ABSTRACT This study aimed to evaluate the effects of daily phase feeding (DP) and sequential feeding (SEQ) on the feeding behavior, performance, and body composition of growing-finishing pigs. Sixty barrows at 29.7 ± 2.8 kg body weight (BW) were assigned to one of four treatments: DP with a blended proportion of feeds A (high nutrient density) and B (low nutrient density) was adjusted to match 100 % of daily amino acid (AA) diet recommendations (DP100); a negative treatment, which matched 70 % of daily AA diet recommendations (DP70); and two SEQ with a blend of feeds A and B, adjusted twice a day (at 00h00 and 12h00), to match 70 or 110 % of daily AA diet recommendations during two 12 h intervals: SEQ110-70 and SEQ70-110. DP70 and SEQ showed a lower feed consumption rate compared to DP100 (p < 0.05). Compare to DP100, pigs in both SEQ programs had a similar average daily feed intake (ADFI), average daily gain (ADG), feed efficiency ratio (G:F) and body fat and lean mass ( p > 0.05). SEQ110-70 and SEQ70-110 showed similar ADFI, ADG, G:F and body lean mass (p > 0.05). However, fat gain was greater in SEQ110-70 than in SEQ70-110 (p < 0.05). Overall, the SEQ program does not improve performance and body composition. Furthermore, feeding pigs a diet with a higher AA level during the first 12 h of the day and a lower AA level during the remainder of the day increases fat deposition.

ABSTRACT The objective of this study was to evaluate the behavior of immunocastrated male pigs compared with females and castrated males during the period before and after full immunization. A total of 30 animals were divided into three treatments, with ten animals in each (females, barrows, and immunocastrated males). The experiment was divided into three periods: 70 to 80 days of age (period 1), 81 to 110 days of age (period 2), and 111 to 140 days of age (period 3). The behavior of animals during these stages was evaluated. Immunocastrated males showed a higher rate of aggressive and sexual behavior during period 2, which decreased after the second vaccine dose. Both barrows and immunocastrated males presented high locomotion in period 1, reducing the frequency of this activity in period 3. All analyzed animals had a higher level of activities such as drinking, playing, and sexual behavior in period 1 than in the other periods, decreasing during the experiment. The remaining behavioral responses did not differ between the studied categories. Immunocastrated males had higher proportions of undesirable behaviors (aggressive and sexual) related to the surgically castrated males and females, and these were reduced after the second vaccine dose. Immunocastration is effective in the reduction of behaviors such as agonistic and sexual at the same levels observed in females and surgically castrated males. However, immunocastrated pigs are more subject to these undesirable behaviors before full immunization.

O estudo foi conduzido com o objetivo de avaliar o desenvolvimento microbiológico em carne suína PSE em comparação à carne normal e o efeito da época do ano sobre a velocidade de proliferação dos mesmos. Amostras do músculo Longissimus dorsi de carcaças classificadas ao abate como PSE (pH45<5,8) e normais (pH45>5,8), foram coletadas após 24 horas de refrigeração, no momento da desossa, em um abatedouro comercial, com serviço de inspeção federal, situado na região da Grande Dourados (MS). As amostras (12 normais e 12 PSE) foram coletadas em duas épocas distintas do ano (outono e inverno) para as análises de coliformes totais, coliformes a 45ºC, mesófilos, psicotróficos, pseudômonas, bolores e leveduras aos 0, 5, 10 e 15 dias de armazenamento por refrigeração. O crescimento microbiano comportou-se de maneira semelhante entre os dois tipos de carne ao longo do período de armazenamento, exceto para a contagem de microorganismos aeróbios mesófilos totais, cujo desenvolvimento foi superior em carnes PSE até o 5º dia de armazenamento, igualando-se entre os dois tipos de carne posteriormente. Houve efeito da época do ano sobre a contagem de coliformes totais e a 45ºC, sendo sua velocidade de proliferação superior em carnes provenientes dos animais abatidos na época mais quente (outono).

The study was conducted to evaluate the microbiological development in PSE pork compared with normal meat and the effect of season of the year on the rate of proliferation of the same. Longissimus dorsi muscle samples from carcasses classified as PSE slaughter (pH45 <5.8) and normal (pH45 > 5.8) were collected after 24 hours of refrigeration, at the time of deboning, in a commercial slaughterhouse, with service federal inspection, located in the Grande Dourados region (MS). The samples (12 normal and 12 PSE) were collected at two different times of the year (fall and winter) for analysis of total and 45ºC coliforms, mesophylls, psychotropic, pseudomonas, yeasts and molds at 0, 5, 10 and 15 days of storage under refrigeration. Microbial growth behaved similarly between the two types of meat throughout the storage period, except for the count of mesophilic aerobic microorganisms, whose development was superior in PSE meat until the 5th day storage, matching between both types of meat later. Was no effect of season on the count of total coliforms and 45ºC, and their proliferation rate higher in meat from the slaughtered animals the warmer season (autumn).

Objetivou-se avaliar as características físicas e sensoriais da carne suína PSE, suas correlações e os prejuízos causados para a indústria, em função de sua ocorrência. Em abatedouro comercial aferiu-se o pH das carcaças (n=1601) aos 45 minutos post mortem (pH45), classificou-as em PSE (pH45<5,8) ou normais (pH45≥5,8). Após 24 horas de resfriamento, foram coletadas amostras do músculo Longissimus dorsi de 26 carcaças PSE e 26 normais, que foram avaliadas quanto à coloração (L*, a*, b*), perda de exsudato, perda de peso por cozimento, força de cisalhamento, atributos sensoriais (maciez, suculência e palatabilidade) e composição centesimal. Foram avaliadas as correlações entre parâmetros físicos e sensoriais. A incidência de carnes PSE foi de 10,06%. O pH final, perda de peso por cozimento, força de cisalhamento e composição centesimal não diferiram entre os tipos de carne. A perda de exsudato foi, aproximadamente, 39% maior para carne PSE. O pH45 correlacionou-se, negativamente, com L* (R= -0,331) e b* (R= -0,528). A suculência correlacionou-se, positivamente, com a palatabilidade (R= 0,436) e maciez (R= 0,297) e, negativamente, com a perda de peso por cozimento (R= -0,326). A força de cisalhamento apresentou correlação positiva com perda de exsudato (R= 0,529) e negativa com maciez (R= -0,767). O prejuízo estimado em função da ocorrência de carnes PSE foi da ordem de R$340.800,00 anuais. Carnes PSE apresentam alterações negativas nas propriedades funcionais e sensoriais, relacionadas com a redução de sua capacidade de retenção de água, o que causa perdas consideráveis para a indústria processadora.

The work was carried out to evaluate the physical and sensory characteristics of PSE pork, their correlations and damages caused to the industry because of its occurrence. In a commercial slaughterhouse has measured the pH of carcasses (n = 1601) at 45 minutes post mortem (pH45), classified them into PSE (pH45 < 5.8) or normal (pH45≥ 5.8). After 24 hours of cooling were collected the samples from the Longissimus dorsi muscle of the 26 normal and 26 PSE carcasses that were evaluated for color (L*, a*, b*), exudate loss, cooking loss, shear force, sensory attributes (tenderness, juiciness and flavor) and centesimal composition. Were evaluated the correlations between the physical and sensory parameters. The final pH, cooking loss, shear force and centesimal composition did not differ between the types of meat. The exudate loss was 39% higher for the PSE meat. The pH45 was negatively correlated with L* (R= -0.331) and b* (R = -0.528). The juiciness was positively correlated with flavor (r = 0.436) and tenderness (R = 0.297) and negatively with cooking loss (R = -0.326). The shear force was positively correlated with exudate loss (R = 0.529) and negatively with tenderness (R = -0.767). The estimated loss due to the occurrence of PSE meat were of R$340,800.00 per year. The PSE meat show negative changes in the functional and sensory properties, almost all related to reducing its water holding capacity, causing considerable losses to the processing industry.