Plasma Melatonin and Progesterone Profiles of Suffolk and Romney Marsh Ewes Implanted with Melatonin during Anoestrus Season at Lower Latitudes in Southern Hemisphere

Background: The subcutaneous implants of melatonin are stimulatory and mimic the positive effects of short photoperiod on reproduction in small ruminants. This study investigated the daily plasma melatonin profiles in ewes treated with melatonin implants and kept under natural photoperiod in Southeastern Brazil. The plasma progesterone concentrations were also investigated before and after melatonin implantation.Materials, Methods & Results: Romney Marsh (n = 11) and Suffolk (n = 10) ewes, which had been isolated from rams for at least 2 months prior to the beginning of the trial, were randomly allocated in two groups based on melatonin implant treatment (with or without melatonin implant). For plasma melatonin concentration, 43 days after melatonin implantation and 3 days before the ram introduction blood samples were collected every 2 hours during 24 hours. For plasma progesterone concentrations, blood samples were collected every once to twice a week for 2 different periods: prior to melatonin implantation and 46 days after the melatonin implantation and at the same day of the introduction of rams. The hormonal concentrations were determined by the radioimmunoassay method (RIA). The data were analyzed according to MIXED procedure (SAS) as repeated measurements for random animal effects. The effect of melatonin treatment on plasma melatonin 24-h period varied according to the breed. At the dark-phase, there were no plasma melatonin differences (P > 0.05) between implanted and no-implanted (228.02 ± 58.39 vs. 169.59 ± 48.39) Romney Marsh ewes whereas for Suffolk ewes the plasma melatonin levels were higher in implanted (305.61 ± 68.39 pg/mL) than no-implanted (151.26 ± 38.35 pg/mL) ones. At the light-phase, melatonin treatment effects could be evidenced and these differences (P than 1 ng/mL in implanted and no-implanted Suffolk ewes. In implanted Romney Marsh ewes the elevation of progesterone mean values was weak whereas in no-implanted Romney Marsh ewes the progesterone levels were maintained ˂ 1 ng/mL during all the blood sample collection times.Discussion: The melatonin treatment also produced a similar model of daily melatonin levels as reported previously by others, which is characterized by high plasma melatonin concentrations during the light phase of the day. The effect of melatonin implants on plasma melatonin profiles interacted with breed confirming an individual response to melatonin implantation which is proportional to genetic individual variation pattern of melatonin secretion. Before the melatonin implantation all Romney Marsh and Suffolk ewes were judged to be in non-ovulatory period (anoestrus) with plasma progesterone mean values lower than 1 ng/mL. The melatonin treatment helped to induce the ovulatory activity in most of the ewes that were in anestrous at the time of melatonin implantation and the efficacy of this treatment depends on the individual variation in ovulatory response to ram introduction. In Southeastern Brazil., melatonin implant altered the daily plasma melatonin profiles of Suffolk and Romney Marsh ewes by increasing the melatonin levels during the light-phase of the day. Melatonin implant also induced an ovulatory response in Suffolk and Romney Marsh after the introduction of the rams. For no-implanted Suffolk ewes, the male effect is sufficient to provoke an ovulatory response

Carcass characteristics from three swine stocks in different slaughters ages

O objetivo deste trabalho foi estudar as características da carcaça de suínos de diferentes linhagens genéticas, em diferentes idades ao abate. Foram utilizados 88 suínos por linhagem, fêmeas e machos castrados, com idade e peso médio iniciais de 74 dias e 30kg, respectivamente, pertencentes a três linhagens genéticas distintas, designadas de AgroceresPic, Dalland e Seghers. A etapa experimental foi dividida em quatro fases (Crescimento I, Crescimento II, Terminação I e Terminação II). Ao final de cada etapa, foram abatidos 60 animais (10 por linhagem/sexo), para as caracterizações: Peso (PCQ) e Rendimento de Carcaça Quente (RCQ), Área de Olho de Lombo (AOL) e Espessura de Toucinho (ET). Na análise dos resultados foi utilizado um delineamento inteiramente casualizado com desdobramento dos graus de liberdade em esquema fatorial 4 x 3 x 2, sendo quatro idades ao abate (90, 119, 150 e 186 dias), três linhagens (AgroceresPic, Dalland e Seghers) e dois sexos (fêmea e macho castrado), com 10 repetições por tratamento, sendo utilizado o pacote PROC MIXED do Softwear SAS. Os valores médios de peso vivo apresentaram diferença entre as linhagens e interação entre fase e linhagem (P<0,05). Os valores médios das demais variáveis estudadas apresentaram diferença e a interação (P<0,05) entre fase, linhagem e sexo, sendo que de maneira geral as principais diferenças ocorreram a partir da fase de Terminação I, em que as fêmeas das linhagens AgroceresPic e Dalland apresentaram melhores resultados (P<0,05) de RCQ (80,4 e 80,7%, respectivamente) em comparação com os machos (78,8 e 78,7%, respectivamente) e além disso as fêmeas Dalland apresentaram valores superiores (P<0,01) de AOL e ET (45,7cm² e 11,4mm x 38,3cm² e 18,3mm). Conclui-se que as linhagens genéticas avaliadas apresentaram características de carcaça muito interessantes para o mercado atual e que as fêmeas suínas podem ser utilizadas em programas que visem o abate de animais mais pesados.The aim of this research was to study the carcasses characteristics of swine sire lines from different slaughter weights. In this study were used 88 castrated piglets (castrated males and females) per sire line (AgroceresPic, Dalland and Seghers), with initial age of 74 days and live weight of 30kg. The experiment was divided in four phases (Growing I, Growing II, Finishing I and Finishing II). Sixty animals were slaughtered (10 by stock/sex) at the end of each experimental phase to determine the post mortem measurements: Carcass Weight (CW), Hot Carcass Yield (HCW), Loin Eye Muscle Area (LMA) and Back Fat Thickness (BT). This study was conducted using a completely randomized design, with treatments in complete factorial 4 x 3 x 2, being 4 slaughters ages (90, 119, 150 and 186 days), 3 sire lines (AgroceresPic, Dalland and Seghers) and 2 sexes (female and male castrated) with 10 repetitions by treatment. The PROC MIXED from the Software SAS was applied for statistical analysis. The mean values for Live Weight present difference (P<0.05) sire line and interaction between phase and stock. The mean values for the other studied variables presented significant differences and interaction between phase, sire line and gender, remarking that in general the major differences occurred after the phase Finishing I, where the females of AgroceresPic and Dalland tended to present better results (P<0.05) of HCW (80.4 and 80.7%, respectively) than the castrated males (78.8 and 78.7%, respectively) and the females Dalland were better than the castrated males (P<0.01) on LMA and BT values (45.7cm² and 11,4mm x 38.3cm² and 18.3mm). It can be concluded that the all sire lines studied presented interesting carcass characteristics for the actual market, and that the females can be used in programs aimed at animals with more slaughter weights

Evaluation of Serum and Urine Amino Acids in Dogs with Chronic Kidney Disease and Healthy Dogs Fed a Renal Diet

This observational study aimed to evaluate serum and urinary amino acid (AA) concentrations in healthy dogs and dogs with chronic kidney disease (CKD) fed a commercial therapeutic renal diet with reduced protein and phosphorus levels. Ten dogs with CKD stages 3 or 4 composed the study group and received the renal diet for 180 days (RG T180). A control group (CG T30) composed of seven healthy dogs was fed a renal diet for 30 days. When comparing serum AA between RG T180 and CG T30, histidine, isoleucine, leucine, lysine, phenylalanine, tryptophan, cysteine, citrulline, ornithine, taurine, branched-chain amino acids (BCAA), and total essential amino acids (EAA) were higher in RG T180. Meanwhile, arginine, asparagine, aspartate, glutamine, serine, and tyrosine were higher in CG T30. Serum phenylalanine, tryptophan, and hydroxyproline were higher in RG T0 (dogs with CKD before consuming a renal diet) when compared to RG T180. In addition, the serum ratios of arginine/citrulline, tyrosine/phenylalanine, and serine/glycine were higher in CG T30 than in RG T180. Concerning urinary AA concentrations in CKD dogs, isoleucine, phenylalanine, tryptophan, aspartate, cysteine, and BCAA were higher in RG T180. In urine, the total EAA/total non-essential AA ratio in RG T180 was higher than in CG T30 as well as tyrosine/phenylalanine ratio higher in CG T30. In conclusion, the combination of renal diet and conservative treatment over 6 months in dogs with CKD stages 3 or 4 affected the AAs metabolism when compared to healthy adult dogs