Perfil metabólico de filhotes de peixe-boi da Amazônia (Trichechus inunguis) em cativeiro, alimentados com diferentes sucedâneos do leite materno / [Metabolic profile of captive Amazonian manatee calves (Trichechus inunguis), fed different substitutes for maternal milk]

Dez filhotes de peixe-boi da Amazônia criados em cativeiro foram amamentados com diferentes dietas lácteas em duas etapas. Na primeira, com sucedâneo 1 (S1), utilizado rotineiramente no Inpa e, na segunda, com sucedâneo 2 (S2), elaborado com base na composição centesimal do leite materno da espécie. Cada etapa durou 62 dias, realizando-se coleta de sangue ao final de cada uma para avaliação dos valores de proteínas totais (PT), albumina (ALB), globulinas (GLO), glicose (GLI), lipídeos totais (LT), colesterol (COL), triglicerídeos (TRI), cálcio (Ca), fósforo (P), magnésio (Mg), sódio (Na), potássio (K), hematócrito (Ht) e hemoglobina (Hb). Houve redução dos níveis séricos de PT, ALB, GLO, Ca, P, K, GLI, LT, COL e TRI, após a alimentação dos animais com S2 quando comparados aos valores obtidos com S1. Os níveis de Na foram maiores quando administrado o S2 (143,47±0,99mmol/L). Valores de Ht e Mg não diferiram entre os tratamentos. O perfil metabólico, em geral, esteve dentro dos níveis normais para a espécie.(AU)

Ten Amazonian manatee calves who live in captivity were fed with different substitutes for maternal milk in two phases. During the first phase, the calves were fed substitute 1 (S1), which is what was routinely used by INPA, and during the second phase they were fed substitute 2 (S2), which was formulated based on the nutritional composition of T. inunguis maternal milk. Each phase lasted 62 days, when blood samples were collected for analysis of values of total protein (PT), albumin (ALB), globulin (GLO), glucose (GLI), total lipids (LT), cholesterol (COL), triglycerides (TRI), calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K), hematocrit (Ht) and hemoglobin (Hb). There was a decrease in PT, ALB, GLO, Ca, P and K after feeding the animals with S2 when compared to values obtained with S1. Sodium levels were higher when S2 was administered (148.16±1.15mmol/L) than when S1 was given (143.47±0.99 mmol/l). Values of Ht and Mg did not differ between treatments. The metabolic profile was within normal levels for this species.(AU)

Seasonal variation in urinary and salivary reproductive hormone levels in Amazonian manatees (Trichechus inunguis).

The Amazonian manatee (Trichechus inunguis) is a threatened aquatic mammal endemic to the Amazon basin. The aim of this study was to evaluate the urinary and salivary reproductive hormone levels of captive Amazonian manatees collected during two seasons of the year. Salivary samples from four males and urinary and salivary samples from three females were collected during two seasons (March-June and September-November) over two consecutive years. Salivary testosterone in males was measured by radioimmunoassay and reproductive hormones in females (salivary progesterone and oestradiol and urinary progestogens, oestrogens and luteinising hormone) were measured by enzyme immunoassay. The data were analysed in a 2×2 factorial design, where the factors were year and season. There was no effect of year or season for salivary testosterone. All female hormones showed a seasonal effect (higher hormone levels during March-June than September-November) or an interaction between year and season (P<0.05). These results strongly indicate the existence of reproductive seasonality in Amazonian manatees; however, apparently only females exhibit reproductive quiescence during the non-breeding season. Further long-term studies are necessary to elucidate which environmental parameters are related to reproductive seasonality in T. inunguis and how this species responds physiologically to those stimuli.

Noninvasive monitoring of androgens in male Amazonian manatee (Trichechus inunguis): biologic validation.

The Amazonian manatee (Trichechus inunguis) is endemic in the Amazonian basin and is the only exclusively fresh water sirenian. Historically hunted on a large scale, this species is now considered endangered, and studies on the reproductive physiology are critical for the improvement of reproductive management of captive and wild populations of manatees. The aim of this study was to verify the viability of androgen measurement in saliva, lacrimal, urine, and fecal samples of the Amazonian manatee by conducting a hormone challenge. Two adult male manatees (A-1 and A-2) were submitted to an experimentation protocol of 12 day (D1 to D10). On D0, the animals received an intramuscular injection of gonadotropin-releasing hormone (GnRH)-analogue. Salivary, lacrimal, urinary, and fecal samples were collected daily (between 0800 hours and 0900 hours) and frozen at -20 degrees C until assayed. Fecal samples were lyophilized, extracted with 80% methanol, and diluted in buffer before the radioimmunoassay (RIA). Urine samples underwent acid hydrolysis and were diluted in depleted bovine serum. Salivary and lacrimal samples were assayed without the extraction step. Hormonal assays were conducted with a commercial testosterone RIA kit. An androgen peak (> median + 2 interquartile range [IQR]) was observed in all matrices of both animals, although it was less prominent in the lacrimal samples of A-2. However, the fecal androgen peak (A-1 peak = 293.78 ng/g dry feces, median [IQR] = 143.58 [32.38] ng/g dry feces; A-2 peak = 686.72 ng/g dry feces, median [IQR] = 243.82 [193.16] ng/g dry feces) occurred later than urinary (A-1 peak = 648.16 ng/mg creatinine [Cr], median [IQR] = 23.88 [30.44] ng/mg Cr; A-2 peak = 370.44 ng/mg Cr, median [IQR] = 113.87 [117.73] ng/mg Cr) and salivary (A-1 peak = 678.89 pg/ml, median [IQR] = 103.69 [119.86] pg/ml; A-2 peak = 733.71 pg/ml, median [IQR] = 262.92 [211.44] pg/ml) androgen peaks. These intervals appear to be correlated with the long digesta passage time in this species. The salivary and urinary peaks were closely associated. These results demonstrate that androgen concentrations in saliva, urine, or feces samples reflect reliably physiologic events and are a powerful tool for noninvasive reproductive monitoring of Amazonian manatees.