Efeito do peso de abate nos rendimentos do processamento da piracanjuba (Brycon orbignyanus, Valenciennes, 1849) Effect of body weight on processing yields of piracanjuba (Brycon orbignyanus Valenciennes, 1849)

Objetivou-se, com o presente trabalho, avaliar o efeito do peso de abate sobre os rendimentos do processamento do peixe teleósteo piracanjuba (Brycon orbignyanus, Valenciennes, 1849). Inicialmente, alevinos com peso médio de 12 g, oriundos da Estação Experimental da Usina Hidrelétrica de Itutinga, foram estocados e cultivados em um viveiro de terra na Estação de Piscicultura do Departamento de Zootecnia da Universidade Federal de Lavras. Ao final de 18 meses de cultivo, 121 peixes foram insensibilizados, abatidos, pesados e dissecados, para a determinação das porcentagens de cabeça (%CAB), nadadeiras (%NAD), vísceras (%VIS), pele com escamas (%PE), e resíduos da filetação (%RF) e dos rendimentos de carcaça (RCAR) e de filé sem pele (RFSP), em relação ao peso de abate. Para as análises de variância, os dados obtidos foram agrupados em 4 classes de peso (CP1=515 g a 629 g; CP2=630 g a 744 g; CP3=745 g a 859 g; e CP4=860 g a 975 g) e as equações de regressão estimadas em função do peso médio de cada classe. Não foi constatado (P>0,05) efeito de classe de peso sobre RCAR, %NAD e %PE. Por outro lado, observaram-se efeito linear do peso de abate sobre %CAB (PThe objective of this study was to evaluate the effect of body weight on processing yields of a teleost fish piracanjuba (Brycon orbignyanus, Valenciennes, 1849). Firstly, fingerlings were reared in ponds in the Fish Culture of the Animal Sciences Department, Federal University of Lavras, M.G. - Brazil, for 18 months. Then, 121 fishes were insensibilized, slaughtered, weighed and dissected, in order to determine the percentages of head (%CAB), fins (%NAD), visceras (%VIS), skin with scales (%PE), and fillet residues (%RF), and the carcass yield (RCAR) and fillet without skin yield (RFSP), in relation to body weight. For analyses of variances, data were distributed over four weight classes (CP1 = 515 to 629g; CP2 = 630 to 744g; CP3 = 745 to 859g; and CP4 = 860 to 975g) and the regression equations were estimated in function of mean weight of each class. There was no effect (P>0,05) of weight class on RCAR, %NAD and %PE. However, a linear effect of body weight on %CAB (P<0,01), %RF (P<0,01) and RFSP (P<0,09) and a quadratic effect on %VIS (P<0,05) were observed. The %CAB and %RF decreased while RFSP and %VIS increased, with the increase of body weight. Based on these results, it can be concluded that heavier piracanjubas provide larger RFSP, smaller %CAB and smaller %RF. The smaller %CAB on heavier fish did not increase RCAR, as expected probably because of the increase on %VIS

Efeito de diferentes dosagens de vitamina A injetável na produção e qualidade de embriões bovinos da raça Nelore Effect of different dosages of vitamin A injection on production and quality of cattle embryos

Conduziu-se este trabalho com o objetivo de avaliar o efeito de quatro diferentes doses de vitamina A (0 - (n=14), 500.000 (n=15), 1.000.000 (n=17) e 1.500.000 (n=16) (UI) (na forma de palmitato de retinol) na produção e qualidade de embriões coletados de vacas doadoras da raça nelore (n=64). O experimento foi realizado na Central de Transferência de Embriões Cauembryo no município de Funilândia - MG. As vacas foram superovuladas no 10º (n=18), 11º (n=10), 12º (n=26) ou 13º (n=10) dia após a data do cio com 20 ml de Folltropin® (Vetrepharm, Belleville, Canada) ou 10 ml Pluset® (I.F. Serono, Roma, Itália) distribuídos em dosagens decrescentes durante quatro dias, em duas aplicações diárias (intercaladas de doze horas). Os tratamentos com vitamina A foram iniciados juntamente com a primeira dose de FSH. A luteólise foi induzida no quarto dia do tratamento de FSH com uma aplicação de 0,75 mg de cloprostenol sódico (Ciosin®, Coopers do Brasil, São Paulo, Brasil) e as doadoras observadas em cio foram inseminadas às 12 e 24 horas após o seu início, usando sêmen de diferentes touros. As análises estatísticas foram feitas utilizando o procedimento GENMOD do SAS (SAS INSTITUTE, 1995). O número de embriões viáveis aumentou significativamente (P0,05) entre as doadoras suplementadas (9,5, 8,3 e 10,5, respectivamente para 500.000, 1.000.000 e 1.500.000 UI de vitamina A) e não-suplementadas (8,2). Por meio desses dados, verifica-se que a suplementação de vitamina A injetável antes da coleta melhora a qualidade dos embriões coletados, sem interferir na quantidade de estruturas produzidas.The objective was to evaluate the effect of four different dosages of retinol palmitate 0 - (n=14), 500,000 (n=15), 1,000,000 (n=17) and 1,500,000 (n=16) International Units (IU) of vitamin A in the form of retinol palmitate on production and quality of embryos recovered from Nelore donor cows (n=64). The experiment was carried out in the Embryo Transfer Company Cauembryo in the county of Funilândia - MG. Cows were superovulated on the 10th (n=18),11th (n=10),12th (n=26) or 13th (n=10) days after estrus onset with an injection of 20 ml of Folltropin® (Vetrepharm, Belleville, Canada) or 10 ml of Pluset® (I.F. Serono,Roma, Itália) administered in decreasing doses for four days twice daily (each 12 h). Vitamin A injection was delivered with the first FSH injection. Luteolysis was induced on the 4th day of FSH treatment by giving 0.75 mg of sodium cloprostenol (Ciosin®, Coopers do Brasil, São Paulo, Brasil) and donors observed in estrus were artificially inseminated 12 and 24 hours after the onset of estrus using semen of different bulls of proven fertility. Statistical analysis was carried out using the GENMOD procedure of SAS (SAS INSTITUTE, 1995). The number of viable embryos differed (P<0.0001), between control (3.6), and 500,000 (6.1), 1,000,000 (6.5) and 1,500,000 (6.7) vitamin A treatments. Percentage of viable embryos also increased (P<0.01), from 0.51 in the control, to 0.57, 0.63 and 0.60 in order of increasing Vitamin A treatment groups, respectively. Number of total structures recovered (ER) was not different between supplemented (9.5, 8.3 and 10.5 respectively for 500,000, 1,000,000 e 1,500,000 IU of vitamin A) and not supplemented (8.2). These results indicate that supplementation of vitamin A i.m. before flushing improves embryo quality without interfere in the quantity of embryos recovered

The effects of cryoprotectants on chilled pirapitinga (Piaractus brachypomus) embryos at various ontogenetic stages

Cryopreservation has not been successfully used to preserve fish embryos, although chilling techniques have been used with good results. The aim of this study was to chill Piaractus brachypomus embryos at different stages of development in some cryoprotectants and for various periods of chilling. Embryos at the following ontogenetic stages were used: blastoderm – 1.2 hours post-fertilization (hpf); epiboly – 5 hpf; blastopore closure – 8 hpf; and appearance of optic vesicle – 13 hpf. One hundred embryos were selected from each of the four stages and chilled in methanol, methylglycol or dimethylsulfoxide (DMSO) for 6, 8, 10 or 12 hours, at 2ºC. The total number of treatments was 4 stages x 3 cryoprotectants x 4 periods of chilling. The highest percentage of normal and live larvae (30.6%) was observed when embryos were chilled at 13-hpf in methanol for 6 hours. In general, larvae chilled at a more developed stages (8 and 13 hpf), in methanol and for shorter periods could survive chilling and develop normally, compared to the other treatments. Therefore, P. brachypomus embryos at the optical vesicle appearance stage (13 hpf) should be chilled in a solution containing  17.5%  glucose and 10% methanol for up to eight six at 2°C