The effect of nutrition on the reproductive performance of first-litter sows 4. The relative effects of energy and protein intakes during lactation on the performance of sows and their piglets

Abstract

Eighty-eight first-litter sows were used in a factorial experiment to examine the effects of energy and protein intakes during lactation on subsequent performance. Some received either 45 MJ (E,) or 60 to 63 MJ (E 2 ) digestible energy per day and either 508 to 511 (P,) or 703 to 815 (P 2 ) g crude protein per day during a 28-day lactation.Sows on the E 2 P 2 treatment lost less body weight during lactation than sows on the other three treatments (P < 0-05). Average live-weight losses during lactation were 21-8, 20-8, 17-8 and 9-6 kg for the E^,, EiP 2 , E 2 P, and E 2 P 2 sows, respectively. The corresponding reductions in backfat measurements during lactation were 5-5, 7-9, 3-2 and 4-0 mm. Backfat losses were greater for sows given either moderate energy intakes or high protein intakes (P < 0-01).Neither protein intake nor energy intake during lactation affected subsequent ovulation rate, but piglets sucking sows given high protein intakes grew faster, particularly during the last week of lactation, than piglets sucking sows receiving low protein intakes (P < 0-05).Within 8 days of weaning, more sows given high intakes of protein during lactation exhibited oestrus than did sows which received lower intakes of protein (27/44 v. 14/44, x 2 = 7-7, P < 0-01). Protein intake during lactation affected the nitrogen balance of sows in a similar way. The nitrogen balances were estimated during the 3rd week of lactation, and for sows given rations E,P,, E,P 2 , E 2 P, and E 2 P 2 were -20-2, -11-5, -17-5 and -7-2 g/day respectively.

Dietary protein restriction during lactation in primiparous sows with different live weights at farrowing: I. Consequences on sow metabolic status and litter growth

“…Low protein intake during lactation amplifies muscle protein mobilization [3][4][5]. It may compromise milk production in primiparous sows [4,6,7], but this effect of dietary protein restriction during lactation on litter growth is not always observed [8]. Such discrepancies between experiments could be explained by restriction intensity or by differences in sow body weight.…”

Effect of feeding supplemental fat or lysine during the postweaning period on the reproductive performance of sows with low or high lactation body weight and fat losses

“…Restricted feeding (King and Williams 1984a) and a low intake of energy (Reese et al 19821, Nelssen et al 1985) or protein (King and Williams 1984b;King and Dunkin 1986) during lactation can increase weight and backfat loss in sows. The current trend of selecting gilts with a lower backfat thickness and breeding at a younger age may lead to insufficient reserves of nutrients and excessive body weight loss during lactation which may result in the postweaning reproductive problems described above.…”

“…Feeding higher lysine levels during lactation has been shown to reduce the weaning-to-estrus interval in first-parity sows (King and Dunkin 1986 …”

Efeito da ventilação natural e mecânica sobre o desempenho de porcas em lactação

“…ferenças existentes no condicionamento térmico entre os tratamentos não foram suficientes para provocar alterações na resposta animal. A temperatura retal média diária (TR) manteve-se, em todos os tratamentos, dentro do limite de 38,6 ± 0,8°C referido por Carvalho (1982) King & Dunkin (1986) como nível crítico para ocorrência de efeitos deletérios sobre a reprodução, respectivamente. No entanto, a ingestão diária de proteína durante o verão (678, 610 e 626 g PB/dia) foi inferior aos 700 g PB/dia consideradas por King & Williams (1984) como o nível de efeito positivo para a indução do estro, mas superior no inverno (738, 731 e 757 g PB/dia, respectivamente).…”