High Crude Protein Diets Research Articles

Regulation of hepatic peroxisome proliferator‐activated receptor α expression but not adiponectin by dietary protein in finishing pigs

Soy protein regulates adiponectin and peroxisome proliferator-activated receptor alpha (PPARalpha) in some species, but the effect of dietary soy protein on adiponectin and PPARalpha in the pig has not been studied. Therefore, the objective of this study was to determine whether soya bean meal reduction or replacement influences serum adiponectin, adiponectin mRNA, serum metabolites and the expression of PPARalpha and other genes involved in lipid deposition. Thirty-three pigs (11 pigs per treatment) were subjected to one of three dietary treatments: (i) reduced crude protein (CP) diet containing soya bean meal (RCP-Soy), (ii) high CP diet containing soya bean meal (HCP-Soy) or (iii) high CP diet with corn gluten meal replacing soya bean meal (HCP-CGM) for 35 days. Dietary treatment had no effect on overall growth performance, feed intake or measures of body composition. There was no effect of dietary treatment on serum adiponectin or leptin. Dietary treatment did not affect the abundance of the mRNAs for adiponectin, PPARalpha, PPARgamma2, lipoprotein lipase or fatty acid synthase in adipose tissue. The mRNA expression of PPARalpha, PPARgamma2, lipoprotein lipase or fatty acid synthetase in loin muscle was not affected by dietary treatment. In liver tissue, the relative abundance of PPARalpha mRNA was greater (p < 0.05) in pigs fed the HCP-Soy diets when compared to pigs fed RCP-Soy or HCP-CGM diets. Hepatic mRNA expression of acyl-CoA oxidase or fatty acid synthase was not affected by dietary treatment. Western blot analysis indicated that hepatic PPARalpha protein levels were decreased (p < 0.05) in pigs fed the RCP-Soy diets when compared to pigs fed the HCP-Soy diets. These data suggest that increasing the soy protein content of swine diets increases hepatic expression of PPARalpha without associated changes in body composition.

Impaired translation initiation activation and reduced protein synthesis in weaned piglets fed a low-protein diet

Weanling mammals (including infants) often experience intestinal dysfunction when fed a high-protein diet. Recent work with the piglet (an animal model for studying human infant nutrition) shows that reducing protein intake can improve gut function during weaning but compromises the provision of essential amino acids (EAA) for muscle growth. The present study was conducted with weaned pigs to test the hypothesis that supplementing deficient EAA (Lys, Met, Thr, Trp, Leu, Ile and Val) to a low-protein diet may maintain the activation of translation initiation factors and adequate protein synthesis in tissues. Pigs were weaned at 21 days of age and fed diets containing 20.7, 16.7 or 12.7% crude protein (CP), with the low-CP diets supplemented with EAA to achieve the levels in the high-CP diet. On Day 14 of the trial, tissue protein synthesis was determined using the phenylalanine flooding dose method. Reducing dietary CP levels decreased protein synthesis in pancreas, liver, kidney and longissimus muscle. A low-CP diet reduced the phosphorylation of eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1) in skeletal muscle and liver while increasing the formation of an inactive eIF4E·4E-BP1 complex in muscle. Dietary protein deficiency also decreased the phosphorylation of mammalian target of rapamycin (mTOR) and the formation of an active eIF4E·eIF4G complex in liver. These results demonstrate for the first time that chronic feeding of a low-CP diet suppresses protein synthesis in animals partly by inhibiting mTOR signaling. Additionally, our findings indicate that supplementing deficient EAA to low-protein diets is not highly effective in restoring protein synthesis or whole-body growth in piglets. We suggest that conditionally essential amino acids (e.g., glutamine and arginine) may be required to maintain the activation of translation initiation factors and optimal protein synthesis in neonates.

Effects of ammonia load on glucose metabolism by isolated ovine duodenal mucosa1,2

To determine the effects of ammonia load on glucose metabolism in ruminant small intestinal tissues, duodenal mucosal cells (DMC) were isolated from growing female sheep (n = 10; 46. 0 +/- 0. 8 kg of BW) fed diets differing in CP content: high (19. 4%) vs. low (13. 1%). Ammonia concentration in the duodenal digesta fluid was greater for sheep fed a high CP diet compared with those fed a low CP diet (16. 4 +/- 1. 0 vs. 9. 1 +/- 1. 8 mM). The isolated primary mucosal cells were incubated for 90 min with [2-(13)C] glucose (3 mM) and ammonium chloride (0, 0. 1, 1, 5, 10, 20, or 50 mM) in Krebs-Ringer HEPES buffer. It was hypothesized that DMC would increase glucose carbon utilization for the synthesis of nonessential AA when the ammonia concentration in the incubation media increased. However, utilization of glucose carbon for alanine synthesis decreased linearly (P = 0. 03) as the ammonia concentration in the incubation media increased. Furthermore, glucose disappearance and utilization of glucose carbon for aspartate synthesis were not affected (P > 0. 47) by the ammonia concentration. Contrarily, in vitro glucose disappearance was greater (P = 0. 03) for DMC isolated from sheep fed a low CP diet vs. a high CP diet [14. 6 +/- 1. 6 vs. 8. 6 +/- 1. 3 nmol.(10(6) cells)(-1).(90 min) (-1)], and hexokinase activity was greater (P = 0. 01) in the mucosa of sheep fed a low CP diet compared with a high CP diet (1. 22 +/- 0. 05 vs. 1. 04 +/- 0. 02 mUnit/mg of protein). These observations indicate that ammonia load does not affect the extent of glucose utilization by DMC, and that glucose carbon may not play a significant role for the synthesis of alanine, aspartate, or glutamate when DMC are exposed to increased concentrations of ammonia.

Effect of varying dietary energy and protein on broiler performance in hot climate

The experiment was conducted to evaluate the effect of varying dietary metabolizable energy (ME) and crude protein (CP) concentrations on broiler performance during hot summer conditions. One day old straight-run (0.50 male and 0.50 female) Starbro broiler chicks ( n = 600) were randomly divided into 30 experimental units of 20 chicks each. Two levels of dietary ME (12.13 and 12.55 MJ/kg) and three levels of dietary CP (190, 210 and 230 g/kg) were used in a 2 × 3 factorial arrangement giving six dietary treatments. Level of essential amino acids were maintained in all the diets by supplementing low CP diets with crystalline amino acids. Each of the experimental diets was offered to five replicates from hatching to 28 d of age. At the end of the experiment, two birds from each replicate were randomly selected for data on dressing yield, breast meat yield, abdominal fat, and liver and gizzard weights. Increasing dietary ME significantly increased the BW gain, abdominal fat and liver weights, and protein and fat contents of the carcass whereas the dry matter of carcass was reduced by increasing dietary ME. Dietary CP had quadratic effects on BW gain, F:G, carcass weight, and dry matter and protein contents of the meat. Breast weight and fat contents of meat increased linearly with increasing CP of the diets. The low CP diets ( i.e., 190 g/kg) at high ME ( i.e., 12.55 MJ/kg) increased the BW gain, feed intake, carcass weight and improved F:G. However, lowest F:G was observed in birds fed 210 g CP and 12.13 MJ ME/kg of diet. Protein and fat contents of the carcass were increased in birds fed on diets having high CP and ME whereas dry matter contents of meat improved with high CP and low ME diets. The results of the trial showed a correlation between dietary CP and ME and hence the optimal value for one cannot be predicted without considering the other. Briefly, low CP with high ME diets improved the overall performance when environmental temperature ranged from 32 to 39 °C.

Effects of Level and Degradability of Dietary Protein on Ruminal Fermentation and Concentrations of Soluble Non-ammonia Nitrogen in Ruminal and Omasal Digesta of Hanwoo Steers

Four ruminally fistulated Hanwoo steers were used to determine the effects of level and degradability of dietary protein on ruminal fermentation, blood metabolites and concentration of soluble non-ammonia nitrogen (SNAN) in ruminal (RD) and omasal digesta (OD). Experiments were conducted in a 4x4 Latin square design with a 2x2 factorial arrangement of treatments. Factors were protein supplements with two ruminal crude protein (CP) degradabilities, corn gluten meal (CGM) that was low in degradability (rumen-degraded protein (RDP), 23.4% CP) or soybean meal (SBM) that was high in degradability (RDP, 62.1% CP), and two feeding levels of CP (12.2 or 15.9% dry matter). Ruminal fermentation rates and plasma metabolite concentrations were determined from the RD collected at 2-h intervals and from the blood taken by jugular puncture, respectively. The SNAN fractions (free amino acid, peptide and soluble protein) in RD and OD collected at 2-h intervals were assessed by ninhydrin assay. Mean ruminal ammonia concentrations were 40.5, 74.8, 103.4 and 127.0 mg/L for low CGM, high CGM, low SBM and high SBM, respectively, with statistically significant differences (p<0.01 for CP level and p<0.001 for CP degradability). Blood urea nitrogen concentrations were increased by high CP level (p<0.001) but unaffected by CP degradability. There was a significant (p<0.05) interaction between level and degradability of CP on blood albumin concentrations. Albumin was decreased to a greater extent by increasing degradability of low CP diets (0.26 g/dl) compared with high CP diets (0.02 g/dl). Concentrations of each SNAN fraction in RD (p<0.01) and OD (p<0.05) for high CP diets were higher than those for low CP diets, except for peptides but concentrations of the sum of peptide and free amino acid in RD and OD were significantly higher (p<0.05) for high CP diets than for low CP diets. Soybean meal diets increased free amino acid and peptide concentrations in both RD (p<0.01) and OD (p<0.05) compared to CGM diets. High level and greater degradability of CP increased (p<0.001) mean concentrations of total SNAN in RD and OD. These results suggest that RDP contents, increased by higher level and degradability of dietary protein, may increase release of free amino acids, peptides and soluble proteins in the rumen and omasum from ruminal degradation and solubilization of dietary proteins. Because SNAN in OD indicates the terminal product of ruminal metabolism, increasing CP level and degradability appears to increase the amount of intestine-available nitrogen in the liquid phase.

Seasonal Diet Affects Ammonia Emissions from Tie-Stall Dairy Barns

Federal and state regulations are being promulgated under the Clean Air Act to reduce hazardous air emissions from livestock operations. Although much is known about air emissions from livestock operations in Europe, few data are available on emissions from livestock facilities in the United States and the management practices that may minimize these emissions. The objective of this study was to measure seasonal and diet effects on ammonia emissions from experimental tie-stall dairy barns located in central Wisconsin. Four experimental chambers each housed 4 lactating Holstein dairy cows for three 28-d trial periods corresponding to spring, early fall, and winter. A 4×4 Latin square statistical design was used to evaluate 4 diets [corn silage (CS)- or alfalfa silage (AS)-based diets at low or high crude protein] in each chamber for a 4-d ammonia monitoring period. Partially due to higher crude protein levels, average ammonia-N emissions during spring (18.8 g/cow per d) were approximately twice the emissions recorded during early fall (8.4 g/cow per d) and 3 times greater than emissions during winter (6.7 g/cow per d). Ammonia-N emissions accounted for approximately 1 to 3% of consumed feed N, 2 to 5% of excreted manure N, and 4 to 11% of manure ammonical N. Nighttime ammonia emissions were on average 30% lower than daytime emissions. Forage type did not affect ammonia emissions during winter or early fall. Only during early spring were ammonia emissions lower from chambers containing cows fed low-CP diets than from cows fed high-CP diets. Of the total chamber N inputs (feed and bedding), 93, 91, and 95% were recovered in N outputs (milk, manure, body weight change, and ammonia N) during spring, early fall, and winter trials, respectively. Confidence in the accuracy of ammonia emission results was gained by the relatively high chamber N balances and favorable comparisons of study data with published relationships among the variables of feed N intake, milk urea N, manure N, and urine N excretion, and ammonia emissions.

Effects of Dietary Metabolizable Energy and Protein on Early Growth Responses of Broilers to Dietary Lysine

Two studies evaluated effects of metabolizable energy (ME), digestible Lys (dLys), and amino acid (AA) balance on broiler performance. In experiment 1 diets contained 3 levels of ME (3,000, 3,100, and 3,200 kcal/kg) in combination with 4 levels of dLys (1.05, 1.13, 1.21, and 1.29%). A fixed proportion of dLys relative to CP and key indispensable AA was maintained in graded increments of CP from 21.9 to 26.9%. There was no interaction of ME and dLys for 21 d BW gain or adjusted feed conversion ratio, which improved linearly with dietary dLys. Increasing the dLys or ME had no effect on feed intake, and the linear improvement in performance was attributed to a step-wise increase in dLys when diets contained a balance of AA and CP. Experiment 2 evaluated broiler response to 20 d of age when diets contained graded increments in dLys while maintaining a fixed proportion of dLys relative to CP and indispensable AA (balanced CP), or when dLys was increased in diets by supplementing synthetic l-Lys to 1 of 2 basal diets with 22.0% CP (low CP) or 27.0% CP (high CP) without adjusting concentrations of other AA or CP. The BW gain of broilers fed the low CP diet series followed a quadratic response, and the dLys requirement was estimated to be 1.19 ± 0.03% (1.30% total Lys). By contrast, BW gain on both the high CP and balanced CP diet series increased linearly. The higher BW gain and continued response to dLys above 1.19% when CP and AA concentrations were increased confirmed that the dLys requirement of broilers was dependent on the dietary CP. When a fixed ratio of dLys to CP was applied and indispensable and dispensable AA were not limiting, broiler BW gain and adjusted feed conversion ratio responded positively to incremental dLys up to at least 1.32% (27.2% CP) and was independent of the dietary ME over a range from 3,000 to 3,200 kcal/kg.

조단백질 수준에 따른 갯벌 미생물 유래 단백질 분해 효소제의 급여가 육계의 생산성, 영양소 소화율 및 혈액 내 총 단백질과 혈중 요소태 질소 함량에 미치는 영향

본 연구는 육계 사료 내 조단백질 수준에 따른 갯벌 미생물 유래 단백질 분해효소제를 첨가하였을 때 생산성, 영양소 소화율 및 혈액 내 total protein과 BUN 함량에 미치는 영향을 알아보기 위해 실시하였다. 사양 시험은 2일령 Arbor Acres 육계(male) 480수를 공시하여 5주간 실시하였다. 시험 설계는 기초 사료 내 조단백질 함량과 효소제의 첨가 유무에 따라 high crude protein diet 처리구, high crude protein diet에 단백질 분해 효소제를 첨가한 처리구(high crude protein diet+0.1% protease), low crude protein diet 처리구 및 low crude protein diet에 단백질 분해 효소제를 첨가한 처리구(low crude protein diet+0.1% protease)로 4처리(<TEX>$2{\times}2$</TEX> factorial)를 하여 처리당 6반복, 반복당 20수씩 완전 임의 배치하였다. 전체 사양 시험 기간 동안, 증체량은 high crude protein diet 처리구들과 low crude protein diet에 단백질 분해 효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 높게 나타났다(P<0.05). 사료 섭취량에서는 처리구간에 유의적인 차이를 보이지 않았다. 사료 요구율에서는 high crude protein diet 처리구들과 low crude protein diet에 단백질 분해 효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 낮게 나타났다(P<0.05). 또한, 건물 소화율은 high crude protein diet 처리구들과 low crude protein diet에 단백질 분해효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 높게 나타났고(P<0.05), 질소 소화율에서는 high crude protein diet에 단백질 분해 효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 증가하였다(P<0.05). 혈액 내 total protein 함량은 high crude protein diet 처리구가 다른 처리구들과 비교하여 유의적으로 증가하였고(P<0.05), BUN 함량은 처리구들 간에 유의적인 차이를 보이지 않았다. 결론적으로, 육계 사료 내 조단백질 수준에 따른 갯벌 미생물 유래 단백질 분해효소제의 첨가는 증체량, 사료 요구율, 영양소 소화율을 개선시켰고, 혈액 내 total protein 함량에 영향을 미쳤다. This study was conducted to investigate the effects of mud flat bacteria origin protease supplementation by crude protein level on growth performance, nutrient digestibility, total protein and BUN (blood urea nitrogen) concentration in broilers. A total of four hundred eighty broilers were randomly allocated into four treatments with six replications for five weeks. Dietary treatments included 1) high crude protein diet, 2) high crude protein diet + 0.1% protease, 3) low crude protein diet and 4) low crude protein diet + 0.1% protease. During the entire experimental period, weight gain and feed/gain were improved in treatments of high crude protein diets and low crude protein diet added protease compared with treatment of low crude protein diet without protease (P<0.05). Similarly, DM digestibility was also improved in treatments of high crude protein diets and low crude protein diet added protease compared with treatment of low crude protein diet without protease (P<0.05). N digestibility was improved in treatment of high crude protein diet added protease compared with low crude protein diet without protease (P<0.05). Total protein concentration in blood was increased in treatment of high crude protein diet without protease compared with other treatments (P<0.05). In conclusion, mud flat origin protease was effective in improving weight gain, feed/gain and nutrient digestibility, and influenced blood total protein in broilers.

Interactive effects of dietary crude protein and fermentable carbohydrate levels on odour from pig manure

The objective of this study was to determine the effects of dietary levels of crude protein (CP) and levels of fermentable carbohydrates (FC) and their interaction on odour emission, odour intensity, odour hedonic tone, and ammonia emission from pig manure, and manure characteristics. An experiment was conducted with finishing pigs ( n = 36) in a 2 × 3 factorial randomized complete block arrangement with 6 treatment combinations in 6 blocks. There were 2 dietary CP levels (low 12%; high 18%) and 3 digestible FC levels: (low 95.5; medium 145.5; and high 195.5 g/kg feed, as-fed basis). Pigs with an initial body weight (BW) of 57.7 ± 2.5 kg were penned individually in partly slatted floor pens. Faeces and urine of each pig accumulated in separate manure pits under the slatted floor. In the 6th week of the collection period air samples were collected directly above the manure in each pit. Manure samples were taken for manure characteristics. Air samples were analyzed for odour concentration and for hedonic tone and odour intensity. Manure samples were analyzed for volatile fatty acids (VFA), indoles, phenoles, sulphurous compounds, ammonium, and total N concentrations. Dietary CP level and FC level did not affect odour emission, odour intensity and hedonic tone but their interaction affected odour emission at P = 0.06. At a high dietary CP level, increased FC level decreased odour emission, while at a low CP level, increased FC level increased odour emission from pig manure. Total N and ammonium concentrations, and ammonia emission from pig manure were reduced at low dietary CP level ( P < 0.001). High FC level led to low ammonia emission from pig manure ( P = 0.01). Manure pH increased at high dietary CP level ( P < 0.001) and decreased when FC level increased ( P < 0.05). Total VFA concentration increased at high dietary CP level ( P < 0.001) and when FC level increased ( P < 0.001). Enhanced dietary CP increased the manure concentrations of phenol (P < 0.001), cresols ( P = 0.01), indole ( P < 0.001), 4-ethylphenol ( P < 0.001) and carbon disulfide ( P < 0.001), but FC did not affect concentrations of these compounds ( P > 0.05) in the manure. We conclude that the interaction between dietary CP and FC plays a role in odour production and emission. Ammonia emission from pig manure can be reduced substantially by decreasing dietary CP and by increasing FC.

Effect of Dietary Cation-Anion Difference and Dietary Crude Protein on Performance of Lactating Dairy Cows During Hot Weather

Thirty-two lactating Holstein cows (225±63 d in milk) were used in a 6-wk trial to determine the effect of dietary cation-anion difference (DCAD) and dietary crude protein (CP) concentration on milk and component yield, acid-base status, and serum AA concentrations during hot weather. Treatments were arranged as a 2×2 factorial within a randomized complete block design to provide 15 or 17% CP and a DCAD of 25 or 50 mEq (Na + K-Cl)/100g of dry matter (DM). A DCAD×CP interaction was detected for milk yield; milk yield was less for high DCAD than for low DCAD for the high-CP diets. No differences were noted at low dietary CP. Milk fat percentage was greater for high DCAD than for low DCAD, and high-CP diets supported greater milk fat percentage than low-CP diets. No differences were observed among treatments for dry matter intake or milk protein percentage. Serum total AA and essential AA concentrations and ratio of essential AA:total AA were greater for high DCAD. These results suggest that increasing DCAD improves AA availability for protein synthesis by taking the place of AA that would otherwise be used for maintenance of acid-base balance. A better understanding of the mechanisms behind this AA-sparing effect will improve management of protein nutrition in the lactating dairy cow.

Dietary protein and fermentable carbohydrates contents influence growth performance and intestinal characteristics in newly weaned pigs

Abstract Increasing the dietary amount of fermentable carbohydrates (FC) may counteract the negative effects of protein fermentation in newly weaned piglets. To study this hypothesis, 272 newly weaned piglets were allotted to 4 dietary treatments in a 2 × 2 factorial arrangement with low and high FC (7.5 and 13.5%) and crude protein (CP, 15 and 22%) content as respective factors. Intestinal histology, enzyme activity, microbiota and fermentation products were determined in 8 pigs per treatment 7 days post-weaning. In the 4 wk experimental period, interactions between dietary CP and FC content were found for feed intake ( P = 0.022), daily gain ( P = 0.001), and gain:feed ( P = 0.033). The high-FC content reduced daily gain by 50 g/d in the low-CP diet, whereas the FC content did not affect growth performance in the high-CP diet. Over the 4 wk experimental period, daily gain (350 g/d) and feed intake (519 g/d) were highest for piglets on the low-CP low-FC diet. The high-FC content resulted in an increase in number of lactobacilli ( P = 0.047) and a decrease of total coliforms ( P = 0.06) in the small intestine. It increased the lactic acid content ( P = 0.08) and reduced the ammonia content ( P = 0.04) in the small intestine and increased the VFA content in the colon ( P = 0.009). The reduction in CP content reduced ammonia concentration in the small intestine ( P = 0.003). We concluded that dietary FC influenced microbial population and fermentation products in the gut. However, this was not reflected in an increased growth performance.

The effect of dietary crude protein concentration and inulin supplementation on nitrogen excretion and intestinal microflora from finisher pigs

A 2 × 2 factorial experiment was used to investigate the interaction between dietary crude protein (CP) concentration (200 vs 140 g/kg) and inulin supplementation (0 vs 12.5 g/kg) on nitrogen (N) excretion and intestinal microflora from 16 boars (n = 4, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high CP diets had a higher excretion of urinary N (P < 0.01), faecal N (P < 0.01) and total N (P < 0.001) than the pigs offered the low CP diets. Inulin supplementation increased faecal N excretion (P < 0.05) and decreased urine: faeces N ratio (P < 0.05) compared to the inulin free diets. There was no significant effect (P > 0.05) of dietary treatment on N retention. There was an interaction (P < 0.05) between dietary CP concentration and inulin supplementation on caecal E.coli. Pigs offered the diet containing 200 g/kg CP plus inulin decreased the population of E.coli compared to the inulin supplemented 140 g/kg protein diet. However, CP concentration had no significant effect on the population of E.coli in the unsupplemented diets. Inulin supplementation increased caecal bifidobacteria (P < 0.01) compared to the inulin free diets. In conclusion, inulin supplementation favourably altered N excretion and lowered the population of E.coli at high CP concentrations.

The effect of high and low dietary crude protein and inulin supplementation on nutrient digestibility, nitrogen excretion, intestinal microflora and manure ammonia emissions from finisher pigs

A 2 × 2 factorial experiment was performed to investigate the interaction between a high- and low-crude-protein (CP) diet (200 v. 140 g/kg) and inulin supplementation (0 v. 12.5 g/kg) on nutrient digestibility, nitrogen (N) excretion, intestinal microflora, volatile fatty acid (VFA) concentration and manure ammonia emissions from 24 boars (n = 6, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high-CP diets had a higher excretion of urinary N (P < 0.001), faecal N (P < 0.01) and total N (P < 0.001) than the pigs offered the low-CP diets. Inulin supplementation increased faecal N excretion (P < 0.05) and decreased the urine N : faeces N ratio (P < 0.05) compared with the inulin-free diets. There was no effect (P > 0.05) of dietary treatment on N retention. There was an interaction (P < 0.05) between dietary CP concentration and inulin supplementation on caecal Enterobacteria spp. Pigs offered the diet containing 200 g/kg of CP plus inulin decreased the population of Enterobacteria spp. compared to those with the inulin-supplemented 140 g/kg CP diet. However, CP level had no significant effect on the population of Enterobacteria spp. in the unsupplemented diets. Inulin supplementation increased caecal Bifidobacteria (P < 0.01) compared with the inulin-free diets. There was no effect of inulin supplementation on VFA concentration or intestinal pH (P > 0.05). Pigs offered the 200 g/kg CP diets had higher (P < 0.05) manure ammonia emissions from 0 to 240 h of storage than pigs offered the 140 g/kg CP. In conclusion, inulin supplementation resulted in an increase in Bifidobacteria concentration and a reduction in Enterobacteria spp. at the high CP level indicating that inulin has the ability to beneficially manipulate gut microflora in a proteolytic environment.

The effect of dietary protein and fermentable carbohydrates levels on growth performance and intestinal characteristics in newly weaned piglets1

Reducing the CP content and increasing the fermentable carbohydrates (FC) content of the diet may counteract the negative effects of protein fermentation in newly weaned piglets fed high-CP diets. To study the synergistic effects of CP and FC on gut health and its consequences for growth performance, 272 newly weaned piglets (26 d of age, 8.7 kg of BW) were allotted to 1 of 4 dietary treatments in a 2 x 2 factorial arrangement, with low and high CP and low and high FC content as the factors. Eight piglets from each dietary treatment were killed on d 7 postweaning. Feces and digesta from ileum and colon were collected to determine nutrient digestibility, fermentation products, and microbial counts. In addition, jejunum tissues samples were collected for intestinal morphology and enzyme activity determination. During the entire 4-wk period, interactions between the dietary CP and FC contents were found for ADFI (P = 0.022), ADG (P = 0.001), and G:F (P = 0.033). The high-FC content reduced ADFI, ADG, and G:F in the low-CP diet, whereas the FC content did not affect growth performance in the high-CP diet. Lowering the CP content of the low-FC diet improved ADFI and ADG, whereas lowering the CP content of the high-FC diet did not influence growth performance. The low-CP diets resulted in a lower concentration of ammonia in the small intestine (P = 0.003), indicating reduced protein fermentation. In the small intestine, the high FC content increased the number of lactobacilli (P = 0.047), tended to decrease the number of coliforms (P = 0.063), tended to increase the lactic acid content (P = 0.080), and reduced the concentration of ammonia (P = 0.049). In the colon, the high-FC diets increased the concentration of total VFA (P = 0.009), acetic acid (P = 0.003), and butyric acid (P = 0.018), and tended to decrease the ammonia concentration (P = 0.076). Intestinal morphology and activity of brush border enzymes were not affected by the diet, although maltase activity tended to decrease with increasing dietary FC (P = 0.061). We concluded that an increase in the dietary FC content, and to a lesser extent a decrease in the CP content, reduced ammonia concentrations and altered the microflora and fermentation patterns in the gastrointestinal tract of weaned piglets. However, these effects were not necessarily reflected by an increased growth performance of the piglets.

Effects of different diets on utilization of nitrogen from cattle slurry applied to grassland on a sandy soil in The Netherlands

Dietary adjustments have been suggested as a means to reduce N losses from dairy systems. Differences in fertilizing value of dairy slurry as a result of dietary adjustments were evaluated in a 1-year grassland experiment and by long-term modelling. Slurry composition of non-lactating dairy cows was manipulated by feeding diets with extreme high and low levels of dietary protein and energy. C:Ntotal ratio of the produced slurries ranged from 5.1 to 11.4. To evaluate their short-term fertilizer N value, the experimental slurries (n = 8) and slurries from commercial farms with variable composition (n = 4), were slit-injected in two grassland fields on the same sandy soil series in the north of The Netherlands (53°10?N, 6°04?E), with differences in sward age and ground water level. The recently established grassland field (NEW) was characterized by lower soil OM, N and moisture contents, less herbs and more modern grass varieties compared to the older grassland field (OLD). Slurry was applied in spring (100 kg N ha?1) and after the first cut (80 kg N ha?1) while in total four cuts were harvested. Artificial fertilizer N treatments were included in the experiment to calculate the mineral fertilizer equivalent (MFE) of slurry N. The OLD field showed a higher total N uptake whereas DM yields were similar for the two fields. Average MFE of the slurries on the OLD field (47%) was lower than on the NEW field (56%), probably as a result of denitrification of slurry N during wet conditions in spring. Slurries from high crude protein diets showed a significantly higher MFE (P <0.05) compared to low crude protein diets. No significant differences in MFE were observed between slurries from high and low energy diets. On both fields, MFE appeared to be positively related to the ammonium content (P <0.001) and negatively to the C:Ntotal ratio of the slurry DM (P = 0.001). Simulation of the effect of long-term annual application of 180 kg N ha?1 with highest and lowest C:Ntotal ratio suggested that both slurries would lead to an increase in annual soil N mineralization. Both soil N mineralization and SOC appeared to be substantially higher in equilibrium state for the slurry with the highest C:Ntotal ratio. It is concluded that in a situation with slit-injection, the reduced first-year N availability of slurry with a high C:Ntotal ratio as observed in the grassland experiment will only be compensated for by soil N mineralization on the very long term.

Dietary Energy and Crude Protein Requirement for Chicks of Nigeria Local Fowl and Crossbreeds

2 Abstract: Unsexed chicks of the Nigeria local fowl were mated inter se and the birds mated with males of improved eggs strain (local x medium) or from broiler strain (local x large) were raised on 240g/kg or 200g/kg dietary crude protein and 3000kcal/kg of metabolizable energy from day old to 12 weeks of age on deep litter to determine their performance on different dietary energy and crude protein rations. Whereas the pure local birds grew significantly (P<0.05) slower than the crossbreeds and were not affected in growth rate by dietary regime, the crossbreeds showed improved benefit from the higher dietary crude protein with age to the extent of their growth potentials. Initial rearing of the birds had the most favourable effect with the local birds crossed with broiler type on 240g/kg followed by 200g/kg crude protein transferred at 8 weeks of age of the birds, while the local birds crossed with egg type males are intermediate. The performance of the birds was worse regardless of the initial dietary crude protein and the age of transfer. It is concluded that the Nigerian Local fowl performs slower than their crossbreeds and are unaffected in growth rate by dietar y manipulations.

Effect of Varying Levels of Energy and Protein on Live Performance and Carcass Characteristics of Broiler Chicks

An experiment involving 270 straight run one-day-old Hubbard broiler chicks was conducted on floor pens to investigate the effect of different levels of energy and protein on live performance and carcass responses of broilers chicks. Six broiler starter diets with two levels of metabolizable energy (ME) i.e., 2800 and 3000kcal/kg each with three levels of crude protein (CP) i.e., 20, 21 and 22% were offered to birds from hatching to 28d of age. Similarly, six broiler finisher diets with two levels of ME i.e. 3000 and 3200kcal/kg and 3 levels of CP i.e. 16, 17 and 18%, and 18, 19 and 20%, respectively, were offered during 29-42d of age. The chicks were randomly divided into 18 replicate of 15 chicks each and there were 3 replicates under each diet. Feed intake was significantly (p<0.05) high in diet having low ME during both phase, with 20 and 22% CP during starter phase whereas all CP levels showed non-significant effects on feed intake at finisher phase. Low ME and high CP diets showed high feed intake (p<0.05) during starter and finisher phases. Higher weight gains (p<0.05) were observed at low ME diets during the experiment. Dietary CP contents at low ME did not affect the weight gain during starter phase whereas high CP with low ME showed high weight gain in finisher phase. The response of CP and ME was similar for good feed conversion ratio (FCR) as was observed for feed intake and weight gain. No significant differences of dietary treatments were observed on any of the carcass characteristics. From the recent study, it is obvious that low ME and high CP diets promised optimum performance for broiler chicks at both starter and finisher phases.

Effect of dietary protein and rumen degradable organic matter on milk production and efficiency in heat-stressed goats

Four Israeli mix-breed Saanen dairy goats were used in a 2×2 factorial design to evaluate the effect of the level of dietary crude protein (CP) and ruminally degradable OM (RDOM) concentration on the production, composition and efficiency of milk production under hot ambient conditions. Daily ration comprised of 30% hay and 70% concentrates was divided into 12 equal meals. Treatment factors were 18% (HCP) or 15% (LCP) of CP in the diet DM, and 56% (HRDOM) or 50% (LRDOM) of RDOM. Goats were housed in metabolic crates in air-conditioned room. Air temperature ranged between 25 °C and 36 °C, and the thermal humidity index (THI) between 74 and 90 units. Daily amplitude of goat's body temperature was 1.2 °C and was unaffected by treatments. The DM intake, milk yield, and concentrations of protein, fat, and lactose, as well as total tract apparent digestibility of DM and OM were similar among treatments ( P>0.1). Digestibility of CP was higher in the HCP diets ( P<0.01), and digestibilities of NDF was higher in the LRDOM diets ( P<0.01). Digestibility of non-structural carbohydrates was higher in the high RDOM diets and high CP diets ( P<0.1). Blood glucose and insulin concentrations were similar among treatments ( P>0.1), while NEFA level was higher in LRDOM ( P<0.1). Rumen N-ammonia ( P<0.05) and milk N-urea ( P<0.01) were lower, and plasma N-urea tended to be lower in LCP diets ( P<0.15). Overall, these data indicate that N utilization was lowered in goats consuming the high CP diets. It was concluded that diets comprising 15% of CP in DM are adequate for dairy goats exposed to daily high environmental temperatures, and moderate temperatures at night. Though varying dietary RDOM levels did not affect milk N efficiency, the higher NSC digestibility, and the concomitant lower blood NEFA suggest a reduced heat increment in dairy ruminants consuming HRDOM diets.

The effect of protein intake on performance of cows in hot environmental temperatures.

Two trials were conducted with cows in commercial herds during midlactation to evaluate the effect of dietary crude protein (CP) concentration on the production, composition, and efficiency of milk production under hot ambient conditions. Cows were group-fed in trial 1, which was conducted in two herds, and were fed individually in trial 2. The respective average ambient temperature, relative humidity, and temperature-humidity index (THI) were 31 degrees C, 45%, and 78 in trial 1 and 27 degrees C, 70%, and 76 in trial 2. Cows were cooled by forced evaporative means six times daily in trial 1 and three times daily in trial 2. Dietary CP was 15.3 or 17.3% of dry matter (DM) in trial 1 and 15.1 or 16.7% of DM in trial 2. The respective ratios of rumen-degradable organic matter (RDOM) to rumen-degradable protein were 5.3 and 4.8 for the low CP (LP) and high CP (HP) diets. Average DM intake, milk yield, and milk fat and protein concentrations were 22 and 23 kg/d, 34 and 35 kg/d, 3.1 and 3.4%, and 3.2 and 3.1% in trials 1 and 2, respectively, and were similar among diets in both trials. The resultant calculated milk protein efficiency ratio and overall CP efficiency were 0.31 and 0.32 for the LP diets and 0.28 and 0.29 for the HP diets. In cows fed the LP diet, diet rumen ammonia was lower in trial 1, and milk urea N was lower in trial 2. The BW change was higher in trial 1, and tended to be higher in trial 2, with the LP diets. Changes in body condition score in trials 1 and 2 tended to be higher with the LP diets. It was concluded that a dietary CP content of 15.3% is adequate to maintain production in heat-exposed dairy cows producing 35 kg of milk/d, provided that the forced evaporative cooling and the ratio of RDOM to rumen-degradable protein is appropriate

Effects of dietary threonine and crude protein on growth performance, carcase and meat composition of broiler chickens

1. The aim of the study was to investigate the effects of dietary threonine (Thr) and crude protein (CP) in maize–soybean meal based diets on the growth performance, carcase traits and meat composition of broiler chickens and to determine the dietary Thr requirement for optimum performance (weight gain and feed conversion efficiency (FCE)) at 0 to 3 weeks and 3 to 6 weeks of age. 2. Two basal diets that differed in CP (191·3 or 179·7 and 176·7 or 165·4 g/kg at 0 to 3 and 3 to 6 weeks, respectively) were formulated to have identical contents of Thr (6·0 and 5·4 g/kg), energy (12·97 and 13·39 MJ ME/kg) and other essential amino acids except for Gly + Ser. Basal diets were supplemented with l-Thr from 0·6 to 1·8 g/kg in 0·6 g/kg increments. Broiler chicks (540) were randomly allocated to 9 dietary treatments with 6 replicates of 10 (5 female, 5 male) chicks. 3. A significant interaction between dietary CP and Thr was found for feed intake, body weight (BW) gain and FCE. Increasing Thr supplementation improved feed intake, BW gain and FCE, especially in high CP diets in both feeding periods. 4. Incremental increases in dietary Thr increased breast yield at both CP levels and drumstick yield only on high CP diets. The proportion of thigh decreased with Thr concentration. Liver weight was significantly reduced by Thr supplementation; abdominal fat was not affected. 5. Estimated Thr requirements for FCE increased as dietary CP increased according to an exponential model. This model indicated higher Thr requirements than those of broken-line models for growth performance.