Factors influencing colostrum yield by sows / Fatores que influenciam a produção de colostro em porcas

An adequate colostrum intake, in order to ensure the survival and weight gain of piglets, depends on the sow's ability to produce enough colostrum for the whole litter. The aim of this study was to evaluate factors involved in colostrum yield (CY) variability related to the sow, the litter and the farrowing process. The experiment was conducted with 96 Camborough 25(r) sows of parities one to seven, whose farrowing was spontaneous. Colostrum production of each sow was estimated by summing up the colostrum intake of each piglet in the litter, estimated by an equation that takes into account the birth weight and weight gain during the first 24h of life. The multiple regression model explained 28% of variation in CY, with 24% and 4% respectively of variation being explained by the litter birth weight and the width of the first mammary glands. Litter birth weight was positively correlated with the number of total born (r= 0.73) and born alive piglets (r= 0.83). When categorised into two groups of colostrum yield (LOWCY; ≤3.4kg; n= 46 vs HIGHCY; >3.4kg; n= 50), LOWCY sows had fewer total born and born alive piglets and lighter litters (P<0.05). The logistic regression analysis showed that sows from parities 1, 2 and >3 had greater odds (P≤0.05) of belonging to the LOWCY group than parity 3 sows. Sows with two or more obstetrical interventions had higher odds (P<0.05) of belonging to the LOWCY group than sows without interventions during farrowing. The higher colostrum yield observed in sows of parity 3 and sows with less than two obstetrical interventions during farrowing was associated with a greater number of nursed piglets. This study showed that total birth weight of born alive piglets is the most important factor involved in colostrum yield variability, indirectly representing the number of piglets nursed by the sow.(AU)

Um consumo adequado de colostro, para assegurar a sobrevivência e o ganho de peso, dos leitões, depende da capacidade da porca em produzir colostro suficiente para toda a leitegada. O objetivo deste estudo foi determinar fatores relacionados com a porca, com a leitegada ou com o parto que possam influenciar a produção de colostro (PC). O experimento foi conduzido com 96 porcas Camborough 25, de ordem de parto (OP) 1 a 7, cujo parto foi espontâneo. A produção de colostro das porcas foi estimada pela soma do consumo individual de colostro pelos leitões, o qual foi estimado por equação que considera o peso ao nascimento e o ganho de peso nas primeiras 24h de vida. Por meio de modelo de regressão múltipla, 28% da variação na PC foi explicada pelo peso da leitegada (24%) e pela largura do primeiro par de glândulas mamárias (4%). O peso da leitegada foi positivamente correlacionado com o número total de leitões nascidos (r= 0.73) e com o número de leitões nascidos vivos (r= 0.83). Quando separadas em dois grupos de PC (BAIXAPC; ≤3.4kg; n=46 e ALTAPC; >3.4kg; n=50), as porcas do grupo BAIXAPC tiveram menor número total de leitões nascidos, menor número de leitões nascidos vivos e leitegadas mais leves (P<0.05). Por regressão logística, foi observado que porcas da OP 1, 2 e >3 tiveram maior chance (P≤0.05) de pertencer ao grupo BAIXAPC do que porcas de OP 3. Porcas com duas ou mais intervenções obstétricas tiveram maior chance (P<0.05) de pertencer ao grupo BAIXAPC do que as porcas sem intervenção durante o parto. A maior PC observada nas porcas de OP 3 e nas porcas com menos intervenções obstétricas foi associada com um maior número de leitões amamentados. Foi mostrado, neste estudo, que o peso total da leitegada viva, o qual indiretamente representa o número de leitões amamentados pela porca, é o fator mais importante envolvido na produção de colostro.(AU)

Bacillus subtilis induces morphological changes in Fonsecaea pedrosoi in vitro resulting in more resistant fungal forms in vivo

Interactions among microorganisms may be the cause of morphological modifications, particularly in fungal cells. The aim of this work was to examine the changes that occur in cells of the fungus Fonsecaea pedrosoi after in vitro co-culturing with Bacillus subtilis and to explore the results of this interaction in vivo in an experimental murine infection. B. subtilis strain was inoculated into a 15-day pure culture of F. pedrosoi. In vitro, after 48 hours of co-culturing, the fungal cells were roundish. The secretion of fungal dark pigments and production of terminal chlamydoconidia were observed in hyphae after one week. In the in vivo study, two animal groups of 30 BALB/c mice each were employed. One group was inoculated intraperitoneally with hyphal fragments from the co-culture of bacteria and fungi; the other group was infected only with F. pedrosoi hyphae. After seven days of infection, both animal groups developed neutrophilic abscesses. Phagocytosis of bacilli by macrophages occurred at three days. At later periods, generally after 25 days, only roundish cells similar to sclerotic bodies remained in the tissues while hyphae were eliminated by 15 to 20 days. These fungal forms originated mainly from terminal chlamydoconidia. The co-culturing between bacteria and fungi may constitute a mechanism to rapidly obtain resistant fungal forms for host defenses, especially for chromoblastomycosis (CBM) experimental infections.

Experimental murine chromoblastomycosis obtained from Fonsecaea pedrosoi isolate cultured for a long periodt

The present study aimed to describe F. pedrosoi propagules capable of causing chronic murine disease. Several changes in F. pedrosoi hyphae were identified in fungal cells cultured for a long period. Optical microscopy found many rounded cells with double-rigid melanin-rich walls. Terminal and intercalary chlamydoconidia were also frequently observed. Analyses of images from transmission electron microscopy (TEM) revealed several cells with walls composed of at least three layers and an outer layer enriched with melanin. Two groups of twenty BALB/c mice were subcutaneously infected in their footpads with F. pedrosoi cells at an inoculum concentration of approximately 1 x 10(4) cells/mL. In one group, long-term cultured F. pedrosoi cells were inoculated in one footpad, whereas in the other group, both footpads were infected. Active lesions were observed up to seven months post-infection, particularly in mice inoculated at two sites. After this period, animals were killed. Histological sections revealed characteristics bearing a strong resemblance to the human form of the disease such as tissue hyperplasia, granulomas with microabscesses and sclerotic cells. Based on this study, we identified fungal cells from old cultures capable of provoking chronic chromoblastomycosis under experimental conditions, especially when more than one site is infected.