Mosnier E, Dourmad J-Y, Etienne M, Le Floc'h N, Père M-C, Ramaekers P, Sève B, Van Milgen J, Meunier-Salaün M-C
Institut National de la Recherche Agronomique, UMR1079 SENAH, F-35000 Rennes, France.
J Anim Sci. 2009 Apr;87(4):1282-91. doi: 10.2527/jas.2008-1009. Epub 2008 Dec 19.
Voluntary feed intake in sows after parturition may be related to the capacity of the sow to cope with the numerous changes occurring around farrowing. This experiment was undertaken to investigate whether the feed intake during lactation was related to the reactivity of the sow during gestation and plasma Trp and cortisol concentrations. On d 58 of pregnancy, 37 sows were individually placed in a novel environment, and their behavior was observed during a 5-min open-field test. This test allowed the selection of 12 reactive (R) and 8 nonreactive (NR) sows for the study. Sows were fed 3 kg of a standard gestation diet/d before farrowing and a standard lactation diet ad libitum thereafter. The behavioral reactivity of sows when a human touched their neck in the farrowing crate was evaluated on d 72 of gestation, and their behavior during farrowing was analyzed. Sows were catheterized on d 70 of gestation, and blood samples were taken after an overnight fast on d 37 before farrowing, daily during the week before and the week after parturition, and on d 14 and 21 of lactation for plasma Trp and cortisol determination. The NR sows were less reactive to human contact (P=0.02), had a shorter farrowing duration (P=0.02), and tended to have a shorter birth interval between piglets (P=0.09) than the R sows. Feed intake was greater for the NR sows than for the R sows during wk 1 of lactation (P=0.02), as well as during the whole lactation (P=0.03). Plasma cortisol concentration was maximal on the day after farrowing (P=0.01) and returned to basal concentration within 4 d postpartum. No relationship was observed between sow behavior and plasma concentration of cortisol. For both groups of sows, plasma concentrations of Trp between d 2 and 4 postpartum were less than during gestation (P<0.05). The NR sows had decreased plasma Trp concentrations compared with the R sows during wk 1 of lactation (P=0.02). A low reactivity during gestation was associated with behavior of the sow that was favorable to piglet survival during farrowing, increased feed intake, and decreased plasma Trp concentration during wk 1 of lactation. Further research is needed to elucidate whether Trp or Trp metabolites are related to reactivity and ADFI of the reproducing sow.
母猪产后的自愿采食量可能与母猪应对分娩前后发生的众多变化的能力有关。本试验旨在研究泌乳期采食量是否与妊娠期母猪的反应性以及血浆色氨酸和皮质醇浓度有关。在妊娠第58天，将37头母猪单独置于一个新环境中，并在5分钟的旷场试验中观察它们的行为。通过该试验挑选出12头反应性（R）母猪和8头非反应性（NR）母猪用于研究。分娩前，母猪每天饲喂3千克标准妊娠日粮，此后自由采食标准泌乳日粮。在妊娠第72天评估母猪在分娩栏中被人触摸颈部时的行为反应性，并分析其分娩期间的行为。在妊娠第70天给母猪插入导管，在分娩前第37天禁食过夜后、分娩前一周和分娩后一周每天以及泌乳第14天和21天采集血样，用于测定血浆色氨酸和皮质醇。与R组母猪相比，NR组母猪对人接触的反应性较低（P = 0.02），产程较短（P = 0.02），且仔猪出生间隔有缩短趋势（P = 0.09）。在泌乳第1周（P = 0.02）以及整个泌乳期（P = 0.03），NR组母猪的采食量均高于R组母猪。血浆皮质醇浓度在分娩后第一天最高（P = 0.01），并在产后4天内恢复到基础浓度。未观察到母猪行为与血浆皮质醇浓度之间的关系。对于两组母猪，产后第2至4天的血浆色氨酸浓度均低于妊娠期（P < 0.05）。在泌乳第1周，NR组母猪的血浆色氨酸浓度低于R组母猪（P = 0.02）。妊娠期反应性较低与母猪在分娩期间有利于仔猪存活的行为、采食量增加以及泌乳第1周血浆色氨酸浓度降低有关。需要进一步研究以阐明色氨酸或色氨酸代谢产物是否与繁殖母猪的反应性和平均日采食量有关。
