Dietary Crude Protein Levels Research Articles

Effects of dietary crude protein level and N-carbamylglutamate supplementation on nutrient digestibility and digestive enzyme activity of jejunum in growing pigs.

Three experiments were conducted to investigate the effects of dietary crude protein (CP) level and N-carbamylglutamate (NCG) supplementation on apparent total tract digestibility (ATTD) and ileal digestibility of nutrients and digestive enzyme activity of jejunum in growing pigs. In experiment 1, 10 Duroc × Landrace × Yorkshire barrows (initial BW: 48.7 kg) were allotted to a three-period switchback design with five experimental diets and two replicate pigs per diet in each period. Diets were categorized as high CP (HP, 18% CP), moderate low CP (MLP, 15% CP), very low CP (VLP, 12% CP), and MLP and VLP with 0.1% NCG supplementation. Feces and urine were collected from day 6 to day 11 after a 5-d adaptation period. The DE, ME, and ATTD of GE, OM, CP, NDF, ADF, and P decreased (P < 0.01) with a reduction of dietary CP, but no effect of dietary treatments on pig daily N retention was detected. The NCG supplementation increased (P < 0.01) DE and ATTD of ADF of the VLP diet. In experiment 2, 10 jejunal-cannulated Duroc × Landrace × Yorkshire barrows (initial BW: 44.5 kg) were fed five diets for three periods as experiment 1. Jejunal fluid was collected on days 6 and 8 after a 5-d adaptation period. The digestive enzymes activity was not affected by dietary CP level, except for α-amylase, for which there was a decrease (P < 0.01) in pigs fed VLP diets compared to HP and MLP diets. In experiment 3, 12 ileal-cannulated Duroc × Landrace × Yorkshire barrows (initial BW: 46.7 kg) were allotted to a three-period switchback design with six diets and two replicate pigs per diet in each period. The six experimental diets consisted of five experimental diets as experiment 1 and one N-free diet. Ileal digesta was collected from day 6 to day 8 after a 5-d adaptation period. Results indicated that apparent ileal digestibility (AID) of CP and P and ileal digestibility of Arg, His, Ile, Leu, Phe, and all dispensable AA, except Pro, decreased (P < 0.01) in pigs fed VLP diet compared to HP and MLP diets, but AID of GE, OM, EE, NDF, and ADF were not affected. The supplementation of NCG in the VLP diet increased (P < 0.01) the AID of CP and ileal digestibility of Arg, His, Leu, Phe, Val, Ser, and Tyr. In conclusion, reducing dietary CP level decreased nutrient digestibility, but improved the efficiency of dietary N utilization and reduced N emission. Moderate reduction of dietary CP level had a minimal effect on nutrient digestibility and digestive enzyme activity. Additionally, NCG supplementation plays a beneficial effect on nutrient digestion only if the dietary CP level is extremely lowered.

Crude protein in diets for European quail (Coturnix coturnix)

The aim of this study was to evaluate the influence of dietary crude protein (CP) levels on the production performance, carcass traits and dietary nutrient metabolizability of European quail from one to 35 days of age. A total of 250 quail were allotted to one of five treatments (21, 22, 23, 24 and 25% CP) in a completely randomized experimental design with five replicates of 10 birds per plot. The following variables were evaluated: feed intake; weight gain; feed conversion; energy and protein intakes; weight and yield of carcass, cuts and edible offal; metabolizability coefficients (MC) of dry matter, crude protein, ether extract and gross energy; and nitrogen intake, excretion, retention and metabolizability. Weight gain rose linearly (P 0.05) feed intake, weight gain or feed conversion from one to 35 days of age. Protein intake increased linearly (P < 0.05) in all evaluated periods. The absolute and relative weights of legs responded quadratically (P < 0.05). At 35 days of age, the absolute and relative weights of liver had decreased linearly (P < 0.05). In the metabolism trial, a linear decrease was observed (P < 0.05) for the MC of dry matter, crude protein and nitrogen, whereas the MC of ether extract, nitrogen intake and nitrogen excretion increased linearly (P < 0.05). Diets with 21% CP are recommended for European quail from 1 to 35 days of age.

Effects of dietary protein on growth performance, nutrient utilization, digestive enzymes and physiological status of grey mullet,Mugil cephalusL. fingerlings reared in inland saline water

A 60 days feeding trial was conducted to illustrate the effect of graded levels of protein on the growth and metabolic enzymes of grey mullet (Mugil cephalus L.) fingerlings reared in inland saline water (ISW). Six isoenergetic (16 MJ/kg) and isolipidic (60 g/kg) diets containing 240, 260, 280, 300, 320 and 340 g crude protein (CP)/kg diet were formulated and fed to triplicate. Weight gain %, specific growth rate, protein utilizing efficiency, feed efficiency and RNA:DNA ratio were significantly higher (p .05) variations were observed for lactate dehydrogenase, oxidative stress enzymes, blood parameters and serum osmolality among all the treatment groups, but red blood cell count increases with increasing dietary CP levels. Based on the results, feeding dietary protein level of 300 g CP/kg is economically viable for rearing of grey mullet in ISW.

Low Protein-High Carbohydrate Diets Alter Energy Balance, Gut Microbiota Composition and Blood Metabolomics Profile in Young Pigs

Reducing dietary crude protein (CP) beyond a certain threshold leads to poor growth performance in pigs; however, the underlying mechanisms are not well understood. Following an adaption period, thirty-seven weaned pigs were weight matched (8.41 ± 0.14 kg), housed individually and randomly assigned into three groups with different dietary CP levels: 24% CP (CON; n = 12), 18% CP (n = 12) and 12% CP (n = 13) for 28 days. The body weight was not different between the CON and 18% CP diets, but 12% CP significantly decreased body weight after day 21. Compared to the CON, pigs fed with 12% CP decreased feed intake day 17 onwards. The 12% CP diet increased the energy expenditure during week 1 compared to the CON. The 12% CP influenced starch and sucrose, nitrogen, and branched-chain amino acids metabolism pathways. The feces of pigs fed with 12% CP were less enriched in Prevotella, but had higher relative abundance of Christensenedilaceae, Aligiphilus and Algoriphagus than CON and 18% CP. Overall, reducing dietary CP by 50%, but not by 25%, significantly influenced the physiological responses in nursery pigs. The pigs fed with low or standard protein diets had differential bacterial communities in their feces as well as serum metabolomics profile.

Effect of Dietary Crude Protein on Productive Efficiency, Nutrient Digestibility, Blood Metabolites and Gastrointestinal Immune Markers in Light Lambs.

Simple SummaryAnimal production is considered to compete with human food due to land use for feed ingredients and their relationship with environmental pollution. Crude protein (CP) is vital for the normal development of growth and carcass conformation in lambs. Dietary CP may be dependent on breed, age and market weights at slaughter. However, it appears that the feed industry formulates dietary CP levels above the physiological needs of these animals. Therefore, this study was designed to assess the effect of reducing the level of dietary CP (−2%) in intensively-fed growing (14–19 kg of body-weight) and finishing (19–25 kg of body-weight) lambs. Our findings revealed that a 2% reduction of dietary protein did not negatively affect some selected nutrient metabolism or mucosal immune function markers in the gastrointestinal tract. In addition, it was observed that the growth performance and feed efficiency of lambs fed lower CP levels would be the same as those fed higher levels.This study hypothesized that reducing the level of crude protein (CP) in lambs′ feed may improve nutrient utilization and did not negatively affect their productive efficiency, blood metabolites, oxidative status (OS) or intestinal immune barrier function. A total of 120 weaned male Ripollesa lambs (45–60 days old and 15.0 ± 1.5 kg of body weight) were used. Four feed concentrates were formulated for two different phases (growing and finishing): CP20/19 group (20% and 19% of CP on dry matter basis, for each phase, respectively) and CP18/17 group (18% and 17% of CP on dry matter basis, for each phase, respectively). Lambs were randomly assigned to feeding treatments by balancing initial body weight between groups. The reduction of dietary CP level did not impair their growth performance parameters, while it did improve the apparent digestibility of organic matter. Furthermore, the lambs of the CP18/17 group showed lower plasma urea levels with no effect on OS (malondialdehyde levels) or gastrointestinal immunity markers (gene expression of interleukin 10 (IL10), tumor necrosis factor-α (TNFA) and transforming growth factor-β1 (TGFB)).

How can nutritional strategies and feed technologies in pig production affect the logistical costs of manure distribution?

ABSTRACT The objective with this study was to evaluate the impact of different swine nutritional strategies and technologies, as well as the land spread system, on logistical costs of pig manure distribution. For this, pigs were fed a conventional diet (C0) or a diet supplemented with 0.01% phytase (C1); organic minerals (40% substitution; C2); synthetic amino acids at reduced dietary crude protein levels (C3); or a combination of the three strategies (C4). All pig manure was weighed, then its chemical [...]

Effects of Decreasing Dietary Crude Protein Level on Growth Performance, Nutrient Digestion, Serum Metabolites, and Nitrogen Utilization in Growing Goat Kids (Capra hircus).

Simple SummaryReducing the dietary protein content could potentially reduce losses of nitrogen from ruminant farms and mitigate pressure on the protein ingredient supply. However, there is little information in the literature on the effect of low-protein diets in growing Anhui white goat kids. We demonstrated that decreasing the dietary crude protein level in Anhui white goat kids affected growth performance, improved nitrogen utilization, and reduced environmental nitrogen pollution. The key finding of this study was that a diet containing 13.4% crude protein supplied adequate protein to improve nitrogen utilization in white goat kids without any adverse effect on growth performance.The effects of decreasing dietary crude protein (CP) level on growth performance, nutrient digestion, serum metabolites, and nitrogen utilization in growing goat kids were investigated in the current study. Thirty-six male Anhui white goat kids were randomly assigned to one of three CP content diets: 14.8% (control), 13.4%, and 12.0% of dry matter, respectively. Diets were isoenergetic. The experiment lasted for 14 weeks, with the first two weeks being for adaptation. Results showed that the low-CP diet decreased average daily gain, feed efficiency, digestibility of dry matter, organic matter, crude protein, and fiber. No significant changes were observed in dry-matter intake. With a decrease in dietary CP level, fecal nitrogen excretion (% of nitrogen intake) increased linearly, whereas CP intake, blood urea nitrogen, urinary nitrogen excretion (% of nitrogen intake), and total nitrogen excretion (% of nitrogen intake) decreased. Serum glucose concentration decreased, while concentrations of low-density lipoproteins and non-esterified fatty acids increased with the low-CP diet. In conclusion, decreasing the dietary CP level decreased goats’ nitrogen excretion, but with restrictive effects on growth performance. A diet containing 13.4% CP is optimal for reducing nitrogen excretion without any adverse effect on growth performance of Anhui white goat kids. This concentration is 1.4% points lower than the NRC recommendations and thus is also environmentally beneficial on the input side because it decreases the use of feed (soy) protein.

Ruminal Microbiota and Fermentation in Response to Dietary Protein and Energy Levels in Weaned Lambs.

Simple SummaryRuminants, such as sheep, are economically important because they contribute to digesting and converting plant materials into edible meat and milk for humans to consume. An adequate plane of nutrients, such as energy and protein, is essential for rumen development and growth. However, sheep production is mostly affected by inadequate nutrition in rural areas of China. As one of the most prolific and perennial estrus breeds in China, Hu sheep has huge potential for catering to the growing meat demands of the market and consumers. In this study, the effects of dietary energy and protein levels on growth performance, microbial diversity, and physiological properties of the rumen in weaned lambs were evaluated. The results showed that a low dietary energy level restrained growth performance and changed the microbiota and associated ruminal fermentation phenotypes of lambs. However, protein had a minor effect. The findings are of great significance for promoting rumen development and establishing the optimal nutrient supply strategy for lambs.Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.

Effect of Coarse Wheat Bran and Crude Protein Level in Nursery Pig Diets Without Pharmacological Levels of Zinc Oxide

A total of 360 pigs (200 × 400; DNA, Columbus, NE, initially = 12.4 lb) were used in a 45-d growth trial to evaluate the effects of coarse wheat bran and crude protein level in diets without pharmacological levels of zinc oxide (ZnO) on growth performance of nursery pigs. Upon arrival to the nursery research facility, pigs were randomly assigned to pens with 5 pigs per pen. Pens were allotted to 1 of 6 dietary treatments in a completely randomized design with 12 pens per treatment. Treatment diets were offered in two dietary phases (phase 1 fed from d 0 to 7, and phase 2 from d 7 to 21 post-weaning). A post-treatment period with a common diet was fed from d 21 to 45. Treatment diets included a positive control diet with pharmacological ZnO (3,000 ppm Zn in phase 1 and 2,000 ppm in phase 2); negative control without pharmacological ZnO (110 ppm Zn added from premix); and negative control with 4% coarse wheat bran and formulated to contain 21, 19.5, 18, or 16.5% crude protein (CP). The two control diets and the 21% CP diet contained 1.40% standardized ileal digestible (SID) lysine in phase 1 and 1.35% SID lysine in phase 2, with the 19.5, 18, and 16.5% CP diets containing 1.33, 1.25 and 1.20% lysine, respectively in both phases. Fecal samples were collected from the same three pigs per pen on d 7, 14, 21, and 45 then pooled within pen for each day of collection and dried at 55°C in a forced air oven. All pens were individually scored on d 7, 14, 21, and 45 by the same three individuals to determine visual fecal consistency. Data were analyzed using the lmer function from the lme4 package in R. From d 0 to 21, pigs fed the positive control diet containing ZnO had increased (P < 0.001) average daily gain (ADG) and average daily feed intake (ADFI) and improved (P < 0.050) feed efficiency (F/G) compared to the negative control and the high CP coarse wheat bran diet. Reducing crude protein levels in diets containing coarse wheat bran resulted in decreased ADG and poorer feed efficiency (linear, P = 0.002); however, fecal dry matter percentage was increased (linear, P = 0.006), suggesting a greater occurrence of solid feces throughout the experimental period. Overall from d 0 to 45, decreasing crude protein level decreased (linear, P = 0.012) ADG, ADFI (linear, P = 0.038), and d 45 body weight (linear, P = 0.010). Pigs fed the positive control diet with ZnO experienced increased ADG (P = 0.014) and increased ADFI (P = 0.008) compared to the negative control. There was no evidence for differences in overall growth for the positive control compared with the 21% CP diet with coarse wheat bran. In summary, decreasing crude protein in diets with coarse wheat bran decreased overall ADG and ADFI, resulting in lower body weight throughout the study. The pigs fed these diets had poorer feed efficiency and decreased ADG during the experimental period; however, these pigs had increased fecal dry matter. Further research is warranted to determine if low crude protein diets can be modified to achieve increased fecal dry matter while maintaining growth performance of nursery pigs.

Evaluating the Effects of Pharmacological Levels of Zinc Oxide, Diet Acidification and Dietary Crude Protein on Growth Performance of Nursery Pigs

A total of 360 weaned pigs (DNA 200 × 400; initially 12.9 lb BW) were used in a 42-d growth study to evaluate the effects of pharmacological levels of zinc oxide (ZnO), diet acidification, and dietary crude protein (CP) on pig performance. Pigs were weaned at approximately 21-d of age and were randomly assigned to pens (5 pigs per pen) and allotted to 1 of 8 dietary treatments with 9 pens per treatment. Experimental diets were fed from d 0 to 21 with a common diet fed from d 21 to 42. The eight treatment diets were arranged as a 2 × 2 × 2 factorial with main effects of Zn from ZnO (110 ppm from d 0 to 21 or 3,000 ppm from d 0 to 7, and 2,000 ppm from d 7 to 21), diet acidification, (without or with 1.2% sodium diformate), and dietary CP (21 or 18%, [1.40 vs. 1.20% standardized ileal digestible Lys, respectively]). Fecal samples were collected weekly to determine dry matter content. No 2- or 3-way interactions (P > 0.05) were observed throughout the 42-d growth study for growth performance; however, there was a ZnO × acidifier × CP interaction (P < 0.05) for fecal dry matter on d 7 and overall, where reducing CP without acidification increased fecal DM when ZnO was not in the diet, but had little effect when ZnO was present in the diet. From d 0 to 21, pigs fed added ZnO had improved (P < 0.05) average daily gain (ADG), average daily feed intake (ADFI), feed efficiency (F/G), and increased d 21 body weight (BW) compared to those fed 110 ppm Zn. Added sodium diformate improved (P < 0.05), ADG, F/G, and BW. Pigs fed 21% CP had improved (P < 0.05) ADG and F/G and tended (P < 0.10) to have increased d 21 BW. In the subsequent period (d 21 to 42) after the experimental diets were fed, there was no evidence of difference in growth perfor­mance among treatments. Overall (d 0 to 42), adding ZnO or sodium diformate from d 0 to 21 tended to increase ADG (P ≤ 0.10) with no evidence of difference in ADFI and F/G. Increasing dietary CP from 18 to 21% from d 0 to 21 improved (P < 0.05) overall F/G. In summary, dietary addition of ZnO or sodium diformate independently improved nursery pig performance.

Influence of low-protein diet with different levels of amino acids on laying hen performance, quality and egg composition.

The present study aimed to investigate the consequences of dietary levels of crude protein (CP) and total sulfur amino acids (TSAA, Met+Cys) on productive performance, egg quality and egg components for Lohmann Brown laying hens through 18-34 weeks of age. A 2×3 factorial design experiment was conducted using two levels of CP (16 and 18 %) and three levels of Met+ Cys (0.67, 0.72 and 0.77 %). A total of 144 Lohmann Brown laying hens at 18 weeks of age were randomly divided into 6 treatment groups. The best values of final body weight and body weight change were recorded by the hens fed 18 % CP diet. Increasing dietary CP up to 18 % accompanied with the best (P> 0.01) feed conversion, egg weight and egg mass. The combination between low-CP diet (16 %) and 0.72 % Met+ Cys gave the best percentage of egg production. The majority of egg quality traits were not significantly altered by dietary treatments. The interaction between CP and Met+Cys levels had a statistical (P>0.01) impact on egg content of moisture and total solids only. It could be concluded that the best production criteria could be obtained by using 0.72% Met+Cys. Moreover, dietary level of 16 or 18 % CP with 0.72% Met+Cys is recommended for feeding Lohmann hens.

Effect of Crude Protein Level and Coarse Wheat Bran on Nursery Pig Growth Performance

Two experiments were conducted to determine the effect of adding coarse wheat bran with reduced crude protein level in diets without pharmacological levels of zinc oxide on the growth performance and fecal dry matter of nursery pigs. Our objective was to determine if a low-crude protein diet with an added fiber source might provide similar growth performance and reduce the incidence of scours in weanling pigs compared to a typical, high-protein diet with added Zn. A total of 300 and 350 pigs (DNA 241 × 600), initially 15.4 and 13.7 lb body weight (BW), were used in Exp. 1 and 2, respectively. There were 5 pigs per pen and 12 and 14 replicates per treatment in Exp. 1 and 2, respectively. After weaning, pigs were fed a common pelleted diet with phar­macological levels (3,000 ppm Zn) of ZnO for 10 d in Exp. 1, and without pharmaco­logical levels of ZnO for 14 d in Exp. 2. Then, pens were assigned to one of 5 dietary treatments in a randomized complete block design with BW as the blocking factor. In Exp. 1 and 2, treatment diets were offered in mash form and in one dietary phase. All dietary treatments contained 4% coarse wheat bran and consisted of: 1) positive control with ZnO (2,000 ppm Zn) and 21% crude protein (CP) formulated to 1.35% standardized ileal digestible (SID) lysine; 2) a diet with 110 ppm added Zn and 21% CP (1.35% SID lysine); 3) a diet with 110 ppm added Zn formulated to 18% CP (1.20% SID lysine); 4) an 18% CP diet with 110 ppm added Zn formulated to 1.35% SID lysine by the addition of feed grade amino acids; and 5) diet 4 with the addition of non-essential amino acids (glycine and glutamic acid). A common post-treatment pelleted diet was fed for 14 d in Exp. 2 but not in Exp. 1. Data were analyzed using the lmer function from the lme4 package in R. In Exp. 1, pigs fed diets with 21% CP had increased (P < 0.05) ADG and heavier (P < 0.05) final BW; however, treatment means did not separate when Tukey adjustment was applied during statistical analysis. Pigs fed diets with 21% CP had improved (P < 0.05) feed efficiency similarly to pigs fed 18% CP diets with the addition of non-essential amino acids. During the experimental period in Exp. 2, pigs fed high CP diets

Impact of reduced dietary crude protein levels and phytase enzyme supplementation on growth response, slurry characteristics, and gas emissions of growing pigs.

This experiment was carried out to evaluate the effect of reduced dietary crude protein (CP) levels supplemented with or without exogenous phytase on growing pigs. Six dietary treatments arranged in a 3×2 factorial arrangements of 3 CP levels (containing 14%, 16%, and 18% CP) supplemented each with or without 5,000FTU/g phytase enzyme. Thirty growing pigs (average weight of 17.80±0.10kg) were allotted to the six dietary treatments in a complete randomized design. The final weight, daily weight gain, and feed conversion ratio (FCR) increased significantly with increasing CP levels. While, phytase supplementation improved (p=.044) FCR in pigs. Total solid and volatile solid content of the slurry were higher (p=.001) in pigs fed 14% and 16% CP diets supplemented with phytase when compared with other treatment groups. Concentration of methane gas emitted was lowest (p=.001) in the slurry of pigs fed 14% CP diet with or without phytase and those fed 16% CP diet with phytase supplementation. In conclusion, reduction in dietary CP levels resulted in reduced weight gain and poor FCR. While, reduced CP with phytase supplementation reduced concentration of methane gas emitted.

Effect of dietary supplementation of microbial protease on performance, egg quality and nitrogen retention in white leghorn layers

Context Protease supplementation increases the digestibility of protein, which enables reduction in the requirement of crude protein (CP) in the diet for optimum performance and egg quality in laying chickens. Aims An experiment was conducted to study the effects of protease supplementation (0 and 4000 u/kg) in diets containing three graded levels of CP on egg production, egg quality and nitrogen retention in layers. Methods Three diets with 15, 16.5 and 18% CP with uniform metabolisable energy (10.67 MJ/kg) were prepared. Each diet was supplemented with (4000 u/kg) or without protease in a 3 × 2 factorial arrangement. Each diet was fed ad libitum to six replicates consisting of 88 white leghorn laying chickens in each from 53 to 72 weeks of age. Key results Supplementation of protease significantly (P < 0.05) improved performance (egg production, feed efficiency and bodyweight) and egg albumen quality (Haugh unit score). Layer performance was not affected by reducing the dietary CP from 18 to 15%. The interaction between CP level and protease supplementation did not influence the laying performance and egg quality parameters studied. Nitrogen retention reduced significantly (P < 0.05) with increase in dietary CP level from 15 to 18%. Supplementation of protease significantly (P < 0.05) improved the N retention. Conclusions The results suggested that 15% CP was adequate for optimum layer performance during the latter part of egg production phase (53 to 72 weeks of age). Protease supplementation improved the layer performance, egg albumen quality and nitrogen retention. Implications The results of this study will contribute for optimisation of dietary protein level in layer diet. Utilisation of dietary protein can be enhanced with protease supplementation which results in enhanced egg production and albumen quality in egg laying chickens.

Dietary Protein Level Influences on Neurotensin-immunoreactive Cells in the Chicken Ileum.

Neurotensin is secreted from intestinal N cells in response to the food ingestion. Influences of different dietary protein levels on neurotensin-immunoreactive cells in the chicken ileum were examined by using immunohistochemical and morphometrical techniques. The results showed that dietary protein had an obvious influence on neurotensin-immunoreactive cells in the chicken ileum. Four experimental groups were used, with dietary crude protein (CP) levels of 18% (control), 9%, 4.5% and 0%. Enteroendocrine cells showing neurotensin-immunoreactivity were located in crypts and villous epithelium in all groups. Most of the neurotensin-immunoreactive cells in the villous epithelium showed pyramidal or spindle-like shape with a long cytoplasmic process reaching the intestinal lumen, but cells with round or oval shape were found in the CP4.5% and 0% groups. Frequencies of occurrence of neurotensin-immunoreactive cells in the CP18%, 9%, 4.5% and 0% groups were 42.4±3.3, 36.6±2.2, 30.8±2.6 and 25.4±3.8 (cell count per mucosal area: cells/mm2, mean±SD), respectively. There were significant differences in neurotensin-immunoreactive cell frequency between the control and lower CP level, 4.5% and 0%, groups. A significant correlation was found between frequency of occurrence of neurotensin-immunoreactive cells and daily protein intake. These results indicate that ingested protein is likely to be a potential signal for neurotensin production and secretion of N cells in the chicken ileum.

Proper dietary crude protein and metabolizable energy levels on growth performance, carcass characteristics and meat quality of Royal Project Bresse capon

Proper dietary crude protein and metabolizable energy levels on growth performance, carcass characteristics and meat quality of Royal Project Bresse capon

Effect of supplementary betaine on growth performance, blood biochemical profile, and immune response in heat-stressed broilers fed different dietary protein levels

Summary This experiment was planned to investigate the efficiency of dietary crude protein (CP) levels (normal, medium [90% of the normal CP level] and low [80% of the normal CP level]) and betaine (Bet; 0 and 1 g/kg of diet) in broilers under heat stress (HS) conditions. A total of 672 one-day-old male broiler chickens were randomly assigned to 7 treatments (4 pens/treatment with 24 birds/pen). All experimental diets were supplemented with synthetic feed-grade lysine, methionine, and threonine at levels sufficient to meet dietary requirements. The positive control (PC) chickens were housed in a thermoneutral chamber and fed with a basal diet (normal diet without Bet supplementation). The other 6 groups were kept in a HS chamber (34°C) for 8 h (9:00–17:00). For the overall period of rearing (0–42 D), the HS control group (normal CP diet with no additive) exhibited lower (P

413 Effect of chitosan inclusion and dietary crude protein level on rumen fermentation in beef heifers fed a total mixed ration

Abstract Chitosan (N-acetyl-D-glucosamine polymer) is a natural biopolymer, which is the second most abundant organic compound on earth, found in lower plants and some arthropods and crustaceans. Studies with ruminants have shown that supplementing with chitosan can alter ruminal fermentation, including higher propionate concentration and lower acetate to propionate ratio, improving the energy efficiency within the rumen though data on nitrogen metabolism is lacking. Therefore, the objective of this study was to evaluate the effects of chitosan with different dietary crude protein (CP) inclusion on rumen fermentation in beef heifers. Eight ruminally cannulated Belgian Blue x Holstein Friesian heifers (752 ± 52Kg BW) were allocated one of four dietary treatments in a 2 x 2 factorial Latin Square design (n = 8). Diets were offered as total mixed ration (TMR) consisting of grass silage plus concentrate. Diets were offered once daily ad libitum. Dietary treatments were as follows: high CP (16%) +/- chitosan (10g kg-1 DMI) supplementation (HP+) or (HP-) and low CP (12%) +/- chitosan supplementation (LP+) or (LP-). Experimental periods were 25d in duration (14 d dietary adaptation and 10 d sampling). Rumen fluid was collected via cannula every 2 h post feeding for analysis of ruminal pH, ammonia (NH3) and volatile fatty acids (VFA) over a 48-hour period. Data was analysed using Proc Mixed procedure in SAS. Significant differences were considered when P &amp;lt; 0.05. Dietary treatment had no effect on ruminal pH (P &amp;gt; 0.05). Chitosan supplementation had no effect on ruminal NH3 and VFA concentrations (P &amp;gt; 0.05), whereas, animals offered 16% CP had higher concentrations of ruminal NH3 (P &amp;lt; 0.001). In conclusion, supplementing a TMR diet fed to beef heifers with chitosan had no effect on rumen fermentation. However, reducing dietary CP concentration fed to beef animals resulted in lower rumen NH3 concentrations.

PSIV-18 Effect of two dietary crude protein levels on finishing performance, meat quality, and genomic changes of lambs

Abstract This study investigated the effects of 2 different CP levels on the finishing performance, meat quality, and genomic changes of market lambs. Seventeen crossbred lambs were assigned randomly to low-protein (LP; 8% CP, n = 9) and high-protein (HP; 13% CP, n = 8) diets, with initial mean body weights tabulated (37.5±1.97 and 39.5±2.17 for LP and HP group), and allowed ad libitum access to diets and water in individual, indoor digestibility pens for 9 weeks. The final BW, ADFI, and ADG of the HP lambs were significantly greater (P &amp;lt; 0.05) than the LP lambs; however, G:F for the LP lambs was significantly greater (P &amp;lt; 0.05) than the HP lambs. Hot carcass weight, adjusted fat thickness, and drip loss of LM was significantly greater (P &amp;lt; 0.05) for the HP than LP lambs. In contrast, instrumental color values L*, a*, b*, C*, and hue angle of meat from the LP lambs scored higher (P &amp;lt; 0.05) than the HP lambs. Oxymyoglobin percentage from LP lambs tended greater (P &amp;lt; 0.10) than HP lambs. Deoxymyoglobin from HP lambs was significantly greater (P &amp;lt; 0.01) than LP lambs. Metmyoglobin from HP lambs was significantly greater (P &amp;lt; 0.01) than LP lambs. The n6:n3 of the LM from LP lambs tended to be greater than that of HP lambs (P &amp;lt; 0.10); conversely, the LM from HP lambs had significantly greater CLA of cis-9 trans-11 isomer (P &amp;lt; 0.05) than the LP lambs. According to the RNA-Seq data, genes that were highly expressed in the LP group (fold change &amp;gt; 3, P &amp;lt; 0.05) were involved in lipid metabolism (GRAMD2, PIK3R3), fatty acid composition (CHAC1), IMF content (ATXN7L1), and carcass quality traits (CCDC158). These results demonstrated that higher CP protein promotes growth performance for finishing lambs, whereas lower CP is beneficial for meat quality, especially when evaluating color characteristics in the final product.

Effects of dietary crude protein levels on ammonia emission, litter and manure composition, N losses, and water intake in broiler breeders

This study determined the effects of different dietary crude protein (CP) levels on ammonia emission (NH3), litter and manure composition, nitrogen (N) losses, and water intake in broiler breeders. A total of 480 females and 64 males (Ross 308) 20 wk of age were randomly allotted to 2 dietary treatments with 8 replicates of 30 females and 4 males per replicate. Birds were fed either high CP (CPh) or low CP diets (CPl) supplemented with free amino acids (AA). Both diets consisted of 3 sub-diets; 1 for each phase of the laying period. Diets were formulated to be iso-caloric and calculated CP content of the CPl diets was 15 g/kg lower than the CPh diets (Breeder 1 (23 to 34 wk): 135 vs. 150, Breeder 2 (35 to 46 wk): 125 vs. 140 and Breeder 3 (47 to 60 wk of age): 115 vs. 130 g/kg, respectively). Pens consisted of an elevated slatted floor (25% of the floor surface) and a litter floor. Water and feed intake were recorded daily. Litter (floor) and manure (below slatted floor) composition and ammonia concentration were measured at 34, 44, and 54 wk of age. Ammonia concentration was measured using a flux chamber on top of the litter or manure. Estimated N losses were calculated. Dietary protein level did not affect water intake and dry matter (DM) content of the litter or manure. Compared to birds fed the CPh diets, the litter and manure samples of broiler breeders fed the CPl had 8% lower total-N and 13% lower ammonia-N content resulting in a 9% lower ammonia concentration, 9% lower ammonia emission, and 11% lower total-N losses. In conclusion, this study shows that reducing CP level in the diet of broiler breeders reduces ammonia emission and total N-losses from litter and manure.