Alysson Saraiva

Effect of social ranks and gestation housing systems on oxidative stress status, reproductive performance, and immune status of sows

Ninety-six multiparous sows were randomly assigned into 2 different gestation housing systems on d 35 of gestation: individual gestational crates (n = 24) or small groups with 3 sows in gestational pens (n = 24). Sows were classified into 4 treatments based on gestation housing systems and social ranks within each gestational pen: sows housed in individual gestational crates were in control treatment (CON), and sows destined to high, middle, or low social ranks within each pen were classified into high social rank treatment (HR), middle social rank treatment (MR), and low social rank treatment (LR). The social rank of sows within a pen was determined by their winning percentage during aggressive interactions observed for a 4-d period after mixing on d 35 of gestation. Plasma samples collected from each sow on d 35, 60, 90, and 109 of gestation and d 1 and 18 of lactation were used to determine concentrations of malondialdehyde (MDA), protein carbonyls, 8-hydroxy-deoxyguanosine (8-OHdG), IgG, and IgM. Sows in HR had higher (P < 0.05) body weight during gestation and lactation, smallest (P < 0.05) litter weight at birth, increased (P < 0.05) number of stillborn than sows in MR and LR, and tended to have decreased (P = 0.073, P = 0.064) number of born alive compared with sows in CON and LR. Sows in LR had lower farrowing rate compared with sows in MR. Plasma concentration of protein carbonyl in HR was higher (P < 0.05) than that in MR on d 3 of lactation. Plasma concentrations of 8-OHdG in LR was greater (P < 0.05) than that in HR on d 90 of gestation, d 3 and 18 of lactation, and greater (P < 0.05) than CON on d 18 of lactation. The reproductive performance of sows from all of the social ranks was related to their oxidative stress status during gestation and lactation. Collectively, the reproductive performance, oxidative stress status, and immune status did not differ between sows housed in gestational crates (CON) and pens (HR + MR + LR). Sows in CON and MR did not show inferior reproductive performance during gestation and lactation. Sows in HR and LR had increased oxidative damage during late gestation and lactation which could contribute to the reduced litter size and litter weight in HR and lower farrowing rate in LR.

Available phosphorus levels in diets for swine with high genetic potential for meat deposition from 30 to 60 kg.

With the objective of evaluating levels of available phosphorus (AP) in diets for swine with high genetic potential for meat deposition,sixty female commercial hybrid swine were used, with initial weight of 30 ± 0.618 kg, distributed in a completely randomized experimental design, with five treatments, six replications and two animals per experimental unit. The treatments consisted of a basal diet without phosphorus supplementation and another four diets obtained by supplementing the basal diet with dicalcium phosphate to obtain five available phosphorus levels (0.115, 0.195, 0.275, 0.355 and 0.435%). No effect of the available phosphorus levels was observed on the feed daily intake. The available phosphorus levels influenced linearly the daily weight gain (DWG) and the feed conversion (FC), and the daily weight gain increased up to the level of 0.349% available phosphorus, and remained on a plateau. The feed conversion decreased to 0.345% of available phosphorous and remained on a plateau. The bone strength, phosphorus levels and ash percentage in the bones linearly increased as available phosphorous levels increased in the rations. There was no effect of the available phosphorous levels of the diets on the amount of calcium in the bones. The available phosphorous levels that showed the best results for daily weight gain and feed conversion in female swine with high genetic potential for meat deposition, from 30 to 60 kg, are, respectively, 0.349 e 0.345%, corresponding to the estimated daily intakes of 7.45 and 7.36 g.

Available phosphorus levels in diets for swine from 15 to 30 kg genetically selected for meat deposition

Com o objetivo de avaliar niveis de fosforo disponivel (PD) em racoes para suinos selecionados geneticamente para deposicao de carne, utilizaram-se 60 leitoes hibridos comerciais (30 machos castrados e 30 femeas) com peso inicial de 15,00 ± 0,41 kg, distribuidos em delineamento experimental inteiramente casualizado, com seis racoes, cinco repeticoes e dois animais (um macho e uma femea) por unidade experimental. Avaliaram-se uma racao basal e outras cinco racoes, obtidas pela suplementacao da racao basal com fosfato bicalcico, totalizando seis niveis de fosforo disponivel (0,114; 0,221; 0,328; 0,435; 0,542 e 0,649%). Os niveis de fosforo disponivel promoveram aumento linear no consumo diario da racao. O ganho de peso diario e a conversao alimentar variou de forma quadratica de acordo com os niveis de PD, com valores maximos de 0,509 e 0,477% de PD na racao, respectivamente. A resistencia ossea e os teores de calcio e fosforo no osso tambem aumentaram de forma quadratica de acordo com os niveis de PD, com valores maximos de 0,529; 0,619 e 0,596% de PD na racao, respectivamente. Nao houve efeito dos niveis de PD nas racoes sobre o teor de cinza ossea. Os melhores resultados de ganho de peso e conversao alimentar de suinos, machos castrados e femeas, na fase dos 15 aos 30 kg, selecionados geneticamente para deposicao de carne, sao proporcionados pelos niveis de fosforo disponivel de 0,509 e 0,477%, respectivamente, correspondentes a consumos diarios de 6,39 e 5,93 g de fosforo disponivel.

Níveis de proteína bruta em dietas para alevinos de acará-bandeira

The aim of this experiment was to evaluate dietary protein requirements of freshwater angelfish fry. A complete randomized design with four dietary crude protein levels (34, 38, 42, and 46% of CP) and four replicates was used. Fish averaging 0.44±0.05 g were reared in sixteen 25L-aquarium with aeration, biological filter and controlled temperature (26 ± 0.5°C), in a stocking density of six fish/aquarium. Fish were fed ad libitum at 8:00 a.m., 11:00 a.m., 2:00 p.m, and 5:00 p.m, during 60 days. Final weight, weight gain, feed intake, feed:gain ratio, specific growth rate and protein efficiency ratio (PER) were the evaluated parameters of productive performance. At the end of the experiment, no treatment effect on productive performance, with the exception of PER was observed. Fishes fed diets with 46% CP showed PER significant smaller than those fed diets with 34 and 38% of CP. PER of fish fed diets with 42% of CP did not differ from the other treatments. Diets with 34% of CP can meet the protein nutritional requirements of freshwater angelfish fry.

Available phosphorus levels in diets for pigs with high genetic potential for lean meat deposition kept in thermoneutral environment from 15 to 30 kg

It was used 72 pigs, 36 castrated males and 36 females, with initial weight of 14.97 ± 0.36 kg to evaluate levels of dietary available phosphorus (aP). The animals were distributed in a completely randomized block design, with six levels of aP (0.107; 0.214; 0.321; 0.428; 0.535 and 0.642%), six replicates and two animals (one castrated male and one female) per experimental unit. Air temperature and relative humidity in the room were kept at 24.5 ± 1.2°C and 76.3 ± 8.5%, respectively. The levels of aP influenced both daily feed intake and daily weight gain, which increased in a quadratic way up to the estimated levels of 0.420% and 0.443%, respectively and feed conversion, which improved in a quadratic manner up to the estimated level of 0.461%. It was observed the effects of levels of aP on quantity of phosphorus and ash in the bone, which increased in a quadratic manner up to the estimated levels of 0.525% and 0.520%, respectively. Levels of Ap affected daily protein deposition in the carcass, which increased in a quadratic way up to the estimated level of 0.394%. There was no effect of levels of aP on daily fat carcass deposition. Levels of aP that provided the best results for daily weight gain, feed conversion and bone mineralization in swines with high genetic potential for lean meat kept in thermoneutral environment, from 15 to 30 kg are 0.443, 0.461 and 0.525%, respectively, corresponding to estimated daily intakes of 5.25, 5.45 and 6.14 g of aP.

Glutamina, nucleotídeos e plasma suíno em rações para leitões desmamados

The effect was asessed of adding glutamine, nucleotides and spray-dried swine plasma on the performance, intestinal mucosal structure and immune response of piglets weaned at twenty one days. Two hundred and fifty two piglets, initial weight 6.35 ± 0.80 kg, were used placed in a randomized complete block deaign conducted in seven treatments, six replications and six animals per experimental unit. The initial weight of the animals was considered in the formation of the blocks. The treatments consisted of: the control diet, diet with 1.0% glutamine, diet with a commercial nucleotide product, diet with 2.0% swine plasma, diet with 4.0% swine plasma, diet with 2.0% swine plasma and 1.0% glutamine, diet with 2.0% swine plasma and commercial nucleotide product (PN). The diets with swine plasma gave the greatest weight gains to the piglets at 35 and 42 days of age. In the first fourteen days, with exception of piglets in treatment PN, all piglets fed diets with plasma had higher intake (IRD). The best results for daily weight gain (WGD) were obtained with diets with nucleotides, 2% and 4% plasma, Plasma + glutamine and plasma + nucleotides. The feed:gain ratio (FGR) of the animals was not effected by the experimental diets in the first two weeks after weaning. In the whole period (21 to 42 days of age) the best results for intake and weight gain were observed with the supply of diets with 2% swine plasma and plasma + glutamine. The animals fed the control diet presented the worst performance results. The animals fed diets with glutamine, 2% plasma and plasma + nucleotides presented the best feed conversion throughout the experimental period. The villous height, crypt depth and the leukocyte and lymphocyte populations were not influenced by the treatments. The use of glutamine, nucleotide and swine plasma improves the performance of piglets weaned at 21 days of age.

L-glutamine and L-glutamate in diets with different lactose levels for piglets weaned at 21 days of age

This study was developed to evaluate the effects of adding L-glutamine and L-glutamate in diets with no lactose or with 4.0 or 8.0% lactose inclusion for piglets weaned at 21 days old. One hundred and eight piglets with initial weight of 6.12±0.70 kg were allotted in a complete randomized block design, in a 3 × 2 factorial arrangement, with six treatments, six replicates, and three piglets per experimental unit. The experimental diets were supplied from 21 to 35 days. From 36 to 49 days, animals received the same diet with no lactose inclusion, but the animals in the treatments with L-glutamine + L-glutamate in the previous phase continued to receive diets containing these ingredients. There was no interaction between the level of lactose and the inclusion of L-glutamine + L-glutamate on the parameters evaluated. The levels of lactose did not affect the performance of piglets in either of the two periods. Adding L-glutamine and L-glutamate in the diet positively influenced the weight gain of pigs from 21 to 49 days of age and increased the villous height in the duodenum, jejunum and ileum. Inclusion of L-glutamine + L-glutamate in diets for piglets weaned at 21 days of age improves the performance and the intestinal mucosa morphology, regardless of lactose addition.

Available phosphorus levels in diets for 30 to 60 kg female pigs selected for meat deposition by maintaining calcium and available phosphorus ratio

With the objective to evaluate levels of available phosphorus (aP) in diets for pigs selected for meat deposition by maintaining the calcium and available phosphorus ratio, it was used 50 commercial hybrid female pigs with initial weight of 30.32 ± 0.29 kg, distributed in a complete randomized experimental design, with five treatments, five replicates, and two animals per experimental unit. Treatments were composed of a corn-soybean meal basal diet and four diets obtained by supplementation of basal diet with dicalcium phosphate, resulting in diets with 0.144; 0.224; 0.304; 0.384 and 0.464% of aP. Calcium levels were adjusted by varying the quantities of limestone in the diets. There was no effect of aP on both daily feed intake and feed conversion. Levels of aP affected daily weight gain which increased quadratically up to the estimated level of 0.372%. There was no effect of aP on quantity of phosphorus in the bones. The quantity of calcium in the bones and percentage of ash in the bones were influenced in an increasing linear way by the aP in the rations. The best result of weight gain of swine females, from 30 to 60 kg, genetically selected for meat deposition, is provided by the level of available phosphorus of 0.372%, which corresponds to a relationship with calcium of 2.06:1 and to a daily intake of 8.20 g of available phosphorus.

Effect of heat stress and feeding phosphorus levels on pig electron transport chain gene expression

The purpose of this study was to evaluate the effect of temperature and different levels of available phosphorus (aP) on the expression of nine genes encoding electron transport chain proteins in the Longissimus dorsi (LD) muscle of pigs. Two trials were carried out using 48 high-lean growth pigs from two different growth phases: from 15 to 30 kg (phase 1) and from 30 to 60 kg (phase 2). Pigs from growth phase 1 were fed with three different levels of dietary aP (0.107%, 0.321% or 0.535%) and submitted either to a thermoneutral (24°C and RH at 76%) or to a heat stress (34°C and RH at 70%) environment. Pigs from growth phase 2 were fed with three different levels of dietary aP (0.116%, 0.306% or 0.496%) and submitted either to a thermoneutral (22ºC and RH at 77%) or to a heat stress (32ºC and RH at 73%) environment. Heat stress decreased (P<0.001) average daily feed intake at both growth phases. At 24°C, pigs in phase 1 fed the 0.321% aP diet had greater average daily gain and feed conversion (P<0.05) than those fed the 0.107% or 0.535% while, at 34°C pigs fed the 0.535% aP had the best performance (P<0.05). Pigs from phase 2 fed the 0.306% aP had best performance in both thermal environments. Gene expression profile was analyzed by quantitative real-time polymerase chain reaction. Irrespective of growing phase, the expression of six genes was lower (P<0.05) at high temperature than at thermoneutrality. The lower expression of these genes under high temperatures evidences the effects of heat stress by decreasing oxidative metabolism, through adaptive physiological mechanisms in order to reduce heat production. In pigs from phase 1, six genes were differentially expressed across aP levels (P<0.05) in the thermoneutral and one gene in the heat stress. In pigs from phase 2, two genes were differentially expressed across aP levels (P<0.05) in both thermal environments. These data revealed strong evidence that phosphorus and thermal environments are key factors to regulate oxidative phosphorylation with direct implications on animal performance.

Níveis de lisina digestível para suínos machos castrados de alto potencial genético dos 95 aos 125 kg

This work evaluated levels of digestible lysine on performance and carcass composition of barrows with high genetic potential for meat deposition. It was used 80 animals with initial body weight of 95.55 ± 1.04 kg, distributed in a completely randomized block design, with 5 diets (0.540; 0.642; 0.744; 0.846 and 0.948% of digestible lysine), eight replicates and two animals per experimental unit. The experimental diets and water were provided ad libitum throughout the experimental period. Digestible lysine levels did not change daily feed intake and carcass weight of the animals. Daily weight gain and feed conversion improved in a quadratic way up to the estimated levels of 0.803 and 0.871% of digestible lysine, respectively. It was observed an increasing linear effect of the treatments on daily lysine intake and amount of meat. Although daily meat deposition had increased in a linear way, the LRP was the model that best adjusted to the data which remained on a plateau from 0.803% of digestible lysine level. The levels of digestible lysine influenced the P2 backfat thickness of the animals which decreased in a linear way. The digestible lysine level of 0.803%, corresponding to an intake of 24.60 g/day of digestible lysine provides the best results of weight gain and meat deposition whereas the level of 0.817% corresponding to an intake of 25.30 g/day of lysine provides the best result of feed conversion, and the digestible lysine level of 0.948% corresponding to an intake of 29.09 g/day of digestible lysine provides the best results of meat deposition and backfat thickness of barrows from 95 to 125 kg.