Effects of heat treatment on protein feeds evaluated in vitro by the method of estimating utilisable crude protein at the duodenum

Exploring protein structural adaptations and polyphenol interactions: Influences on digestibility in pigeon pea dal and whole grains under heat and germination conditions

Pigeon pea, a protein-rich legume with low protein digestibility (PD) due to its high polyphenol content and other antinutritional factors (ANFs). Consequently, processing methods are crucial to improve PD. We investigated the effects of thermal treatments (cooking, hydrothermal, autoclaving, infrared rays) treatments and germination on modulation of PD, its properties and association with ANFs in two distinct genotypes based on polyphenol content: high (Pusa Arhar 2018-4) and low (ICP-1452). Treatments improved in vitro PD and essential amino acid content, with autoclaving showing significantly higher PD (ICP-1452: 90.4%, Pusa-Arhar 2018-4: 84.32%) ascribed to disruption of tight protein matrices. Significant increase in β-turn, reduction in protein: starch, protein: polyphenol interactions as well as breakdown of storage proteins revealed by the analysis of protein structural properties. This study suggests thermal treatments, particularly autoclaving, can enhance pigeon pea protein's nutritional quality for its utilization as a new ingredient in development of healthy foods.

Rumen degradable protein levels on fatty acid profile of rumen bacteria and milk fat of dairy cows supplemented with calcium salts of fatty acids

This study aimed to evaluate the effects of calcium salts of fatty acids (CSFA) from soybean oil in diets with different levels of rumen degradable protein (RDP) on bio-hydrogenation extent, and fatty acid (FA) profile intake, omasal digesta, rumen bacteria, and milk fat. Eight Holstein lactating cows were used in a replicated 4 × 4 Latin square design. Treatments were arranged in a 2 × 2 factorial design with two CSFA levels (0 or 33.2 g/kg DM of CSFA) and two RDP levels (98.0 or 110 g/kg DM). There was RDP and CSFA interaction effect on the omasal flow of total FA and some specific FA. Only in -CSFA diets, the higher RDP level increased omasal flow of total FA. Dietary RDP levels did not affect the FA profile of bacteria and milk fat. Feeding CSFA reduced or tended to reduce the bacterial proportion of C15:0, C16:0, C16:1, C17:0, and C18:0 FA and decreased the concentrations of short- and medium-chain FA (<18C) and increased the concentrations of unsaturated and long-chain FA (≥18C) in milk fat. Feeding CSFA of soybean oil increases the intake and omasal flow of FA and augments unsaturated FA content in bacteria pellets and milk fat.

Intake, Growth and Carcass Traits of Steers Offered Grass Silage and Concentrates Based on Contrasting Cereal Grain Types Supplemented with Field Beans, Peas or Maize By-Products

The study objective was to determine intake and performance of beef cattle individually offered perennial ryegrass-dominant grass silage ad libitum supplemented with 4 kg dry matter daily of, rolled barley or maize meal-based concentrate rations containing supplements of flaked field beans, flaked peas, maize dried distillers grains (MDD) or maize gluten feed (MGF) for 110 days (Experiment 1), rolled barley or rolled oats with or without supplements of flaked field beans or flaked peas for 146 days (Experiment 2), and to quantify the nitrogen balance of diets similar to those offered in Experiment 2 (Experiment 3). The protein supplements were formulated to have similar crude protein concentrations. Cereal type or protein source did not affect intake, growth, feed efficiency and carcass traits in Experiment 1 or 2. Inclusion of a legume protein supplement with barley or oats had no effect on intake or growth performance (Experiment 2), whereas their exclusion decreased nitrogen intake, plasma urea concentrations and urinary and total nitrogen excretion (Experiment 3). The feeding value of barley was similar to oats and maize meal, and flaked beans and peas were similar to MGF and MDD, as supplements to grass silage. Excluding protein ingredients from a cereal-based concentrate did not affect animal performance and reduced nitrogen excretion.

Field pea can replace soybean meal-corn mixtures in the fattening concentrate of young bulls improving the digestibility

The inclusion of pea (Pisum sativum) in the fattening concentrate at 0%, 15%, 30%, and 45% as a replacement for soybean meal and corn was evaluated on in vitro and in vivo digestibility studies of young Parda de Montaña bulls. In the in vitro trial, gas production was determined with an Ankom system for 48 h. The 30%pea and 45%pea concentrates increased the organic matter (OM) degradability, the ammonia-N content and the ratio of acetic:propionic, with no effect on gas production, final ruminal pH and total volatile fatty acid production. In the in vivo assay, 4 young bulls (initial weight 251 ± 4 kg) received restricted amounts of concentrates plus straw during 4 consecutive experimental periods. No differences in intake were observed and 30%pea and 45%pea had higher digestibility of crude protein (CP), and OM than the rest of treatments. The nitrogen intake increased linearly with the inclusion of pea with similar nitrogen urinary and faecal excretions, and the nitrogen retained was greater in 30%pea and 45%pea than the rest of treatments. The plasma concentrations of IGF-1, total protein, β-hydroxybutyrate and urea at the beginning and at the end of each period were not affected by the inclusion of pea. In conclusion, the total replacement of soybean-corn mixtures by pea in the fattening concentrate of bulls could be recommended as it improved the CP digestibility and nitrogen retention.

Effect of heat-treated green tea waste feeding on fermentation kinetics, in vitro degradability, in vivo apparent digestibility, nitrogen balance, and blood metabolites in Black Bengal goat

The study was conducted to examine the effect of heat treatment of green tea waste (GTW) on rumen degradability, apparent digestibility, and plasma metabolites in Black Bengal goat based on in vitro and in vivo studies. The in vitro incubation was performed with autoclaved, oven, and freeze-dried GTW, whereas animal study was conducted using 12 Black-Bengal goats in a 3 × 3 Latin-square design. Goats were fed a total-mixed-ration without (control) or with the partial replacement of soybean meal and barley with 50 g/kg dry matter (DM) of either oven-dried or autoclaved GTW. Heat treatments reduced ether extract and tannins concentration but increased the effective DM and crude protein (CP) degradability of GTW. The highest values of in vitro volatile fatty acid concentration, molar proportion of propionate, ammonia-nitrogen concentration, and cumulative gas production were observed for oven-dried GTW among the tested GTW. Dietary treatment did not alter the DM intake, but apparent CP digestibility and retained nitrogen (N) were increased in goats fed control or oven-dried GTW incorporated diets. Feeding autoclaved GTW diet increased the urinary and fecal N excretion in goats. In contrast, plasma glucose concentration was highest in goats fed control or oven-dried GTW diet. In conclusion, oven drying could be a practical approach to increase protein digestibility and retained N in goats.

Nutritive value of faba bean (Vicia faba L.) as a feedstuff resource in livestock nutrition: A review

The review evaluates faba bean (Vicia faba L.; FB) seeds relative to their nutritional composition, their content of antinutritional factors, and their impact on animal performance. The literature indicates that FB plant is a cool-season, annual grain legume that grows the best in cool and humid conditions. Its seeds are rich in protein, energy, and mineral compounds and have particularly high unsaturated fatty acid levels. However, FB seeds also contain various proportions of antinutritional factors (ANFs) that can interfere with nutrient utilization in nonruminants. The various processing methods are efficient in either reducing or inactivating the ANFs of FB seeds, with extrusion treatment offering the most effective method of improving apparent nutrient and energy digestibility of nonruminants. In vivo studies on ruminants, pigs, poultry, and fishes reveal that FB seeds have the potential to be used as a substitute for soybean meal and/or cereal seeds in livestock diets in order to support milk, meat, and/or egg production.

Effect of toasting grain silages from field peas (Pisum sativum) and field beans (Vicia faba) on in vitro gas production, methane production, and post-ruminal crude protein content

Legume grains such as field peas and field beans can be produced on a local level, and may be reliable sources of dietary protein and energy apart from common soybean and rapeseed meals. In ruminants, protein, starch, and carbohydrates from peas and field beans are fermented in large part before reaching the small intestine. The objective of this study was to evaluate the effects of a combination of ensiling and hydro-thermic treatment (i.e., toasting at 160 °C for 30 min) of grains of peas and field beans on the concentrations of post-ruminal crude protein (PRCP) and rumen-undegraded protein (RUP). Moreover, 24-h gas production and methane production were measured. For this, an in vitro batch culture system with ruminal fluid from sheep was used. Rumen-undegraded protein was determined using the Streptomyces griseus protease test. Scanning electron micrographs were used to visualize morphological changes of starch granules and their joint matrices in peas and field beans after ensiling, toasting, or a combination of both. Native pea grains contained crude protein (CP) at 199 g/kg DM, PRCP at 155 g/kg DM at a ruminal passage rate of 0.08/h (Kp8), RUP at 33 g/kg DM at Kp8, and starch at 530 g/kg DM. Native field beans contained CP at 296 g/kg DM, PRCP at 212 g/kg DM at Kp8, RUP at 54 g of/kg DM at Kp8, and starch at 450 g/kg DM. The PRCP did not considerably differ among native and treated peas or field beans. Especially in the peas, RUP at Kp8 increased after ensiling by 10 g/kg DM (i.e., 30%; P < 0.05). Toasting increased RUP (Kp8) in ensiled peas by another 28% (P < 0.05). Toasting had no effect on PRCP or RUP when the peas or field beans were not ensiled before. Gas and methane production were not affected by any treatment, and scanning electron micrographs did not reveal structural changes on the starches doubtless of any treatment. Protein seemed to be more affected by treatment with ensiled + toasted peas than with ensiled + toasted field beans, but starches and other carbohydrates from both legumes remained unaffected.

Ruminal In Vitro Protein Degradation and Apparent Digestibility of Energy and Nutrients in Sheep Fed Native or Ensiled + Toasted Pea (Pisum sativum) Grains

Simple Summary

Pea grains may partially replace soybean or rapeseed meals and cereals in ruminant diets, but this is limited by high solubility of pea protein in the rumen. Hydro-thermic treatments such as toasting may stabilize the protein and shift digestion from the rumen to the small intestine. The effect of toasting of ensiled pea grains on rumen-undegraded protein was tested in vitro and on apparent digestibility of organic matter, gross energy, and proximate nutrients in a digestion trial with sheep. Ensiling plus toasting increased rumen-undegraded protein from 20 to 62% of crude protein, but it also increased acid detergent insoluble protein, which is unavailable for digestive enzymes in the small intestine from 0.5 to 2.6% of crude protein. Ensiling plus toasting did not, however, affect total tract apparent digestibility of organic matter, energy, crude protein, or any other nutrient fraction, nor did it alter the concentration of metabolizable energy or net energy lactation in the peas. The technique can be implemented on farms and might have a positive impact on field pea production.

Abstract

Pea grains may partially replace soybean or rapeseed meals and cereals in ruminant diets, but substitution by unprocessed peas is limited by high ruminal protein solubility. The effect of combined ensiling and toasting of peas using a mobile toaster (100 kg/h throughput rate, 180 to 190 °C supplied air temperature) on rumen-undegraded protein (RUP) was tested in vitro using the Streptomyces griseus protease test. The effects of ensiling plus toasting on apparent digestibility of organic matter (OM), gross energy (GE), and proximate nutrients were examined in a digestion trial. Concentrations of metabolizable energy (ME) and net energy lactation (NEL) were calculated. Native peas had 38 g RUP/kg dry matter (DM), which was 20% of crude protein (CP). Rumen-undegraded protein increased three-fold after ensiling plus toasting (p < 0.001). Acid detergent insoluble protein increased five-fold. Apparent digestibility was 0.94 (OM), 0.90 (CP), and above 0.99 (nitrogen-free extract, starch, and sugars) and was not altered by the treatment. The ME (13.9 MJ/kg DM) or the NEL (8.9 MJ/kg DM) concentration was similar in native and ensiled plus toasted peas. This technique can easily be applied on farms and may increase RUP. However, it needs to be clarified under which conditions pea protein will be damaged.

Effects of Heat Treatment of Green Protein on in Situ Protein Disappearance and in Vitro Fatty Acid Biohydrogenation

Soluble protein extracted from leaves and stems of grasses and forage legumes is defined as green protein. The present study was conducted to evaluate in situ green protein degradability, intestinal protein disappearance, and in vitro fatty acids biohydrogenation (BH) in dairy cows. Three green protein concentrates (red clover, ryegrass, and grass clover) were heat treated as follows: oven-drying at 70 °C, subsequent autoclaving at 121 °C for 45 min, and for grass clover also spin flash-drying. Freeze-dried green protein was considered as a control (untreated). Autoclaving and oven-drying of green protein reduced the crude protein and dry matter degradability. The linolenic acid BH rate was lowest in heat-treated grass clover concentrate ( P < 0.01). In conclusion, green proteins are heat sensitive, and oven-drying can be an appropriate method to increase the amount of protein and unsaturated fatty acids escaping from the rumen.

Predicting omasal flow of nonammonia N and milk protein yield from in vitro-determined utilizable crude protein at the duodenum

This study evaluated the relationship between utilizable crude protein (uCP) at the duodenum estimated in vitro and omasal flow of crude protein (CP; omasal flow of nonammonia N × 6.25) measured in lactating dairy cows. In vivo data were obtained from previous studies estimating omasal digesta flow using a triple-marker method and ¹⁵N as microbial marker. A total of 34 different diets based on grass and red clover silages were incubated with buffered rumen fluid previously preincubated with carbohydrates for 3 h. The buffer solution was modified to contain 38 g of NaHCO₃ and 1 g of (NH₄)HCO₃ in 1,000 mL of distilled water. Continuous sampling of the liquid phase for determination of ammonia-N was performed at 0.5, 4, 8, 12, 24, and 30 h after the start of incubation. The ammonia N concentrations after incubation were used to calculate uCP. The natural logarithm of uCP [g/kg of dry matter (DM)] at time points 0.5, 4, 8, 12, 24, and 30 h of incubation was plotted against time to estimate the concentration of uCP (g/kg of DM) at time points 16, 20, and 24 h using an exponential function. Fixed model regression analysis and mixed model regression analysis with random study effect were used to evaluate the relationships between predicted uCP (supply and concentration) and observed omasal CP flow and milk protein yield. Residual analysis was also conducted to evaluate whether any dietary factors influenced the relationships. The in vitro uCP method ranked the diets accurately in terms of total omasal CP flow (kg/d) or omasal CP flow per kilogram of DM intake. We also noted a close relationship between estimated uCP supply and adjusted omasal CP flow, as demonstrated by a coefficient of determination of 0.87, although the slope of 0.77 indicated that estimated uCP supply (kg/d) was greater than the value determined in vivo. The linear bias with mixed model analysis indicated that uCP supply overestimated the difference in omasal CP flow between the diets within a study, an error most likely related to study differences in feed intake, animals, and methodology. Predicting milk protein yield from uCP supply showed a positive relationship using a mixed model (coefficient of determination = 0.79), and we observed no difference in model fit between the time points of incubation (16, 20, or 24 h). The results of this study indicate that the in vitro method can be a useful tool in evaluating protein value of ruminant diets.