Reduction of ammonia emission from growing pig rooms by feeding a lower protein diet supplemented with apple pomace

An experiment was conducted to determine the effect of supplementing a reduced crude protein (CP) diet with apple pomace on the ammonia emissions from growing pig rooms. Four pigs (45 kg BW) each were assigned to one of two diets. Each group was housed in a separate room and fed a standard diet (CP 16.6%) or a low CP, amino acid‐supplemented diet (CP 9.1%) containing 23.1% of dried apple pomace for two 7‐day experimental periods. After the completion of the first period, the pigs were switched to the other diet. The daily ammonia emissions, measured for 3 days after a 4‐day adaptation period, were much lower for pigs fed the apple pomace‐supplemented diet than for pigs fed the standard diet (0.47 g/pig vs 7.30 g/pig, respectively). The daily nitrogen intake for the standard diet and the apple pomace‐supplemented diet was 58.1 and 35.5 g/pig, respectively. The pigs fed the apple pomace‐supplemented diet excreted more fecal nitrogen than pigs fed the standard diet (17.5 g/day vs 11.0 g/day, respectively), but urinary nitrogen excretion with the apple pomace‐supplemented diet was estimated to be 2.9 g/day, which was much lower than that for the standard diet (27.0 g/day). The addition of apple pomace to a reduced CP, amino acid‐supplemented diet reduces urinary nitrogen excretion and thereby ammonia emission.     

Effect of soybean hull supplementation to finishing pigs on the emission of noxious gases from slurry

Ninety six pigs were assigned on the basis of body weight (BW) to one of four dietary treatments (4 pigs per pen and 6 pens per treatment) and fed for 4 weeks. Four 14.85% CP diets were formulated to contain graded levels of soybean hulls at 0, 5, 10, or 15%, respectively. The results showed that treatments did not affect growth performance. Coefficient of total tract apparent digestibility (CTTAD) for dry matter (DM) and blood urea nitrogen (BUN) concentrations were decreased linearly ( P  < 0.05) with the addition level of soybean hulls. Slurry ammonia nitrogen (NH₃-N) was not affected with the increased soybean hulls levels, but volatile fatty acids (VFA) were linearly ( P  < 0.05) increased. Slurry pH and ammonia (NH₃) emissions were significantly decreased by the addition of soybean hulls (Linear, P  < 0.05). Conversely, slurry hydrogen sulphide (H₂S) emissions exhibited an increase with the addition of soybean hulls (Linear, P  < 0.10). Our data indicate that soybean hulls inclusion can decrease slurry pH value and NH₃ emission without any negative influence on growth performance.     

低蛋白饲粮添加植酸酶和非淀粉多糖酶对生长猪生长性能和养分排泄量的影响

试验旨在研究低蛋白质饲粮添加植酸酶和非淀粉多糖(NSP)酶对生长猪生长性能、养分排泄量的影响。54头平均初始体重为(41.92±2.6)kg的杜长大三元杂交猪分为3组,每组3个重复,每个重复6头猪。1组为对照组(饲粮粗蛋白质水平为17.4%),2、3组为试验组,2组在1组基础上,饲粮粗蛋白质水平降至14.3%、总磷水平降低0.1个百分点,添加植酸酶;3组在2组基础上添加NSP酶,试验期38 d。试验结果表明,2组的平均日增重、料重比比1组分别提高7.64%和1.94%(P0.05),其余各组间差异不显著(P0.05);粪N浓度2、3组比1组分别降低18.58%、23.01%(P0.05);粪P浓度2、3组比1组分别降低40.23%、39.08%(P0.01)。由此可见,将常规饲粮粗蛋白质水平降低3个百分点、总磷水平降低0.1个百分点,并添加植酸酶,能显著提高生长猪平均日增重,显著减少粪氮含量,极显著减少粪磷含量;在此基础上,继续添加NSP酶不影响生长猪生长性能和粪中养分含量。     

Nutrient digestibility, faecal physicochemical characteristics and bacterial glycolytic activity of growing pigs fed a diet supplemented with oligofructose or trans-galactooligosaccharides

The effect of oligofructose (FOS) or trans-galactooligosaccharides (TOS) inclusion at 10 g/kg diet for growing pigs, at the expense of cornstarch (CON), on growth performance, nutrient digestibilities, and faecal physicochemical parameters was determined. In addition, concentration of volatile fatty acids (VFA) and bacterial -glucosidase, β-glucosidase, β-galactosidase and β-glucuronidase activities in faeces were determined as markers of intestinal microflora metabolic activity. Twelve 35-day-old castrated pigs were allocated to CON, FOS and TOS dietary treatments for an experimental period of 4 weeks. Dietary treatments did not affect animal growth performance. FOS and TOS pigs tended to have a lower faecal output than CON pigs by approximately 6.0% and 1.7% respectively. FOS and TOS did not affect total tract apparent digestibility of dry matter, organic matter, fat, crude protein, crude fiber, ADF and cellulose. Digestibility of carbohydrate components such as nitrogen free extract and NDF was significantly (P ≤ 0.05) higher in TOS pigs compared to CON and FOS. Digestibility of hemicellulose in TOS pigs did not differ from FOS but was significantly higher from CON. The experimental period had a significant effect on most of the parameters determined. There were no significant (P ≤ 0.05) differences between treatments regarding total VFA concentration and faecal bacterial enzyme activities. Nevertheless, an increased saccharolytic activity in the gut of FOS and TOS pigs could be postulated by the trends for apparently higher VFA concentration and bacterial -glucosidase and β-galactosidase activities.     

Apparent and standardized ileal digestibility of amino acids in diverse barley cultivars fed to growing pigs

The objectives of this study were to determine the chemical composition, ileal amino acid (AA) digestibility of barley varieties and to develop equations to predict the AA digestibility based on the chemical characteristics of individual barley. A wide selection of nine barley varieties in the main growing regions of China was used in the experiment. Ten crossbred pigs (30.9 ± 1.8 kg) were allotted to a 6 × 10 Youden Square. The treatments included a nitrogen‐free diet and nine barley test diets. Considerable variation was observed in the content of neutral detergent fiber, acid detergent fiber, crude protein (CP) and all AAs among the barley samples. The standardized ileal digestibility (SID) of indispensable AAs with the exception of arginine, phenylalanine and threonine were different (P < 0.05) among the nine barley sources tested. With R² values exceeding 0.50, significant linear regression equations for CP and threonine were obtained. In conclusion, significant differences existed in the ileal digestibility of CP and AAs among barley varieties. It is difficult to predict the SID of most of the amino acids in barely based upon chemical characteristics.     

Efficacy of probiotics from anaerobic microflora with prebiotics on growth performance and noxious gas emission in growing pigs

We investigated the effect of probiotics from anaerobic microflora with prebiotics (synbiotics) on growth performance, noxious gas emission and fecal pathogenic bacteria populations in growing pigs. The basal diet, which contained approximately 25% corn, 24% whey, 12% wheat and 12% soybean meal, was supplemented alternatively with 0.15% antibiotics (US diet), prebiotics and 0.2% probiotics from anaerobic bacteria (BS diet), yeast (YS diet), mold (MS diet) or compounds (CS diet). One hundred and fifty pigs were fed an experimental diet for 15 days. Although the growth performance was not affected by supplemental synbiotics, the BS group showed higher dry matter and crude protein digestibility. The BS group decreased fecal ammonia and amine gas emissions, and increased fecal acetate gas emission compared with the US group. All synbiotics groups decreased in fecal propionate gas emission. Fecal Escherichia coli population was lower in the synbiotics groups than in the US group. Therefore, the results of the present study suggest that synbiotics exert similar effects with antibiotics on the nutrient digestibility and fecal microflora composition in growing pigs. Moreover, synbiotics can also decrease the fecal noxious gas emission in growing pigs.     

精油对生长猪蛋白质和氨基酸等回肠末端表观消化率的影响

试验旨在通过采用T型瘘管法,研究精油对生长猪蛋白质和氨基酸等回肠末端表观消化率的影响。试验选用6头(杜×长×大)去势公猪([28.6±1.3)kg],采用3×3双拉丁方试验设计,分别饲喂正对照日粮:玉米-豆粕型基础日粮+抗生素;负对照日粮:无抗基础日粮;精油组日粮:负对照+0.01%精油。每个试验期为7 d,前5 d为适应期,后2 d为食糜收集期。结果表明,在日粮中添加精油可提高(P<0.05)蛋白质、能量、精氨酸、赖氨酸、亮氨酸、色氨酸、蛋氨酸、丙氨酸、总必需氨基酸、总氨基酸的回肠末端表观消化率,并有提高干物质、苏氨酸、天冬氨酸、丝氨酸和酪氨酸表观消化率的趋势(P<0.10)。在日粮中添加0.01%的精油可提高生长猪蛋白质、能量、总必需氨基酸和总氨基酸的回肠末端表观消化率,并有提高干物质表观消化率的趋势。     

Growth performance, energy, and nitrogen balance of weanling pigs fed a cereal-based diet supplemented with Chinese rhubarb

Forty Swiss Large White piglets of 4 weeks of age were used to determine the effect of dietary Chinese rhubarb on growth performance, as well as on energy and nitrogen metabolism by means of indirect respiration calorimetry studies. A cereal-based diet, supplemented with four different dosages of Chinese rhubarb (0.0%, 0.25%, 0.5%, 1%), was offered ad libitum to the piglets. Gaseous exchange was measured, and urine, faeces, and blood samples were taken. The addition of 0.25% dietary rhubarb increased feed intake (+32%) and daily weight gain (+67%) compared to the diet containing the greatest amount of rhubarb (1%). The piglets fed diet supplemented with 0.25% rhubarb digested and metabolised more energy and nitrogen relative to the animals of treatment 1%. As a consequence, the same group (0.25%) converted more energy and nitrogen into body protein than piglets receiving diet supplemented with 1% rhubarb. However, compared to the control group, the addition of 0.25% rhubarb to the diet resulted in not significantly alter growth performance, energy, and nitrogen metabolism of the animals.Blood parameters were not affected by the rhubarb supplementation. The dose-responding effect of Chinese rhubarb was reflected by the dry matter content of faecal samples. According to the laxative effect of higher doses of rhubarb, the addition of 1% rhubarb to the diet reduced dry matter content of faeces. This effect was well visible in practice, although not relevant in statistical terms. The addition of 0.5% dietary rhubarb had no relevant effect on growth performance or on energy and nitrogen metabolism of treated animals.     

Reduced diet crude protein level, benzoic acid and inulin reduced ammonia, but failed to influence odour emission from finishing pigs

Intensified pig production is associated with odour and ammonia emissions causing nuisance and environmental concerns. The aim of four experiments was to investigate the effect of different dietary interventions on odour and ammonia emissions from finishing pigs. In exp. 1, diet crude protein levels of 16% and 14% were compared. In exps. 2 and 3, the effect of adding 1% and 3% benzoic acid, respectively, to the diets was studied. In exp. 4, inclusion of 15% inulin in the diet was investigated. All experiments were carried out in two identical climate chambers with three pens. There were 12 pigs per pen in total 36 pigs per chamber. Each dietary treatment was repeated two times. The temperature, ventilation rate and concentrations of NH₃ in the exhaust air were measured every hour. Odour concentration was measured in samples of the exhaust air by olfactometry. Reduced diet crude protein, the addition of 3% benzoic acid and inclusion of 15% inulin reduced ammonia emission by 30%, 57% and 34%, respectively. It was not possible to influence odour emission in any of the experiments.     

The effects of birth weight and estimated breeding value for protein deposition on nitrogen efficiency in growing pigs

The effects of birth weight (BiW; low BiW [LBW] vs. high BiW [HBW]) and estimated breeding value (EBV) for protein deposition (low EBV [LBV] vs. high EBV [HBV]) on N retention, N efficiency, and concentrations of metabolites in plasma and urine related to N efficiency in growing pigs were studied. At an age of 14 wk, 10 LBW–LBV (BiW: 1.07 ± 0.09 [SD] kg; EBV: −2.52 ± 3.97 g/d, compared with an average crossbred pig with a protein deposition of 165 g/d), 10 LBW–HBV (BiW: 1.02 ± 0.13 kg; EBV: 10.47 ± 4.26 g/d), 10 HBW–LBV (BiW: 1.80 ± 0.13 kg; EBV: −2.15 ± 2.28 g/d), and 10 HBW–HBV (BiW: 1.80 ± 0.15 kg; EBV: 11.18 ± 3.68 g/d) male growing pigs were allotted to the experiment. The pigs were individually housed in metabolism cages and were subjected to an N balance study in two sequential periods of 5 d, after an 11-d dietary adaptation period. Pigs were assigned to a protein adequate (A) or protein restricted (R, 70% of A) regime in a change-over design. Pigs were fed 2.8 times the energy requirements for maintenance. Nontargeted metabolomics analyses were performed in urine and blood plasma samples. The N retention (in g/d) was higher in the HBW than in the LBW pigs (P < 0.001). The N retention (in g/[kg metabolic body weight (BW^0.75) · d]) and N efficiency, however, were not affected by the BiW of the pigs. The N retention (P = 0.04) and N efficiency (P = 0.04) were higher in HBV than in LVB pigs on the A regime but were not affected by EBV in pigs on the R regime. Restricting the dietary protein supply with 30% decreased the N retention (P < 0.001) but increased the N efficiency (P = 0.003). Nontargeted metabolomics showed that a hexose, free amino acids (AA), and lysophosphatidylcholines were the most important metabolites in plasma for the discrimination between HBV and LBV pigs, whereas metabolites of microbial origin contributed to the discrimination between HBV and LBV pigs in urine. This study shows that BiW does not affect N efficiency in the later life of pigs. Nitrogen efficiency and N retention were higher in HBV than in LBV pigs on the A regime but similar in HBV and LBV pigs on the R regime. In precision feeding concepts aiming to further optimize protein and AA efficiency in pigs, the variation in EBV for protein deposition of pigs should be considered as a factor determining N retention, growth performance, and N efficiency.     

Effects of low protein diet and low protein diet supplemented with synthetic essential amino acids on meat quality of broiler chickens

We investigated the effects of a low crude protein (CP) diet and a low CP diet supplemented with synthetic essential amino acids (EAA) on the meat quality of broiler chickens. Twenty‐one‐day‐old chickens were assigned to one of three diets: control, low CP (LCP), or low CP supplemented with EAA (ELCP). The chickens received these diets for 10 days. The shear force value (SFV) and free glutamate content of the Pectoralis major muscle were measured as indicators of the meat toughness and taste. The collagen and crude fat content of the muscle and the cross‐sectional area of myofibers were measured to evaluate the effects of the LCP and ELCP diets on meat toughness. The SFV of the ELCP group was 47% lower than that of the control group (P < 0.01). However, the LCP diet did not affect the SFV. The collagen and crude fat content were not affected by the dietary treatment. The cross‐sectional area was lower in the LCP and ELCP groups (P < 0.05) than the control group. The free glutamate content of muscle was not affected by the dietary treatment. Thus, a low CP diet supplemented with EAA is an effective means of producing tender meat.     

低蛋白质日粮补充赖氨酸、蛋氨酸对离乳期梅花鹿氮代谢的影响

为研究低蛋白质日粮添加赖氨酸和蛋氨酸对仔鹿氮代谢的影响,采用4×4完全拉丁方试验,选取3月龄、健康、离乳梅花鹿仔鹿4只,体重为(30±0.12)kg(X?±SD),进行消化代谢试验。对照组(Ⅰ组)饲喂16.28%粗蛋白质的高蛋白质日粮,试验组饲喂13.40%粗蛋白质,添加0.23%赖氨酸,并分别添加0(Ⅱ组)、0.06%(Ⅲ组)、0.12%(Ⅳ组)蛋氨酸的低蛋白质日粮。结果表明:1)对照组蛋白质消化率显著高于Ⅱ组(P<0.01)、Ⅲ组和Ⅳ组(P<0.05),脂肪消化率显著低于Ⅱ组(P<0.01),其他营养物质消化率差异不显著(P>0.05)。2)对照组和Ⅳ组蛋氨酸消化率显著高于Ⅱ组和Ⅲ组(P<0.05),对照组其余氨基酸消化率(赖氨酸、胱氨酸除外)显著高于各试验组(P<0.05)。3)对照组吸收氮显著高于Ⅱ组(P<0.01)、Ⅲ组和Ⅳ组(P<0.05),尿氮排放量显著高于各试验组(P<0.05),氮利用率及氮生物学效价低于各试验组(P>0.05)。4)对照组尿嘌呤衍生物总排放量显著大于Ⅱ组(P<0.01)和Ⅲ组(P<0.05),尿囊素显著大于Ⅱ组(P<0.01)、Ⅲ组和Ⅳ组(P<0.05),对照组、Ⅲ组和Ⅳ组黄嘌呤和次黄嘌呤显著高于Ⅱ组(P<0.01)。补充赖氨酸、蛋氨酸可改善低蛋白质日粮仔鹿营养物质消化率利用率,除粗蛋白外其他营养物质消化率与常规蛋白质水平相近,甚至更好,提高氮沉积、氮利用率和生物学效价,改善氮平衡,减少氮排放,降低环境污染。     

Standardized ileal digestibility of amino acids in European soya bean and rapeseed products fed to growing pigs

This study was conducted to determine the chemical composition and standardized ileal digestibility coefficients (SID) of crude protein (CP) and amino acids (AA) of European soya bean and rapeseed products in pigs. Six soya bean and two rapeseed products were used as the sole dietary source of CP and AA, including raw (FFSB) and roasted full‐fat soya beans (FFSB_Roasted), soya bean (SBC) and rapeseed cake (RSC), and rapeseed meal (RSM) from Bavaria (Germany), soya bean meal (SBM) from the Danube region (Austria; SBM_Austria), a commercially available standard SBM (SBM_Std) and an imported genetically modified organism‐free SBM (SBM_GMO‐free). Eight ileal‐ cannulated pigs with an initial body weight of 32 ± 2 kg were allotted to a row‐column design with eight diets and six periods of seven days each. Trypsin inhibitor activity (TIA) ranged from 1.8 in SBM_Std to 24.5 mg/g DM in FFSB. The SID of CP and all AA in FFSB_Roasted were greater than in FFSB, but lower when compared to SBC and SBM_Austria (p < .05). The SID of CP and all AA (except glutamic acid) were not different between SBC and SBM_Austria, but the SID of CP and all AA (except methionine) were greater (p < .05) in SBC than in SBM_GMO‐free. Furthermore, the SID of CP and most AA showed a quadratic response with decreasing TIA, and there exists a quadratic response in SID of CP and all AA with increasing lysine to CP ratio and neutral detergent insoluble nitrogen (p < .05). In conclusion, variation in chemical composition and SID of CP and AA was observed in different European soya bean and rapeseed products as influenced by differences in processing conditions. European SBC and SBM_Austria can be used as alternative to imported SBM_GMO‐free and SBM_Std in diets for growing pigs.     

Effect of removal of caecal contents on nitrogen utilisation and nitrogen excretion in caecally ligated chickens fed on a low protein diet supplemented with urea

1. The effect of washing out the caecal contents on nitrogen utilisation and nitrogen excretion were examined in Single Comb White Leghorn cockerels fed on a 50 g/kg protein diet supplemented with urea. 2. Flushing out the caecal contents with saline in caecally ligated chickens produced a significantly increased nitrogen balance and increased nitrogen utilisation (P<0.05). 3. Washing out the caecal contents significantly decreased uric acid excretion but the treatment had no effect on urea and ammonia excretion. 4. Caecal bacterial contents were significantly decreased by caecal ligation and decreased further by washing out the caecal contents. 5. It is concluded that nitrogen metabolism in chickens is affected by possible changes in caecal fermentation produced by preventing substances from urine and digesta from entering the caeca.     

A longer adaptation period to a functional amino acid-supplemented diet improves growth performance and immune status of Salmonella Typhimurium-challenged pigs

We recently showed that dietary supplementation with key functional amino acids (FAA) improves growth performance and immune status of Salmonella Typhimurium (ST)-challenged pigs. It is not known if ST-challenged pigs will benefit from a longer adaptation period to FAA. The objective of this study was to evaluate the effects of different adaptation periods to diets containing FAA above requirements for growth on performance and immune response of weaned pigs subsequently challenged with ST. A total of 32 mixed-sex weanling pigs (11.6 ± 0.3 kg) were randomly assigned to 1 of 4 dietary treatments, being a basal amino acid (AA) profile fed throughout the experimental period (FAA−) or a functional AA profile (FAA+; Thr, Met, and Trp at 120% of requirements) fed only in the postinoculation (FAA+0), for 1 wk pre- and postinoculation (FAA+1), or throughout the experimental period (FAA+2). After a 14-d adaptation period, pigs were inoculated with ST (2.15 × 10⁹ CFU/mL). Growth performance, body temperature, fecal score, acute-phase proteins, oxidant/antioxidant balance, score for ST shedding in feces and intestinal colonization, and fecal and digesta myeloperoxidase (MPO) were measured pre- and postinoculation. Postinoculation body temperature and fecal score, serum haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), and fecal MPO were increased while serum albumin and plasma reduced glutathione (GSH):oxidized glutathione (GSSG) were reduced compared to pre-inoculation (P < 0.05). Average daily gain and G:F were greater in FAA+2 pigs compared to FAA− pigs (P < 0.05). Serum albumin was higher in FAA+2 and FAA+1 compared to FAA+0 and FAA− pigs (P < 0.05) while FAA+2 pigs had lower haptoglobin compared to FAA− (P < 0.05). Plasma SOD was increased and GSH:GSSG was decreased in FAA− pigs compared to the other treatments (P < 0.05). Score for ST shedding in feces was progressively lower from d 1 to 6 regardless of treatment (P < 0.05) and was lower in FAA+2 pigs compared to FAA− and FAA+0 (P < 0.05). Counts of ST in colon digesta were higher in FAA− and FAA+0 pigs compared to FAA+2 (P < 0.05). Fecal and colonic digesta MPO were lower in FAA+2 and FAA+1 pigs compared to FAA− (P < 0.05). These results demonstrate a positive effect of a longer adaptation period to FAA-supplemented diets on performance and immune status of weaned pigs challenged with Salmonella.     

Supplementation of protease,alone and in combination with fructooligosaccharide to low protein diet for finishing pigs

Effects of adding protease with or without fructooligosaccharide (FOS) to low protein diet on growth performance, nutrient digestibility and fecal noxious gas emission were evaluated in 160 finishing pigs (57.70 ± 1.16 kg) in a 9‐week study. Pigs were randomly divided into four dietary treatments, PC: positive control diet (15.97% crude protein (CP)); NC: negative control diet (12.94% CP); PRO: NC supplemented with 0.05% protease; PROFOS: NC supplemented with 0.05% protease and 0.1% FOS. During weeks 4–9 and weeks 0–9, gain : feed ratio was impaired (P < 0.05) in pigs fed NC diet compared with those fed PC, PRO and PROFOS diets. Pigs fed PC, PRO and PROFOS diets had higher (P < 0.05) apparent total tract digestibility (ATTD) of CP than pigs fed NC diet. Pigs fed PROFOS diet had reduced (P < 0.05) ammonia emissions compared to pigs fed NC and PRO diets. These data indicate that reducing dietary CP concentrations impaired growth performance, decreased ATTD of CP and reduced ammonia emissions. Supplementation of protease in low CP diet improved growth performance and increased ATTD of CP. Dietary supplementation with protease and FOS in low CP diet improved growth performance, increased ATTD of CP and decreased fecal ammonia emission.     

Performance,serum amino acid concentrations and expression of selected genes in pair‐fed growing pigs exposed to high ambient temperatures

Heat stress (HS) depresses pig performance mainly because of appetite reduction, although other factors involved in the cellular availability of nutrients may also contribute to that depression. An experiment was conducted with twelve pair‐fed pigs (30.3 ± 2.7 kg BW) to examine the effect of severe HS (up to 45 °C) on the expression of genes coding for two cationic amino acid (AA) transporters (b^0,+AT and CAT‐1), leptin, heat‐shock protein (Hsp‐90) and myosin in several tissues; serum concentrations (SC) of AA; and performance. There were two treatments: Comfort, pigs housed at an average temperature of 22 (±2) °C; and HS, pigs housed in a similar room with no climate control, where temperature was raised up to 45 °C. All pigs received the same wheat–soybean meal diet and had similar daily feed intake. Comfort pigs had a higher daily gain and better gain/feed ratio than HS pigs (p < 0.05). The expression of b^0,+AT in jejunum and liver, that of myosin in the Semitendinosus muscle, and leptin in adipose tissue was lower, but CAT‐1 in jejunum and liver, and Hsp‐90 in liver was higher in HS pigs. The SC of Lys and Met in HS pigs were around 55% and 20%, respectively, of that in Comfort pigs (p < 0.05). In conclusion, HS affects the expression of cationic AA transporters, myosin, Hsp‐90, leptin; the SC of Lys and Met; and the performance of pair‐fed pigs. These results suggest that HS‐related changes in gene expression affect the performance of pigs beyond the effect caused by the reduction in voluntary feed intake.     

Effects of reducing dietary crude protein on growth performance, odor gas emission from manure and blood urea nitrogen and IGF-1 concentrations of serum in nursery pigs

Two experiments were conducted to investigate the effects of reducing dietary crude protein on growth performance, odor gas emission from manure and blood urea nitrogen and IGF-1 concentrations of serum in nursery pigs. In experiment 1, the dietary treatments were (i) CON (CP 19.5%) and (ii) T1 (CP 16.0%). In feces samples, NH₃, H₂S, acetic acid and butyric acid emissions during the T1 treatment were lower than during the CON treatment ( P  < 0.05). In feces-urine samples, NH₃ emission during the T1 treatment was lower than during the CON treatment ( P  < 0.05). In experiment 2, 28 crossbred (Landrace × Yorkshire × Duroc) pigs (13.58 ± 0.10 kg) were used for a 42-day growth trial. Throughout the entire experimental period, ADG and ADFI of the CON treatment were higher than the T1 treatment ( P  < 0.05). On day 14, N digestibility in pigs fed the CON diet was higher than that of pigs fed the T1 diet ( P  < 0.05). On days 28 and 42, DM digestibility of the CON diet was greater than the T1 treatment ( P  < 0.05). On dat 42, serum BUN concentration of pigs fed the CON diet was higher than that of pigs fed the T1 diet ( P  < 0.05). In conclusion, these results indicate that reduction in dietary CP concentration decreased NH₃, H₂S and VFA emissions in feces and growth performance in nursery pigs.     

Effects of grass forage species and long‐term period of low quality forage diet feeding on growth performance,nutrient utilization and microbial nitrogen yield in growing wether lambs

Six growing lambs were used to evaluate the feeding value of two forage‐based diets in a long‐term feeding period by measuring body weight (BW) gain, digestibility, nitrogen (N) retention and microbial N (MBN) yield. The animals were fed imported low‐quality timothy hay (TH) with concentrate diet (THD) or imported low‐quality Italian ryegrass straw (IR) with concentrate diet (IRD) for 9 months. The forages were offered at 2% BW, and concentrate was fed at 40% of forage intake. The BW gain averaged 82.6 and 66.2 g/day for THD and IRD, respectively, without showing significant difference. Average forage intake (% BW) was significantly greater for IR than for TH, although it was not affected by feeding periods. The digestibility did not differ between diets or periods. The numerically greater (P = 0.06) ratio of retained N to absorbed N for IRD than that for THD was prominent. Neither diet nor period had significant effect on MBN supply and efficiency of MBN synthesis. The results suggest that the IR‐based diet can be also used for long‐term periods of feeding to growing ruminant animals as a grass hay‐based diet without any detrimental effects on nutrient utilization and growth performance.     

Effects of high peanut meal with different crude protein level supplemented with amino acids on performance,carcass traits and nitrogen retention of Chinese Yellow broilers

This study assessed the effects of feeding high peanut meal diets of reduced crude protein (CP) content supplemented with essential amino acids (EAA) on growth performance, carcass traits, biochemical indices in plasma, and nitrogen (N) retention of male and female Lingnan Yellow broilers from day 22 to day 42 of age. Each of four dietary treatments (19%, 18%, 17% or 16% CP, dietary CP level reduced by the reduced dietary peanut meal) contained six replicate pens with 35 birds of each sex (males and females with equal number), separately (1680 in total). The three diets with reduced CP were supplemented with 5 EAA to meet the requirements and provide the same levels as in the 19% CP diet. Average daily gain decreased and feed:gain ratio was worse in both sexes with reduced CP% (linear, p < 0.05). Dressing percentage increased as CP% decreased in males (linear, p < 0.05) and thigh muscle percentage reduced slightly in females (linear, p < 0.05). Abdominal fat percentage of males fed the 17% CP was the lowest (quadratic, p < 0.05). The plasma metabolic indices, concentrations of triglycerides and malondialdehyde, showed linear responses to reduced CP% (p < 0.05) with triglycerides increasing while malondialdehyde decreased. Plasma uric acid increased in females (linear, p < 0.05), but not in males, as CP% decreased. Efficiency of N retention increased and N excretion strikingly decreased with lower CP diets (p < 0.001), and both variables showed significant (p < 0.05) linear and quadratic effects. It is concluded that there was a limit to which dietary CP of broilers could be reduced without adverse effects. Dietary CP could be reduced to 17% for males and 18% for females (or 18% when fed together) between day 22 and day 42, if diets are supplemented with synthetic EAA.