Increased vitamin supplement to sows, piglets and finishers and the effect in productivity.

With still limited information on vitamin requirements and considering that many commercial practices adopt dietary vitamin levels above the values suggested by nutritional tables, this study aimed to assess the effect of administering vitamin supplementation to sows in gestation and lactation and to their litters on the reproductive performance and body condition of the sows and on the performance and immune profile of the litters until slaughter. The trial was split into two phases. The first phase used 104 sows, assigned to be randomized to blocks according to parity, submitted until 21 days of lactation to two treatments: control-standard (standard levels of vitamins) and test-elevated (elevated levels of vitamins). Each sow and its respective farrow were considered an experimental unit. The sows underwent evaluations of body condition score, back fat thickness and reproductive performance. In the second phase, 60 barrows and 60 gilts at 21 days of age and mean initial weight of 5.33 ± 1.5 kg until slaughter at 164 days of age. The piglets were assigned to randomized blocks according to the weight and sex of the animals in a 2 × 2 factorial model, with 10 replicates per treatment, where a pen with three animals represented the experimental unit. Following the same treatments of the first phase, the piglets were evaluated for daily weight gain, daily feed intake, feed conversion, mortality rate and humoral immune response. Vitamin supplementation had no positive effects on the reproductive parameters or body composition of sows. However, it positively impacted the performance of the litters in the early nursery stage, but did not lead to superior effects on the immune responses to vaccination against circovirus or mycoplasma.

Role of BMP-4 during tooth development in a model with complete dentition.

There are no reports in literature about roles of bone morphogenetic protein 4 (BMP-4) in tooth development in mammals with complete dentition (with all dental groups). The classical model of study is the mouse, which has distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars and four molars, on each side of the jaw, seems to be a convenient model for odontogenesis study. This investigation searched for similarities and differences in BMP-4 expression pattern between the opossum and the mouse. BMP-4 cDNA was obtained by RT-PCR and the expression pattern during molar tooth development was investigated by the immunoperoxidase method. Opossum BMP-4 mature protein has 95% of sequence similarity in relation to mouse and 94% to human. The BMP-4 expression pattern during opossum tooth development was suggestive of a role in dental organ initiation and morphogenesis.

Morphological changes and EGF expression in the granular convoluted tubule cells of submandibular glands of Trypanosoma cruzi infected rats.

We have previously demonstrated in rats that Chagas' disease affects the salivary glands, by promoting an enlargement of the submandibular gland. In order to further investigate possible functional alterations on infected submandibular glands, the objective of the present study was to analyze epidermal growth factor (EGF) expression on rat submandibular glands during Trypanosoma cruzi infection. Results demonstrated that infected rats presented lower levels of testosterone, and morphological changes in the granular convoluted tubule (GCT) cells of the submandibular glands, along with acinar enlargement and delayed ductal maturation at the developing granular ducts. Immunohistochemistry analysis additionally showed that only few cells immunolabelled with anti-EGF on infected rats during the acute phase of Chagas' disease, while after 64 and 90 days (chronic phase) of infection, EGF expression was similar to non-infected rats. The present findings suggest that at the acute phase of Chagas' disease, lower levels of testosterone may lead to a delayed maturation of GCT, which positively correlates with decreased EGF production by submandibular glands cells.

Dental development of Didelphis albiventris (Marsupialia): I--incisors and canines.

The formation of incisors and canines in marsupials of D. albiventris was studied at various stages of development. Seventy-six specimens, with ages varying from 0 to 100 days, were used in this investigation. Serial sections of the maxilla were obtained in the transverse plane and stained with hematoxylin and eosin. Histological analyses were made to verify the pattern of teeth development, as well as their chronology of eruption. The period of time from birth to 100 days comprised the entire process of teeth development, from epithelial bud formation to early eruption of the teeth. Oral epithelium thickening gave rise to the functional incisors and canines. In addition, a secondary dental lamina emerged in different phases of development in the outer epithelium of incisors and canines, which degenerated when it reached the bud stage. No evidence of deciduous dentition was observed. The results of this investigation suggest that secondary dental lamina represents remnants of a primitive condition in which secondary dentition used to be present.

Factors affecting the daily feed intake and feed conversion ratio of pigs in grow-finishing units: the case of a company.

BACKGROUND: The aim of this study was to use mathematical modeling to identify and quantify the main factors that affect daily feed intake (DFI) and feed conversion ratio (FCR) in grow-finishing (GF) pig units. We evaluated the production records of 93 GF farms between 2010 and 2013, linked to a company, working in a cooperative system, located in western Paraná State, Brazil. A total of 683 batches, consisting of approximately 495,000 animals, were used. Forty production factors related to the management, health, plant and equipment, nutrition, genetics and environment were considered. The number of pigs per pen, type of feeder, origin and sex (the last two variables were combined in the models) of the animals and initial and final body weights were included in the final models to predict DFI and FCR (dependent variables). Additionally, the duration of the GF phase was included for the parameter FCR. All factors included in the final models had significant effects for both dependent variables. RESULTS: There was a reduction in DFI (0.04 kg) (P < 0.001) and an improvement in FCR (6.0 points) (P < 0.001) in batches from pens with less than 20 animals compared with batches from pens with more than 20 animals. In barns with "other" feeder types (mostly the linear dump type) different of conical semiautomatic feeder, a reduction of DFI (0.03 kg) (P < 0.05) and improved FCR (3.0 points) (P < 0.05) were observed. Batches of barrows from units specialized for producing piglets (SPU) had higher DFI (approximately 0.02 kg) (P < 0.01) than batches of females and batches of mixed animals from SPU, and batches of mixed animals from farms not specialized for piglet production (farrow-to-finish farms). Batches of females from SPU and mixed batches from SPU had better FCR (5.0 and 3.0 points respectively) (P < 0.001 and P < 0.001, respectively) than batches of piglets originating from farrow-to-finish farms. The variables selected for the final models explained approximately 50 and 64 % of the total variance in DFI and FCR, respectively. CONCLUSIONS: The models are tools for the interpretation of the factors related to the evaluated parameters, aiding in the identification of critical aspects of production. The main parameters affecting DFI and FCR in this company during the GF period were the number of pigs per pen, the type of feeder used and the combination origin-sex of the animals.

Changes in acetylcholinesterase-positive nerves of the submandibular salivary gland during experimental infection with a protozoon, Trypanosoma cruzi, in rats.

Using a thiocholine acetylcholinesterase histochemical technique, an appreciable reduction of the innervation was demonstrated in the submandibular glands of rats inoculated with the Y strain of Trypanosoma cruzi, at the early chronic phase of the infection. During the chronic phase of the disease there was recovery of the normal pattern of innervation in all infected animals.

Cystatin S in secretory granules fractions isolated from submandibular gland of infected rats by Trypanosoma cruzi.

We have measured the relative concentrations of cysteine proteinase in the granular fractions of submandibular glands of control and Trypanosoma cruzi infected rats by using a sensitive solid phase ELISA. Gland samples were homogenized in 0.34 M sucrose and 0.5 mM EDTA in 10 mM HEPES buffer at a pH of 7.4. The extract was centrifuged and filtered through Millipore filters to prepare a purer granular fraction. Immunochemical studies using antibody against cystatin S and electrophoretic analysis showed higher cystatin S levels in infected rats than in control. The role of this inhibitor during acute phase of Chagas disease is discussed.

Effect of adrenoceptor blockers on the acinar enlargement induced by Chagas' disease in the rat submandibular glands.

Chagas' disease induces acinar enlargement in the submandibular salivary gland of rats inoculated with the Y strain of Trypanosoma cruzi at the age of 27-28 days and killed 18 days after inoculation (acute phase). Propranolol, a beta-adrenoceptor blocker, prevents the acinar enlargement induced by T. cruzi infection. Phenoxybenzamine, an alpha-adrenoceptor blocker, enhances this enlargement. These results suggest that catecholamines are involved in the genesis of the acinar hypertrophy induced by Chagas' disease.

Morphology of rat submandibular gland acinar secretory granules and their alteration during the acute phase of experimental Chagas' disease.

In a morphometric study at the electron microscope level immature submandibular glands of 8 normal male Holtzman rats were compared to those of 12 rats (46 days old) infected with the Y strain of Trypanosoma cruzi at day 18 of infection. In the fasted animals, the acinar cells of controls exhibited a variety of morphological types of immature secretory granules with lamellar substructure composed of swirling cords of electron-dense material, whereas in the infected rats mature secretory granules containing dense aggregates of short or long filamentous material were more abundant. These results suggest an acceleration of acinar maturation in infected animals.

Determination of age from cemental incremental lines for forensic dentistry.

Determination of age from cemental incremental lines was evaluated in intact teeth obtained from 17 individuals aged 23-77 years. Mineralized 100 microm cross sections were subjected to one of three treatments: unstained, stained with Villanueva's blood stain, and stained with acridine orange. Ideal areas were selected by light microscopy and photographed. Countability of incremental lines from photographic enlargements were evaluated. The average number of years required for the eruption of a particular tooth was added to the incremental lines count to determine the estimated age for that individual. Results obtained from unstained mineralized 100 microm thick cross sections using differential interference microscopy (Nomarsky) provided the most countable lines. The accuracy and repeatability of the method is not dependent on tooth type or location, but on the average obtained from making as many counts as possible. This method can be applied to general populations regardless of systemic or periodontal health.

Histological and histoquantitative study of the rat parotid gland after Trypanosoma cruzi infection.

The present study deals with the morphology of the rat parotid gland and its changes after Trypanosoma cruzi infection. The glands of control and infected animals were analyzed by histologic and histoquantitative methods. After 18 days of infection with T. cruzi, a significant reduction of the density of the volume of the acini and duct system, as well as a significant increase in the amount of connective tissue was noted. In addition, these animals displayed an increase in the number of cells undergoing mitosis. In the 45 day infected rats, there was return to the normal pattern. It is suggested that in the infected animals the decrease in body weight could be responsible for retarded sexual maturity, leading to the lower level of testosterone. It can be assumed that decreased levels of epidermal growth factor (EGF) and neural growth factor (NGF) caused by the lack of testosterone in infected animals also contribute to the atrophy of the parotid gland and to the proliferation of the connective tissue.

Enhanced bone formation during healing process of tooth sockets filled with demineralized human dentine matrix.

BACKGROUND: Orthodontic procedures are often limited by the presence of bone defects caused by trauma, periodontal diseases or surgeries, thus requiring the development of materials capable to compensate such deficiencies. Since bone morphogenetic proteins (BMPs) are indicative of bone reconstitution, this study aimed to evaluate histological and immunohistochemically the temporal location of BMP-2 and BMP-4 in osteoblasts of rat alveolar wounds filled with demineralized human dentine matrix (DHDM), used as a graft material. METHODS: After extraction of the upper second molars, the left side alveoli were filled with DHDM and the right side served as the control. The animals were euthanized after 3, 5, 10 and 14 days of surgery. After fixation, demineralization and paraffin embedding, representative samples of each group were stained with H&E and immunohistochemically evaluated. RESULTS: The data showed a statistically significant (p < 0.05) increased number of osteoblasts positively immunostained for BMP-2 and BMP-4 on the experimental side (left) at 10 days. Our results also showed that even when not degraded, dentine matrix was incorporated to new bone formation after 14 days of surgery. CONCLUSIONS: The results suggest that DHDM acts as a scaffold for osteoblast differentiation, actively yielding new bone formation, and it may represent an effective bone implant material.

Caracterização dos fatores de produção e uso de modelos matemáticos para estimar sua influência sobre o consumo diário de ração e a conversão alimentar de suínos nas fases de crescimento e terminação / Characterization of production factors and use of mathematical models to estimate their influence on daily feed intake and feed conversion ratio of grow-finishing pigs

O objetivo deste estudo foi identificar e quantificar os fatores de produção presentes em granjas de crescimento e terminação (CT) de suínos, em um sistema cooperativo do estado do Paraná, Brasil, e determinar a influência desses fatores no consumo diário de ração (CDR) e na conversão alimentar (CA). Foram avaliados, entre os anos de 2010 e 2013, os históricos produtivos de 538 lotes de engorda, alojados em 175 granjas comerciais, totalizando aproximadamente 404.000 animais. Foram considerados 40 fatores de produção, relacionados ao manejo, à sanidade, às instalações e aos equipamentos, à nutrição, à genética e ao ambiente. Em baias com menos de 20 suínos, o CDR diminuiu (P<0,05) e a CA melhorou (P<0,01). Nas baias com comedouros basculantes (lineares), o CDR reduziu (P<0,01) e a CA melhorou (P=0,001). Em baias com lâmina d'água, o CDR aumentou (P<0,01) e a CA piorou (P<0,01). Lotes formados apenas por fêmeas apresentaram menor CDR (P<0,001) e melhor CA (P<0,001), quando comparados aos lotes mistos. As variáveis selecionadas para os modelos finais explicaram cerca de 25% e 46% da variância total para CDR e para a CA, respectivamente. Os modelos constituem um instrumento de auxílio efetivo para tomadas de decisões técnicas dentro do setor suinícola.(AU)

The aim of this study was to identify and quantify the production factors present in growing and finishing (GF) pig farms partners of a cooperative in Paraná State, Brazil, and to determine the influence of these factors on daily feed intake (DFI) and the feed conversion ratio (FCR). From 2010 to 2013, the historical production of 538 batches of fattening pigs in 175 commercial farms were analyzed, in an amount approximately 404,000 animals. A total of 40 production factors regarding the management, sanity, plant and equipment, nutrition, genetics and environment were taken into consideration. Pens with less than 20 pigs resulted in a reduction in DFI (P<0.05) and an improved FCR (P<0.01). In pens that used linear dump feeders, the DFI was less (P<0.01) and the FCR was better (P=0.001). Pens with shallow pools had higher DFI (P<0.01) and worse FCR (P<0.01). Batches of females had lower DFI (P<0.001) and better FCR (P<0.001) compared to mixed-sex batches. The factors used for the final models explained the 25% and 46% of the total variance for the DFI and FCR, respectively. The models consist in effective aid instruments for technical decision making in the swine industry.(AU)

Use of ractopamine during compensatory gain of finishing pigs on carcass and meat performance and quality / Uso de ractopamina durante ganho compensatório de suínos em terminação sobre o desempenho e a qualidade da carcaça e de carne

The objective of this study was to evaluate the effects of compensatory gain associated with the use of 10ppm ractopamine after a period of feed restriction in finishing pigs on performance, carcass and meat quality. Twenty castrated males and 20 females, at 110 days of age and 66.137±6.13kg live weight, were submitted to four treatments using a 2 x 2 factorial design (fed ad libitum or with 20% restriction between 0(21 days of age and fed with or without 10ppm ractopamine for 22(42 days of experimentation), with 10 replicates (animals). There was no interaction between the factors for any of the evaluated parameters. Animals treated with ractopamine presented better weight gain (1.083 versus 1.259kg), feed conversion (2.910 versus 2.577), warm and cold carcass weight (86.08 versus 89.00 and 83.46 versus 87.20kg, respectively), loin depth (63.02 versus 68.40mm), loin eye area (41.43 versus 46.59mm2) and muscle fiber diameter (27.48 versus 35.85µm). Animals submitted to feed restriction followed by ad libitum feed presented compensatory gain without losses to carcass and meat characteristics, but with a reduction in the ethereal extract (2.19 versus 1.64%) and lower water loss due to thawing in the meat (11.35 versus 9.42%). The effects of compensatory gain after food restriction and ractopamine are independent of the parameters evaluated.(AU)

Objetivou-se avaliar os efeitos do ganho compensatório associado ao uso de 10ppm de ractopamina após um período de restrição alimentar, em suínos em terminação, sobre características de desempenho, carcaça e qualidade de carne. Foram utilizados 20 machos castrados e 20 fêmeas, com 110 dias de idade e 66,137±6,13kg de peso vivo, submetidos a quatro tratamentos, fatorial 2 x 2 (alimentação à vontade ou com 20% de restrição entre zero e 21 dias de experimentação; e alimentação à vontade, sem ou com 10ppm de ractopamina, durante 22 a 42 dias de experimentação), com 10 repetições, sendo o animal a repetição. Não houve interação entre os fatores para nenhum dos parâmetros avaliados. Animais tratados com ractopamina apresentaram melhor ganho de peso (1,083 versus 1,259kg), conversão alimentar (2,910 versus 2,577), peso da carcaça quente e fria (86,08 versus 89,00 e 83,46 versus 87,20kg, respectivamente), profundidade do lombo (63,02 versus 68,40mm), área de olho de lombo (41,43 versus 46,59mm2) e diâmetro de fibras musculares (27,48 versus 35,85µm). Animais submetidos à restrição alimentar seguida de arraçoamento ad libitum apresentaram ganho compensatório sem prejuízos às características de carcaça e à carne, mas com redução do extrato etéreo (2,19 versus 1,64%) e menor perda de água por descongelamento na carne (11,35 versus 9,42%) Os efeitos do ganho compensatório após a restrição alimentar e da ractopamina mostram-se independentes sobre os parâmetros avaliados.(AU)

Secretory granules in rat submandibular acinar cells during experimental Chagas disease.

The fine structure of rat submandibular glands has been compared in control and infected-rats with Y strain of Trypanosoma cruzi at day 18 of infection. In the acinar cells of the infected rats the secretory granules exhibit a variety of morphological types suggesting and early form of secretion product or a new secretory protein.

Induction of synthesis of the rat cystatin S protein by the submandibular gland during the acute phase of experimental Chagas disease.

Rats experimentally infected with Trypanosoma cruzi Y strain exhibited hypertrophy of the submandibular gland at 18 days after infection. SDS-PAGE of infected rats saliva revealed the presence of an additional band with an apparent molecular weight of about 13KDa. Electrophoresis of protein saliva and immunochemical analysis with antibody against rat cystatin S confirmed that the protein was identical to that induced by beta adrenergic stimulation.