Evidence of a dietary selection for methionine by the piglet

The objective of the current study was to investigate if there is a preference of piglets for diets varying in Met content and whether these preferences change with time. For this purpose, a feeding trial was carried out over a period of 6 wk. Piglets (equal numbers of males and females) with an initial BW of 7.2 +/- 0.1 kg were randomly subdivided into 4 groups of 12 pigs each. Two reference groups were fed either 0.19% Met (low-Met group) or 0.26% Met (high-Met group) diets. Two other groups had the choice between 2 diets containing 0.19 or 0.23% Met (Met-choice 1 group), or 0.19 or 0.26% Met (Met-choice 2 group). Compared with the low-Met group (397 g), daily feed intake was increased by 43%, 60%, and 82% (P < 0.05) in the Met-choice 1, Met-choice 2, and the high-Met group, respectively. Piglets on the Met-choice 1 and Met-choice 2 groups, respectively, selected 72 and 80% of the higher Met diet. In the first week, piglets on both Met-choice groups selected the diets at random, but they increased their preference for the diets higher in Met up to 81 and 89%, respectively, in the last experimental week. For the total experiment, mean Met contents of total diets were 0.22 and 0.25% in the Met-choice 1 and Met-choice 2 groups, respectively. Average daily gain of 195 g in the low-Met group was more than doubled (P < 0.05) in the high-Met group. Daily gains of 306 and 366 g in the Met-choice 1 and 2 groups, respectively, were (P < 0.05) improved compared with the low-Met group but lower (P < 0.05) than in the high-Met group. Plasma Met concentration of 46.3 micromol/mL in the Met-choice 2 group was greater than in the low-Met or the Met-choice 1 groups (25.3 and 32.8 micromol/mL, respectively) but lower (P < 0.05) compared with the high-Met group (59.6 micromol/mL). Conversely, the sum of essential AA showed a greater (P < 0.05) concentration in plasma from pigs on the low-Met and Met-choice 1 groups than in plasma from pigs on Met-choice 2 group and the high-Met group. In conclusion, the present data demonstrate that piglets are able to discriminate among diets of varying Met content. When given a choice, they prefer a diet better balanced for Met to a Met-deficient diet. As a result of the altered feeding pattern, piglets are able to partly redress the depressed performance and altered plasma AA pattern resulting from the ingestion of the diet more limiting in Met concentration.     

Reduced dietary nitrogen with a high Lys:CP ratio restricted dietary N excretion without negatively affecting weaned piglets

We hypothesized that balancing the content of exogenous amino acids, especially lysine, to reduce protein content in swine diets could reduce nitrogen (N) pollution associated with animal husbandry. Two experiments (45 d each experiment) were performed on weaned piglets (Duroc × Landrace × Yorkshire, 28 d of age) to test this and to determine the optimal lysine to crude protein (Lys:CP) ratio in diet. In Exp. 1, 12 piglets (6 replicates [n = 6]) were fed diets containing different levels of CP (17% and 20%) but the same level of Lys. Increased CP content resulted in significant increases (P < 0.05) of average daily gain (ADG), average daily feed intake (ADFI), and body weight (BW), but did not affect the feed to gain ratio. In Exp. 2, 24 piglets (8 replicates [n = 8]) were fed 1 of 3 diets as follows: 1) 20% CP with a regular Lys:CP ratio (6.23%, control); 2) 17% CP with a reduced Lys:CP ratio (6.14%, LL); or 3) 17% CP with a standard Lys:CP ratio (7.32%, SL). The ADG, final BW, serum concentrations of growth hormone and insulin-like growth factor-1, villus height in the jejunum, and villus height to crypt depth ratio were the lowest in piglets fed LL diet, whereas blood urea N concentration was the lowest and the value of lipase activity was the highest in the piglets fed SL diet. The SL diet did not affect growth performance, intestinal morphology, or serum hormone concentrations, indicating that reduced dietary N with a high Lys:CP ratio can efficiently reduce dietary N excretion without negatively affecting weaned piglets.     

蛋白水平及Lys/Met对早期断奶藏羔羊生长发育的影响

旨在研究藏羔羊早期断奶料蛋白水平及Lys/Met配比对其生长发育的影响。试验选取(55±2)日龄断奶、体重(10.85±0.65)kg藏羔羊98只,随机分为7组,每组14只,公母各半。分别饲喂不同蛋白水平和Lys/Met配比的藏羔羊早期断奶料,试验期20 d。结果:藏羔羊早期断奶料蛋白水平在15%～21%,随断奶料蛋白水平的提高,采食量和日增重增加、腹泻率降低、血清蛋白含量增加;18%蛋白,Lys/Met配比为3.1∶1的日粮最为合理,可以替代21%高蛋白断奶料;在15%蛋白水平的日粮,Lys/Met配比为3.1∶1最为合理,可以替代18%中蛋白断奶料。结果提示:早期断奶料营养水平影响藏羔羊早期的生长发育和血清指标,本试验推荐的早期断奶藏羔羊断奶料适宜的配比为18%蛋白水平和Lys/Met配比为3.1∶1。     

Shade effects on feeding behavior,feed intake,and daily gain of weight in female goat kids

Solar radiation and high ambient temperatures negatively affect feeding time, performance, and animal welfare in several species. The provision of shade is a simple method that helps to minimize the negative effects. To determine whether shade influences feeding behavior, feed intake, and daily weight gain (DWG) in female goat kids, 40 dairy goat kids were used in 2 similar pens whose feeders were shaded (n = 20) or unshaded (n = 20) during 60 days. From May to July, behavioral data were collected through 10-minute scan samples during a 24-hour period for a total of 300 hours. Both pens were shaded on the opposite side to the feeder with 15 m² each in a resting area. All goat kids were observed for their position inside the pen, and the number of times they were seen eating was recorded. When the concentrate was provided (between 13:00 and 13:30 hours, as usually in the farm), the time was recorded until >50% of the animals stopped feeding and went back to the resting area (concentrate test). Food wastes were collected and weighed daily to calculate the food consumption. Ambient and black globe temperatures were daily recorded. Body weight was recorded every week to calculate DWG. A higher percentage of animals feeding was recorded in the shaded feeders than that in the unshaded feeders (P < 0.05). Food refusal was higher in the unshaded feeders (30 ± 1.8%) than that in the shaded feeders (25 ± 1.9%; P = 0.05). The concentrate test duration was 26.6 minutes (±1.3) in the shaded feeders and 16.1 minutes (±1) in the unshaded feeders (P < 0.05). The concentrate test duration was negatively correlated to the ambient temperature in the unshaded animals (r = ?0.50 and r² = 0.25; P = 0.02), and it was not significant in the shaded ones (r = ?0.23, r² = 0.05; P > 0.05). DWG was not different between groups (0.08 ± 0.03 kg per group; P > 0.05). Results suggest that shade on feeders helps to ameliorate some negative effects of solar radiation increasing feeding time and feed intake in female goat kids. This could be of great interest to prevent performance and welfare negative affectations.     

Effects of feeding diets containing low crude protein and coarse wheat bran as alternatives to zinc oxide in nursery pig diets

Two experiments were conducted to determine the effects of crude protein (CP) level in diets containing coarse wheat bran (CWB) with or without pharmacological levels of Zn (provided by zinc oxide: ZnO) on growth performance and fecal DM of nursery pigs. In experiment 1, 360 barrows (Line 200 × 400, DNA, Columbus, NE, initially 5.6 kg) were allotted to 1 of 6 dietary treatments from d 0 to 21 after weaning with 5 pigs per pen and 12 pens per treatment. Treatments included a positive control diet (21% CP) with 3,000 mg/kg Zn in phase 1 and 2,000 mg/kg in phase 2; negative control (21% CP) with 110 mg/kg added Zn, and 4 diets containing 4% CWB and 110 mg/kg added Zn formulated to contain 21%, 19.5%, 18%, or 16.5% CP. The 2 control diets and 21% CP CWB diet contained 1.40% standardized ileal digestible (SID) Lys in phase 1 and 1.35% SID Lys in phase 2, while the 19.5%, 18%, and 16.5% CP diets contained 1.33, 1.25 and 1.20% Lys, respectively, in both phases. Pigs fed the positive control diet containing pharmacological ZnO had increased (P < 0.05) ADG and G:F compared with the negative control and the 21% CP CWB diet. Reducing CP (concurrently with SID Lys) in diets containing CWB decreased ADG and G:F (linear, P = 0.002); however, fecal DM increased (linear, P = 0.005). In experiment 2, two groups of 300 and 350 pigs, initially 7.0 and 6.2 kg, respectively, were used with 5 pigs per pen and 26 pens per treatment. The objective was to determine if adding back essential AA would improve growth performance of pigs fed the low CP diets. All dietary treatments were fed for 13 days, contained 4% CWB, and consisted of: (1) positive control with 2,000 mg/kg of Zn and 21% CP (1.35% SID Lys); (2) no ZnO and 21% CP; and 3 diets with no ZnO formulated to 18% CP and (3) 1.2% SID Lys; (4) 1.35% SID Lys by the addition of feed grade amino acids (AA), and (5) diet 4 with non-essential amino acids (NEAA; Gly and Glu). Pigs fed 21% CP with ZnO had increased (P = 0.001) ADG compared to those fed 18% CP (1.35% SID Lys) with high levels of feed grade amino acids or those fed the reduced SID Lys (1.2%) diet. Overall, G:F was improved (P < 0.001) for pigs fed 21% CP diets and those fed the 18% CP diet with NEAA compared to pigs fed 1.2% SID Lys and pigs fed high levels of feed grade amino acids. Fecal DM was increased for pigs fed the reduced SID Lys diet. In summary, pharmacological levels of Zn improve pig growth performance, but reducing CP (and subsequently SID Lys) decreased nursery pig growth performance.     

Evaluation of standardized ileal digestible lysine requirement for 8–20 kg pigs fed low crude protein diets

Two experiments were conducted to determine the standardized ileal digestible lysine (SID Lys) requirement for weaned pigs fed with low crude protein (CP) diet. In Experiment 1, 144 pigs were fed a normal CP (20%) diet with 12.3 g/kg SID Lys and five low CP (18.5%) diets providing SID Lys levels of 9.8, 11.1, 12.3, 13.5, and 14.8 g/kg, respectively, for 28 days. Reducing dietary CP from 20% to 18.5% enhanced (p < 0.05) the growth performance. The average daily gain (ADG) and gain to feed ratio (G:F) increased (linear and quadratic; p < 0.05), serum urea nitrogen (SUN) decreased (linear and quadratic; p < 0.05) as SID Lys increased. The SID Lys levels required to maximize ADG and optimize G:F were 12.8 and 13.1 g/kg using a curvilinear plateau model, and to minimize SUN was 13.4 g/kg using a two‐slope broken‐line model, which averaged 13.1 g/kg SID Lys. In Experiment 2, 18 pigs were used in a 12‐day N balance trial and received the same diets of Experiment 1. Total N excretion was decreased when dietary CP reduced and further decreased when SID Lys increased. Collectively, 1.5% dietary CP reduction improved the growth performance and decreased the N excretion; the optimal SID Lys requirement was at 13.1 g/kg of 8–20 kg pigs fed with 18.5% CP diet.     

低蛋白质饲粮中添加DL-蛋氨酸和赖氨酸对冬毛期蓝狐生产性能、氮平衡及毛皮质量的影响

本文旨在探讨低蛋白质饲粮中添加DL-蛋氨酸和赖氨酸对冬毛生长期蓝狐生长性能、氮平衡和毛皮质量的影响,并研究低蛋白质饲粮中蛋氨酸和赖氨酸的最适添加量.对照组饲粮蛋白质水平为27%(P27),低蛋白质饲粮蛋白质水平为19%(P19),选择健康的生长后期雄性蓝狐120只(17周龄左右),随机分成10组,每组12只.本试验采用3×3双因子交叉试验设计,有3个赖氨酸水平(0.3%、0.5%、0.7%)和3个含硫氨基酸水平(0.4%、0.6%、0.8%),试验组编号分别为P27、L1M1、L1M2、L1M3、L2M1、L2M2、L2M3、L3M1、L3M2和L3M3,饲养试验试验期为61 d(2007-10-12～2007-12-12).结果表明,如果考虑蓝狐平均日增重、日氮沉积、氮沉积率,0.6%的蛋氨酸水平最佳;如果考虑日氮沉积和毛皮质量,0.3%和0.5%的赖氨酸水平最佳;如果考虑氮的表观消化率、日粪氮排出量,0.3%的赖氨酸水平最佳;各处理蓝狐的毛皮质量与对照组差异不显著(P＞0.05).综合各项指标,L1M2 (0.3% Lys×0.6% Met)组蓝狐生产性能最佳;低蛋白质饲粮中添加蛋氨酸和赖氨酸不影响冬毛期蓝狐的生产性能;应用低蛋白质饲粮降低了排泄物中氮的含量,减轻了环境污染,节约了蛋白质资源.     

Estimation of the standardized ileal digestible lysine requirement and optimal sulphur amino acids to lysine ratio for 30–50 kg pigs

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID sulphur amino acids (SAA) to Lys ratio for 30–50 kg crossbred pigs. In experiment 1, a total of 72 crossbred pigs with an average initial body weight (BW) of 28.9 kg were allotted to one of six dietary treatments in a randomized complete block design. Each diet was assigned to six pens containing two pigs each. Six diets were obtained by supplementing graded levels of L‐Lysine?HCl to create six dietary levels of SID Lys (0.70%, 0.80%, 0.90%, 1.00%, 1.10% and 1.20%). Responses of weight gain (ADG) and gain:feed (G:F) to increasing the SID Lys content of the diet fitted well with the curvilinear‐plateau model; whereas, for plasma urea nitrogen (PUN) two‐slope linear broken‐line model was well fitted. The optimal SID Lys requirement for the pigs of this period was 1.10%. Experiment 2 was a dose–response study using SID Met+Cys to Lys ratios of 50%, 55%, 60%, 65%, 70% and 64%. A total of 72 crossbred pigs with initial BW of 32.9 kg were randomly allotted to receive one of the six diets. Diets 1–5 were formulated to contain 1.0% SID Lys to be second limiting in Lys and diet 6 contained 1.11% SID Lys to be adequate in Lys. The average optimal SID SAA:Lys ratio for maximal ADG and G:F and minimal PUN was 65.2% using curvilinear‐plateau and linear broken‐line models.     

Specific dietary selection for tryptophan by the piglet

The aim of the present study was to investigate whether pigs prefer diets varying in Trp content and whether these preferences change with time. To that end, a feeding trial was carried out over a 6-wk period. Piglets (equal proportion of males and females) with an initial BW of 8.20 +/- 0.90 kg were randomly subdivided into four groups of 12 pigs each. Two reference groups were fed (as-fed basis) either 0.11% Trp (Trp-deficient) or 0.20% Trp (Trp-adequate) diets. Two other groups had a choice of two diets containing either 0.11 or 0.16% Trp (Trp-choice 1), or 0.11 or 0.20% Trp (Trp-choice 2). Average daily feed intake reached 335 and 366 g in pigs fed Trp-deficient and Trp-choice 1 diets, respectively. For Trp-choice 2 and Trp-adequate diets, a higher (P < 0.05) feed intake of 589 and 645 g/d, respectively, was observed. Piglets on Trp-choice 1 and Trp-choice 2, respectively, selected 87 and 93% of the higher Trp diet. Resulting Trp contents of total diets were 0.15 and 0.19% (as-fed basis) in Trp-choice 1 and Trp-choice 2, respectively. In wk 1, pigs on Trp-choice 2 chose lower proportions of the Trp-deficient feed (31% of total diet) than did pigs on Trp-choice 1 (44%), but at the end of the experiment, pigs of both groups almost exclusively chose the feed with the higher Trp content (96 and 98% for Trp-choice 1 and 2). Pigs on Trp-choice 1 had an ADG of 218 g, which was only slightly above the ADG of Trp-deficient pigs (198 g). Pigs on Trp-choice 2 and Trp-adequate diets had ADG of 404 and 458 g, respectively, which were higher (P < 0.05) than those observed for Trp-deficient and Trp-choice 1 groups. Plasma Trp concentrations in Trp-choice 2 and Trp-adequate groups (9.21 and 9.01 micromol/mL, respectively) were higher (P < 0.05) than in Trp-deficient and Trp-choice 1 groups (5.88 and 4.96 micromol/mL, respectively). Conversely, the sum of essential AA showed a higher (P < 0.05) concentration in plasma from pigs on the Trp-deficient and Trp-choice 1 diets than in plasma from pigs on Trp-choice 2 and Trp-adequate diets. Nutritional depletion of Trp influences the food selection behavior of piglets. Results of growth performance and the dietary preferences suggest that piglets are able to detect Trp-deficiency-induced metabolic changes and respond with an aversion against the Trp-deficient diet.     

The effect of different high‐fat diets on erythrocyte osmotic fragility,growth performance and serum lipid concentrations in male,Japanese quail (Coturnix coturnix japonica)

Poultry diets are formulated with additional animal fat or vegetable oils to improve growth rate and feed conversion efficiency. High‐fat diet feeding in rats and fish has been shown to result in alterations in the phospholipid composition and cholesterol content of the erythrocyte membrane, in turn affecting erythrocyte osmotic fragility. In contrast, the few studies performed using high‐fat diet feeding in avian species show no changes in erythrocyte osmotic fragility. This study made use of the Japanese quail as no data exists on investigation of this species with respect to high‐fat diet feeding and erythrocyte osmotic fragility. Fifty‐seven male quail were randomly divided into six groups and fed either a standard diet (commercial poultry feed) or one of five high‐fat diets (commercial poultry feed with 22% of either coconut oil, lard, palm oil, soya bean oil or sunflower oil on a weight/weight basis) for 12 weeks. All birds on the high‐fat diets were significantly heavier (p < 0.05) after the 12‐week feeding period, than when commencing the dietary intervention. Serum triglyceride concentrations of birds in all high‐fat diet groups were significantly lower (p < 0.05) than birds in the standard diet group, whereas only birds in the palm oil group had significantly lower (p < 0.05) serum cholesterol concentrations compared to the standard diet group. Fragiligrams of erythrocytes from birds in the various dietary groups were similar. High‐fat diet feeding with different types of additional fat did not affect the osmotic fragility of the quail erythrocytes. Feeding quail high‐energy diets of varying degrees of fatty acid saturation was well tolerated and did not seem to affect the overall health status of the birds. Resistance of avian erythrocytes to modification by excess dietary fat may be a general characteristic of avian erythrocytes.     

Enzymatically Digested Animal Protein as a Source of Protein for Weanling Pigs

Three experiments were conducted to evaluate the use of an enzymatically digested animal protein (EDAP) as a source of protein for weanling pigs. In each experiment, treatments were replicated with four (Experiments 1 and 2) or seven (Experiment 3) pens of three to five pigs each. Each experiment lasted 3 to 4 wk for the combined Phase I (1.5% Lys in Experiments 1 and 2, 1.6% Lys in Experiment 3) and Phase II (1.3% Lys) periods. In Experiments 1 (6.7 kg; 23 d of age) and 2 (6.1 kg; 22 d of age), pigs were fed one of the following Phase I diets: 1) basal (B) diet containing corn, soybean meal (SBM), whey, fish meal, and blood cells (AP-301 G; American Protein Corporation, Ames, IA); 2) B + 4% spray-dried animal plasma (SDAP); or 3) B + 2% SDAP + 2% EDAP (SDAP + EDAP). In Phase II, the dietary groups from Phase I were divided into two subsequent groups. One group received a diet containing corn, SBM, whey, fish meal, and 2% blood cells, and the second group received the same diet with 2% EDAP, resulting in six treatments for Phase II and overall periods. In Experiment 1, ADG and ADFI were increased (P<0.10) during Phase I for pigs fed SDAP + EDAP, and ADFI was increased (P<0.10) in pigs fed SDAP. In Phase II, the EDAP addition did not affect (P>0.10) ADG, ADFI, or the ratio of gain to feed. Also, Phase I diets did not affect (P>0.10) growth performance during Phase II. Overall, ADG (P<0.10) and ADFI (P<0.04) were increased (P<0.10) in pigs fed SDAP + EDAP during Phase I. In Experiment 2, ADG and the ratio of gain to feed were increased (P<0.10) in pigs fed SDAP + EDAP during Phase I. During Phase II, ADFI was increased in pigs fed SDAP + EDAP or B + SDAP (P<0.01) relative to those fed B only (P<0.003) in Phase I. Also in Phase II, the ratio of gain to feed was increased in pigs fed SDAP + EDAP (P<0.03) relative to those fed B + SDAP. Overall, ADG and the ratio of gain to feed were not affected (P>0.10) by diet, but ADFI was increased (P<0.03) in pigs fed SDAP + EDAP relative to those fed B. In Experiment 3, all pigs (5.7 kg; 17 d of age) were fed a common Phase I diet containing SDAP + EDAP. In Phase II, ADG, ADFI, and the ratio of gain to feed were not affected (P>0.10) by the addition of 2% EDAP or 2% blood cells. In summary, pigs fed SDAP + EDAP perform equally well compared with those fed B + SDAP.     

Effect of dietary concentrate content on feed intake,feed efficiency,and meat quality of Holstein steers fattened in a hot environment

The objective of this study was to investigate the effect of feeding high and low concentrate diets on feed intake and feed efficiency, the morphological characteristics of the rumen papillae, and meat quality of Holstein steers fattened under hot climate conditions in Oman. Ten male Holstein calves, of 5 months of age, were selected for the experiment. The animals were fed concentrate and Rhodes grass hay and were divided into two groups of high concentrate (HC, n = 5) and low concentrate diets (LC, n = 5), in which their feed intake, weight gain, and feed efficiency were evaluated across three growing periods. Feed intake and efficiency and average daily gain (ADG) of the HC group were significantly greater than for the LC group and were affected by the diet (p < .01) and the period (p < .001). Across the fattening periods, ADG declined in both groups, with ADG improved by 35% for steers on the HC diet compared to steers on the LC diet. Carcass meat quality was not affected significantly by the dietary concentrate level. In conclusion, our results can be used to make improvements in feed efficiency of Holstein steers under hot climate conditions.     

Fibre supplementation to pre-weaning piglet diets did not improve the resilience towards a post-weaning enterotoxigenic E. coli challenge

Dietary fibre (DF) is implicated in gastrointestinal health of weaned piglets, either through its physiochemical properties, through modulation of gut microbiota and (or) improved gut integrity. We aimed to study the effect of DF enriched supplemental diets fed to suckling piglets (‘creep feed’) on health and performance after weaning when challenged with an enterotoxigenic E. coli (ETEC). Seventy-two piglets originating from 28 litters had been fed four creep diets, that is a low-fibre control (CON); a diet containing 2% long-chain arabinoxylans from wheat (lc-AXOS) or 5% purified cellulose (CELL) or a diet containing the high fermentable and the low-fermentable fibre source (i.e. 2% lc-AXOS and 5% CELL). Upon weaning, piglets were individually housed and all fed the same diet. On days 7, 8 and 9, animals received an oral dose of ETEC (5 ml containing 10⁷ to 10⁸ CFU/ml). Besides growth performance, faecal and skin scores were recorded daily. Gut permeability was assessed by urinary excretion of Co-EDTA prior and post-ETEC challenge. Repeated measures in time were statistically evaluated with generalized linear mixed models. We used a binominal distribution for evaluating the faecal and skin scores. Feed intake and body weight gain did not differ between treatments (p > .05). Piglets on CELL decreased gain:feed ratio in week 2 + 3 week compared to CON (p = .035). Prior to ETEC challenge, gut permeability tended to increase for lc-AXOS (p = .092). Moreover, lc-AXOS as main effect increased intestinal permeability before ETEC challenge (p = .013), whereas the low-fermentable fibre lead to elevated intestinal permeability after ETEC challenge (p = .014). The incidence of diarrhoea was higher for lc-AXOS + CELL compared with lc-AXOS (p = .036), while skin condition was unaffected. In conclusion, neither the high fermentable nor the low-fermentable fibre source improved post-weaning growth or gastrointestinal health of the piglets.     

Effect of nutrient density on production performance, egg quality and humoral immune response of brown laying (Dahlem Red) hens in the tropics

A study was conducted to evaluate the effect of various concentrations of metabolizable energy (ME) with graded incremental levels of crude protein (CP) and essential amino acids (lysine and methionine) on production performance, egg quality and humoral immune response of Dahlem Red laying hens. Four experimental diets based on maize–soybean meal-deoiled rice bran were prepared. Diet 1 was fed as a control diet containing 2,600 kcal ME/kg, 15% CP, 0.75% Lys and 0.36% Met, and in the other three diets (D2, D3 and D4), concentrations of the above nutrients were increased by 2.5%, 5.0% and 7.5%, respectively. The levels of Ca (3.5%) and available P (0.32) were constant in all the diets. Each diet was offered ad libitum from 28 to 40 weeks of age to eight replicates containing six birds in each replicate. The egg production, egg weight and egg mass (in grams of egg per hen per day) were not affected by increasing the nutrient density up to 7.5% (2,795 kcal ME/kg diet) compared to the control group (2,600 ME/kg diet). However, feed consumption and feed efficiency (in grams of egg per gram of feed) were influenced by the variation in the nutrient density of diets. As the nutrient density increased by 5% (2,730 ME/kg diet), birds consumed significantly (P < 0.001) less feed. The birds in the 7.5% higher density group produced significantly (P < 0.05) higher egg mass per unit feed consumption compared to the control diet. Increasing nutrient density up to 7.5% had no effect on relative weight of albumen, yolk or shell. The Haugh unit, yolk colour and shell thickness were also not affected due to variation in the nutrient density. The humoral immune response measured at 34 and 40 weeks was progressively improved by increasing the nutrient density up to 5%. Increasing the nutrient density beyond 5% in the diet had no further influence on the humoral immune response. Based on the results of the present study, it can be concluded that Dahlem Red laying hens required 2,795 kcal/kg ME, 16% CP, 0.8% lysine and 0.4% methionine for eliciting optimum performance and immune response during 28 to 40 weeks of age.     

The crucial role of lysine in the hepatic metabolism of growing Holstein dairy heifers as revealed by LC-MS-based untargeted metabolomics

The objective of this experiment was to evaluate the effect of supplementing rumen-protected Lys based on a Lys-deficient diet on liver metabolism in growing Holstein heifers. The experiment was conducted for 3 months with 36 Holstein heifers (initial body weight: 200 ± 9.0 kg; 7-month-old). Heifers were randomly assigned to 2 diets based on corn, soybean meal, alfalfa hay, and wheat bran: control, Lys-deficient diet (LD; 0.66% Lys in diet), and Lys-adequate diet (LA; 1.00% Lys in diet). The results showed no difference in growth performance between the 2 groups (P > 0.05). However, there was a clear trend of increasing feed conversion rate with Lys supplementation (0.05 < P < 0.01). The serum urea nitrogen concentration was significantly decreased, and the aspartate aminotransferase-to-alanine aminotransferase ratio was significantly decreased by Lys supplementation (P < 0.05). Moreover, growing heifers fed a Lys-adequate diet had lower levels of urine nitrogen excretion and higher levels of the biological value of nitrogen (P < 0.05). Metabolomic analysis revealed that 5 types of phosphatidylcholine and 3 types of ceramide were significantly increased and enriched in sphingolipid metabolism and glycerophospholipid metabolism (P < 0.05). His, Leu, and Asp levels were significantly decreased in the liver following Lys supplementation (P < 0.05). In conclusion, Lys supplementation may promote the synthesis of body tissue proteins, as evidenced by significantly decreased amino acids in the liver and urine N excretion, it also improves hepatic lipid metabolism by providing lipoprotein precursors.     

Yellow mealworm,Tenebrio molitor (Col: Tenebrionidae), larvae powder as dietary protein sources for broiler chickens: Effects on growth performance,carcass traits,selected intestinal microbiota and blood parameters

This study was conducted to evaluate the effects of dietary Tenebrio molitor larvae meal (TM meal) inclusion on the performance, carcass traits, caecum microbiota and blood parameters of broiler chickens. A total of 180-day-old chickens were allocated to three dietary groups with five replicate pens (12 birds/pen). Experimental diets were included a corn-soybean basal diet, and two diets with 2.5% and 5% TM. TM-included diets have been administered for periods of starter (1–10 days) and grower (11–25 days). A regular finisher diet was given to all groups during the 26–42 days of age. Diets containing TM meal did not influence feed intake and mortality percentage. Feed conversion ratio was lower with the 2.5% TM meal diet compared with the control group at starter period (p < .05). Besides, broiler chickens fed TM meal included diet had a higher body weight gain than the control group during 1–10 days of age (p < .05). The carcass characteristics and length and weight of different parts of small and large intestines were not influenced by diets. TM meal inclusion decreased the albumin-to-globulin ratio compared with the control group (p < .05). Additionally, lower total count of aerobic and Escherichia coli bacteria was observed in response to diet inclusion of 5% TM meal. Overall, the inclusion of TM meal in broilers' diet improved body weight gain and feed conversion ratio in the starting period, decreased albumin-to-globulin ratio and E. coli bacteria content.     

Effects of essential oils from fennel (Foeniculi aetheroleum) and caraway (Carvi aetheroleum) in pigs

The ban of antibiotics as a feed additive requires alternatives to stabilize the health and performance particularly of the young animals. Essential oils obtained from fennel seed (Foeniculi aetheroleum) and caraway seed (Carvi aetheroleum) were tested in diets for weaned piglets in comparison with either a diet without feed additive or with a combination of formic acid and copper (positive control). Four groups of sixteen piglets (live weight 7 kg, age 26 days) received diets without (1) or with supplements of 7.5 g formic acid + 160 mg Cu/kg (2), 100 mg fennel oil/kg (3) or 100 mg caraway oil/kg (4) during 3 weeks after weaning. In the subsequent 4 weeks, all piglets were fed a diet without these additions. Fennel oil contained almost 2/3 anethol, approximately 1/5 fenchon and the remaining part consisting of alpha + beta-pinen, limonen (p-mentha-1,8-dien) and estragol. In the caraway oil, half of the contents was represented by limonen and the other half by carvon. There were no piglet losses and only few cases of diarrhoea. The combination of formic acid and copper increased feed consumption by 27% and daily weight gain by 25%. There were no differences in the performance between the group fed fennel oil and the control without additives. Piglets fed caraway oil tended to consume less feed and to gain approximately 10% less. In feed choice experiments, pigs consumed the same two diets from two troughs with 50% of total feed amount, as expected. The diets containing fennel or caraway oils were consumed at less than 50%. If the diet contained 100 mg fennel oil/kg, the decrease of percentual feed intake was significant. The results of the feeding experiment and of the feed choice experiment question the classification of fennel and caraway oils as flavour additives or as 'appetite promoters' in diets for weaned piglets.     

The Effect of Season and Vaccination for Glässer's Disease and Post‐weaning Colibacillosis in an Outdoor Pig Unit Endemically Infected with Virulent Strain of Haemophilus Parasuis Serotype 5 and Pathogenic Escherichia coli

The objective of this field trial was to determine if vaccination against Haemophilus parasuis serovar 5 (HPS 5) and pathogenic serotypes of Escherichia coli would improve nursery pig performance in an outdoor unit in different seasons. The unit was concurrently infected with HPS 5 and with different serotypes of E. coli. All piglets were born to HPS 5 vaccinated sows. The trial was carried out in four (two summer and two winter) groups. Group 1 (E. coli and HPS vaccinated, summer season) (n = 362): Piglets were vaccinated pre‐weaning with inactivated E. coli‐VT2e‐toxin and post‐weaning against HPS 5. Group 2 (non‐vaccinated, summer season) (n = 349): Piglets were not vaccinated. Group 3 (E. coli and HPS vaccinated, winter season) (n = 358): The animals were analogously treated as Group 1. Group 4 (non‐vaccinated, winter season) (n = 353): Piglets were not vaccinated. The following parameters were evaluated: A: average daily nursery weight gain (ADG), B: nursery mortality, C: feed efficiency (FE). No significant weight differences were detected within the vaccinated and non‐vaccinated summer or winter raised groups of weaners. Summer raised weaners were significantly (P<0.05) heavier from day 35 on than winter raised animals. ADG and FE of summer raised pigs were significantly better (weeks 1–3 P<0.05; fourth week post‐weaning P<0.01) during the nursery period than that of the winter raised groups. Winter raised vaccinated weaners showed during the last week of nursing significantly (P<0.05) better daily gain and feed efficiency compared with the non‐vaccinated winter raised animals. Non‐significant ADG and FE differences were detectable between the summer raised vaccinated or non‐vaccinated groups of pig. Winter raised non‐vaccinated animals suffered significantly (P<0.05) higher nursery mortality (10.63%) compared to the winter raised vaccinated animals. Implication: In cases of concurrent infections with HPS 5 and with different serotypes of E. coli, especially during winter season, vaccination against both diseases is suggested.     

Effect of protease derived from Pseudoalteromonas arctica supplementation on growth performance,nutrient digestibility,meat quality,noxious gas emission and blood profiles in finishing pigs

This study was conducted to evaluate the effects of dietary supplementation of protease derived from Pseudoalteromonas arctica (PPA) in finishing pigs. A total of 160 pigs were used in this 10‐week trial. Dietary treatment groups were as follows: CON (basal diet); TRT1 (basal diet + 0.1% PPA); TRT2 (basal diet + 0.2% PPA); and TRT3 (basal diet + 0.3% PPA). During weeks 1–5, pigs fed with different levels of PPA‐supplemented diet showed linear increase (p < .05) in the apparent total tract digestibility (ATTD) of nitrogen (N) and linear decrease (p < .05) in the concentrations of serum total protein. During weeks 6–10, pigs fed with different levels of PPA‐supplemented diet showed a linear decrease in feed conversion ratio (p < .05). During the overall period, there was a linear decrease in feed conversion ratio (p < .05) associated with the inclusion of PPA. Pigs fed diets with 0.2% PPA supplementation had lower (p < .05) feed conversion ratio than those fed CON diet during weeks 6–10 and the overall period, and had higher (p < .05) ATTD of N than those fed CON diet during weeks 1–5. Pigs fed diets with PPA supplementation had lower (p < .05) concentrations of serum total protein than those fed CON diet on week 5. In conclusion, dietary supplementation with PPA diet has beneficial effects on growth performance, nutrient digestibility, backfat thickness and the concentrations of serum total protein.     

Free versus microencapsulated organic acids in medicated or not medicated diet for piglets

Aim of the study was to investigate the growth performance of weaned piglets fed either a medicated or not medicated diet supplemented with either a blend of formic and lactic (64/36) acids (FL, 11 kg/ton) or a microencapsulated blend of organic acids and flavors (T) (1 kg/ton, Tetracid®S, EU patent 1391155B1,Vetagro srl, Italy). 480 three-week old SCAAPAG × Goland piglets were fed four diets (4 pens of 30 piglets per diet): FL or T with or without the medication (M) comprising colistin 180 ppm + amoxicillin 600 ppm for the 1st phase and chlortetracycline 1000 ppm + sulphadiazine 1250 ppm + trimetoprim 250 ppm for the 2nd phase. The piglets received a two-phase diet (I:18% CP, 1.3% Lys, 7.5% CF and 2600 kcal/kg NE; II:18% CP, 1.2% Lys, 5.6% CF and 2400 kcal/kg NE). All data were analysed by ANOVA. After 49 days, animals fed the medicated diets had higher feed intake (+ 24.5% for group FL + M vs FL − M and + 22.3% for group T + M vs T − M; P < 0.01) and lower mortality (overall 1.2% for the medicated diets fed animals vs 9.2% for the non-medicated ones). Final weights were: 26.8 ± 1.0 kg, 25.7 ± 0.8 kg for FL + M, T + M, 20.9 ± 0.7 kg, 21.6 ± 0.8 kg for FL − M and T − M, respectively (P < 0.05). The medication resulted in maintaining animals in good health status. The microencapsulation technique allowed to lower the acids dose to be included in the feed by ten fold at least maintaining the same effects that a high dose can give without medication.