Thomaz Lucia Júnior

Effects of different litter depths on environmental parameters and growth performance of growing finishing pigs

Deep litter systems represent low cost alternatives to raise growing-finishing pigs, reducing slurry accumulation, although pigs thermal comfort may be negatively affected by the heat produced inside the litter. This study compared environmental and performance parameters for growing-finishing pigs raised on deep litter systems having distinct depths and on solid floor. The experiment was conducted in a region of temperate climate of Brazil, comparing three treatments: litter having rice husk 0.5m (T1); and 0.25m deep (T2); and solid concrete floor (T3). The first litter was used in two lots and replaced by a second litter used in other two lots, during 52 weeks. Each lot included five pigs in a 7m2 pen, from 60 to 145 d of age. Environmental parameters were determined at weekly intervals, including: atmospheric temperature; relative humidity; temperature at the center of the pen, in the surface (TSF); and at half of the depth (THD), only for T1 and T2. Feed consumption and weight of pigs were measured every four weeks. Atmospheric temperature and relative humidity were not influenced by the treatments (P>0.05). Mean TSF was 22.8 ± 3.6°C, being lower for T3 (P 0.05). TSF was higher for new than for used litters (P 0.05). Despite the potential unfavorable thermal comfort under high temperatures, deep litter systems can be used to raise pigs in the growing-finishing phases due to the absence of negative effects for growth performance.

Inseminação artificial intra-uterina em leitoas com sêmen criopreservado com dimetilacetamida e glicerol

Este estudo teve por objetivo avaliar o uso da dimetilacetamida (DMA) e de glicerol na criopreservacao de semen suino sobre as taxas de concepcao e fertilizacao in vivo, utilizando o metodo de inseminacao artificial pos-cervical. Foram sincronizadas 60 leitoas pre-puberes e inseminadas com o uso de semen congelado com glicerol 3% (30 femeas) e DMA 5% (30 femeas). O metodo de inseminacao utilizado foi o pos-cervical, com concentracao de 1 x 109 espermatozoides vivos por dose. Apos 36 a 40h da inseminacao, as femeas foram abatidas, sendo realizada a contagem de corpos hemorragicos (CH) nos ovarios. Foi realizada a lavagem dos ovidutos das femeas, verificando o numero de estruturas recuperadas (oocitos e embrioes), calculando-se as taxas de concepcao e fertilizacao. A media de CH nas femeas do grupo glicerol 3% nao diferiu (P>0,05) daquelas do grupo DMA 5% (10,4 x 10,2, respectivamente). Nao houve diferenca (P>0,05) nas taxas de recuperacao de estruturas entre os grupos glicerol 3% (68,9%) e DMA 5% (66,9%). Os resultados obtidos nos grupos glicerol 3% e DMA 5% para as taxas de concepcao (73,3 x 76,6%) e fertilizacao (48,6 x 59,4%) nao apresentaram diferenca (P>0,05). Conclui-se que nao ha diferencas nas taxas de concepcao e fertilizacao in vivo utilizando-se semen congelado com o uso de dimetilacetamida ou de glicerol.

Concentração de lactato de cálcio e tempo de incubação sobre a capacidade de adesão e penetração de espermatozoides suínos na membrana perivitelina do ovo da galinha

This study tested the effect of different calcium lactate concentrations and incubation periods on the binding and penetration capacity of swine sperm to the perivitelline layers (PL) of chicken eggs, with the expectation of developing a test to estimate the potential fertility of boars used as sperm donors. In the first experiment, semen samples (n=12) were incubated with TCM medium ant two calcium lactate levels: 1.1 and 2.2µg mL-1. After the set up of fixed calcium lactate level (1.1µg mL-1), the second experiment compared three incubation periods: 10, 15 and 20min. The observed variables were binding rate (BR) and number of bound sperm (NB) in the outer PL, and penetration rate (PR) and number of holes (NH) in the inner PL. The BR to the outer MP was 100%, regardless of the tested concentrations and incubation periods. The NB to the outer perivitelline layer and the PR and the NH in the inner perivitelline layer were greater with 1.1µg mL-1 calcium lactate than 2.2µg mL-1. The NB in the outer PL was greater with 20min incubation than with shorter period (P<0.05). Using 10min incubation, there was no penetration in the inner PL, but, with incubation for 20min, the PR and the NH in the inner PL were greater than those with incubation for 15 min (P<0.05). Using 1.1µg mL-1 calcium lactate and incubation for 20min, the in vitro test using PL can be efficiently conducted to assess important steps of the fertilization process.

Indicadores de desempenho relacionado ao parto de fêmeas suínas de primeiro e segundo partos

This study aimed to identify some performance parameters associated with the farrowing efficiency in sows. From a total of 636 births and 7,100 piglets born, data was collected for: parity (OP), number of piglets born alive (NV), stillborns (NAT), mummified (MUM), total litter size (TN), use of vaginal palpation and oxytocin injection, time of birth for each piglet, and beginning and end of the parturition. The average interval among piglets birth was 16.7 min and the average duration of parturition was 247 min. The average duration of parturition increased regarded to the number of born piglets, the use of oxytocin and with the ocurence of vaginal palpation. The total number of births in the long parturitions (> 211 min), with 13.1 piglets was higher than in the short parturitions (< 210 min), with 11.7 piglets, therefore, the higher the number of total piglets born, the longer is the duration of parturition. Litter size was higher for sows of the second parity (12.8) than for sows of first parity (11.9). The duration of parturition is affected by the number of piglets born, which is higher in second parity than first parity females and it is associated to the higher occurence of stillbirths and mummified piglets.

Motilidade de espermatozoides bovinos após incubação em fluído folicular

The objective of this work was to evaluate sperm cell motility after intrafollicular artificial insemination (IFAI) in vivo or after incubation in follicular fluid in vitro. In the in vivo experiment, IFAI was performed, followed by the recovery of follicular content 1 to 4 hours later, in order to assess sperm motility. In the in vitro experiment, spermatozoa from a pool of commercial frozen-thawed semen were evaluated for their kinetics after incubation for 1 or 3 hours, either pure (pool, control group) or in follicular fluid (FF). A low motility of sperm cells was observed in the FF samples, both in vitro and in vivo. In vitro, the main parameters negatively affected in the sperm cells incubated in FF, compared with the control, were: total motility (TM), progressive motility (PM), curvilinear distance, and straightness, after 1 hour of incubation; and TM, PM, average path velocity, and curvilinear velocity after 3 hours of incubation. The ovarian follicle and follicular fluid do not provide a suitable environment to maintain bovine sperm cell motility.

Identification of Virulence Factors of Escherichia coli Isolates from Fecal Samples of Calves in Southern Brazil

Background: Escherichia coli (E. coli) is an enteropathogen that commonly causes diarrhea in calves. However, not all E. coli isolates are pathogenic. The aim of this study was to identify E. coli virulence factors derived from fecal samples collected in the southern region of Rio Grande do Sul state (RS) from calves with and without diarrhea, as well as investigate the antimicrobial susceptibility of E. coli isolates from calves with diarrhea. Materials, Methods & Results: Forty stool samples were collected in 12 farms, each one from calves having one day to six months of age, with and without diarrhea. The total DNA of from these isolates was extracted and a PCR using primers specific for the virulence factors Stx1, Eae, F41, F5 and STa was conducted. The susceptibility testing used the disk diffusion method and the susceptibility profile was evaluated against the following antimicrobials: ampicillin, penicillin, chloramphenicol, enrofloxacin, gentamicin, trimethoprim, sulfonamide, tetracycline and streptomycin. From all calves, 15 (15/40, 37.5%) had diarrheal stools and 25 (25/40, 62.5%) had normal or semi-liquid stools. Twelve (12/40; 30%) E. coli isolates showed at least one virulence factor. These factors were found in four isolates (4/15; 26.6%) from diarrheal stools and eight isolates (8/25; 28.5%) from normal stool. The Stx1 factor was identified in five isolates (5/40; 12.5%), and the Eae and the Sta factors in one (1/40; 0.2%) and in atypical associations between Stx1 and Eae and also between Eae and F41 in two isolates (2/40; 0.5%). Also, the Eae and Sta factors were identified in one isolate (1/40; 0.2%). The susceptibility test showed resistance to penicillin and tetracycline in 93% and 80% of the tested isolates, respectively. Discussion: The identification of virulence factors is necessary because E. coli is an enterobacterium present in calves gastrointestinal tract, to prove its pathogenicity. The virulence factor most commonly found in E. coli isolates derived from feces of calves with and without diarrhea in the southern region of the RS was the Stx1 (Shiga toxin-producing E. coli STEC). It is likely that the highest occurrence of E. coli isolates positive for the Stx1 virulence factor was due to the fact that cattle were the main reservoirs of this type of bacteria. The occurrence of enterohemorrhagic E. coli (EHEC) in animals of nine and 34 days of life, respectively, is highlighted. Studies have shown that contamination of animal foods with EHEC can cause enteric disorders, hemorrhagic colitis, and uremic hemolytic syndrome (UHS) in humans. Although in the present study the identification of the Stx2 factor was not performed, authors describe that the presence of the genes encoding Stx2 and Eae is determinant in the occurrence of UHS. In the susceptibility test, it was observed that E. coli isolates from diarrheal stools showed resistance to antimicrobials penicillin (10 mg) and tetracycline (30 mg) [93% and 80%, respectively], ampicillin (10 mg) [47%], streptomycin (10 mg) [47%], trimethoprim (5 mg) [47%] and sulfonamide (300 mg) [53%]. Although the percentage of antimicrobial resistance varies among studies, it is believed that the indiscriminate use of antimicrobial therapies as a common practice among rural properties contributes to bacterial resistance to these drugs. The sensitivity profile to antimicrobials showed that the analyzed Escherichia coli isolates are resistant to the antimicrobials commonly used for diarrhea treatment in the southern region of the Rio Grande do Sul state, Southern Brazil.