Abstract
Highly intensified rearing conditions and precarious sanitary management predispose pigs to immune system activation, altered amino acid (AA) metabolism, and decreased growth performance. ...Thus, the main objective of this study was to evaluate the effects of increased dietary tryptophan (Trp), threonine (Thr), and methionine + cysteine (Met + Cys) supplementation on performance, body composition, metabolism, and immune responses of group-housed growing pigs under challenging sanitary conditions. A hundred and twenty pigs (25.4 ± 3.7 kg) were randomly assigned to a 2 × 2 factorial arrangement, consisting of two sanitary conditions (SC, good GOOD or salmonella-challenge and poor housing condition Salmonella Typhimurium (ST) + POOR) and two diets, control (CN) or supplemented with AA (Trp, Thr, and Met + Cys:Lys ratios 20% higher than those of the CN diet AA>+). Pigs were followed during the growing phase (25–50 kg) and the trial lasted 28 d. The ST + POOR SC pigs were challenged with Salmonella Typhimurium and raised in a poor housing condition. The ST + POOR SC increased rectal temperature, fecal score, serum haptoglobin, and urea concentration (P < 0.05) and decreased serum albumin concentration (P < 0.05) compared with GOOD SC. Body weight, average daily feed intake, average daily gain (ADG), feed efficiency (G:F), and protein deposition (PD) were greater in GOOD SC than in ST + POOR SC (P < 0.01). However, pigs housed in ST + POOR SC fed with AA+ diet had lower body temperature (P < 0.05), increased ADG (P < 0.05) and nitrogen efficiency (P < 0.05), and a tendency for improved PD and G:F (P < 0.10) compared with CN diet fed pigs. Regardless of the SC, pigs fed AA+ diet had lower serum albumin (P < 0.05) and tended to decrease serum urea levels (P < 0.10) compared with CN diet. The results of this study suggest that the ratio of Trp, Thr, and Met + Cys to Lys for pigs are modified by sanitary conditions. Furthermore, supplementation of diets with a blend of Trp, Thr, and Met + Cys improves performance, especially under salmonella-challenge and poor housing conditions. Dietary tryptophan, threonine, and methionine supplementation can modulate immune status and influence resilience to sanitary challenges.
The impaired growth performance and protein deposition of pigs under sanitary challenge can be attenuated by dietary tryptophan, threonine, and methionine supplementation. The amino acid supplementation mitigates immune system activation and improves the efficiency of nitrogen utilization, increasing pigs’ resilience with no in-feed antibiotics in a group-housed system.
Lay Summary
Immune system activation alters pigs’ physiology and metabolism, increasing maintenance requirements and reducing voluntary feed intake and weight gain. Dietary functional amino acid supplementation (tryptophan, threonine, and methionine) is a strategy to support the immune system activation for immune components production, maintenance of the gut barrier integrity, and reduction of the oxidative status. Additionally, amino acid supplementation may mitigate growth performance losses. In this context, this study was conducted to investigate the effect of diets with or without tryptophan, threonine, and methionine supplementation on the performance and immune system activation of growing pigs under a sanitary challenge. The amino acid supplementation mitigated the immune system activation of challenged growing pigs and improved growth performance when compared to pigs fed diets with no supplementation. The functional amino acid supplementation may be an efficient nutritional strategy to optimize health and growth performance of immune-challenged pigs.
Abstract
This study investigated the effects of a low-protein diet with or without an increase in dietary protein and feed-grade amino acids (AAs) on the growth performance, body composition, ...metabolism, and serum acute-phase proteins of finishing pigs reared in thermoneutrality or cyclic heat stress conditions. A total of 90 gilts (67.7 ± 6.2 kg) were distributed in a 2 × 3 factorial arrangement (two ambient temperatures and three diets). Ambient temperatures (AT) were thermoneutral (TN, 22 °C for 24 h) and cyclic heat stress (CHS, 12 h to 35 °C and 12 h to 22 °C). The evaluated diets (D) were high crude protein (HP); low CP-free AA-supplemented diets (LPAAs); low CP-free AA-supplemented diets and digestible Lys level (+20%), and Lys:AA ratios above recommendations (LPAA+). The experimental period lasted 48 d (two experimental phases: days 0–27 and days 28–48, respectively). CHS pigs had higher skin temperature (P < 0.05) than TN pigs. Pigs in CHS had higher rectal temperature (P < 0.05) than TN pigs until day 38 but similar (P > 0.10) to TN pigs from 38 to 45 d. For the entire experiment, CHS pigs had lower (P < 0.05) final BW, average daily gain and daily feed intake, net energy intake, body lipid, bone mineral, lipid deposition, energy retention, Lys and CP intake, and nitrogen excretion than TN pigs. The level of CP intake impacted nitrogen excretion, nitrogen retention efficiency, and urea as pigs fed HP had the highest values, and pigs fed LPAA had the lowest values (P < 0.05). On day 27, CHS pigs had lower (P < 0.05) free triiodothyronine than TN pigs. LPAA+ pigs had lower (P < 0.05) insulin than LPAA. On day 48, CHS pigs had lower (P < 0.05) thyroxine, albumin, and lactate than TN pigs. On day 27, pigs fed LPAA+ had higher (P < 0.05) lactate than pigs fed HP or LPAA. Both AT and D were enough to stimulate the immune system as CHS pigs had lower (P < 0.05) transferrin and 23-kDa protein levels than TN pigs, and HP pigs had higher haptoglobin than LPAA on day 27. These results confirm the deleterious effects of high AT on performance, body composition, metabolism, and immune system stimulation in finishing pigs. These data also show that a diet with low levels of CP can be provided to pigs in CHS without affecting performance and body composition while reducing nitrogen excretion. However, the use of a diet with an AA level above the requirements obtained by increasing intact protein and free AA did not attenuate the impact of CHS on performance and body composition of pigs.
The slightly impaired growth performance and body composition of pigs under daily cyclic heat stress cannot be overcome by nutritional strategies differing in protein and amino acid content. However, reducing protein levels associated with amino acid supplementation attenuates nitrogen excretion without compromising nitrogen retention regardless of ambient temperature, contributing to more sustainable pig production.
Lay Summary
High ambient temperature and air humidity are the most important climatic factors that jeopardize pig production. Multiple strategies can be applied for pigs under heat stress, including recent research to improve understanding the use of nutrition to attenuate the impact of heat stress. Heat stress impairs digestion, absorption, and amino acid metabolism with changes in amino acid requirements. Updates on the nutritional assessment strategies by differing the diets by protein and amino acid content (protein-bound or feed-grade) seem to be efficient tools for pork producers as amino acids play a functional role in challenged pigs apart from the beneficial effects on performance.
This study aimed to evaluate the effects of a sequential feeding program (SEQ) with diets varying in amino acid (AA) concentrations in the first and last 12 h of the day on the performance, body ...composition, and nutrient balance of growing-finishing pigs. Sixty-eight castrated male pigs were distributed in four treatments: a daily feeding program (DP) and three SEQs. In the DP, dietary requirements of AA were adjusted daily. In the SEQ, dietary daily requirements of AA were adjusted every 12 h, providing a low AA concentration in period 1 (P1; 00:00-11:59 h) and a high AA concentration in period 2 (P2; 12:00-23:59 h). In the SEQ, three different levels of low and high AA concentrations were evaluated: ±20%, ±30%, and ±40%. The experiment lasted 82 days and was divided into phase 1 (25-50 kg body weight; BW), phase 2 (50-70 kg BW), and phase 3 (70-100 kg BW). During phase 1, irrespective of dietary AA concentration, SEQ pigs had higher lysine intake, protein gain, and phosphorus efficiency than DP pigs (P ≤ 0.05). Pigs in the SEQ showed a tendency for greater average daily gain, body protein, and body lipids compared to the DP pigs (P ≤ 0.10). During phase 2, SEQ pigs showed a tendency for higher average feed intake in P2 compared to DP pigs (P = 0.07); consequently, average daily gain, body protein, and phosphorus retention tended to increase (P ≤ 0.10). During phase 3, SEQ pigs had a higher average feed intake in P2 than DP pigs (P = 0.03). However, they had a similar body composition (P > 0.05) and a tendency for higher nitrogen excretion (P = 0.06) than DP pigs. Our results suggest that SEQ is an effective approach for improving the performance and body composition of growing pigs.
This paper presents a scientometric and bibliometric review of the research on autonomous vehicles (AVs) to identify its main characteristics, evolution, and potential trends for future studies. ...Relevant articles were searched on WoS, yielding a research corpus of 10,580 papers, and the software CiteSpace was subsequently used for analysis. The results showed that AV research is heterogeneous and registered a growing demand over time. Multidisciplinarity is present, with 96 science fields being identified. As in any other sector, it is necessary to understand broader aspects of this industry such as the market factors surrounding it, as well as other economic and managerial issues. In this sense, we observed a migration of the research field from multidisciplinarity to pluridisciplinarity with a greater number of studies focusing on the latter. We understand that terminology standardisation contributes to achieving pluridisciplinarity. As such, it is important to highlight that sustainability, public policies, liability, and safety, as well as business issues such as performance and business models are some of the tendencies in the field of AVs. For future studies, we suggest a more in-depth analysis of publications in terms of individual search terms, as well as the sub-areas identified as trends in this paper.
The impact of cyclic heat stress (CHS) and turning the lights on and off on pig feeding behavior (FB) was investigated. The FB of 90 gilts was recorded in real-time under two ambient temperatures ...(AT): thermoneutrality (TN, 22 °C) or CHS (22/35 °C). The day was divided into four periods: PI
; PII
; PIII
; and PIV
. Automatic and Intelligent Precision Feeders recorded each feed event for each pig. An estimated meal criterion (49 min) was used to calculate the FB variables. Feed behavior in both ATs followed a circadian pattern. The CHS reduced the feed intake by 6.9%. The pigs prioritized feed intake during the coolest hours of the day; however, nocturnal cooling did not allow the pigs to compensate for the reduced meal size due to CHS. The highest meal size and most of the meals were observed during the lighting-on period. The pigs reduced their interval between meals during PII and PIII. The lighting program increased the meal size when the lights were switched on and reduced the meal size when the lights were switched off. Thus, the dynamics of the FB were largely influenced by AT, whereas the meal size was affected by the lighting program.
A sanitary challenge was carried out to induce suboptimal herd health while investigating the effect of amino acids supplementation on piglet responses. Weaned piglets of high sanitary status (6.33 ± ...0.91 kg of BW) were distributed in a 2 × 2 factorial arrangement into two similar facilities with contrasting sanitary conditions and two different diets. Our results suggest that increased Trp, Thr, and Met dietary supplementation could support the immune systems of piglets under a sanitary challenge. In this manner, AA+ supplementation improved the performance and metabolism of piglets under mixed management and poor sanitary conditions. No major temporal microbiome changes were associated with differences in performance regardless of sanitary conditions or diets. Since piglets often become mixed in multiple-site production systems and facility hygiene is also often neglected, this study suggests that increased Trp, Thr, and Met (AA+) dietary supplementation could contribute to mitigating the side effects of these harmful risk factors in modern pig farms.
This study identified the effects of dietary supplementation with ractopamine, chromium picolinate, chromium yeast, or an energetic feed restriction on the growth performance and lipid profile of ...subcutaneous fat, in late finishing gilts. Twenty genetically similar gilts with initial body weight of 105.35 ± 4.77 kg and a final body weight of 131.37 ± 5.58 kg were distributed in a completely randomized block design with five treatments (control; ractopamine: 20 ppm; chromium picolinate: 0.48 ppm; chromium yeast: 0.80 ppm; and energetic feed restriction: -150 kcal kg-1 of metabolizable energy), with four replicates of one animal each. The experimental diets were isonutritives, except for the metabolizable energy level of the diet fed to the group subjected to energy restriction. There were no effects on the growth performance and carcass characteristics. Ractopamine and organic chromium (picolinate and yeast) supplementation increased the concentration of total polyunsaturated fatty acid. The proportion of α-linolenic fatty acids were higher when the diets were supplemented with ractopamine or chromium yeast. The energy restriction increased the n-6:n-3 ratio and reduced α-linolenic acid concentration. Therefore, ractopamine, chromium picolinate, chromium yeast supplementation, and energetic feed restriction did not affect the growth performance or carcass characteristics but altered the lipid profile of subcutaneous fat in finishing gilts. Ractopamine and organic chromium supplementation increased PUFA in the fat of finishing female pigs.
RESUMO: Este estudo foi conduzido com o objetivo de identificar os efeitos da suplementação com ractopamina, cromo picolinato, cromo levedura, ou da restrição alimentar energética, sobre o desempenho e o perfil de ácidos graxos da gordura subcutânea de fêmeas suínas em fase final de terminação. Foram utilizadas 20 fêmeas suínas, geneticamente similares, com peso inicial de 105,35 ± 4,77 kg e peso final de 131,37 ± 5,58 kg, distribuídas em delineamento experimental de blocos ao acaso em cinco tratamentos (controle; ractopamina: 20 ppm; picolinato de cromo: 0,48 ppm; cromo levedura: 0,80 ppm; e restrição energética: -150 kcal kg-1 de energia metabolizável) com quatro repetições de um animal cada. As dietas experimentais foram isonutritivas, exceto para o nível de energia metabolizável da dieta fornecida ao grupo submetido à restrição energética. Não houve efeito dos tratamentos sobre o desempenho e as características de carcaça. As suplementações com ractopamina e cromo orgânico (picolinato ou levedura) aumentaram a concentração de ácidos graxos poli-insaturados. A proporção do ácido α-linolênico foi maior com a inclusão da ractopamina ou do cromo levedura na dieta. A restrição energética aumentou a proporção n-6:n-3 e reduziu a concentração do ácido α-linolênico. As suplementações com ractopamina, picolinato de cromo, cromo levedura, ou restrição alimentar energética, não influenciaram o desempenho e as características de carcaça, mas alteraram o perfil lipídico da gordura subcutânea de fêmeas suínas. As suplementações com ractopamina e cromo orgânico aumentaram a proporção de AGPI.
ABSTRACT This study aimed to evaluate different periods of chromium yeast (CrY) supplementation on growth performance and quantitative carcass characteristics of growing-finishing pigs. We used ...eighty barrows (Duroc/Pietran × Large White/Landrace) with an initial body weight of 24.5±2.4 kg. A completely randomized block design was used within four periods of dietary CrY supplementation (control diet: CrY-free, from 25 to 110 kg; Cr25-110 kg: diet with 0.4 mg kg−1 of CrY, from 25 to 110 kg; Cr50-110 kg: diet with 0.4 mg kg−1 of CrY, from 50 to 110 kg; and Cr70-110 kg: diet with 0.4 mg kg−1 of CrY, from 70 to 110 kg), with ten replicates and two animals each. The CrY supplementation did not affect (P>0.05) either the grow performance or the carcass characteristics evaluated. The dietary supplementation of 0.4 mg kg−1 of CrY for growing-finishing pigs (25 to 110 kg) does not alter the performance neither the quantitative carcass characteristics.
Typhimurium is the most frequent serovar in pigs and causes infections in humans. However, the dosage used for experimentation is not well defined. The present study aimed to evaluate a dosage for ...oral inoculation with
Typhimurium to assess immunological and growth performance alterations in pigs. Gilts were randomly allocated into one of three experimental treatments: no
Typhimurium inoculation (Basal), or oral inoculation of 1 × 10
or 1.5 × 10
colony-forming units of
Typhimurium. Growth rate, rectal temperature, and fecal
shedding were recorded. Blood samples were taken. Inoculated pigs shed the bacteria for up to 7 days, but no differences were observed between the groups. No differences were observed in rectal temperature, body weight, or average daily feed intake. However, reductions in average daily gain (-17 and -22%) and feed efficiency (-14 and -20%) were observed in pigs inoculated with 1 × 10
and 1.5 × 10
colony-forming units, respectively. The hemoglobin and hematocrit concentrations increased in challenged pigs compared to Basal pigs. The oral dosage of 1.5 × 10
colony-forming units of
Typhimurium is suitable for activating the immune system of pigs and assessing the impact of
on pig performance.
This study evaluated the effect of dietary net energy (NE) levels on growth performance and carcass characteristics of barrows from 30 to 70 kg of body weight (BW). Sixty barrows with initial body ...weight (IBW) of 31.94 ± 3.54 kg and final body weight (FBW) of 71.98 ± 5.99 kg were allotted to one of five dietary NE levels (2.40, 2.45, 2.50, 2.55, and 2.60 Mcal kg-1), using a completely randomized block design with six replicates and two barrows per replicate. The experimental period was divided into phase I: 30 to 50 kg and phase II: 50 to 70 kg. The variables analyzed were average daily feed intake (ADFI), net energy intake (NEI), digestible lysine intake (LysI), average daily gain (ADG), feed conversion (FC), FBW, digestible lysine conversion:gain (LysI:G), Cost:Gain (C:G), loin eye area (LEA), muscle depth (MD), first backfat layer (BF1), second backfat layer (BF2), total backfat (BFt), lean meat percentage, and carcass bonus index (BI). In phase I, there was a linear increase (P < 0.05) in FBW, ADG, NEI, and LysI with increasing NE levels in the diet. In phase II, increasing dietary NE levels also increased (P < 0.05) FBW, ADG, NEI, LysI, and FC linearly. Overall, there was a linear increase (P < 0.05) in ADG, NEI, LysI, and FC with increasing NE levels in the diet. The other performance variables were not affected (P > 0.05) by the NE levels. There was an increase (P < 0.05) in BF2 with increasing NE levels, but the other carcass characteristics were not altered (P > 0.05). We recommended 2.60 Mcal of NE kg-1 in the diet for growing barrows from 30 to 70 kg.
RESUMO: Realizou-se este estudo com o objetivo de avaliar níveis de energia líquida (EL), mantendo a relação caloria: nutriente, no desempenho e características de carcaça de suínos dos 30 aos 70 kg. Foram utilizados 60 suínos machos castrados, com pesos iniciais de 31,94 ± 3,54 kg e finais de 71,98 ± 5,99 kg. Os animais foram distribuídos em delineamento experimental de blocos casualizados, em cinco níveis de EL (2,40; 2,45; 2,50; 2,55; 2,60 Mcal de EL kg-1 de dieta), com seis repetições e dois animais por unidade experimental. O período experimental foi dividido em fase I: 30 aos 50 kg e fase II: 50 aos 70 kg. As variáveis analisadas foram os consumos de ração diária (CRD), energia líquida (CEL) e lisina digestível (CLdig), ganho de peso diário (GPD), conversão alimentar (CA), peso final (PF), conversão de lisina digestível: ganho (CLdig:G), custo: ganho (C:G), área de olho de lombo (AOL), profundidade de músculo (PM), espessura de toucinho da primeira camada (ET1), espessura de toucinho da segunda camada (ET2), espessura de toucinho total (ETt), percentual de carne magra (CM) e o índice de bonificação de carcaça (IB). Dos 30 aos 50 kg, verificou-se aumento linear (P < 0,05) do PF, GPD e dos CEL e CLdig com o aumento dos níveis de EL na dieta. Dos 50 aos 70 kg, o aumento dos níveis de EL na dieta promoveu melhora linear (P < 0,05) do PF, GPD, CEL, CLdig e da CA dos suínos. No período total, verificou-se aumento linear (P < 0,05) do GPD, CEL, CLdig e melhora linear (P < 0,05) da CA de acordo com o aumento do nível de EL na dieta. As demais variáveis de desempenho não foram afetadas (P > 0,05) pelos níveis de EL. Verificou-se aumento (P < 0,05) da ET2 de acordo com o aumento do nível de EL, porém sem alterar (P > 0,05) as demais características de carcaça. Recomenda-se o nível 2,60 Mcal de EL kg-1 de dieta para suínos machos castrados dos 30 aos 70 kg.
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