Lactation body condition loss impaired conceptus development and plasma progesterone concentration at day 8 post-ovulation in primiparous sows.

The current study investigated effects of dietary amino acid (AA) availability on lactational body condition loss and metabolic status, in relation to reproductive parameters after weaning up to Day 8 post-ovulation. Primiparous sows (n = 35) were allocated to one of two lactation diets containing either low crude protein (CP, 140 g/kg) with a low percentage (8%) of slow protein in total protein (LL, n = 18) or high CP (180 g/kg) with a high (16%) percentage of slow protein (HH, n = 17). The HH diet was expected to improve AA utilization by supplying more AA, in a more gradual fashion. The diets did not affect sow body condition loss during lactation, while the HH diet tended to increase litter weight gain during the week 3 of lactation (Δ = 1.3 kg, P = 0.09). On Day 14 post-farrowing, HH diet led to higher plasma urea both pre-feeding and post-feeding (Δ = 2.3 mmol/L, P < 0.01, Δ = 2.4 mmol/L, P < 0.01, respectively), whilst plasma creatinine, NEFA and IGF-1 were similar. No dietary effects on reproductive parameters were found, however several relationships were found between body condition and reproductive parameters. Sows with higher body weight on Day 1 or Day 21 post-farrowing had greater follicle size on Day 3 post-weaning (ß = 0.03 mm/kg, P < 0.01, ß = 0.04 mm/kg, P < 0.01, respectively). At Day 8 post-ovulation, plasma progesterone concentration was negatively related to loin muscle loss (ß = -0.67 ng/ml · mm-1, P = 0.02), backfat loss (ß = -2.33 ng/ml · mm-1, P = 0.02), and estimated body fat loss (ß = -0.67 ng/ml · mm-1, P = 0.02). Both plasma progesterone and the number of corpora lutea were positively related to the energy balance during lactation (ß = 0.03 ng/ml · ME MJ-1, P = 0.01, ß = 0.01 CL/ME MJ, P = 0.02, respectively). The conceptus size at Day 8 post-ovulation was negatively related to body weight loss (ß = -0.01 mm/kg, P = 0.01), estimated body fat loss (ß = -0.02 mm/kg, P = 0.03) and estimated body protein loss (ß = -0.06 mm/kg, P = 0.04), and was positively related to the energy balance during lactation (ß = 5.2*10-4 mm/ME MJ, P = 0.01). In conclusion, body protein and fat losses during lactation reduced subsequent plasma progesterone concentration and conceptus development at Day 8 post-ovulation.

Weaned piglets prefer feed with hydroxychloride trace minerals to feed with sulfate minerals.

The aim of this study was to determine whether newly weaned piglets had a preference for diets containing hydroxychloride trace minerals (HTM). To test this, two preference tests were set up. In Exp. 1, the piglets could choose between HTM or inorganic, originating from sulfate trace minerals (STM) in the form of sulfates. Two treatments were applied with high Cu levels (160 ppm Cu added) or low Cu levels (15 ppm Cu added). All diets contained 110 ppm added Zn from the same source as Cu in the respective diet. The pigs could choose between a diet with hydroxychloride Cu and Zn or with Cu and Zn originating from sulfates at the same mineral levels. The piglets were included in the study from weaning until 34 d after weaning. In Exp. 2, the piglets could also choose between HTM and STM. However, automated feeding stations were used to collect individual feed intake data. Similarly two treatments were applied, one with high Cu levels (160 ppm added Cu) and one with slightly lower Cu levels (140 ppm added Cu until 28 d after weaning, thereafter 15 ppm added Cu). All diets contained 110 ppm added Zn from the same source as Cu in the respective diet. The piglets were followed until 35 d after weaning. The current studies showed that when piglets were given a choice, they preferred diets with HTM. This effect resulted only in a significant (P < 0.05) preference for HTM at high dietary Cu levels (160 ppm) ranging from 76% to 81% in the first and second week of Exp. 1 to between 53.4% and 57.8% in the overall experiment period of Exp. 2. This preference was less pronounced at levels of 140 ppm added or less. Individual feed intake and gain measurements did not show any link between the preference and the performance.

The Course of Parturition Affects Piglet Condition at Birth and Survival and Growth through the Nursery Phase.

The aim of this study was to relate the course of parturition to the condition of piglets at birth, based on umbilical cord blood acid-base values, and relate the condition at birth to neonatal survival and performance up to 10 weeks of life. Data were collected from 37 spontaneous unassisted parturitions, and neonatal performance was based on observations of 516 piglets. Stillbirth rate increased from 2% in the first piglets, to 17% in piglets born 13th in the litter or later. This was aggravated in sows with longer than average stage II of parturition. Umbilical cord blood values also reflected the effect of birth order, with pH decreasing and lactate increasing in the course of parturition. Interestingly, sows that had a long expulsion stage of parturition also took longer to give birth to the first four piglets (r = 0.74), suggesting that sows with complicated parturition were already experiencing problems at the start of expulsion of piglets. Piglets with signs of asphyxia, based on umbilical blood lactate higher than 4.46 mmol/L, were slower to start suckling, had a higher risk of neonatal mortality, and had a slower growth rate over the first 10 weeks of life.