Citrate, calcium, phosphate and magnesium in sows' milk at initiation of lactation

Analysis of Faecal pH in Piglets from Birth to Weaning

The health of the gastrointestinal system of pigs is still a topical issue. When focusing on the youngest categories of pigs, we routinely evaluate it on the basis of appetite assessment and physical examination of faeces. A piglet’s gut health is also related to the development and changes of pH in the digestive system. Because there is little scientific work in this area, the aim of this study was to evaluate the physiological range of faecal pH in healthy suckling piglets from birth to weaning. Faecal pH measurements were performed in thirty-five suckling piglets at the time of the piglets’ birth, on the 7th, 14th, 21st, and 28th day of their life. We found the mean pH values to be 6.38 ± 0.46 within 24 hours after birth; 7.14 ± 0.23 on the 7th day after birth; 7.23 ± 0.23 on the 14th day after birth; 7.42 ± 0.60 on the 21st day after birth; and 7.72 ± 0.61 on the 28th day after birth. Statistical analysis showed significant differences between the pH of the faeces of new-born piglets and the samples taken in the following weeks of the experiment (P < 0.05; P < 0.01; P < 0.001). Measuring faecal pH can be a simple, quick and inexpensive method used to determine the health status of piglets’ intestines.

Lowering dietary cation-anion difference increases sow blood and milk calcium concentrations

A study was conducted to evaluate the effects of feeding an acidogenic diet with a low dietary cation-anion difference (DCAD) on acid-base balance, blood, milk, and urine Ca concentrations of sows during lactation. A total of 30 multiparous sows (parity: 4.5 ± 2.9, Smithfield Premium Genetic, Rose Hill, NC) were allotted to 1 of 2 dietary treatments: CON (control diets were corn-soybean meal based with a calculated DCAD of 170 and 226 mEq/kg during late gestation and lactation, respectively) or ACI (acidogenic diets had a DCAD 100 mEq/kg lower than the control diets). The lower DCAD was achieved by the addition of an acidogenic mineral. The DCAD was calculated as mEq (Na + K - Cl)/kg diet. Sows had a daily access to 2-kg feed from day 94 of gestation to parturition and ad libitum access to feed during lactation. Blood and urine pH and Ca, serum macrominerals, serum biochemistry, Ca-regulating hormones, and milk composition were measured. Sows in ACI had a lower (P < 0.05) blood pH than sows in CON at day 1 of lactation. Sows in ACI had a lower (P < 0.05) urine pH at day 108 of gestation, days 1, 9, and 18 of lactation compared with sows in CON. Sows in ACI had greater (P < 0.05) concentrations of serum total Ca at days 1 and 18 of lactation than sows in CON. There was a greater (P < 0.05) concentration of colostrum Ca in ACI than in CON. There was no difference in urine Ca concentration between treatments during lactation. Concentrations of parathyroid hormone and 1,25-dihydroxycholecalciferol were not different between treatments at either day 1 or 18 of lactation. Sows in ACI tended to have a smaller (P = 0.086) concentration of total alkaline phosphatase in serum at day 18 of lactation compared with sows in CON. At day 1 of lactation, the concentration of serum Cl in ACI was greater (P < 0.05) than that in CON. Feed intake, BW loss, and litter performance were not different between treatments. Collectively, feeding an acidogenic diet with a low DCAD to sows can induce a mild metabolic acidosis at farrowing, reduce the urine pH consistently, and increase serum total Ca and colostrum Ca concentrations during lactation but without altering the parathyroid hormone and 1,25-dihydroxycholecalciferol levels during lactation.

Bioinformatics and Gene Network Analyses of the Swine Mammary Gland Transcriptome during Late Gestation

We used the newly-developed Dynamic Impact Approach (DIA) and gene network analysis to study the sow mammary transcriptome at 80, 100, and 110 days of pregnancy. A swine oligoarray with 13,290 inserts was used for transcriptome profiling. An ANOVA with false discovery rate (FDR < 0.15) correction resulted in 1,409 genes with a significant time effect across time comparisons. The DIA uncovered that Fatty acid biosynthesis, Interleukin-4 receptor binding, Galactose metabolism, and mTOR signaling were among the most-impacted pathways. IL-4 receptor binding, ABC transporters, cytokine-cytokine receptor interaction, and Jak-STAT signaling were markedly activated at 110 days compared with 80 and 100 days. Epigenetic and transcription factor regulatory mechanisms appear important in coordinating the final stages of mammary development during pregnancy. Network analysis revealed a crucial role for TP53, ARNT2, E2F4, and PPARG. The bioinformatics analyses revealed a number of pathways and functions that perform an irreplaceable role during late gestation to farrowing.

A lactational study of the composition and integrity of casein micelles from the milk of the tammar wallaby (Macropus eugenii)

The amount of casein found in the milk of the tammar wallaby increases as lactation progresses. The increase is due to increasing amounts of beta-casein; the alpha-casein remains largely constant. The alpha-casein is the more highly phosphorylated; the most abundant form is the 10-P, throughout lactation. The level of phosphorylation of beta-casein shifts to lower average values in late lactation, possibly indicating the enzymatic reaction is overloaded by the increasing amounts of beta-casein. Unlike bovine casein micelles, the wallaby micelles are not completely disrupted at pH 7.0 by sequestration of their calcium content with ethylene diamine tetraacetic acid (EDTA). Complete disruption only follows the addition of sodium dodecyl sulphate, indicating considerably greater importance for hydrophobic bonds in maintaining their integrity. This micellar behaviour indicates that, despite the evolutionary divergence of marsupials millennia ago, the caseins of wallaby milk assemble into micelles in much the same fashion as in bovine milk.