA availability. The objective of this study was to explore the use of VFA dynamics generated by meal feeding to derive time-series rates of VFA apparent appearance and disappearance driven by different protein and fiber sources. Six ruminally cannulated wethers were fed diets containing timothy hay or beet pulp (TH and BP) and soybean meal (SBM) or heated soybean meal (HSBM). Diets were, TH + HSBM; TH + SBM; BP + HSBM; and BP + SBM and the experimental design was a partially replicated 4 × 4 Latin Square. Concentrations of VFA and polyethylene glycol (PEG) in rumen fluid samples were estimated. Concentrations of PEG were used to estimate fluid passage and volume to calculate VFA mass, and fluid-mediated exit. Maximum apparent appearance rate (mmol/h), the rate of apparent appearance decline (mmol/mmol/h), mean apparent appearance flux (mmol/h), mean apparent disappearance (mmol/h), and apparent disappearance rate (mmol/mmol/h) were estimated by deriving a 1 pool model for each VFA on a mass basis where appearance was assumed to follow an exponential decay pattern and disappearance followed mass-action kinetics. Statistical analyses were conducted using a linear mixed effect regression with fixed effects for fiber source, protein source, and their interaction, as well as random effects for animal and period. Rumen fluid volume (L) was greater in HSBM diets (P = 0.033) and fluid passage (%/h) was greater in SBM diets (P = 0.048). Concentrations (higher acetate and butyrate, P = 0.002 and 0.004, respectively) and molar proportions (higher valerate, P = 0.035) of VFA were affected only by fiber source; however, protein source and fiber source interacted to significantly influence apparent appearance rates and absorption rates of many major VFA. On a flux basis, HSBM supported significantly elevated mean disappearance of propionate (P = 0.033). This data demonstrates that time-series evaluation of fermentation dynamics, including fluid dynamics and VFA concentrations can be used to estimate apparent appearance and disappearance of VFA. Although further work is needed to confirm the alignment of these estimates with measurements of VFA supplies to the animal, this modeling approach may provide a simpler way to better understand the kinetics of rumen.

Replacement of corn silage with shredded beet pulp and dietary starch concentration: Effects on performance, milk fat output, and body reserves of mid-lactation dairy cows

We aimed to evaluate the interaction between dietary starch concentration, varied by replacing wheat bran with dry ground corn, and replacement of corn silage (CS) with shredded beet pulp (BP) on production, milk fat output, milk fatty acid profile, and body reserves in dairy cows. Sixty-four Holstein dairy cows (140 ± 26 d in milk) were randomly assigned to 8 pens (8 animals per pen). Treatments were arranged in a 2 × 2 factorial arrangement with 2 concentrations of starch and 2 sources of fiber and were allotted to 8 pens (2 pens per treatment). Treatments were (1) 15% dry ground corn and 24% CS, (2) 15% dry ground corn and 24% BP replacing CS, (3) 30% dry ground corn and 24% CS, and (4) 30% dry ground corn and 24% BP replacing CS. The trial lasted for 47 d and final 7 d of experimental period was used for data and sample collection. Cows fed the BP-based diets had greater dry matter intake than those offered the CS-based diets, whereas no effects were observed with starch concentration. Milk yield increased by 1.8 kg/d with BP-based diets compared with CS-based diets and by 2.5 kg/d when cows received the high-starch compared with low-starch diets. Interactions between dietary starch concentration and forage substitution were detected for milk fat concentration and yield as BP inclusion lowered milk fat output with high-starch diet. Milk trans-18:1 concentration was lower with 15% dry ground corn and 24% CS compared with other diets. In conclusion, the effects of dietary starch concentration (22 and 32% dry matter) and forage substitution on production responses were independent except for milk fat output and milk trans 18:1 isomers. Substituting CS with BP is effective at increasing milk yield regardless of starch concentration; however, milk fat yield is lower when BP is used with high-starch concentration.

Effects of crude protein and neutral detergent fiber percentages in the diet of Japanese Black steers on rumen fluid properties, blood biochemical properties, and carcass characteristics

The effects of crude protein (CP) and neutral detergent fiber (NDF) percentages in the diet of Japanese Black steers on rumen fluid properties, blood biochemical properties, and carcass characteristics were examined. Twelve 13-month-old Japanese Black steers were used for this study and slaughtered at 30 months of age. Steers were assigned to a control group (n = 6) and test group (n = 6) and were fed a concentrate containing 12.9%-13.9% CP and 26.5%-29.8% NDF or 9.1%-9.6% CP and 29.9%-31.2% NDF, respectively. Lipopolysaccharide activity levels in rumen fluid were lower in the test group than in the control group. Plasma urea nitrogen concentration and activities of aspartate aminotransferase and γ-glutamyltransferase remained lower in the test group than in the control group. In contrast, plasma vitamin A concentrations remained higher in the test group than in the control group. Carcass characteristics did not significantly differ between the two groups. These results suggest that dietary CP and NDF percentages in feed for Japanese Black steers older than 13 months of age affected rumen fluid properties and blood biochemical properties, indicating a reduced load on the liver with a small effect on carcass characteristics.

Effects of maize silage substitution with sugarbeet or citrus pulp ensiled with corncobs on growth performance, digestibility, and economic benefits in buffalo calves

Ensiling of high-moisture agro-industrial wastes with dry roughage as animal feeds may be a secure way to reduce the feeding cost. The objective of this study was to investigate the effects of either sugarbeet or citrus pulp ensiled with ground corncobs and used as a replacement of maize silage or maize fodder in total mixed ration (TMR) for fattening of buffalo calves. Twenty male calves of Nili-Ravi buffalo (aged 14 ± 2 months weighing 133 ± 5 kg) were randomly assigned to one of four iso-nutritious (12% CP and 69% TDN) experimental diets with 50:50 forage to concentrate ratio (dry matter basis) as: (1) TMR maize silage, (2) TMR sugarbeet pulp ensiled with corncobs, (3) TMR citrus pulp ensiled with corncobs, and (4) TMR green maize fodder with wheat straw. All calves received TMRs for ad libitum intake twice daily for 80-day period. Daily feed intake, fortnightly body weights, and digestibility and N balance study during last 15 days were recorded of individual animals. The calves fed TMR sugarbeet pulp silage got highest daily gain (856 g/d, P < 0.05) than citrus pulp silage (776 g/d) or green maize fodder (704 g/d). Average intake of nutrients was same among all the calves. Feed conversion ratio and digestibility of DM, NDF, and ADF were higher (P < 0.05) with TMR sugarbeet pulp silage compared to other TMRs. Economic benefit (output/input) with TMR sugarbeet pulp silage had 15.46, 34.27, and 37.36% higher effect for fattening of buffalo calves compared to citrus pulp silage, green maize fodder, and maize silage-based TMRs, respectively. In conclusion, sugarbeet pulp ensiled with ground corncobs is simple and appropriate method for silage making and its inclusion up to 50% of DM in TMR had pronounced economic impact to the production of buffalo calves.

Partial Substitution of Corn Grain in the Diet with Beet Pulp Reveals Increased Ruminal Acetate Proportion and Circulating Insulin Levels in Korean Cattle Steers

We investigated the effects of the partial substitution of corn grain in the diet with beet pulp on growth performance, ruminal fermentation characteristics, microbial profiles, and blood lipogenic parameters in fattening steers. Twelve Korean cattle steers (body weight, 485 ± 19.32 kg; age, 18.0 ± 0.17 months) were equally divided into corn grain (CG) and beet pulp (BP) groups. Approximately 75% of dry matter of the requirement was offered as a concentrate portion, and the remaining 25% was offered as oat straw. Eighty percent of the concentrate portion was provided by a pelleted basal concentrate, and the remaining 20% with corn grain for the CG group, or 18% beet pulp plus 2.0% rumen-protected fat for the BP group, respectively, by top dressing. The experiment was conducted for 14 weeks, including a 2-week acclimation period. Growth rate was not affected by beet pulp feeding (p = 0.55). The molar proportions of ruminal acetate (p < 0.05) on wk 4, the relative abundances of ruminal cellulolytic bacteria, including Fibrobacter succinogenes (p = 0.01) and Ruminococcus albus (p = 0.04) on wk 12, and serum insulin concentrations (p < 0.05) on wk 12 were higher in the BP group than in the CG group, whereas the molar proportions of propionate (p < 0.05) on wks 8 and 12 and serum nonesterified fatty acids (p < 0.05) on wk 12 were lower in the BP group. Beet pulp could be used as a lipogenic energy source without affecting growth performance during the fattening period of cattle.

Rumen fermentation and epithelial gene expression responses to diet ingredients designed to differ in ruminally degradable protein and fiber supplies

Although numerous studies exist relating ruminal volatile fatty acid (VFA) concentrations to diet composition and animal performance, minimal information is available describing how VFA dynamics respond to diets within the context of the whole rumen environment. The objective of this study was to characterize how protein and fiber sources affect dry matter intake, rumen pH, fluid dynamics, fermentation parameters, and epithelial gene expression. Four diet treatments (soybean meal or heat-treated soybean meal and beet pulp or timothy hay) were delivered to 10 wethers. The soybean meals served as crude protein (CP) sources while the beet pulp and timothy hay represented neutral detergent fiber (NDF) sources. Feed intake, rumen pH, fluid pool size, and fluid passage rate were unaffected by treatment. Butyrate synthesis and absorption were greater on the beet pulp treatment whereas synthesis and absorption of other VFA remained unchanged. Both CP and NDF treatment effects were associated with numerous VFA interconversions. Expression levels of rumen epithelial genes were not altered by diet treatment. These results indicate that rumen VFA dynamics are altered by changes in dietary sources of nutrients but that intake, rumen environmental parameters, and the rumen epithelium may be less responsive to such changes.

Influence of reducing starch in the diets with similar protein and energy contents on lactation performance, ruminal fermentation, digestibility, behaviour and blood metabolites in primiparous and multiparous dairy cows

Background

It is not clearly known whether parity can affect the outcomes of starch reduction in the diet of lactating dairy cows.

Introduction

A 2 × 2 factorial study was conducted to evaluate the effects of reducing starch in the diets with similar protein and energy contents on lactation performance, ruminal fermentation, nutrient digestibility, behaviour and blood metabolites in primiparous (PP) and multiparous (MP) dairy cows.

Methods

Twenty PP cows (DIM = 37 ± 10; 40 ± 5 kg/day of milk; mean ± SD) and 20 MP cows (DIM = 37 ± 9; 48 ± 5 kg/day of milk) were used in present study. Treatments were a factorial arrangement of two levels of starch (high vs. low) and two parity categories (PP vs. MP): (1) high‐starch diet (29.2% ± 0.70) and PP cows (HS‐PP); (2) low‐starch diet (22.3% ± 0.52) and PP cows (LS‐PP); (3) high‐starch diet and MP cows (HS‐MP) and (4) low‐starch diet and MP cows (LS‐MP). All diets were formulated to be similar in crude protein (16.1 % of dry matter) and NEL (1.60 Mcal/kg of dry matter) contents. The amount of metabolise protein was 2688 g/day in high‐starch diet and 2728 g/day in low‐starch diet. The experiment was conducted over two consecutive periods and included 4 weeks for adaptation and 3 weeks for data collection.

Results

Dry matter intake and the yield of milk true protein and lactose increased but milk fat: protein ratio and nutrient digestibility decreased for cows fed the HS diets compared with the LS diets. The ruminal proportion of propionate was greater but acetate, the acetate to propionate ratio and sorting against long particles (19 and 8 mm) were lower for cows fed the HS diets than the LS diets. Multiparous cows had a greater nutrient intake and milk yield, longer rumination meal length, greater BW, but lower plasma total antioxidant capacity, non‐esterified fatty acids, faeces pH compared with PP cows. An interaction between parity and the dietary level of starch was detected on feed efficiency measured as FCM yield/DMI in the way that only within PP cows low‐starch diet was more efficient than HS diets. We found another interaction effect of parity × starch on back fat thickens (BFT) change in the way that only within PP cows BFT change was greater for HS compared with LS diet.

Conclusion

Overall, regardless of the benefit derived from feeding a reduced‐starch diet by partially replacing grains with sugar beet pulp in the diets on nutrient digestibility, a reduced‐starch diet may be used more efficiently in PP than in MP cows but at expense of body reserves (i.e. BFT) loses.

Effects of substitution of beet pulp for barley or corn in the diet of high-producing dairy cows on feeding behavior, performance, and ruminal fermentation

This study investigated the effects of substituting beet pulp (BP) for different grains (barley or corn) in the diet of high-producing dairy cows on intake, feeding behavior, nutrient digestibility, ruminal fermentation, milk production, and feed conversion efficiency. Eight second-parity Holstein cows (62 ± 2 d in milk; milk yield = 54 ± 1.2 kg/d; body weight = 624 ± 26; all mean ± SE) were used in a replicated 4 × 4 Latin square design during 4 periods of 21 d. Cows were randomly assigned to 1 of 4 treatments that were a 2 × 2 factorial arrangement of 2 grain sources (corn or barley) and 2 levels of BP inclusion [5 or 15% of dry matter (DM)] in the diet: (1) barley-based diet with BP at 5% of dietary DM; (2) barley-based diet with BP at 15% of dietary DM; (3) corn-based diet with BP at 5% of dietary DM; and (4) corn-based diet with BP at 15% of dietary DM. The increasing amount of BP in the diet was at the expense of decreasing an equal proportion of grain (barley or corn). All diets were high in concentrates (65% of diet DM) and formulated to have similar concentrations of energy and protein. The portion of feedstuffs that is potentially able to be consumed by humans is known as human edible. Accordingly, human-edible protein (HEP) and human-edible energy (HEE) inputs were calculated according to the recommended potential human-edible fraction of each dietary ingredient, and HEP and HEE outputs were determined as the amount of gross energy and true protein in the milk. Feed conversion efficiency (FCE) for HEP and HEE were expressed as output per input of each variable, whereas FCE for the production of fat-corrected milk (FCM) and energy-corrected milk (ECM) were expressed as the amount of each variable per DM intake. Results showed that substituting BP for grain did not affect DM intake, crude protein intake, or nutrient digestibility, whereas starch intake (5.70 vs. 7.43 kg/d for the low-BP vs. high-BP diets, respectively), HEP (2.34 and 1.92 kg/d), and HEE (186 and 147 MJ of gross energy/d) decreased. Treatments did not affect sorting and chewing activities, but increasing BP in the diet increased ruminal pH at 4 h after feeding (6.20 vs. 6.39) and milk fat content (2.92 vs. 3.15%). Similarly, FCE for ECM production (1.44 vs. 1.54) as well as FCE for HEE (0.653 vs. 0.851) and HEP (0.629 vs. 0.702) were greater in high-BP diets compared with low-BP diets. The interaction of BP and grain sources significantly affected FCE for ECM production, where improvements were more evident when BP was substituted for barley than for corn. The improvement in FCE for HEE was greater when BP was substituted for barley (0.236) rather than corn (0.161). In conclusion, the substitution of BP for barley or corn grains in high-concentrate diets of high-producing cows decreased starch intake, increased ruminal pH at 4 h after feeding, and improved FCE for FCM production. Substitution for barley, rather than for corn, promoted greater FCE for ECM production and HEE.

Production performance, egg quality, blood biochemical constituents, egg yolk lipid profile and lipid peroxidation of laying hens fed sugar beet pulp

The effect of including sugar beet pulp (SBP) in laying hen diets on performance, egg quality, blood chemistry and egg lipid peroxidation was studied. A total of 200 laying hens were randomly assigned into 4 groups and were offered diets containing SBP at the level of 0%, 3%, 5%, and 7%. The dietary inclusion of SBP linearly (P < 0.01) increased feed intake, egg production, egg weight and mass, and improved feed conversion ratio, yolk color core and Haugh unit. Eggs laid by hens receiving SBP had linearly (P < 0.01) greater protein and lower ether extract. Dietary inclusion of SBP linearly (P < 0.01) decreased egg yolk malondialdehyde, cholesterol, and triglyceride, while increased glutathione peroxidase. Laying hens fed SBP had lower (P < 0.01) serum total lipids, cholesterol, alanine aminotransferase, aspartate aminotransferase, and creatinine. Dietary inclusion of SBP could improve hen performance, health, egg quality, and egg shelf life.

Review: Enhancing gastrointestinal health in dairy cows

Due to their high energy requirements, high-yielding dairy cows receive high-grain diets. This commonly jeopardises their gastrointestinal health by causing subacute ruminal acidosis (SARA) and hindgut acidosis. These disorders can disrupt nutrient utilisations, impair the functionalities of gastrointestinal microbiota, and reduce the absorptive and barrier capacities of gastrointestinal epithelia. They can also trigger inflammatory responses. The symptoms of SARA are not only due to a depressed rumen pH. Hence, the diagnosis of this disorder based solely on reticulo-rumen pH values is inaccurate. An accurate diagnosis requires a combination of clinical examinations of cows, including blood, milk, urine and faeces parameters, as well as analyses of herd management and feed quality, including the dietary contents of NDF, starch and physical effective NDF. Grain-induced SARA increases acidity and shifts availabilities of substrates for microorganisms in the reticulo-rumen and hindgut and can result in a dysbiotic microbiota that are characterised by low richness, diversity and functionality. Also, amylolytic microorganisms become more dominant at the expense of proteolytic and fibrolytic ones. Opportunistic microorganisms can take advantage of newly available niches, which, combined with reduced functionalities of epithelia, can contribute to an overall reduction in nutrient utilisation and increasing endotoxins and pathogens in digesta and faeces. The reduced barrier function of epithelia increases translocation of these endotoxins and other immunogenic compounds out of the digestive tract, which may be the cause of inflammations. This needs to be confirmed by determining the toxicity of these compounds. Cows differ in their susceptibility to poor gastrointestinal health, due to variations in genetics, feeding history, diet adaptation, gastrointestinal microbiota, metabolic adaptation, stress and infections. These differences may also offer opportunities for the management of gastrointestinal health. Strategies to prevent SARA include balancing the diet for physical effective fibre, non-fibre carbohydrates and starch, managing the different fractions of non-fibre carbohydrates, and consideration of the type and processing of grain and forage digestibility. Gastrointestinal health disorders due to high grain feeding may be attenuated by a variety of feed supplements and additives, including buffers, antibiotics, probiotics/direct fed microbials and yeast products. However, the efficacy of strategies to prevent these disorders must be improved. This requires a better understanding of the mechanisms through which these strategies affect the functionality of gastrointestinal microbiota and epithelia, and the immunity, inflammation and 'gastrointestinal-health robustness' of cows. More representative models to induce SARA are also needed.

Graded replacement of maize grain with molassed sugar beet pulp modulated ruminal microbial community and fermentation profile in vitro

BACKGROUND

Molassed sugar beet pulp (Bp) is a viable alternative to grains in cattle nutrition for reducing human edible energy input. Yet little is known about the effects of high inclusion rates of Bp on rumen microbiota. This study used an in vitro approach and the quantitative polymerase chain reaction technique to establish the effects of a graded replacement of maize grain (MG) by Bp on the ruminal microbial community, fermentation profile and nutrient degradation.

RESULTS

Six different amounts of Bp (0-400 g kg^-1 ), which replaced MG in the diet, were tested using the in vitro semi-continuous rumen simulation technique. The increased inclusion of Bp resulted in greater dietary content and degradation of neutral detergent fibre (P < 0.01). Further, Bp feeding enhanced (P < 0.01) the abundance of genus Prevotella and shifted (P < 0.01) the short-chain fatty acid patterns in favour of acetate and propionate and at the expense of butyrate. A total replacement of MG with Bp resulted in an increased daily methane production (P < 0.01).

CONCLUSION

Results suggest positive effects of the replacement of MG by Bp especially in terms of stimulating ruminal acetate and propionate fermentation. However, high replacement rates of Bp resulted in lowered utilization of ammonia and higher ruminal methane production. © 2017 Society of Chemical Industry.

Effects of partially replacing barley with sugar beet pulp, with and without roasted canola seeds, on performance, rumen histology and fermentation patterns in finishing Arabian lambs

This study investigated the effects of partially replacing barley grains with sugar beet pulp (SBP), with and without roasted canola seed (RCS) on ruminal pH, ruminal volatile fatty acid (VFA) concentrations, ruminal histomorphometric characteristics, and performance in finishing lambs fed a high concentrate diet. Twenty-four Arabian male lambs (23.7 ± 2.5 kg bodyweight, 118 ± 10 days in age) were used for 99 days in a completely randomised design with a 2 × 2 factorial arrangement. Lambs were fed with a high concentrate diet containing (1) 68% barley (B) (2) barley plus 7% RCS (B + RCS) (3) 36% SBP, (4) SBP plus 7% RCS (SBP + RCS). Ruminal fluid pH and VFA concentrations were determined at 0, 2, 4 and 8 h post-feeding 1 day before slaughter day. Tissue samples were collected for histomorphometric study at slaughter day. Average daily gain of the lambs was not affected by partial replacement of barley with SBP, however it was improved by RCS inclusion (P < 0.05). Diets with RCS had significantly lower (P < 0.05) neutral detergent fibre and acid detergent fibre digestibility values than diets without RCS (P < 0.05). Both SBP and RCS increased ruminal pH, molar proportions of acetate, isobutyrate but decreased molar proportion of propionate in rumen content (P < 0.05). The height, width, epithelial thickness and tunica muscularis of rumen papilla and reticulum folds were increased by SBP (P < 0.05). Density of reticulum folds were higher in lambs fed by higher SBP (P < 0.05). Inclusion of RCS significantly increased papillae height and thickness of epithelium (P < 0.05). In conclusion, partially replacing barley with SBP as well as RCS inclusion prevented a drop in the ruminal pH, and improved the morphology of the rumen-reticulum in finishing lambs fed a high concentrate diet.

Effect of sugar beet tubers as a partial replacer to green fodder on production performance and economics of lactating Surti buffaloes in lean period

Aim:

The objective of this study was to evaluate the effects of sugar beet tubers as a replacer to green fodder on production performance and economics of lactating Surti buffaloes.

Materials and Methods:

This trial was conducted at the Livestock Research Station, Navsari Agricultural University, Navsari. Twenty lactating Surti buffaloes in a changeover experimental design were selected to assess the effects of replacing green fodder with sugar beet (Beta vulgaris L.) tubers on production performance, economics of feeding sugar beet and blood biochemical profile. Half (50%) of the hybrid Napier was replaced with sliced sugar beet tubers in the ration of experimental animals.

Results:

Partial replacement of hybrid Napier with that of sugar beet tubers numerically improved dry matter intake, milk yield, 4% fat corrected milk and milk composition parameters such as fat, solid non-fat, protein and lactose, but not significantly. The blood parameters were in normal range and non-significant except that of glucose and triglycerides, which were increased in the sugar beet group. Replacing sugar beet tubers also proved to be cost-effective with improved net profit around Rs. 6.63/day.

Conclusion:

It can be concluded that 50% hybrid Napier fodder can be replaced with sugar beet tubers without any adverse effect on animal production performance, milk composition blood biochemical profile and economics of feeding.

Common Prairie feeds with different soluble and insoluble fractions used for CPM diet formulation in dairy cattle: impact of carbohydrate-protein matrix structure on protein and other primary nutrient digestion

An experiment was conducted to investigate the relationship of carbohydrates molecular spectral characteristics to rumen degradability of primary nutrients in Prairie feeds in dairy cattle. In total, 12 different types of feeds were selected, each type of feed was from three different source with total 37 samples. Six types of them were energy-sourced feeds and the others were protein-sourced feeds. The carbohydrates molecular spectral intensity of various functional groups were collected using Fourier transform infrared attenuated total reflectance (ATR-FT/IR) spectroscopy. In the in situ study, the results showed that the rumen digestibility and digestible fractions of primary nutrients (DM, OM, NCP, and CP) were significantly different (P<0.05) among the feeds. The spectral bands features were significantly different (P<0.05) among the feeds. Spectral intensities of A_Cell, H_1415 and H_1370 were weakly positively correlated with in situ rumen digestibility and digestible fractions of DM, OM and NCP. Spectral intensities of H_1150, H_1015, A_1, and A_3 were weakly negatively associated with in situ rumen degradation of CP. Spectral intensities of A_1240 and H_1240, mainly associated with cellulosic compounds, were correlated with rumen CP degradation. The multiple regression analysis demonstrated that the spectral intensities of A_3 and H_1415 played the most important role and could be used as a potential tool to predict rumen protein degradation of feeds in dairy cattle. In conclusion, this study showed that the carbohydrates as a whole have an effect on protein rumen degradation, rather than cellulose alone, indicating carbohydrate-protein matrix structure impact protein utilization in dairy cattle. The non-invasive molecular spectral technique (ATR-FT/IR) could be used as a rapid potential tool to predict rumen protein degradation of feedstuffs by using molecular spectral bands intensities in carbohydrate fingerprint region.

Changes in feed intake, nutrient digestion, plasma metabolites, and oxidative stress parameters in dairy cows with subacute ruminal acidosis and its regulation with pelleted beet pulp

The objectives of this study were to 1) determine the variation of nutrient digestion, plasma metabolites and oxidative stress parameters triggered by induced subacute ruminal acidosis (SARA); and 2) evaluate the ability of pelleted beet pulp (BP) as a replacement for ground corn to alleviate SARA. Eight Holstein-Friesian cows were fed four diets during four successive17-day periods: 1) total mixed ration (TMR) containing 0% finely ground wheat (FGW) (W0); 2) TMR containing 10% FGW (W10); 3) TMR containing 20% FGW (W20); and 4) TMR containing 10% BP as a replacement for 10% ground corn (BP10). The SARA induction protocol reduced the mean ruminal pH from 6.37 to 5.94, and the minimum ruminal pH decreased from 5.99 to 5.41 from baseline to challenge period. Mean ruminal pH increased from 5.94 to 6.05, and minimum daily ruminal pH increased from 5.41 to 5.63, when BP was substituted for corn. The apparent digestibility of nutrients was not affected by the dietary treatments, except that the digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) was reduced in cows fed the W20 diet compared with cows fed the W0 and W10 diets, and cows fed the BP10 diet had higher NDF and ADF digestibility than the cows fed the W20 diet. Cows fed the W20 diet had a lower plasma concentration of β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), cholesterol, triglyceride, and total antioxidative capacity (TAC), and a higher plasma concentration of glucose, insulin, malonaldehyde (MDA), super oxygen dehydrogenises (SOD), and glutathione peroxidase (GSH-Px) than cows fed the W0 diet. Substitution of BP for corn increased concentrations of plasma BHBA and TAC, but decreased concentrations of plasma MDA. Our results indicate that reduction of fibre digestion; the concomitant increase of plasma glucose and insulin; the decrease of plasma BHBA, NEFA, cholesterol, and triglyceride; and changes of plasma oxidative stress parameters are highly related to SARA induced by W20 diets. These variables may be alternative candidates for SARA diagnosis. We also suggest that the substitution of BP for corn could reduce the risk of SARA, increase fibre digestion, and improve the antioxidant status in dairy cows.

Effects of replacing dietary starch with neutral detergent-soluble fibre on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC)

A rumen simulation technique (RUSITEC) apparatus with eight 800 ml fermenters was used to investigate the effects of replacing dietary starch with neutral detergent-soluble fibre (NDSF) by inclusion of sugar beet pulp in diets on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria. Experimental diets contained 12.7, 16.4, 20.1 or 23.8% NDSF substituted for starch on a dry matter basis. The experiment was conducted over two independent 15-day incubation periods with the last 8 days used for data collection. There was a tendency that 16.4% NDSF in the diet increased the apparent disappearance of organic matter (OM) and neutral detergent fibre (NDF). Increasing dietary NDSF level increased carboxymethylcellulase and xylanase activity in the solid fraction and apparent disappearance of acid detergent fibre (ADF) but reduced the 16S rDNA copy numbers of Ruminococcus albus in both liquid and solid fractions and R. flavefaciens in the solid fraction. The apparent disappearance of dietary nitrogen (N) was reduced by 29.6% with increased dietary NDSF. Substituting NDSF for starch appeared to increase the ratios of acetate/propionate and methane/volatile fatty acids (VFA) (mol/mol). Replacing dietary starch with NDSF reduced the daily production of ammonia-N and increased the growth of the solid-associated microbial pellets (SAM). Total microbial N flow and efficiency of microbial synthesis (EMS), expressed as g microbial N/kg OM fermented, tended to increase with increased dietary NDSF, but the numerical increase did not continue as dietary NDSF exceeded 20.1% of diet DM. Results suggested that substituting NDSF for starch up to 16.4% of diet DM increased digestion of nutrients (except for N) and microbial synthesis, and further increases (from 16.4% to 23.8%) in dietary NDSF did not repress microbial synthesis but did significantly reduce digestion of dietary N.