Efecto de la pérdida de grasa dorsal y peso corporal sobre el rendimiento reproductivo de cerdas primíparas lactantes alimentadas con tres diferentes tipos de dietas / Effect of loss of backfat and body weight on the reproductive performance of primiparous lactating sows fed with three different diets

Se evaluaron 90 cerdas híbridas primíparas de traspatio, que se clasificaron de acuerdo al tipo de dieta en 3 grupos: G1, escamocha (residuos alimenticios de consumo humano); G2, escamocha y concentrado y/o granos, y G3, alimento balanceado. La grasa dorsal se registró a la altura de la décima vértebra torácica mediante ultrasonido. Para evaluar el efecto de las reservas corporales sobre 10 indicadores productivos se utilizó la prueba exacta de Fisher; con una significancia de P<0,01. Los resultados señalaron diferencias significativas entre los tres grupos en los indicadores: peso (Kg) de la cerda al parto (X: G1 101,66; G2 111,3; G3 124,1) y al destete (X: G1 94,30; G2 104,5; G3 118,9); grasa dorsal (mm) al parto (X: G1 11,20 G2 12,66; G3 16,2) y al destete (X: G1 9,46; G2 10,70; G3 13,7); intervalo (días) destete estro (X: G1 23,16 G2 20,1; G3 14,5) y destete concepción (X: G1 27,43; G2 23,73; G3 17,16), y peso (g) individual del lechón al nacimiento en el segundo parto (X: G1 891,40; G2 958,5; G3 1054). En todos los grupos las cerdas perdieron en promedio 6 kg y 2 mm de grasa. Estos datos confirman que a medida que la calidad nutritiva de la dieta mejora, decrecen progresivamente los días que las cerdas requieren para entrar en calor una vez que son destetadas. A pesar del bajo peso al destete de las cerdas con alimentación con base en escamocha, éstas entraton en estro y su gestación fue exitosa aunque con un número moderado de lechones nacidos vivos y un pobre peso al nacimiento

[Diagnostic serology of swine leptospirosis in Mexico 1995-2000]. / Serología diagnóstica de leptospirosis porcina en México 1995-2000

Results obtained from sample testing of 1970 swines from a number of Mexican farms were analyzed. Such samples had been received in the Leptospira Lab of Universidad Autonoma Metropolitana de Xochimilco from 1995 to 2000. Sera with titers equal to or higher than 1:1000 were considered positive; 39,8% of the animals were seropositive (784) and the most frequent serovarieties were bratislava, 22.5%; icterohaemorrhagiae strain Palo Alto, 14,5%; portland vere strain Sinaloa ACR, 13,8%; icterohaemorrhagiae, 11,1%; grippotyphosa, 8,9%; hardjo strain H89,7.2%; tarassovi,7.1%; panama, 5.8%, pomona and hardjo, 5.1%; wolffi, 3%; shermani, 2.4%; pyrogenes, 1.2%; canicola, 0.8%; hebdomadis, 0,5%. The bratislava serovariety has been reported as the cause of reproductive failure in several countries and it holds the first place in serological studies. Therefore, the present paper provides information for stating that this is one of the most significant serovarieties in Mexico.

[Serological study of bovine leptospirosis in Mexico]. / Estudio serológico de leptospirosis bovina en México.

The results of 4 043 bovine sera samples from various Mexican regions, which were sent to a diagnosis lab, were analyzed. The method was the agglutination technique, taking the dilution rate 1:1000 or higher as positive. The analysis revealed 31,1% of seroprevalence and the most frequent serovarietes were hardjo (strain H 89 isolated in Mexico), wolffi and tarassovi. There is coincidence with early data obtained in Mexico on a 34% of prevalence found in a similar study performed in 1994, and with the scientific literature from other countries. The former study also indicated that tarassovi and wolffi were the most common leptospira, so there is coincidence with the figures in the reviewed literature. It was concluded that there was no significant variation in the prevalence rate between the 1994 study and the present one; therefore, it is recommended that this study be promoted so as to increase the bovine vaccination and achieve a reduction in leptospirosis in Mexico.