The effect of dietary L-Tryptophan on productive performance and behavion of weaned piglets (original) (raw)
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Aggressiveness and Productive Performance of Piglets Supplemented With Tryptophan
Journal of Animal and …, 2009
Early weaning is a common practice in pig farms, this might cause distress and fighting among piglets. The amino acid tryptophan is the precursor of the neurotransmitter serotonin, which has sedative effects that reduce aggression, however, it also has anorexigenic effects that could reduce feed intake and weight gain. In this study, it was evaluated tryptophan supplementation above requirement levels in social behaviour and productive performance of piglets weaned at 21 days of age. Four levels of dietary tryptophan were used (T , 0.23%, Control; T , 0.27%; T , 0.31% and T , 0.35%). Tryptophan was orally supplemented to each piglet 1 2 3 4 every day. Treatments were randomly assigned to 544 piglets (5.69±1.14 kg) with 8 replicates per treatment. Behavioural observations of piglet activity were done for 6 h daily during four consecutive months, in periods of 8 days, from 14-2 h. Data were analyzed with PROC MIXED according to a completely randomized design with repeated measurements. Aggressiveness measured as biting appendixes (ears and tail) and fighting, were different among treatments (p<0.05) with less activity for T (15.10±0.09, 42.19±0.13) and T (12.25±0.09, 3 4 33.33±0.13%). However, no differences (p>0.05) were found for feed intake, daily weight gain and feed conversion between treatments. Results showed that tryptophan supplementation reduced aggression in weaned piglets, however, there was no change in productive performance.
Journal of Animal Science
Stress occurs in intensive pig farming when piglets are weaned and mixed. In this study, we investigated whether this stress might be reduced with elevated dietary levels of Trp. The effects of supplemental dietary Trp (5 g/kg of feed, as-fed basis) were tested on the neuroendocrine system, intestinal integrity, behavior, and growth performance in nursery pigs, both before and after mixing. Mixing occurred 5 d after weaning and diet introduction. On d 4, 5, and 6, Trp-fed pigs vs. control pigs showed approximately a 2-fold elevation in plasma Trp concentrations (68 ± 7 vs. 32 ± 2 mol/ L; P < 0.001), a 38% increase in hypothalamic serotonin turnover as measured by 5-hydroxyindoleacetic acid:5hydroxytryptamine (P < 0.001), and an 11 to 18% increase (P < 0.05) in the intestinal villus height:crypt depth. Before (d 4) and at (d 5) mixing, saliva but not plasma cortisol concentrations were reduced (P < 0.02) by approximately 2-fold in Trp-fed pigs vs. control pigs.
Impact of two light programs and two levels of dietary tryptophan for weanling piglets
Photoperiod and supplementary tryptophan can attenuate the effects of stressful weaning. However, few studies have evaluated tryptophan metabolism in the presence of light. This study aimed to evaluate the effects of tryptophan levels (TL) on the diet of weanling piglets submitted to different light programs (LP). Seventy-two piglets weaned at 21 days of age (starting weight 6.6 ± 2.33 kg) were used. The experimental design consisted of randomized blocks with 24 days of duration in a 2 × 2 factorial arrangement. Two LP were used: 12-h or 23-h light/day. Two digestible TL were used: 2.6 g or 5.2 g of Trp/kg feed on pre-starter I diet (from 0 to 14 trial days) and 2.4 g or 4.8 g of Trp/kg feed on pre-starter II diet (from 15 to 24 trial days). Six replicates of three animals per treatment were performed. Growth performance, blood glucose, plasma cortisol profiles and animal behavior were assessed. Blood glucose was measured on experimental days 0 and 24, and cortisol was measured on days 0 and 8. Behavior was observed on days 2, 9, 16 and 23. Neither growth performance nor blood glucose were affected by the interaction between LP and TL. The treatments did not influence daily weight gain, daily feed intake and blood glucose during the periods of 0-14, and 0-24 days. Feed:gain ratio improved during the 0-14 days period for piglets receiving 12-h light/day. The treatments did not influence the frequency of "moving" behaviors. However, the interaction between LP and TL affected the plasma cortisol and frequency of "feeding" and "lying" behaviors. Piglets that received the highest TL had lower plasma cortisol levels, reduced "feeding" behaviors and increased "lying" behaviors, compared to animals that received normal TL, when subjected to LP of 23-h light/day. The results suggest that use of LP of 23 h light/day is not indicated for piglets. Dietary composition may be manipulated to alleviate the negative aspects of weaning stress. Tryptophan is the fourth limiting amino acid for piglets fed soybean and corn-based meals. It is essential for protein synthesis, is the precursor of important metabolites, such as serotonin and melatonin that are involved in regulation of gastrointestinal function, expression and secretion of ghrelin, feed intake stimulation, temperature regulation and immune response (Ning and Qian, 2008;
Use of supplementary tryptophan to modify the behavior of pigs1
Journal of Animal Science, 2006
Three experiments were conducted to investigate the short-term use of supplementary Trp on the behavior of grow/finish pigs. Three levels of dietary Trp were used, representing the standard requirement for growth (control), twice (2×), and 4 times (4×) the control amount. In Exp. 1, pigs were fed the diets for 7 d, during which observations were made of their general behavior (time budget), aggression within the group of familiar pigs, and response to a startling auditory stimulus. Behavior effects were evident during the period of supplementation for both the 2× and 4× diets. During the treatment period, pigs fed supplemental Trp spent more time lying (P = 0.04) and less time eating (P = 0.05) than pigs fed the control diet. Although the response of the animals to the startling stimulus was to become alert and stand, similar behavioral effects caused by supplemental Trp also were evident after the startling stimulus (P < 0.01). Based on these observations, the subsequent studies retained the same dietary levels of Trp and incorporated a 3-d feeding of diets before behavior testing. In Exp. 2, pigs were fed the experimental diets for 3 d before being regrouped with
Intraperitoneal Administration of Tryptophan Decreases Liquid Diet Intake in Early Weaned Piglets
Acta Veterinaria Brno, 1996
The aim of the present study was to investigate the effect of intraperitoneal tryptophan (Trp) administration on liquid diet consumption in early weaned piglets. Furthermore, the effects of two chemical forms of the amino acid were compared. Single doses (100 mg.kg-l) ofL-tryptophan (480 mmol.kg-l) or L-tryptophan methyl ester (392 mmol.kg-l) (Sigma, USA) were L p. administered at 07.00 h to 2 groups of 5 piglets each at the age of 3,9, 12, 14 and 16 days. The piglets were weaned on d I, housed individually in cages and offered a commercial diet (Selasan) for suckling from feeding bottles between 06.00 and 22.00 h 9 times a day at 2-h intervals with an 8-h break at night. Control piglets (n=5) were left intact. Compared with intact controls, L-Trp decreased the relative sizes of individual meals in piglets aged 3 d only 5 h (P < 0.02) after its administration, in the 9-d-old ones 1,3 and 5 h (P < 0.05; P < 0.01; P < 0.05, respectively), and in the 16-d-old piglets 3 h (P < 0.01) later. No significant differences between control and L-Trp-treated animals occurred on days 12 and 14. L-Trp methyl ester decreased the diet consumption of piglets at all ages as follows: in 3-, 9-and 16-d-old piglets 3 h (P < 0.05; P < 0.05; P < 0.01, respectively) post-injection, in the 12-d-old animals I h (P <0.01), 3 h (P< 0.001) and 7 h (P< 0.05), and in the 14-d-old piglets I h (P<O.OI) and 3 h (P < 0.01) after L-Trp methyl ester administration. In 12-and 14-d-old piglets its effect was also reflected in 24-h diet intake that was significantly decreased. Similar differences in diet consumption were found when the relative sizes of individual meals were compared to the first morning consumption, Le. I h before Trp treatment. In conclusion, Trp did suppress food consumption in early weaned piglets as soon as on day 3 after birth, indicating that the aminostatic component of their food intake regulation is functional at this age. At the same time it was found that this effect ofL-ttp methyl ester (the actual dose of which was smaller than that ofL-Trp) occurs earlier, is more profound and lasts longer than that ofL-Trp.
Effects of diet protein source on the behavior of piglets after weaning
Livestock Science, 2010
Forty eight piglets with initial body weight of 5.60 ± 0.75 kg, weaned at 21 days of age were used to investigate the effects of diet protein source on their behavior and performance after weaning. The piglets were distributed in a completely randomized experimental design, composed of three treatments (a control diet with soybean meal and maize, diet with nonfat dry milk powder and diet with spray-dried plasma), and four replications, with four animals per experimental unit. The piglets' behavior activities were registered and analyzed through the observation of the videos and registered in a work schedule. These images were analyzed continuously, using the "focal" technique. The animals submitted to a control diet demonstrated during the whole period of evaluation a higher incidence of nosing behavior, less time spent at the feeders more time spent with the manifestation of non-desirable agonistic behaviors (P b 0.05) than other treatments. The values for feed intake and weight gain, for animals submitted to control diet were lower when compared to animals submitted to plasma and milk powder diet (P b 0.05). It is concluded that piglets weaned at 21 days of age and fed with simple diets (control diet), based on corn and soybean meal, demonstrate higher incidence of undesirable behaviors and lower growth performance than the piglets that are fed with diets containing spray-dried plasma or nonfat dry milk powder.
Estimation of the tryptophan requirement in piglets by meta-analysis
Animal, 2011
There is no consensus concerning the Trp requirement for piglets expressed relative to Lys on a standardized ileal digestible basis (SID Trp : Lys). A meta-analysis was performed to estimate the SID Trp : Lys ratio that maximizes performance of weaned piglets between 7 and 25 kg of BW. A database comprising 130 experiments on the Trp requirement in piglets was established. The nutritional values of the diets were calculated from the composition of feed ingredients. Among all experiments, 37 experiments were selected to be used in the meta-analysis because they were designed to express the Trp requirement relative to Lys (e.g. Lys was the second-limiting amino acid in the diet) while testing at least three levels of Trp. The linear-plateau (LP), curvilinear-plateau (CLP) and asymptotic (ASY) models were tested to estimate the SID Trp : Lys requirement using average daily gain (ADG), average daily feed intake (ADFI) and gain-to-feed ratio (G : F) as response criteria. A multiplicative...
Digestible tryptophan levels in diets for pigs weighing 15 to 30 kg
Revista Brasileira de Zootecnia, 2011
In order to evaluate the effects of increasing dietary tryptophan levels on performance and carcass characteristics of growing pigs, a total of 60 crossbred castrated male pigs, with average initial and final body weights of 15.50 ± 1.15 and 30.60 ± 1.35 kg were used. Pigs were allotted in a completely randomized block design, with five dietary treatments (0.149, 0.158, 0.168, 0.177, and 0.187% digestible tryptophan, corresponding to digestible tryptophan:lysine relations of 16.0, 17.0, 18.0, 19.0, and 20.0%), six replicates, and two animals per experimental unit, which was represented by the pen. Experimental diets and water were supplied ad libitum throughout the experimental period. The average maximum and minimum temperatures inside the rooms were of 21.5 ± 1.12°C and 26.4 ± 1.91°C, respectively. There was no effect of digestible tryptophan on daily feed intake or protein deposition of pigs. Body weight gain increased quadratically with increasing digestible tryptophan in the diets up to 0.175% maximum response. Increasing digestible tryptophan in the diets linearly improved feed conversion of pigs. The greatest weight gain of 15 to 30 kg castrated male pigs is obtained at 0.175% digestible tryptophan, corresponding to a digestible tryptophan:lysine relation of 18.82% and an estimated daily intake of 2.32 grams of digestible tryptophan.
Digestible tryptophan levels for 30 to 60 kg pigs
Revista Brasileira de Zootecnia, 2011
The objective of this study was to evaluate the effects of increasing dietary digestible tryptophan levels on performance and carcass traits of growing pigs. Fifty crossbred castrated male pigs, with average initial and final body weight of 29.0 ± 1.20 kg and 60.4 ± 1.95 kg were allotted in a completely randomized block design, with five treatments (0.125, 0.133, 0.141, 0.149, and 0.157% of digestible tryptophan, corresponding to digestible tryptophan:lysine relations of 15.0, 16.0, 17.0, 18.0, and 19.0%, respectively) and five replicates, with two pigs per experimental unit, which was represented by the pen. Experimental diets and water were supplied ad libitum throughout the experimental period. Averages of minimum and maximum temperatures inside the facility were of 24.3 ± 0.87 o C and 28.0 ± 1.82 o C, respectively. Feed intake and body weight gain increased linearly with increasing dietary tryptophan levels. However, there was no effect of digestible tryptophan on feed conversion or protein deposition of pigs. The highest tryptophan level evaluated (0,157%), corresponding to a digestible tryptophan:lysine relation of 19.0%, provided the greatest weight gain of 30 to 60 kg castrated male pigs.
Effects of tryptophan supplementation on aggression among group-housed gestating sows1
Journal of Animal Science, 2011
The objective of this study was to determine the effects of dietary Trp supplementation on mixing-induced aggression and the associated stress, and on reproductive performance in gestating sows. After weaning, sows were mixed in pens with electronic sow feeders on concrete-slatted floors. Each pen housed 21 ± 2.8 sows, with approximately 2.7 ± 0.43 m 2 /sow of floor space allowance. Multiparous sows (n = 168) from 8 breeding groups were used, with 4 groups assigned to a control diet and 4 groups assigned to a high-Trp diet. Control sows received corn-and soybean meal-based diets throughout gestation (0.15% Trp) and lactation (0.21% Trp). Three days before and after mixing, sows assigned to the high-Trp treatment received approximately 2.3 times the dietary Trp (0.35% in the gestation diet and 0.48% in the lactation diet) fed to control sows. Six focal sows (2 sows from each of parity 1, 2, and 3 or greater) in each pen were designated and videotaped for 72 h after mixing to determine the type and number of aggressive interactions among sows. Before and 48 h after mixing, saliva samples were collected from focal sows, and scratches were assessed on all sows. Data were analyzed using the FREQ and GLIMMIX procedures (SAS Inst. Inc., Cary, NC). Aggression among sows was intense during the initial 6 h and decreased between 6 and 72 h after mixing. The initial aggression caused scratches and increased cortisol concentrations (P < 0.05). Mature sows tended to fight for longer periods (112 vs. 52 s/h per sow, SE = 23.8; P < 0.10) but had fewer scratches caused by aggression (injury score = 4.3 vs. 6.5, SE = 1.13; P < 0.01) than parity-1 sows. Supplementation of dietary Trp reduced the total duration of head-to-head knocking (P < 0.05) but did not affect other aggressive behaviors. There was no difference between dietary treatments in injury scores or saliva cortisol concentrations. Sows in the high-Trp treatment had more total piglets born (12.5 vs. 10.5 pigs/litter, SE = 0.55; P < 0.05) and more stillborn piglets (1.5 vs. 0.8 pigs/litter, SE = 0.20; P < 0.05), but had no significant change (P = 0.12) in piglets born alive (10.8 vs. 9.7 pigs/litter, SE = 0.42) compared with control sows. The results indicate that the initial aggression after mixing caused more injuries in young sows than in mature sows. Supplementation of dietary Trp at 2.3 times the control amount for a short period did not effectively reduce aggression and the associated stress in sows at mixing.