Effect of Dietary Energy Levels upon Reproduction and the Relation of Endometrial Phosphatase Activity to Embryo Survival in Gilts

Composition of the bovine uterine proteome is associated with stage of cycle and concentration of systemic progesterone

“…Notably, is has been reported that alkaline phosphatase activity in bovine uterine fluid is stage of cycle dependent . Furthermore, in gilts, a low but significant ( p < 0.05) negative correlation (0.35) between alkaline phosphatase activity in the endometrium and number of viable embryos at Day 25 of gestation has been reported . Superoxide dismutase (SOD3), another enzyme that had higher expression on Day 15 of the cycle, has a role in oxidative stress defence, scavenging potentially damaging superoxide radicals.…”

Factors Affecting The Natural Attainment of Puberty in The Gilt

“…If liveweight does exert little influence on puberty attainment it might also be supposed that the rate of liveweight increase, or growth rate, would also have a minimal effect on the timing of puberty. Many reports do suggest that this is the case in the gilt (Burger, 1952;Haines, Warnick and Wallace, 1959;Gossett and Sorensen, 1959;Sorensen, Thomas and Gossett, 1961;Goode, Warnick and Wallace, 1965), although this is not necessarily true in all species (Brody, 1945;Monteiro and Falconer, 1966). Despite this conclusion Reutzel and Sumption (1968) have demonstrated that a positive genetic relationship exists between age and puberty and daily liveweight gain in the gilt.…”

“…The results available from these studies are both variable and conflicting. Several workers have reported that full feeding of prepubertal gilts results in the early attainment of puberty when compared with their restricted-fed counterparts (Burger, 1952;Zimmerman et al , 1960;Goode, Warnick and Wallace, 1965;Friend, 1974;1976). However, other results suggest that puberty attainment is either unaffected by plane of feeding (Robertson et aL , 1951b;Christian and Nofziger, 1952;Lodge andMacPherson, 1961, Pay andDavies, 1973) or is delayed by full feeding (Self, Grummer and Casida, 1955;Hafez, 1960;MacPherson, Hovell and Jones, 1977).…”

Estrategias en el manejo reproductivo de la cerda para la mejora de la fertilidad = Reproductive management strategies for improving sow fertility

“…En lo referente al índice de crecimiento y su efecto sobre la edad de inicio de la pubertad en la nulípara, son varios los autores que lo han calificado de mínimo (Gossett and Sorensen, 1959;Sorensen et al, 1961;Goode et al, 1965;Sacristán et al, 1996). Este mínimo efecto viene dado por las interrelaciones genéticas positivas existentes entre la edad a la pubertad y la ganancia media diaria de peso vivo en la nulípara (Reutzel and Sumption, 1968), lo que explica que existan variaciones en la edad de la nulípara al inicio de la pubertad entre animales del mismo genotipo, debido a variaciones en su índice de crecimiento.…”

“…Los efectos de la heterosis sobre el inicio de la pubertad han sido repetidamente demostrados, destacando cómo las razas porcinas híbridas producen nulíparas que alcanzan antes la pubertad, con respecto a las hembras de razas puras (Bidanel et al, 1996), debido al efecto dominante heterocigótico para este carácter. Goode et al, 1965 Hampshire 207 207±28 Christenson and Ford, 1979 Large White 205 173±13 Gaughan et al, 1997200±20 Allrich et al, 1985206±21 Sterning et al, 1998208±20 Rydhmer et al, 1994211±21 Christenson and Ford, 1979211±20 Eliasson et al, 1991215±49 Bidanel et al, 1996215 Kerr and Cameron, 1997 Landrace 185 173±25 Christenson and Ford, 1979185±20 Allrich et al, 1985198±35 Bidanel et al, 1996 Meishan 97 81±9 Legault and Caritez, 198394±15 Pickard and Ashworth, 1995115±20 Hunter et al, 1993 3.6.4. Nutrición.…”