The incorporation of carbonate has been recognized as an evident change in bone mineral (bioapatite) during aging. Laying hens (Gushi layer) at 4 stages of age (8 hens each stage) were studied by Raman spectroscopy and X-ray radiography to investigate the mineralogical changes and bone density, respectively. Cortical bones of the humerus and femur show a rapid increase of carbonate (∼1.9 wt.%) from sexual maturity to the peak of hens' laying period, while the densities of the cortical bones are relatively stable. Before sexual maturity, the density of the cortical bones increases considerably during aging. However, after the peak of the laying period, only femoral density continues elevating. Carbonate contents in the cortical bones reach the maximum at the peak of the laying period. Two pathways (halted growth of density and Ca-release due to the CO incorporation) could both contribute to the intense Ca requirement for egg laying. Crystallization, however, has no significant changes during aging and the laying period. This study could shed light on the mechanism of mineral losses due to CO incorporation, and also shows the advantages of Raman spectroscopy in tracking mineral loss in poultry bone.

This study was conducted to investigate the potential effects of prolonged photoperiod on the serum lipids, carcass traits, and meat quality of Jinjiang cattle during winter. Methods: Thirty-four Jinjiang bulls aged between 14 and 16 months were randomly assigned to two groups that were alternatively subjected to either natural daylight +4 h supplemental light (long photoperiod, LP) or natural daylight (natural photoperiod, NP) for 96 days. The potential effects on the levels of serum lipids, carcass traits, meat quality, and genes regulating lipid metabolism in the intramuscular fat (IMF) of the cattle were evaluated. Results: Jinjiang cattles kept under LP showed significant increase in both dry matter intake (DMI) and backfat thickness. the serum glucose (Glu) and the plasma leptin levels were significantly reduced, while that of melatonin and insulin were observed to be increased. The crude fat contents of biceps femoris muscle and longissimus dorsi muscle were higher in LP than in NP group. In longissimus dorsi muscle, the proportions of C17:0 and C18:0 were significantly higher but that of the C16:1 was found to be significantly lower in LP group. The relative mRNA expressions in IMF of longissimus dorsi muscle, the lipid synthesis genes(proliferator-activated receptor gamma, PPAR γ; fatty acid-binding protein,FABP4) and the fatty acid synthesis genes(Acetyl-coa carboxylase, ACACA; fatty acid synthetase, FASN; A c c e p t e d A r t i c l e 1-acylglycerol-3-phosphate acyltransferase, AGPAT) were significantly up-regulated in LP group(P < 0.05); whereas the hormone-sensitive lipase(HSL) and stearoyl-CoA desaturase 1(SCD1) were significantly down-regulated in LP than in NP group. Conclusion: Prolonged photoperiod significantly altered the growth performance, hormonal levels, gene expression and fat deposition in Jinjiang cattle. It suggested that the LP improved the growth performance and fat deposition by regulating the levels of different hormones and genes related to lipid metabolism, thereby improving the fattening of Jinjiang cattle during winter.

This study aimed to explore the dynamic variations in fermentation characteristics, bacterial diversity and community composition at two preservation temperatures as preservation time extended. Six rumen fluid samples collected from high-grain feeding sheep were stored at −20 °C or −80 °C for 0 day, 7 days, 14 days, 30 days, 60 days, 120 days, and 240 days. The results showed that the current preservation temperature did not alter the fermentation characteristics, bacterial diversity and community composition (p > 0.05). The concentrations of ammonia, microbial crude protein, acetate, propionate, butyrate, valerate, and total volatile fatty acids were higher when stored at 60 days (p < 0.05). Preservation time had no influence on bacterial richness and evenness (p > 0.05), whilst the relative abundances of Bacteroidota and Prevotella were numerically higher when stored at 30 days, and the opposite results were observed regarding Firmicutes. Both principal co-ordinates analysis (PCoA) and non-metric multidimensional scaling (NMDS) showed clusters among treatments in terms of preservation time and preservation temperature. Analysis of similarities (ANOSIM) also revealed similarities between treatments (p > 0.05). This study indicates that most fermentation characteristics in rumen fluid were altered after a 60-day preservation, whilst the preservation time for rumen bacterial community profile alteration was 30 days. It is recommended to finish the sample determination of rumen fluid within 30 days. This study may assist decision-making regarding the practicable time for rumen fluid determination, as well as viable preservation conditions for inoculum used for in vitro fermentation testing.