Raul Machado-Neto

IgG absorption by Santa Ines lambs fed Holstein bovine colostrum or Santa Ines ovine colostrum

The objective of this study was to evaluate the immunoglobulin G (IgG) absorption by Santa Ines lambs under two colostrum management systems usually used by producers. Twenty-seven Santa Ines newborn lambs received two meals of 250 ml of bovine colostrum from Holstein cows (BC group) or ovine colostrum from Santa Ines ewes (OC group) at 0 and 6 h of life. Pools of BC and OC were analyzed by radial immunodiffusion to quantify IgG. Results are expressed as least-square means and standard errors of mean (means ± s.e.m.). The concentration of IgG in bovine and ovine pools averaged 115.7 ± 20.5 and 48.1 ± 5.0 mg/ml, respectively, levels of concentration found in similar regular colostrum managements. The efficiency of IgG absorption was evaluated under two aspects, maximum apparent efficiency of absorption and total apparent efficiency of absorption (AEAmax and AEAtotal, respectively). The AEAmax was calculated taking into account the mass of IgG ingested just in the first meal of colostrum at birth and the serum IgG concentration at 6 h while the AEAtotal took into account the serum IgG concentration at 24 h of life that reflects the first colostrum offered at birth and the second meal at 6 h. The IgG and apparent efficiency of absorption results were transformed into the square root and log base 10, respectively, and were presented as geometric least-square means. In BC, lower (P < 0.05) AEAmax and AEAtotal were verified (14.2% and 15.6%, respectively), in relation to OC (23.6% and 24.4%, respectively). Serum IgG concentrations at 24 h were significantly higher (P < 0.05) in BC (31.4 mg/ml, respectively) compared with OC (22.2 mg/ml, respectively). The results in this study confirm that there is a limitation to the process of IgG absorption by the enterocytes of newborn lambs, which determined a nonlinear behavior of passive immunity acquisition. Similar values of AEAmax and AEAtotal for the two sources of colostrum reveal that the process of IgG absorption from the first and second meals during the first 6 h of life did not change and indicates that the ingestion of a second feeding of quality colostrum can enhance the acquisition of immune protection of newborn lambs.

Flutuação das variáveis séricas em cabras e estudo comparativo da absorção de anticorpos em cabritos recém-nascidos utilizando colostro bovino e caprino

Objetivou-se determinar a flutuacao no nivel de anticorpos sericos em cabras nos periodos pre e pos-parto e a eficiencia do processo de aquisicao de imunidade passiva em cabritos recem-nascidos utilizando colostros bovino e caprino, visando a avaliacao de uma alternativa de manejo de colostro. Foram utilizadas 18 cabras e suas respectivas crias, num total de 33 animais. A coleta de sangue das cabras foi iniciada 45 dias antes da data prevista para o parto e foi realizada em intervalos de cinco dias ate o 5o dia apos o parto. Os cabritos foram distribuidos em dois grupos: um grupo recebeu colostro caprino e o outro colostro bovino. As coletas de sangue foram feitas as 0, 12, 24 e 48 horas e aos 5, 10, 15, 17, 20, 25, 30, 35, 40, 50 e 60 dias de vida. Foram analisadas as concentracoes sericas de proteina total e imunoglobulinas, alem da concentracao de imunoglobinas no colostro. O delineamento experimental foi o inteiramente casualizado e as variaveis sericas analisadas como medidas repetidas. A ausencia de queda na concentracao serica de proteinas totais e imunoglobinas no periodo pre-parto indica que a mobilizacao de anticorpos para glândula mamaria ocorre em concentracoes que permitem o animal manter essas variaveis sem grandes alteracoes. No grupo que recebeu colostro bovino, a data de concentracao maxima de proteinas totais (7,16 ± 0,28 g/dL) foi verificada as 48,68 ± 0,70 horas de vida e a de imunoglobinas, as 48,75 ± 0,73 horas, com media de 37,56 ± 2,38 unidades ZST (turvacao por sulfato de zinco). No grupo que recebeu colostro caprino, os valores maximos de proteinas totais e imunoglobinas sericas ocorreram mais tardiamente, aos 20,05 ± 1,36 e 20,11 ± 1,72 dias de vida, com medias de 5,91 ± 0,22 g/dL e 28,17 ± 2,05 unidades ZST, respectivamente. O colostro caprino pode ser substituido pelo colostro bovino, que promove melhor aquisicao inicial de imunoglobulinas aos neonatos.

Intestinal histomorphology in Pseudoplatystoma fasciatum fed bovine colostrum as source of protein and bioactive peptides

Histological responses of the intestine are key for evaluating nutritional value of feed ingredients, since the organ is not only the chief site of feed digestion and nutrient absorption but also plays an important immunological function. Histomorphological alterations were evaluated in the intestine of juvenile striped catfish, Pseudoplatystoma fasciatum, fed diets containing 0 (control), 10 or 20% inclusion of lyophilized bovine colostrum (LBC), as source of protein or bioactive peptides, for either 30 or 60 days. Fish fed 20LBC presented at 60d a distinct pattern of macrophages and, some of them, higher number of vacuoles in rectum mucosa. The thickness of the muscle layer (TML) in fish fed diets with LBC was higher in the first portion of medium intestine than fish fed 0LBC. All fish presented significant increase of TML in the second portion of medium intestine along feeding period, but fish fed 20LBC had smaller values of TML than those of fish fed 0 and 10LBC which might be related to the higher intestinal coefficient found for this group. The TML of rectum was higher just for fish fed 10LBC. Dietary LBC altered morphometrical features of juvenile striped catfish intestine and possibly induced inflammatory reaction in the rectal mucosa, as a function of level of inclusion, feeding period and segment of intestine analyzed.

Efeito da suplementação de colostro enriquecido sobre as características morfológicas da mucosa intestinal de bezerros neonatos

Colostrum intake in neonatal calves is essential to obtain passive immunity and to influence metabolism, endocrine systems and the nutritional state. This study compares morphologic features of small intestine of calves fed a colostrum second meal at 12 hours of life with concentrations of immunoglobulin G (IgG) higher than 100mg mL -1 (fresh colostrum or artificially prepared with addition of lyophilized colostrum) or smaller than 30mg mL -1 . Twenty-four Holstein calves were randomly grouped according to concentration of IgG intake at 12 hours of life: low (less than 30mg mL -1 ); high (more than 100mg mL -1 ); plus lyophilized colostrum (more than 120mg mL -1 ). Intestinal tissue samples were collected at 0, 10, 24 and 72 hours after birth to evaluate morphology in segments: duodenum; proximal, middle and distal jejunum and ileum by examined with a scanning electron microscope. Villi of all segments showed more organized and uniform morphology characteristics with age. Only the animals fed colostrum with more than 100mg mL -1 of IgG at 24 hours after birth still showed the distal jejunum villi disoriented and more united in comparison to the other ages and groups. Intake of lyophilized colostrum affected ileum morphology along experiment period. Higher concentration of immunologic and bioactive elements supplied for longer period of time could be responsible for promoting effects on the enterocytes. Use of colostrum with high IgG concentrations, with or without addition of lyophilized colostrum, influenced the precocity of the intestinal mucosa development in newborn calves, suggesting earlier maturation of the mucosa.