Lower Daily Feed Intake Research Articles

274 Socialization of piglets during suckling enhanced feed intake after weaning but did not alter their response to dietary amino acid concentration

Abstract The present study hypothesized that pre-weaning socialized piglets would reduce damaging behavior and when fed an increased dietary standardized ileal digestible (SID) Lys (and amino acids) to net energy (NE) ratio post-weaning would increase early post weaning feed intake (FI) and growth performance, and in nursery pigs. Socializing included two groups of five sows and their litters for which farrowing pen walls were removed allowing piglets to co-mingle for 10 d before weaning (S) whereas traditionally housed piglets pertained to housing a single sow with her litter (T; n = 15). At weaning, 120 mixed-gender piglets [7.2 ± 0.7 kg body weight (BW)] were allocated based on litter origin, sow parity, and piglet BW to 12 pens equipped with single-space electronic feeding stations with 10 pigs/pen for a 41-d study. In this 2 × 2 factorial arrangement, factors were litter background (socialized vs. traditional) and dietary SID Lys: NE (High 1.32 vs. Low 1.15 SID Lys:NE MJ/kg). Daily individual FI and BW and skin injuries at different timepoints after weaning were determined. Wheat-barley based diets were isoenergetic (10.6 MJ/kg) and offered in two phases (i.e., d 0-14 and d 14-41). The day after weaning, socializing reduced the proportion of piglets with more than five skin injuries from 45.7% to 3.0% compared with traditional housing (P < 0.05). Early post-weaning, daily FI was 50% greater for S-LowLys:NE pigs than S-HighLys:NE on d1, then, T-LowLys:NE was greatest (~25% above other treatments) during d 3-6 (all P < 0.05). The trend maintained during d 6-8 with T-LowLys:NE and S-HighLys:NE being similar each other (P > 0.05). The average number of visits per day during the first 10 d was greater (P < 0.01) for S-HighLys:NE and T-LowLys:NE (33 visits each) compared with T-HighLys:NE (24 visits). Overall, S-HighLys:NE pigs tended (P < 0.10) to have a greater end BW (23.8 vs. 22.1 kg) and a greater d 0-41 average daily gain (ADG) than T-HighLys:NE (530 vs. 472 g/d). For d22-29, the average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (FE), were greater for S-HighLys:NE and T-LowLys:NE compared with S-LowLys:NE and T-HighLys:NE (P < 0.05). No other meaningful interactions were observed between socializing and Lys:NE on growth performance. However, looking at main factors, socializing increased ADG during d 29-41 by 9% (P = 0.01) coinciding with a 4% greater FE (P = 0.09). The data suggest that traditionally housed piglets fed a HighLys:NE diet post-weaning had lower daily FI and growth performance compared with T-LowLys:NE and socialized piglets irrespective of the Lys:NE contrast. In conclusion, the present study led to a better understanding of nutritional requirements and FI in situations with different pre-weaning housing schemes of piglets. In the present conditions, pre-weaning socialization of pigs may stimulate feed intake earlier post-weaning and allow a better transition independently from the Lys (and amino acid) to NE ratio.

Effects of different levels of pistachio (Pistachia vera) green hull aqueous extract on performance, intestinal morphology and antioxidant capacity in Eimeria challenged broilers

a total of 576-day-old Ross 308 broilers chicks (male) were used to evaluate the effect of various levels of pistachio green hull aqueous extract (PHE) and Eimeria challenge on the growth performance, intestinal health and antioxidant capacity. During infection period (25-42 d), treatments included: 1) control + unchallenged (negative control, NC), 2) 200 ppm PHE + unchallenged, 3) 300 ppm PHE + unchallenged, 4) 400 ppm PHE + unchallenged, 5) control + challenged (positive control, PC), 6) 200 ppm PHE + challenged, 7) 300 ppm PHE + challenged and 8) 400 ppm PHE + challenged (with six replications for each treatment). The outcomes revealed that in the challenged birds, average body weight gain (ABW), daily weight gain (DWG), and feed conversion ratio (FCR) linearly improved with increasing the PHE levels (P < 0.05). Infected broilers had lower daily feed intake (DFI) compared to unchallenged birds (P < 0.05). Villus height (VH), villus height to crypt depth (VH: CD) ratio and villus surface area (VSA) reduced linearly (P < 0.05), while muscle layer thickness (MT) increased linearly in challenged birds (P < 0.05). The consumption of the PHE significantly reduced the excreta oocytes and duodenum and jejunum lesion scores in Eimeria-challenged broilers (P < 0.05). By increasing the PHE levels, total antioxidant capacity (TAC) and superoxide dismutase (SOD) levels increased (P < 0.05), while the Eimeria challenge reduced TAC, SOD, and glutathione peroxidase (GPx) levels (P <0.05). In general, the use of PHE in the broilers diet improved the antioxidant capacity, birds performance, but diminished the excreta oocytes and lesion scores with no negative effect on the intestinal morphology.

Plasticity of feeding behaviour traits in response to production environment (temperate vs. tropical) in group-housed growing pigs

Heat stress affects pig metabolism, health and welfare, resulting in reduced growth and important economic losses. The present experiment aimed to evaluate the effects of two climatic environments [temperate (TEMP) vs. tropical humid (TROP)] on feeding behaviour in growing pigs. The feeding behaviour traits were measured with automated feeders and included: daily feed intake, daily eating time, feeding rate, daily number of meals, feed intake per meal, and feeding time per meal. Pigs came from a backcross population between Large White (LW, heat sensitive) and Creole (CR, heat tolerant) pigs. The same 10 F1 LW × CR boars (sire families [SF]) were mated with related LW sows in each environment. Feeding behaviour was recorded for a total of 1,296 pigs (n = 634 pigs for TEMP and n = 662 pigs for TROP) between 11 and 23 weeks of age. Growth performance and thermoregulatory responses (rectal and skin temperatures) were also measured. Results show that TROP conditions affect feeding behaviour traits: animals had more meals per day but these meals were smaller both in duration and in size, resulting in lower daily feed intake and less time eating per day. Significant SF by environment (GxE) interactions were found for all feeding behaviour traits. When SF were distributed into robust and sensitive groups (previously defined according to performance and thermoregulatory traits), results showed group by environment interactions for all feeding traits, except meal frequency. Moreover, a significant difference in feeding rate between robust and sensitive group was detected in TEMP, suggesting that feeding rate may be a good candidate to evaluate heat tolerance.

Effect of Type and Dietary Fat Content on Rabbit Growing Performance and Nutrient Retention from 34 to 63 Days Old.

Simple SummaryAn increase in the fat content of the diet increases the dietary energy concentration, and consequently, the growth and feed efficiency of the animals. The fatty acids (FA) profile of the fat source can also affect animal body composition. The purpose of this study was to test the effect of some fat sources added at different levels in growing rabbit feed. In this study, it was observed that the increment of dietary fat improved nitrogen efficiency utilization and reduced nitrogen excretion; the fat source also affected animal performance and mortality rate.The study was carried out on individually and collectively housed growing rabbits from 34 to 63 days of age. Two experiments were conducted using three fat sources: Soybean oil (SBO), Soya Lecithin Oil (SLO), and Lard (L; Exp. 1), and SBO, Fish Oil (FO), and Palm kernel Oil (PKO; Exp. 2), added at two inclusion levels (1.5 and 4.0%). In both trials, 180 rabbits were housed in individual cages and additional 600 rabbits in collective cages from day 34 to 63. Animals fed with 4% dietary fat showed lower Daily Feed Intake (DFI) and Feed Conversion Ratio (FCR) than those fed with 1.5%, except in the individually housed animals in Exp. 1. In the collective housed group in Exp. 1, DFI was a 4.8% higher in animals fed with diets containing lard than those fed with SBO (p = 0.036). Lard inclusion also tended to reduce mortality (p = 0.067) by 60% and 25% compared with SBO and SLO diets, respectively. Mortality was the highest with the higher level of soya lecithin (14% vs. 1%, p < 0.01). A similar mortality rate was observed in the lowest level of SBO. In the grouped-housed animals in Exp. 2, a decrease of DFI (−12.4%), Bodyweight (BW) at 63 d (−4.8%), and Daily Weight Gain (DWG) (−7.8%) were observed with the inclusion of fish oil (p < 0.01) compared to other fat sources. Fish oil also tended to increase (p = 0.078) mortality (13.2%) compared with palm kernel oil (6.45%); similar results were found when animals were individually housed. The overall efficiency of N retention (NRE) increased with the highest level of fat in Exp. 1 (34.9 vs. 37.8%; p < 0.0001). It can be concluded that lard and palm kernel oil are alternative sources of fat due to the reduction of mortality. The inclusion of fish oil impaired animal productivity and increased mortality. An increment of the dietary fat level improved FCR and overall protein retention efficiency.

Potential of mealworm, Tenebrio molitor, meal as a sustainable dietary protein source for juvenile black porgy, Acanthopagrus schlegelii

A 12-week feeding trial was designed to evaluate the potential of mealworm, Tenebrio molitor, meal (MW) as a locally available unconventional alternative source of protein for fish meal (FM) in a practical diet for juvenile black porgy. Five hundred twenty-five healthy fish (initial weight; 6.43 ± 0.00 g) were randomly distributed into five dietary groups in triplicate (35 fish per tank) and each group was hand-fed with one of the experimental diets containing graded level of a MW replacing 0%, 15%, 30%, 45%, and 60% of FM protein designated as MW0, MW15, MW30, MW45, and MW60, respectively. Although replacing 60% of dietary FM protein resulted in lower daily feed intake, juvenile porgies fed the highest level of dietary MW (MW60) still performed as well as control group (MW0). A significant negative trend was detected between fillet lipid content and increasing inclusion levels of MW in the diets. There was a notable reduction in the n-3 highly unsaturated fatty acids (HUFA) in the fillets of fish fed the MW containing diets, which became more prominent with greater levels of dietary FM replacement. Serum lysozyme activity improved with increasing inclusion levels of MW in the diet. Furthermore, expression of the antioxidant enzyme-related genes including glutathione peroxidase (GPx) and catalase (CAT) were markedly upregulated in liver of the fish fed diets replacing FM with MW when compared to fish fed the MW0 diet. Overall, the efficacy of MW as a promising alternative dietary protein source for juvenile black porgy has been proved not only in relation to weight gain and efficiency of feed utilization, but also the view point of health-promoting effects in fish.

Dietary supplementary glutamine and L-carnitine enhanced the anti-cold stress of Arbor Acres broilers

Newborn poultry in cold regions often suffer from cold stress, causing a series of changes in their physiology and metabolism, leading to slow growth and decreased production performance. However, a single anti-stress substance cannot completely or maximally eliminate or alleviate the various effects of cold stress on animals. Therefore, the effects of the supplemented glutamine and L-carnitine on broilers under low temperature were evaluated in this study. Broilers were randomly allocated into 16 groups which were respectively fed with different levels of glutamine and L-carnitine according to the L (4) orthogonal experimental design for 3 weeks (the first week is the adaptive feeding period; the second and third weeks are the cold exposure period). Growth performance was recorded, and blood samples were collected during cold exposure. The results showed the supplementation had altered the plasma parameters, growth performance and cold-induced oxidative stress. The increase of corticosterone and suppression of thyroid hormone was ameliorated. Supplemented groups had lower daily feed intake and feed-to-gain ratio, higher daily weight gain and better relative weights of immune organs. Plasma glucose, total protein, blood urea nitrogen and alkaline phosphatase changed as well. Oxidative stress was mollified due to the improved activities of superoxide dismutase and glutathione peroxidase, heightened total antioxidant capacity and stable malondialdehyde. Dietary glutamine and L-carnitine improve the growth performance, nutritional status and cold stress response of broilers at low temperature, and their interaction occurred.

Dietary High Chromium-Methionine Supplementation in Summer-Exposed Finishing Lambs: Impacts on Feed Intake, Growth Performance, and Blood Cells, Antioxidants, and Minerals.

This study aimed to investigate the effect of dietary high doses of chromium-methionine (CrMet) supplementation on blood hemato-biochemical parameters and growth performance of finishing lambs reared under warm condition with average temperature-humidity index (THI) of 85.8 unit. Fifteen male lambs (31.9 ± 1.2 kg) fed with either un-supplemented diet (CON) or supplemented with 1.5 (Cr1.5) and 3 (Cr3) mg of Cr/kg dry matter (DM) for 8 weeks. The results showed that high levels of supplemental Cr had no negative impacts on red (RBC) and white blood cells (WBC). Blood total antioxidant capacity (TAOC) tended to be higher in CrMet-fed lambs than those of CON (P < 0.1). Serum malondialdehyde (MDA), as a lipid peroxidation marker, was, respectively, 20.24 and 22.1%, lower in lambs given 1.5 and 3 mg of chromium comparing those of CON (P < 0.05). Moreover, erythrocyte glutathione peroxidase (GSH-PX, U/dL) displayed higher activity in Cr3 (421.2) group than those of CON (334.6) and Cr1.5 (351.2) groups (P < 0.05). Accordingly, GSH-PX activity per gram hemoglobin (U/gHb) was 45.9% greater in lambs of Cr3 than the CON (P < 0.05). Furthermore, feeding 3 mg of Cr led to increased erythrocyte superoxide dismutase (SOD) activity (P < 0.05): as such, SOD was 1193.1, 1281.5, and 1433.0 U/gHb in CON, Cr1.5, and Cr3, respectively. Chromium supplementation linearly decreased serum iron concentration (P < 0.05), but neither blood calcium, phosphorous, copper, zinc, and glucose concentrations nor aspartate aminotransferase and alanine aminotransferase activities were affected by supplemental CrMet. In comparison with CON (1250), lambs in Cr1.5 (1199) and Cr3 (1192) groups had lower daily feed intake (g/d, P < 0.01). In addition, feed to gain ratio was 21.5% lower in the Cr3 group than the control (P < 0.05). Collectively, these findings suggest that feeding summer-exposed finishing lambs with 3 mg of Cr/kg DM improves blood antioxidant status and feed to gain efficiency without adverse effects on lambs' health and metabolism.

Time-based feed restriction and group composition in growing rabbits: Effects on feed intake pattern, growth performance, carcass traits and meat quality

This study aimed to evaluate the effects of the feeding system (AL: ad libitum, R: feed restriction) and group composition (X: only females, Y: only males, XY: mixed sex) on the feed intake pattern, growth, and slaughter results in growing rabbits. A total of 288 crossbred rabbits were housed in 18 pens (16 animals per pen) from weaning to slaughter (33 to 75 d of age). At the beginning of the trial, R rabbits had access to the feeders for 10 h/d, afterwards, feeding time increased by 1 h every 3-4 d in the first three weeks until 16 h/d was reached, and by 1 h per day until 24-h access to feeders was reached in the 4th week; thereafter, all animals were fed ad libitum. On average, the feed intake pattern of AL rabbits was characterized by small and frequent meals throughout the day, with minimum intakes (about 2-3 g/h) occurring in the morning and maximum intakes (7-10 g/h) in the evening. During the restriction period, R rabbits showed a lower daily feed intake (-6 g/d; P < 0.01), better feed conversion (2.29 vs. 2.42; P < 0.001), and a higher hourly feed intake compared to the AL rabbits, reaching peaks of 18, 15, and 14 g/h when the feeding time was 11, 13, and 16 h/d, respectively (P < 0.001). In the second period, once the rabbits were fed freely, R rabbits achieved the same intake as AL rabbits but with a higher feed conversion (4.10 vs. 3.89; P < 0.001). In this study, the feeding system did not affect growth performance, health (mortality 1.4% on average), carcass traits, and meat quality. In terms of group composition, the daily growth and feed conversion were worse in the Y groups than in the X and XY groups in the second period (P ≤ 0.01), with no other differences observed throughout the whole trial. Dressing out percentage was significantly different among the three groups (61.8%, 61.0% and 60.2% in group Y, group XY and group X, respectively; P < 0.001). In conclusion, time-based feed restriction during the first three weeks (based on an access to the feeders increasing from 10 h/d at the beginning until 16 h/d) reduced the feed intake to 95% of ad libitum, without compromising growth performance and slaughter results, but modified the rabbit feed intake pattern during the restriction phase. In terms of gender composition, the separate housing of male and female rabbits was not justified by our results.

EFFECTS OF ADDING ACETIC ACID AND FEED WITHDRAWAL PERIOD ON GROWTH PERFORMANCE OF BROILER CHICKENS DURING THE SUMMER SEASON

The present study evaluates the effects of feed withdrawal period and addition of acetic acid in drinking water on growth performance, physiological measurements, carcass traits, carcass chemical composition, intestinal microbial and economic efficiency of broiler chicks during the period of 22 to 42 days of age under Egyptian condition. A total number of 270 of Cobb broiler chick one day old were randomly assigned to six groups and fed a basal diet through the experimental period. The groups T1 (control), T2, T3, T4, T5 and T6 were fed ad libitum, fasting 8 hours, addition of 6% acetic acid, fasting 8 hours with addition of 6% acetic acid, addition of 8% acetic acid and fasting 8 hours with addition of 8% acetic acid, respectively. The highest (P<0.05) final weight and weight gain were recorded for T5 group. While group T2showed the lowest (P<0.05) value. The highest (P<0.05) averages of daily feed intake were reported by T1, T5 and T3 groups. While, group T2 had (P<0.05) the lowest daily feed intake. The best feed conversion ratio (P<0.05) was recorded by the groups T2 and T4. Mortality rate was significantly the highest for the control. Blood serum traits are significantly affected by feeding dietary treatments within normal rage. Dressing carcass weight of T5 birds was significantly the highest compared to T2. Abdominal fat weight was significantly the highest for the control. The total bacteria account was (P<0.05) higher in birds treated acetic acid and the coliform bacteria was significantly lower. European production efficiency factor (EPEF) increased significantly for all treatments except the control. These results concluded that addition of acetic acids (6 and 8%) with feed withdrawal (8 hours at 22-42 days of age) in drinking water during summer season have a positive effect on growth performance of broiler.

Does light intensity affect the behavior, welfare, performance, meat quality, amino acid profile, and egg quality of Japanese quails?

The current study aimed to explore the impact of different light intensities on behavior, welfare, performance, meat quality, amino acid content, and egg quality of Japanese quails. A total of 600 1-day-old Japanese quail chicks were used (300/batch). Chicks were homogeneously classified into 3 groups (each of 100); low (10 lux), moderate (50 lux). and high light intensity (250 lux) groups. There was a significant effect (P < 0.05) of light intensity in most of the Japanese quails' behaviors. Quails reared on low light intensity showed the lowest behavior of feeding, drinking, flying, and feather picking, while the highest behaviors were preening, dust bathing, leg and wing stretching, and body shaking when compared with the other groups. Moreover, they had the better welfare (lowest H/L ratio and corticosterone levels). Quails of low light intensity groups possessed the heaviest body weight (145.17g, P = 0.000) with the lowest daily feed intake (14.17g) but with the best feed conversion ratio (3.39%, P = 0.000). Moreover, they had the heaviest slaughter (132.47g, P = 0.000) and carcass weight (109.29g, P = 0.000) and carcass yield (75.37%, P = 0.000) when compared with the others groups. Muscles of quails (both of pectoral and thigh) kept under low light intensity revealed the highest percentage of lightness, yellowness, and water-holding capacity with the lowest percentage of cooking loss, thiobarbituric acid reactive substances, and some amino acids. They also had the heaviest egg weight (11.24g, P = 0.000) with the best external and internal egg-quality grades (P < 0.05). Consequently, low light intensity is suggested for improving quail's welfare, performance, and reproduction, while the high light intensity had a detrimental effect on both welfare and performance.

Laying Performance, Physical, and Internal Egg Quality Criteria of Hens Fed Distillers Dried Grains with Solubles and Exogenous Enzyme Mixture.

Simple SummaryThe present study was designed to investigate the simultaneous use of distillers dried grains with solubles (DDGS) and exogenous enzyme mixture (EEM) on layer performance and egg characteristics. Results confirmed that DDGS is an acceptable feed ingredient in layer diets and that the maximum inclusion level of DDGS in the diet should be around 12% for the best performance and egg characteristics.The effects of dietary inclusion of distillers dried grains with solubles in laying hen diets with and without exogenous enzyme mixture (EEM) on performance and egg characteristics were evaluated. One of the main objectives of this study was to examine the effects of distillers dried grains with solubles (DDGS) and enzyme cocktail on egg yolk fatty acids. The study used total of 144 Hisex Brown laying hens in a 4 × 2 factorial arrangement, including four levels of DDGS (0, 6, 12, and 18% of diet) and two levels of enzyme cocktail (0 or 250 mg EEM/kg of diet) through 32–42 weeks of the age. The inclusion of 18% DDGS was associated with the worst (p ≤ 0.001) egg production and the lowest daily feed intake. Numerically, hens fed 6% DDGS diet consumed more feed and had the greatest egg production. The best feed conversion ratio (FCR) was recorded in the control, while the worst was recorded in the 18% DDGS group. Compared with EEM-free diets, EEM supplementation improved FCR by about 2.79%, but the difference was not significant. Shell thickness and shell percentage were significantly increased in hens fed 6% DDGS diet compared to other groups. Egg weights in the 6% and 12% DDGS groups were significantly higher than those in the control and 18% DDGS groups. Non-significant increases in shell and albumin percentages were recorded in groups fed EEM-supplemented diets. The interaction effect of DDGS and EEM was significant (p ≤ 0.01) for the majority of egg characteristics. As dietary DDGS level increased, yolk color density increased. Elevating DDGS level up to 18% increased yolk cholesterol, total fat, and total unsaturated fatty acids. The effects of EEM supplementation on egg yolk fatty acid composition and the interaction effects between DDGS and EEM were not significant. Considering these results, it could be concluded that DDGS is an acceptable feed ingredient in layer diets and that the maximum inclusion level of DDGS should not exceed 12% of the whole diet.

A major gene for host response to porcine reproductive and respiratory syndrome is not unfavorably associated with overall performance under nonchallenging conditions in commercial pig lines

ABSTRACTA QTL for host response to porcine reproductive and respiratory syndrome (PRRS) was identified in a previous study. The SNP WUR10000125 (WUR) is used as a tag SNP for this QTL. The favorable (B) allele at this SNP is in low frequency in commercial populations, possibly because this allele is unfavorably associated with an important trait under nonchallenging conditions and, therefore, may have been selected against. Therefore, objectives of this study were to estimate the effect of WUR on traits under selection in commercial lines under nonchallenging conditions and to estimate the effect of WUR genotype of parents on performance of crossbred progeny in a commercial-like environment. Data were collected on 4 purebred lines: a Landrace dam line (D1), a Large White dam line (D2), a synthetic sire line (S1), and a Pietrain sire line (S2). Traits analyzed included total number born, number stillborn, farrowing survival, lactation survival, litter mortality, daily feed intake (DFI), backfat, average test daily gain (TGR), average lifetime daily gain (LGR), and Topigs Norsvin selection index (TSI) value, indicative of overall economic value. Deregressed EBV were calculated for each trait (except TSI) and analyzed within line. In the S1 line, AB and BB pigs had significantly lower TGR (P = 0.002) and LGR (P = 0.001) than AA pigs but also lower DFI (P = 0.004). Conversely, AB and BB pigs had significantly higher DFI (P < 0.001) and AB pigs had significantly higher TGR (P = 0.03) than AA pigs in the S2 line. The effect of WUR on TSI was not significant for any line (P ≥ 0.15). Analyses of phenotypic records collected on crossbred progeny of S1 sires and D1 × D2 F1 females showed no significant effect of parent WUR genotype on DFI, backfat, TGR, or LGR (P ≥ 0.07). In conclusion, the effect of WUR was nonsignificant for most traits but the magnitude and direction of the effect differed by trait and by line. The favorable allele for host response to PRRS was associated with greater DFI and a tendency for greater TGR in the S2 line, but the opposite direction of effect was detected for the S1 line. Regardless of the effect on individual traits, no significant effect of WUR on TSI was detected for any line. Therefore, selecting for the B allele is expected to result in progeny with increased resistance to PRRS without compromising overall economic value under normal, nonchallenging conditions.

Performance, immunity, and physiological responses of broilers to dietary energy and protein sequential variations

The current trial was designed to examine effects of sequential feeding of diets varying in energy and protein contents on performance, gut development, welfare indices, and immune responses of broiler chicks. A total of 240 one-day-old broiler chicks (Ross 308) were randomly allotted to 4 treatments with 5 replicates in a completely randomized design. Sequential feeding was evaluated in 48-h cycles during 8 to 28 d of age. Diets varied in energy (E+ = 3,210kcal/kg and E- = 2,790kcal/kg) and protein (P+ = 25.14% CP and P- = 16.76% CP) contents. The 4 feeding programs were: control (ME: 3,000kcal/kg, CP: 20.95%); P+/P- (P+ followed by P- containing 3,000kcal/kg energy); E-/E+ (E- followed by E+ containing 20.95% CP), and E-P+ / E+P- (E-P+ followed by E+P-). The experiment lasted 42 d and birds were fed by a standard finishing diet from d 28 to 42. Broilers fed on E-/E+ and E-P+/E+P- had lower daily feed intake than control ones during 8 to 28 d of age (P < 0.05), while daily weight gain and feed conversion ratio were not affected significantly. Footpad dermatitis was lower in birds sequentially fed E-/E+ and E-P+/E+P- at 35 d of age (P < 0.05). Sequential feeding of diets varying in either energy or protein or both increased duration of tonic immobility at d 39 of age (P < 0.05). Feeding with E-/E+ regime decreased jejunal crypt depth, while feeding P+/P- regime increased villus height and crypt depth in the duodenum and ileum (P < 0.05). However, no relationship was found between intestinal morphology and growth performance of broiler chickens. Antibody production against sheep red blood cells as well as Newcastle and influenza disease viruses was not affected by sequential feeding. In conclusion, digestive organs and intestinal morphology might be adjusted to energy and protein variations. Sequential feeding increased the fear level in chickens.

The effects of different cycles of starvation and re-feeding on growth and body composition in rainbow trout (Oncorhynchus mykiss , Walbaum, 1792)

Summary This study was designed to investigate the effects of starvation and re-feeding cycles on the growth performance and body chemical composition of Oncorhynchus mykiss juveniles. A total of 360 juveniles with initial mean weights (IW) of 8.46 ± 0.07 g (n = 360) were stocked into 400-L tanks in triplicate for each group, with 30 juveniles per tanks. The control group received regular feed, as is the common practice. The three other groups were periodically starved: 1 day starvation followed by 6 days re-feeding (S1), 2 days starvation followed by 5 days re-feeding (S2) and 3 days starvation followed by 4 days re-feeding (S3). The experiment lasted for 10 weeks, over the course of which the water flow rate was 4 L min−1 and the water quality parameters determined as: temperature 14.4 ± 1.1°C, oxygen 8.2 ± 0.4 mg L−1 and pH 7.5 ± 0.2. At the end of the study, S1 had the best growth performance (final weight, specific growth rate, average daily growth) of all test groups (P < 0.05). The lowest daily feed intake (DFI) and growth performance parameters were observed in S3 (P < 0.05), while protein efficiency ratio (PER), net protein utilization (NPU) and lipid efficiency ratio (LER) were higher in the S3 fish group than in the other groups (P < 0.05). Whole body protein and lipid contents were highest in S1 fish. The hepatosomatic index (HSI) and viscerosomatic index (VSI) were significantly different among groups (P < 0.05). Feed conversion ratio (FCR) was significantly lower in starvation groups S1, S2 and S3 than in the control (P < 0.05). Compensation coefficient (CC) values were higher than 1 in all starvation groups. The concluding indicate that rainbow trout exposed to 1 and 2 days of starvation in week cycles could achieve over compensation compared to the control. Additionally, partial growth compensation and improved feed utilization could be achieved in a starvation group within 3 days in a week, by beginning with the juvenile size over a 10-week experimental period.

Effects of dietary inclusion of fermented soybean meal on growth, body composition, antioxidant enzyme activity and disease resistance of rockfish (Sebastes schlegeli)

Two experiments were conducted to investigate the effects of replacing fish meal (FM) with fermented soybean meal (FSM) on growth performance, body composition, antioxidant enzyme activity and disease resistance of rockfish, Sebastes schlegeli, at the juvenile and grower stages. Five isonitrogenous (51%) and isocaloric (21.0MJkg−1) diets were formulated to contain 0, 8, 16, 24 and 32% FSM, replacing approximately 0, 10, 20, 30 and 40% of the FM protein (designated as FSM0, FSM8, FSM16, FSM24 and FSM32, respectively). Each experimental diet was fed to triplicate groups of juvenile (1.2±0.04g; EXP I) and grower (148.2±2.9g; EXP II) rockfish to apparent satiation twice daily for 8weeks. Juvenile rockfish fed the FSM32 diet showed significantly lower weight gain (WG) than those fed the FSM0, FSM8 and FSM16 diets. Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed the FSM16, FSM24 and FSM32 diets were significantly lower than those of fish fed the FSM0 and FSM8 diets. Fish fed the FSM24 diet exhibited significantly lower daily feed intake (DFI) than fish fed the FSM0 and FSM8 diets. However, growth performance and feed utilization efficiency of grower rockfish did not show any definite pattern of change due to feed composition. The viscerosomatic index (VSI) of juvenile fish fed the FSM32 diet was significantly lower than those of all the other experimental groups. Replacement of FM with FSM, up to 40%, had no significant effect on whole body and muscle proximate and amino acid compositions of juvenile and grower rockfish, respectively. The plasma antioxidant enzyme activity of grower fish was significantly enhanced by the dietary inclusion of the FSM compared with the control group. Survival of juvenile fish after intraperitoneal injection of Edwardsiella tarda was not affected by dietary treatment. These results indicate that FSM can be used successfully as a replacement for FM at levels up to 10% in diets for juvenile rockfish while at least 40% of dietary FM protein can be replaced by FSM without causing any adverse effect on grower rockfish performance. Statement of relevance1.There have been a few studies examining the efficiency of fermented soybean meal (FSM) as a possible fish meal substitute in fish feed. However, to the best of our knowledge no studies have been reported on the use of FSM as a substitute for fish meal in diet for rockfish.2.The results of this study indicate that FSM can be used successfully as a replacement for FM at levels up to 20% in diets for juvenile rockfish while at least 40% of dietary FM protein can be replaced by FSM without causing any adverse effect on grower rockfish performance.3.As feed cost accounts for almost half of the fish production costs, the results of our experiments can be useful for formulation of more cost-effective practical diets for juvenile and grower rockfish.

Immunocastrated male pigs: effect of 4 v. 6 weeks time post second injection on performance, carcass quality and meat quality

Immunocastration or vaccination against boar taint can be used as alternative for surgical castration of male piglets. The vaccine is administrated twice. After the second vaccination (V2), the pigs behave like barrows instead of boars and their feed intake increases which may result in a lower lean meat percentage. The timing of V2 is therefore crucial to find the right balance between the advantages of entire males and barrows. In this study, we evaluated the effect of time post second injection within the advised time frame (4 v. 6 weeks before slaughter) on behaviour, performance, carcass and meat quality of immunocastrated male pigs. In total, 180 animals (hybrid sow×Piétrain): 60 gilts, 60 male pigs vaccinated 6 weeks before slaughter (IM-6) and 60 male pigs vaccinated 4 weeks before slaughter (IM-4), all slaughtered at comparable slaughter weights. After 20 weeks of age, IM-6 showed more inactive behaviour at the expense of playing and aggressive behaviour. Daily feed intake (DFI), daily gain (DG) and feed conversion ratio (FCR) did not differ significantly between IM-6 and IM-4. Gilts had a lower DFI and DG in the late finishing phase and a higher FCR overall compared with both IM groups. Gilts showed a higher lean meat content compared with both IM groups. Earlier vaccination increased dressing percentage, which could partly be explained by the lower weight of the gastrointestinal tract, but not by testes weight. Meat quality traits and palatability did not differ significantly between IM-6 and IM-4. Vaccination of immunocastrates at 6 compared with 4 weeks before slaughter improved the calmness in the stable and the dressing percentage, while maintaining performance and carcass characteristics.

Effects of feeding different levels of proteins on the performance in Khaki Campbell ducks during starter stage

The present study was conducted on the 225 unsexed day-old Khaki Campbell ducklings in the Regional Centre, CARI, Bhubaneswar during the period between March to June, 2013. The ducklings were randomly distributed into three treatment groups viz. T1, T2 and T3 supplemented with 18, 20 and 22 per cent crude protein respectively and three replicates in each group to study the effect of feeding different levels of proteins on the performance of the ducks during starter stage. It was found that the live weight of ducklings in different treatments group increased steadily up to 8 weeks of age attaining the lowest body weight of 1243.45±23.01 g in T1 and highest body weight of 1292.97±0.71 g in T3. Significantly (p£0.05) lower daily feed intake was observed in T3 during 3rd week of age than T1 and T2 and the intake was significantly (p£0.05) lower in T3 than T1 but not from T2 at 8th week of age. The apparent metabolisibility of dry matter in T1, T2 and T3 were 75.46±0.90, 77.70±0.30 and 79.38±0.89 per cent, respectively and there was a significant difference in the metabolisability of dry matter (per cent) among different treatments. The nitrogen intake was significantly (p£0.05) higher in T3 (3.63 g/day) than T1 (3.16 g/day), but the difference between T3 and T2 was found to be non-significant. The impact of different levels of protein supplementation in the diet of ducks was found to be non-significant with respect to blood glucose, total protein, albumin, globulin, albumin and globulin ratio, total cholesterol and creatinine concentration after 8 weeks of age. It can be concluded that with increase in the supplementation of protein in the Khaki Campbell ducks during the starter period significantly better impact the health and productive traits of the birds and thereby the overall economic status of the farm.

Dietary medicinal herbs and enzyme treated fish meal improve stress resistances and growth performance at early juvenile stage of red sea breamPagrus major

Red sea bream Pagrus major (RSB) weighing 0.09 g were fed on test diets, composed of 65% fish meal supplemented with 0.49% Crataegi fructus (Cf) and a mixture of Massa medicata, Cf, Artemisia capillaries and Cnidium officinale (HM) or a control diet without herbs, in trial 1. After air exposure and anaesthesia treatment, higher stress tolerances were obtained in herbal groups than control group. Moreover, after challenge test with Vibrio anguillarum, mortalities of the herbal groups were lower than the control group. There was no significant difference in growth performance among the treatments. Feed efficiency (FE) of the test groups was 124–141%. In trial 2, RSB weighing 0.11 g were fed on diets composed of 35% fish meal and 30% enzyme treated fish meal (EFM) with the same herbal treatments as trial 1. The herbal groups revealed higher final body weight and specific growth rate (SGR) and lower daily feed intake than those of the control group. The FE of test groups was 172–203%. These results indicate that the dietary herbs supplementation acts not only as recovery enhancer for some rearing stresses but also as growth enhancer, which is accelerated with dietary EFM in the early juvenile stage of red sea bream.

Effect of relative humidity during incubation at a set eggshell temperature and brooding temperature posthatch on embryonic mortality and chick quality

Previous studies have shown that RH during incubation of chicken eggs influences water loss from the egg and embryonic mortality. In those studies, eggshell temperatures (EST) were not monitored or controlled. Because RH influences the egg's heat loss through evaporation, EST might have been different between RH treatments, influencing embryonic mortality and development. To eliminate the effect of EST, in the current study eggs were incubated at an EST of 37.8°C from embryonic d (E) 0 until E18 and at a high (55 to 60%) or low (30 to 35%) RH from E2 until hatch. Embryonic mortality, hatch curve, and several chick quality characteristics (length, weight, navel quality, organ weights, and DM of the yolk free body mass and yolk) were determined on E18 and at hatch. Low RH increased egg weight loss between E0 and E18 (+3.0%) and third week embryonic mortality (+3.0% of fertile eggs) and decreased hatch of fertile eggs (-2.9% of fertile eggs) compared with high RH. Hatch duration and chick quality characteristics did not differ between RH treatments. To assess the effect of RH during incubation on posthatch performance under suboptimal conditions, hatchlings were brooded at a normal (35.0°C at d 0, decreasing to 27.0°C at d 4) or cold (27.8°C at d 0, decreasing to 25.6°C at d 4) temperature until 4 d posthatch. Incubation RH and brooding temperature significantly interacted with posthatch growth but not development. Both low and high RH × cold brooding temperature resulted in lower (-6.9 and -6.0 g, respectively) BW than high RH × normal brooding temperature at 4 d of age. The cold brooding temperature resulted in lower daily feed intake (-1.3 g/chick) than the normal brooding temperature. In conclusion, incubating eggs at a low RH compared with a high RH and maintaining the EST at 37.8°C decreased hatch of fertile eggs, but had little effect on chick quality or posthatch performance.

Serum adipokine profile and fatty acid composition of adipose tissues are affected by conjugated linoleic acid and saturated fat diets in obese Zucker rats

Conjugated linoleic acid (CLA) has been reported as having body fat lowering properties and the ability to modulate the inflammatory system in several models. In the present study, the effects of CLA added to saturated fat diets, from vegetable and animal origins, on the serum adipokine profile of obese Zucker rats were assessed. In addition, the fatty acid composition of epididymal and retroperitoneal adipose tissues was determined and a principal component analysis (PCA) was used to assess possible relationships between fatty acids and serum metabolites. Atherogenic diets (2 % cholesterol) were formulated with palm oil and ovine fat and supplemented or not with 1 % of a mixture (1:1) of cis-9, trans-11 and trans-10, cis-12-CLA isomers. CLA-fed animals exhibited lower daily feed intake, final body and liver weights, and hepatic lipids content. Total and LDL-cholesterol levels were increased in CLA-supplemented groups. CLA also promoted higher adiponectin and lower plasminogen activator inhibitor-1 (PAI-1) serum concentrations. In contrast to palm oil diets, ovine fat increased insulin resistance and serum levels of leptin, TNF-alpha and IL-1beta. Epididymal and retroperitoneal adipose tissues had similar deposition of individual fatty acids. The PCA analysis showed that the trans-10, cis-12-CLA isomer was highly associated with adiponectin and PAI-1 levels. Summing up, CLA added to vegetable saturated enriched diets, relative to those from animal origin, seems to improve the serum profile of adipokines and inflammatory markers in obese Zucker rats due to a more favourable fatty acid composition.