The effect of gilt age at first estrus and breeding on third estrus on sow body weight changes and long-term reproductive performance1

Abstract

The objective of this trial was to determine the effect of age at first estrus on BW changes and long-term reproductive performance of sows. At approximately 100 d of age, prepubertal C22 gilts (n = 431) were allocated to trial. At a pen average of 140 d of age, gilts began daily direct contact with mature boars to stimulate onset of puberty. Gilts (n = 317, 73%) were recorded as cyclic by 180 d of age (select) and were classified on the basis of age at puberty into 3 puberty groups: 1) early puberty (EP; <153 d of age; n = 85); 2) intermediate puberty (IP; 154 to 167 d of age; n = 140); or 3) late puberty (LP; 168 to 180 d of age; n = 90). Gilts not exhibiting the standing reflex by 180 d of age were considered nonselect (NS; n = 91). Mean day to puberty and age at puberty attainment in each of the classifications were EP: 9.6 +/- 0.5 d and 147.4 +/- 0.5 d; IP: 19.3 +/- 0.5 d and 159.9 +/- 0.3 d; LP: 33.8 +/- 0.7 and 175.7 +/- 0.6 d, respectively. Fewer NS gilts (73.0%) were bred than were EP (97.7%), IP (93.2%), or LP (93.0%) gilts (P < 0.05). Total number of piglets born and born alive were not different between classifications and increased (P < 0.05) over successive parities in EP, IP, and NS gilts. For gilts initially served, there was no effect of puberty group classification on retention in the herd to farrow a third litter, but the rate of fallout per parity tended to be greatest for NS (17.2%) compared with EP (12.4%), IP (15.6%), and LP (14.2%) gilts (P < 0.08). Taken together, these data suggest that the response to a standardized protocol of boar stimulation can identify 50 to 75% of gilts that will have greatest lifetime productivity in the breeding herd. In the known cyclic (select) gilts, BW increased over the productive life of the sow, and EP gilts were lighter than LP gilts at every measured event (P < 0.05). Plasma IGF-1 only differed between puberty groups at d 100 of age (EP: 169.0 +/- 4.4; IP: 157.2 +/- 3.5; LP: 144.0 +/- 4.4 ng/mL), suggesting a mechanism linking IGF-1 status and age at puberty in the present study.

Uterine size in replacement gilts associated with age, body weight, growth rate, and reproductive status

“…Therefore, to obtain a high prolificacy in gilts, the size of the uterus in relation to their age, body weight, and growth rate should be carefully determined. Our previous study found that LY gilts in Thailand attained puberty at 196 days of age (Tummaruk et al 2007), which is about 2-4 weeks later than those in Europe and North America (Karlbom 1982;Patterson et al 2010). Mating decisions for gilts should therefore be made with caution because mating gilts at suboptimal time may result in inferior reproductive performance and longevity (Schukken et al 1994;Koketsu et al 1999;Tummaruk et al 2001).…”

“…Age at first mating in gilts influences their subsequent reproductive performance as sows and their longevity (Koketsu et al 1999;Tummaruk et al 2001;Patterson et al 2010). Under field conditions, the reported age at first mating in gilts varies considerably from 150 up to 348 days (Tummaruk et al 2000), while the mean age at first mating in gilts varies among populations from 198 (Kummer et al 2006) to 268 days (Tummaruk et al 2009a).…”

The impact of season, parity and breed on selected reproductive performance parameters of sows

“…It is estimated that over the course of their whole lives sows rear an average of only 30-40 piglets (Patterson et al, 2010), thus the validity of a careful evaluation of the reproductive performance of sow determinants.…”

Indução da ovulação e características ovarianas de marrãs pre-púberes tratadas com gonadotrofina coriônica humana ou kisspeptina

“…Dependendo das raças e tipos genéticos, as fêmeas suínas podem atingir a puberdade entre 5 a 9 meses de idade (MartiNat-botté et al, 2011). Reduzir esta variação, por meio do controle do início da puberdade, pode ser extremamente benéfico para a produtividade do rebanho, uma vez que as fêmeas que atingem a puberdade mais cedo tendem a permanecer mais tempo no rebanho e ser mais produtivas (PattersoN et al, 2010;. Por esse motivo, nas granjas mais tecnificadas tornou-se prática comum avançar a puberdade das marrãs utilizando terapia hormonal.…”