Feeding lactating primiparous sows to establish three divergent metabolic states: III. Milk production and pig growth

First-litter sows fitted with stomach cannulas were used to test the hypothesis that making gilts anabolic during lactation by providing them with extra nutrition would increase milk production and pig growth. Gilts were allocated to one of three dietary treatments after farrowing: 1) restricted, sows were fed 50% of their estimated ad libitum intake; 2) ad libitum, sows were encouraged to eat as much feed as possible; and 3) superalimented, sows were infused seven times daily through their cannula to achieve a 25 to 30% increase in energy intake in excess of that achieved by sows fed on an ad libitum basis. Milk production was estimated in mid- (d 10 to 15) and late (d 21 to 25) lactation by a modification of the isotope dilution technique. Milk production was similar between treatments in mid- and late lactation (P > .05), and this was reflected in a similarity in weaning litter weight (P = .238). Milk composition was similar also (P > .05) between dietary treatments. Superalimentation provided gilts with 38% more energy (P < .001) than gilts fed on an ad libitum basis, and they accrued live weight (5.1 kg) and backfat (1.8 mm) during lactation (P < .001). These data provide evidence that, unlike multiparous sows that show an increase in milk yield when made anabolic during lactation, primiparous sows seem to partition extra energy into body growth rather than into milk production

Feeding lactating primiparous sows to establish three divergent metabolic states: I. Associated endocrine changes and postweaning reproductive performance

We investigated effects of different metabolic states on reproductive performance in lactating, primiparous sows. Sows were fed ad libitum (AL; n = 12), alimentated via a gastric cannula to 125% of AL feed intake (SA; n = 8), or restricted (R; n = 9) to 50% of AL from d 1 to 28 of lactation. At weaning, all sows were fed 2.5x maintenance energy requirements until standing heat and then fed twice maintenance energy requirement until slaughter. Sow weight, backfat, and litter weights were recorded weekly. After weaning, sows were tested twice daily for the onset of estrus and inseminated twice using pooled semen. At d 28 of gestation, sows were slaughtered, and the reproductive tracts were recovered to determine ovulation rate and embryo survival. Intensive blood sampling was performed before and after weaning for 12-h periods to characterize changes in plasma LH, insulin, and IGF-I. After weaning, additional samples were taken to monitor changes in LH and progesterone. Insulin and IGF-I were determined at standing heat. During lactation, AL and R sows lost, whereas SA sows gained, body weight and backfat (P < .001). Litter growth rates did not differ among treatments. Although plasma insulin was not different among treatments, plasma IGF-I concentration was lower (P < .001) in R sows. Mean LH and pulse frequency before (P < .03 and P < .06, respectively) and after (P < .001; for both) weaning were lower in R than in AL or SA sows. After weaning, SA sows lost more weight (P < .01) and backfat (P < .01) and ate less feed (P < .001) than AL or R sows. At standing heat, no differences in plasma IGF-I or insulin were observed, although energy balance for SA sows was lower (P < .01) than for AL or R sows. Weaning-to-estrus interval was extended (P < .02) in R sows. We observed no treatment difference in ovulation rate or embryo survival. Our results demonstrate that making sows anabolic during lactation did not ameliorate the negative impact of the suckling stimulus or improve fertility after weaning

Níveis de treonina digestível em dietas para fêmeas suínas de alto potencial genético em lactação sob condições de alta temperatura ambiente Digestible threonine levels of high-producing lactating sows maintained under high temperature environment conditions

Foram utilizadas 52 fêmeas suínas em lactação distribuídas em delineamento experimental de blocos ao acaso, composto de quatro níveis de treonina digestível (0,64; 0,67; 0,70 e 0,73%) na dieta e 13 repetições, em que cada unidade experimental foi constituída por uma fêmea. A temperatura do ar no interior das salas foi de 29,7 &plusmn; 2,5ºC. Não houve efeito dos níveis de treonina digestível na dieta sobre o peso das fêmeas ao desmame. As perdas total e percentual de peso das fêmeas durante a lactação reduziram de forma linear com o aumento dos níveis de treonina digestível na dieta. Os níveis de treonina digestível influenciaram a espessura de toucinho (ET) ao desmame e afetaram as variações total e percentual de espessura de toucinho. As composições de gordura e proteína corporal à desmama não foram influenciadas pelos níveis de treonina digestível na dieta. Verificou-se redução linear das mobilizações total e percentual de gordura corporal conforme aumentaram os níveis de treonina digestível na dieta. A mobilização de proteína corporal, a produção de leite e o intervalo desmama-estro não foram influenciados pelos níveis de treonina digestível da dieta. Os níveis de treonina digestível não afetaram os consumos de ração, de lisina e de energia digestível. Contudo, verificou-se aumento linear do consumo de treonina digestível conforme aumentou o nível deste aminoácido na dieta. Os níveis de treonina digestível não influenciaram a eficiência energética das fêmeas e o desempenho dos leitões e das leitegadas. Fêmeas suínas de alto potencial genético em lactação sob condições de temperaturas ambientais elevadas exigem 0,73% de treonina digestível, correspondente ao consumo diário de 32,5 g e à relação treonina digestível:lisina digestível de 73%.<br>Fifty and two lactating sows were allotted to a randomized complete blocks experimental design with four digestible threonine levels (0.64; 0.67; 0.70 and 0.73%) and 13 replications, and each experimental unit was consisted by a female. The temperature inside in the room was of 29.7 &plusmn; 2.5&deg;C. There was no effect of digestible threonine levels in the diet on the weight of the sows at weaning. The total and percentage sow weight losses linearly reduced with the increase of digestible threonine level in the diet during the lactation period. Digestible threonine level in the diets influenced fat thickness (FT) at weaning, and affected the total and percentage variation of FT. The compositions of fat and corporal protein at weaning were not influenced by digestible threonine levels in the diet. A linear reduction for total and percentage of corporal fat mobilizations was observed as digestible threonine levels increased in the diet. The mobilization of corporal protein, milk production and the interval weaning time-estrus were not influenced by digestible threonine levels in the diet. Digestible threonine leveld in the diet had no effect on intake of diet, of lysine and of digestible energy. However, a linear increase was observed for the intake of digestible threonine as the levels of it increased in the diet. Digestible threonine levels in the diet had not influenced the energy efficiency of the females, the performance of the piglets and the litters. High-producing lactating sows under high temperature environmental conditions require 0.73% of digestible threonine, corresponding to a daily intake of 32.5g and the digestible threonine:digestible lysine ratio of 73%

Metanálise da relação entre espessura de toicinho e variáveis corporais e reprodutivas de porcas gestantes e lactantes Meta-analysis of relation among backfat thickness, body and reproductive variables of gestating and lactating sows

Um estudo de metanálise avaliou a relação entre a espessura de toicinho e as variáveis de condição corporal de porcas gestantes e lactantes. A base de dados contemplou 14 artigos publicados de 2000 a 2006 em revistas indexadas. A metanálise foi realizada através de análises gráfica, de correlação e de variância. A correlação da espessura de toicinho (ET) com o peso vivo foi de 0,16 (P<0,01), com a massa protéica de 0,48 (P<0,01) e com a concentração de leptina de 0,88 (P<0,01). A correlação da variação da espessura de toicinho na lactação (ETl) com o peso vivo foi de -0,21 (P<0,01), com variação do peso vivo na lactação de 0,34 (P<0,01) e com variação da massa lipídica na lactação de 0,70 (P<0,01). A correlação entre a ET e o número de leitões nascidos vivos foi de 0,46 (P<0,01), e entre a ETl e o PV dos leitões aos sete dias foi de 0,95 (P<0,01). A ET foi influenciada pelo peso vivo e pela massa protéica na gestação, enquanto a ETl é influenciada pela variação do peso vivo e pela massa lipídica na lactação. As concentrações de leptina ao parto estão correlacionadas positivamente com a ET. A ET é influenciada pelo número total de leitões nascidos vivos e pelo peso vivo dos leitões ao nascimento, enquanto a ETl é influenciada pelo peso vivo dos leitões aos sete dias e pelo ganho de peso vivo da leitegada. Há relação significativa entre espessura de toicinho e variáveis de condição corporal de porcas gestantes e lactantes.<br>A meta-analysis was carried out to evaluate the association between backfat thickness and sow body condition in gestation and lactation. The database assembled 14 publications from 2000 to 2006. The meta-analysis was accomplished by graphical analysis, correlation, and analysis of variance. The correlation between backfat thickness (BT) and body weight was 0.16 (P<0.01), with protein mass was 0.48 (P<0.01) and leptin concentration was 0.88 (P<0.01). The correlation between the backfat variation during and in lactation (VBTl) and body weight was -0.21 (P<0.01), with body weight variation in lactation was 0.34 (P<0.01) and with fat mass variation in lactation was 0.70 (P<0.01). The correlation between BT and born alive litter size was 0.46 (P<0.01), between VBTl and piglets body weight at seven days of age was 0.95 (P<0.01). In the gestation, the BD was influenced by the body weight and protein mass. However, in lactation the VBTl was influenced by the body weight variation and fat mass. The leptin concentration at farrowing was positively correlated with backfat depth. The BT was influenced by born alive litter size and piglets birth weight. The VBTl was influenced by piglets weight at seven days old and litter weight gain. In conclusion, there is a significant relation between backfat thickness and body variables of the sows in gestation and lactation