Cryopreservation of bison epididymal sperm: A strategy for improving post-thaw quality when collecting sperm in field conditions.

This study was conducted to optimize the cryopreservation of epididymal bison sperm harvested in the field. In the first experiment, epididymal bison sperm were treated with or without seminal plasma (n = 6) and cooled to 5 °C over 2 hours. In a separate experiment, glycerol was added at different times and sperm was held at 5 °C for different periods of time before cryopreservation (n = 11). In addition, epididymal sperm frozen with and without seminal plasma (n = 6) and after 4, 24, and 48 hours (n = 5) of equilibration at 5 °C, were evaluated for their in vitro fertilizing ability. Post-thaw motility of bison epididymal sperm was similar when cryopreserved with or without seminal plasma or when glycerol was added at either 0, 4, 24, or 48 hours before freezing (P > 0.05). However, sperm incubated at 5 °C for 24 hours before freezing exhibited higher percentages of motile sperm (44% vs. 35% for 4 hours or 48 hours, P < 0.05). Fertilization rates of bison oocytes were not different for any treatments. Chilling the whole epididymis for 24 or 48 hours resulted in complete loss of sperm viability. In conclusion, bison epididymal sperm can be chilled outside of the epididymis for at least 48 hours before cryopreservation without compromising post-thaw sperm motility providing flexibility for technicians performing field collections.

Nutritional levels of digestible threonine in brown-egg laying hens from 75 to 90 weeks of age / Níveis nutricionais de treonina digestível para poedeiras semipesadas de 75 a 90 semanas de idade

An experiment was conducted in the Department of Experimental Stations of the UniversidadeTecnológica Federal do Parana - UTFPR campus Dois Vizinhos - PR, with the objective of determining the nutritional levels of threonine for laying hens aged 75 to 90 weeks. One hundred fifty laying Shaver Brown pullets were used in a completely randomized design (CRD) submitted to a basal diet containing 2.85 kcal ME/g and 148.7 g/kg CP, supplemented with 4.6; 4.9; 5.2; 5.5 or 5.8 g/kg of digestible Lthreonine(98 %), which provided 0.000, 0.027, 0.058, 0.089 or 0.120% threonine, respectively. Thefeed conversion, egg production, egg weight, egg mass and internal egg quality were not affected (P> 0.05) by the threonine in the diet. The Haugh unit showed a linear effect with threonine consumptionin that it increased levels of digestible amino acids in the diet. The variables percent albumin and shell showed quadratic effects, so the recommended dietary digestible threonine level was 5.20 g/kg, whichcorresponds to 0.648 g threonine/hen/day, and 5.25 g/kg, which is equivalent to 0.654 g threonine/hen/day, respectively. The specific gravity was affected by the level of threonine; the indicated level is 5.22 g/kg, equivalent to 0.651 g of threonine/hen/day obtained by the quadratic effect.(AU)

Conduziu-se um experimento no Núcleo de Unidades de Ensino e Pesquisa da Universidade Tecnológica Federal do Paraná UTFPR, Campus de Dois Vizinhos - PR, com o objetivo de determinar os níveis nutricionais de treonina digestível para poedeiras comerciais, no período de 75 a 90 semanas de idade.Foram utilizadas 150 poedeiras Shaver Brown semipesadas num delineamento inteiramente casualizado (DIC), submetidas à uma ração basal contendo 2,85 Kcal EM/g, 148,7g/kg de PB, suplementada com4,6; 4,9; 5,2; 5,5 e 5,8g/kg de L-treonina digestível (98%), que forneceu 0,000; 0,027; 0,058; 0,089 e 0,120% de treonina digestível, respectivamente. A conversão alimentar, a produção de ovos, o peso do ovo, massa de ovos e a qualidade interna dos ovos não foram influenciados (P>0,05) pelos níveis detreonina na dieta. A unidade Haugh e o consumo de treonina apresentaram efeito linear à medida em que aumentavam os níveis do aminoácido digestível na dieta. As variáveis porcentagem de albúmene casca apresentaram efeito quadrático e os níveis nutricionais de treonina digestível recomendadosforam de 5,20g/kg, o que corresponde a 0,648 g de treonina/ave/dia e, 5,25g/kg que equivale a 0,654g de treonina/ave/dia, respectivamente. A gravidade específica foi afetada pelos níveis de treonina digestível, e o nível indicado é de 5,22g/kg, que equivale a 0,651 g de treonina/ave/dia obtido por meio de efeito quadrático.(AU)

Nutritional levels of digestible threonine in brown-egg laying hens from 75 to 90 weeks of age / Níveis nutricionais de treonina digestível para poedeiras semipesadas de 75 a 90 semanas de idade

An experiment was conducted in the Department of Experimental Stations of the UniversidadeTecnológica Federal do Parana - UTFPR campus Dois Vizinhos - PR, with the objective of determining the nutritional levels of threonine for laying hens aged 75 to 90 weeks. One hundred fifty laying Shaver Brown pullets were used in a completely randomized design (CRD) submitted to a basal diet containing 2.85 kcal ME/g and 148.7 g/kg CP, supplemented with 4.6; 4.9; 5.2; 5.5 or 5.8 g/kg of digestible Lthreonine(98 %), which provided 0.000, 0.027, 0.058, 0.089 or 0.120% threonine, respectively. Thefeed conversion, egg production, egg weight, egg mass and internal egg quality were not affected (P> 0.05) by the threonine in the diet. The Haugh unit showed a linear effect with threonine consumptionin that it increased levels of digestible amino acids in the diet. The variables percent albumin and shell showed quadratic effects, so the recommended dietary digestible threonine level was 5.20 g/kg, whichcorresponds to 0.648 g threonine/hen/day, and 5.25 g/kg, which is equivalent to 0.654 g threonine/hen/day, respectively. The specific gravity was affected by the level of threonine; the indicated level is 5.22 g/kg, equivalent to 0.651 g of threonine/hen/day obtained by the quadratic effect.

Conduziu-se um experimento no Núcleo de Unidades de Ensino e Pesquisa da Universidade Tecnológica Federal do Paraná – UTFPR, Campus de Dois Vizinhos - PR, com o objetivo de determinar os níveis nutricionais de treonina digestível para poedeiras comerciais, no período de 75 a 90 semanas de idade.Foram utilizadas 150 poedeiras Shaver Brown semipesadas num delineamento inteiramente casualizado (DIC), submetidas à uma ração basal contendo 2,85 Kcal EM/g, 148,7g/kg de PB, suplementada com4,6; 4,9; 5,2; 5,5 e 5,8g/kg de L-treonina digestível (98%), que forneceu 0,000; 0,027; 0,058; 0,089 e 0,120% de treonina digestível, respectivamente. A conversão alimentar, a produção de ovos, o peso do ovo, massa de ovos e a qualidade interna dos ovos não foram influenciados (P>0,05) pelos níveis detreonina na dieta. A unidade Haugh e o consumo de treonina apresentaram efeito linear à medida em que aumentavam os níveis do aminoácido digestível na dieta. As variáveis porcentagem de albúmene casca apresentaram efeito quadrático e os níveis nutricionais de treonina digestível recomendadosforam de 5,20g/kg, o que corresponde a 0,648 g de treonina/ave/dia e, 5,25g/kg que equivale a 0,654g de treonina/ave/dia, respectivamente. A gravidade específica foi afetada pelos níveis de treonina digestível, e o nível indicado é de 5,22g/kg, que equivale a 0,651 g de treonina/ave/dia obtido por meio de efeito quadrático.