Influence of flake density on the comparative feeding value of a barley-corn blend for feedlot cattle

Predicting ruminal degradability and chemical composition of corn silage using near-infrared spectroscopy and multivariate regression

The aim of this study was to develop and validate regression models to predict the chemical composition and ruminal degradation parameters of corn silage by near-infrared spectroscopy (NIR). Ninety-four samples were used to develop and validate the models to predict corn silage composition. A subset of 23 samples was used to develop and validate models to predict ruminal degradation parameters of corn silage. Wet chemistry methods were used to determine the composition values and ruminal degradation parameters of the corn silage samples. The dried and ground samples had their NIR spectra scanned using a poliSPECNIR 900-1700 model NIR sprectrophotometer (ITPhotonics S.r.l, Breganze, IT.). The models were developed using regression by partial least squares (PLS), and the ordered predictor selection (OPS) method was used. In general, the regression models obtained to predict the corn silage composition (P>0.05), except the model for organic matter (OM), adequately estimated the studied properties. It was not possible to develop prediction models for the potentially degradable fraction in the rumen of OM and crude protein and the degradation rate of OM. The regression models that could be obtained to predict the ruminal degradation parameters showed correlation coefficient of calibration between 0.530 and 0.985. The regression models developed to predict CS composition accurately estimated the CS composition, except the model for OM. The NIR has potential to be used by nutritionists as a rapid prediction tool for ruminal degradation parameters in the field.

Effect of Cereals and Legumes Processing on In Situ Rumen Protein Degradability: A Review

The determination of the ruminal degradability rate of feeds, mainly starch and crude protein, is one of the most common methods to evaluate the nutritional value of ruminant feed. The protein requirements for ruminants are met from microbial protein and undegraded dietary protein digested in the small intestine. In order to reach maximum productivity, high-quality proteins are needed, and the requirement for undegraded dietary protein increases with the performance of the animal. This protein can be supplied by reducing the ruminal degradation to increase the amount of protein digested post-rumen, but the form in which a feed is administered influences degradability, and grain processing, especially, is a common practice to improve feed efficiency. Despite these aspects, studies on the effects of feed processing methods on protein degradability are limited, even though more and more ruminants are fed with processed feeds. For these reasons, this review investigated the protein degradability of different processed cereals and legumes in ruminants based on the analysis of available literature in order to take stock of the state of the art on this topic. Results showed that: First, the majority of the papers are focused on the energy aspects mainly due to carbohydrate-rich feeds; second, the majority of the studies in the literature are quite old, probably because the changes occurred in the animal testing legislation that made in vivo studies more and more difficult in the last 20 years; third, as a consequence, the few data available in recent years concern in vitro experiments; fourth, we found a high variability of the experimental conditions thus affecting protein degradability and making it quite difficult to compare the different results.

Response of lactating dairy cows to degree of steam-flaked barley grain in low-forage diets

This study was conducted to investigate the effects of processing method (grinding vs. steam flaking) and increasing densities of steam-flaked barley grain on dry matter intake (DMI), rumen pH and fermentation characteristics, digestibility of dry matter in the total digestive tract (DDTT), and milk production of dairy cows. Eight multiparous mid-lactation Holstein cows averaging 103 ± 24 DIM, 44.5 ± 4.7 kg milk/day and weighing 611 ± 43 kg at the start of the experiment were used in a replicated 4 × 4 Latin square design with 21-day periods. Cows were fed diets consisting of (DM basis) 23.8% corn silage, 13.5% chopped alfalfa hay and 62.7% concentrate. The dietary treatments were either ground barley (GB) using a hammer mill or steam-flaked barley (SFB) - varying density at 390, 340 or 290 g/l. Processing method (GB vs. SFB) did not affect DMI (23.6 kg/day on average), DDTT (71.0% on average), milk yield (43.4 kg/day on average), milk components, rumen pH and molar proportions of acetate, propionate, butyrate and sorting activity. Ruminal isovalerate concentration tended (p = 0.06) to be higher for cows fed GB than those fed SFB-based diets. Decreasing the density of SFB from 390, 340 to 290 g/l tended to linearly increase DMI (p = 0.09), decrease total solids percentage of milk (p = 0.10) and linearly decreased milk urea nitrogen (12.8, 12.4 and 12.1 mg/dl; p = 0.04); also, the sorting index (SI) of the particles retained on the 19.0-mm sieve without affecting the SI of the particles retained on 8.0-mm, 1.18-mm or passed through 1.18-mm sieve (p = 0.05). These results indicated the limited effects of processing method (grinding vs. steam flaking) and densities of SFB (390, 290 or 290 g/l) on cows' performance and feed utilization for dairy cows fed low-forage diets. Therefore, both processing methods could be recommended under current feeding conditions of dairy cows.

Effects of different physical forms of concentrate on performance, carcass characteristics, and economic analysis in hanwoo steers

This study was performed to investigate the effects of different forms of concentrate fed to Hanwoo steers on performance, carcass characteristics, and economic performance. Forty-two Hanwoo steers (average age of 5.1 ± 0.8 mo. with body weight of 147.05 ± 10.85 kg) were randomly allotted into FC (animals fed flakes for entire experimental period) and GC (animals fed grounded concentrate during growing and fattening phases followed by flaked concentrate during finishing phase) groups for 758 d after reaching an age of 30.0 ± 0.82 mo. There was no difference in body weight (BW) or ADG between the treatments until fattening (15 ~ 22 mo.) phase. However, by finishing phase (23 ~ 30 mo.), the GC group (739.24 kg BW and 0.67 kg ADG) showed greater (P < 0.05) BW and ADG than the FC group (702.93 kg BW and 0.59 kg ADG). Steers in the GC group also showed greater (P < 0.05) BW and ADG than the FC group throughout the entire experimental period (5 ~ 30 mo.). There was no significant difference in carcass weight or backfat thickness between the treatments. M. Longissimus dorsi area of the GC group (91.00 cm²cm²) was greater (P < 0.05) than that of the FC group (83.59 cm²). Marbling score and percentage of 1⁺⁺ meat quality grade were 14.0 and 48.0% higher in the GC group compared to the FC group. There was no significant difference in physicochemical characteristics, including moisture and crude protein levels, between the treatments. Gross income per head excluding operating expenses was 59.3% greater in the GC group (1,647,512 won) compared to the FC group (1,034,343 won).

Barley grain for ruminants: A global treasure or tragedy

Barley grain (Hordeum vulgare L.) is characterized by a thick fibrous coat, a high level of ß-glucans and simply-arranged starch granules. World production of barley is about 30 % of that of corn. In comparison with corn, barley has more protein, methionine, lysine, cysteine and tryptophan. For ruminants, barley is the third most readily degradable cereal behind oats and wheat. Due to its more rapid starch fermentation rate compared with corn, barley also provides a more synchronous release of energy and nitrogen, thereby improving microbial nutrient assimilation. As a result, feeding barley can reduce the need for feeding protected protein sources. However, this benefit is only realized if rumen acidity is maintained within an optimal range (e.g., > 5.8 to 6.0); below this range, microbial maintenance requirements and wastage increase. With a low pH, microbial endotoxines cause pro-inflammatory responses that can weaken immunity and shorten animal longevity. Thus, mismanagement in barley processing and feeding may make a tragedy from this treasure or pearl of cereal grains. Steam-rolling of barley may improve feed efficiency and post-rumen starch digestion. However, it is doubtful if such processing can improve milk production and feed intake. Due to the need to process barley less extensively than other cereals (as long as the pericarp is broken), consistent and global standards for feeding and processing barley could be feasibly established. In high-starch diets, barley feeding reduces the need for capacious small intestinal starch assimilation, subsequently reducing hindgut starch use and fecal nutrient loss. With its nutritional exclusivities underlined, barley use will be a factual art that can either matchlessly profit or harm rumen microbes, cattle production, farm economics and the environment.

Rumen and post abomasal disappearance of amino acids and some nutrients of barley grain treated with sodium hydroxide, formaldehyde or urea in lactating cows

Four rumen and duodenum cannulated, Holstein lactating cows were used in a change-over design to determine the effects of NaOH, Formaldehyde or Urea treated barley on disappearance of Dry Matter (DM), Crude Protein (CP), Amino Acids (AA), NDF, ADF, hemicelluloses and starch in rumen, Post Abomasal Tract (PAT) and total tract by mobile nylon bag technique. Experimental treatments were coarse milled barley, barley treated with 3.5% NaOH, barley treated with 0.4% formaldehyde and barley treated with 3.5% urea that all chemical treated barley milled coarse before feeding. NaOH Treatment reduced concentrations of Lysine and Cystine in the barley grain. All chemical treatments decreased rumen disappearances of barley CP but only NaOH and Formaldehyde treatments also decrease total AA and some of the AA disappearances in the rumen. All chemical treatments increased DM, OM, CP, starch, NDF, ADF and hemicellulose disappearance of barley in the PAT. But only NaOH and Formaldehyde treatments increased total AA and most of AA disappearances in the PAT. Effect of chemical treatments on increase of disappearance of starch, Met and Gly in the total tract was significant (p < 0.05). Rumen disappearance of TAA was lower than CP but PAT disappearance of TAA was more than CP and finally total tract disappearance of TAA was more than CP. Individual AA in barley disappeared at different rates in the rumen and PAT. Consequently, the proportion of digesta CP and AA entering the intestine must be considered.

Influence of dietary urea level on digestive function and growth performance of cattle fed steam-flaked barley-based finishing diets

Four Holstein steers (282 kg) with cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square experiment to evaluate the influence of dietary urea level (0, 0.4, 0.8, and 1.2%, DM basis) in a steam-flaked barley-based finishing diet on digestive function. There were no treatment effects (P > 0.20) on ruminal digestion of OM and ADF. Increasing dietary urea level increased (linear, P < 0.01) ruminal starch digestion. Ruminal degradability of protein in the basal diet (no supplemental urea) was 60%. Increasing dietary urea level did not increase (P > 0.20) ruminal microbial protein synthesis or nonammonia N flow to the small intestine. There were no treatment effects (P > 0.20) on total-tract ADF digestion. Total tract digestion of OM (quadratic, P < 0.01) and starch (linear, P < 0.05) increased slightly with increasing urea level. Urea supplementation increased (linear, P < 0.01) ruminal pH 1 h after feeding; however, by 3 h after feeding, ruminal pH was lower (cubic, P < 0.05) with urea-supplemented diets. Urea supplementation did not affect (P > 0.20) ruminal molar proportions of acetate and propionate. One hundred twenty crossbred steers (252 kg; approximately 25% Brahman breeding) were used in an 84-d feeding trial (five pens per treatment) to evaluate treatment effects on growth performance. Daily weight gain increased (linear, P = 0.01) with increasing urea level, tending to be maximal (1.53 kg/d; quadratic, P = 0.13) at the 0.8% level of urea supplementation. Improvements in ADG were due to treatment effects (linear, P < 0.01) on DMI. Urea supplementation did not affect (P > 0.20) the NE value of the diet for maintenance and gain. Observed dietary NE values, based on growth performance, were in close agreement with expected based on tabular values for individual feed ingredients, averaging 100.4%. We conclude that with steam-flaked barely-based finishing diets, ruminal and total-tract digestion of OM and ruminal microbial protein synthesis may not be increased by urea supplementation. In contrast, ADG was optimized by dietary inclusion of 0.8% urea. Urea supplementation may not enhance the net energy value of steam-flaked barely-based finishing diets when degradable intake protein is greater than 85% of microbial protein synthesis.