In this study, the content of chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) in domestic and imported infant formulas from Beijing, China were analyzed using inductively coupled plasma mass spectrometry. The content of Cr, As, Cd and Pb was 2.51–83.80, 0.89–7.87, 0.13–3.58 and 0.36–5.57 μg/kg, respectively. Even though there were no significant differences in toxic elements content between domestic and imported infant formulas, Cd content was slightly lower in domestic samples. The estimated daily intake (EDI), target hazard quotient (THQ) and hazard index (HI) were calculated for infants between 0.5 and 5 y of age. The EDIs were lower than the oral reference doses. THQ of As, Cr, Cd and Pb was 0.027–0.103, 0.024–0.093, 0.0025–0.0090 and 0.0015–0.0046, respectively. HI values were 0.055–0.192 for boys and 0.056–0.209 for girls and were inversely associated with age with a threshold < 1. The non-carcinogenic risk value were in the safe range, indicating that exposure of As, Pb, Cr and Cd from infant formulas do not represent a health risk in China.

Maize silage has a significant environmental impact on livestock due to its high requirement for fertilizer and water. Mulberry has the potential to replace much of the large amount of maize silage grown in China, but its feeding value in the conserved form needs to be evaluated. We fed Hu lambs diets with 20–60% of the maize silage replaced by mulberry silage, adjusting the soybean meal content when increasing the mulberry silage inclusion rate in an attempt to balance the crude protein content of the diets. Mulberry silage had higher crude protein and lower acidic and neutral detergent fiber contents compared to maize silage. Replacing maize silage and soyabean meal with mulberry silage had no effect on the feed intake and growth rate of Hu lambs. However, the rumen pH increased, the acetate to propionate in rumen fluid increased, and the rumen ammonia concentration decreased as mulberry replaced maize silage and soyabean meal. This was associated with an increase in norank_f__F082 bacteria in the rumen. Rumen papillae were shorter when mulberry silage replaced maize silage, which may reflect the reduced neutral detergent fiber (NDF) content of the original silage. In conclusion, mulberry silage can successfully replace maize silage and soyabeans in the diet of Hu lambs without loss of production potential, which could have significant environmental benefits.

Maize silage has a high demand for fertilizer and water. As an unconventional feed resource, mulberry silage has the potential to replace most maize silage and to alleviate the shortage of roughage in the mutton sheep industry in China. The purpose of this experiment was to study the effect of the replacement of maize silage and soyabean meal with mulberry silage in the diet of Hu lambs on growth performance, serum biochemical indices, slaughter performance, and meat quality. Ninety-six healthy Hu lambs were randomly divided into four groups with six replicates per group and four lambs per replicate. The amounts of 0, 20, 40, and 60% of maize silage were replaced by mulberry silage in each group (denoted as CON, L, M, and H, respectively). The results showed that replacing maize silage with mulberry silage had no significant effect on the growth performance or the slaughter performance of Hu lambs (p > 0.05). Feeding Hu lambs with mulberry silage significantly reduced serum glucose (GLU) and the blood urea nitrogen (BUN) content (p < 0.05), and it increased the content of ether extract (EE) in the longissimus dorsi muscle (p < 0.05). Meanwhile, the percentage of EAA in the M and H groups was significantly lower than that in the CON and L groups (p < 0.05). In addition, in the fatty acid profile, the percentage of C16:1 in the M group was significantly increased, while the percentage of C18:0 and C20:0 were significantly decreased (p < 0.05). Based on these findings, it was recommended that 20–40% of maize silage be replaced by mulberry silage in the diet of Hu lambs.

In recent years, high levels of hormone residue in food, capable of damaging the health of consumers, have been recorded frequently. In this study, 195 raw milk samples were obtained from Tangshan City, China, and the concentrations of 22 steroid hormones were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Cortisol was detected in 12.5% of raw milk samples (mean 0.61 µg/kg; range: <limit of quantification (LOQ)–0.94 µg/kg). Progesterone was detected in 85.9% of raw milk samples (mean 5.12 µg/kg; range: <LOQ–9.04 µg/kg). The concentration of cortisol present in milk was lower than the maximum residue limit defined in Japan (10 µg/kg). Children aged between one and five years were expected to be the at-risk population when exposed to detectable steroid hormone concentrations. Based on the mean and maximum concentrations of progesterone detected in milk, the contribution was 0.85% and 0.9%, and 1.48% and 1.6% of the acceptable daily intake for boys and girls, respectively. These results imply that the concentrations of steroid hormones present in raw milk should not present a health risk for young children.

To fill the gap in systematic data on mineral contents and their dietary contributions in four mainstream dairy products (sterilized, pasteurized, fermented, modified milk) from Henan Province, China, this study aimed to characterize the mineral profiles [magnesium (Mg), iron (Fe), zinc (Zn), selenium (Se), copper (Cu)] and clarify the mineral nutritional disparities between domestic and imported sterilized milk. A total of 150 samples were analysed via inductively coupled plasma mass spectrometry (ICP-MS). Results revealed significant mineral content differences across dairy types: fermented milk had significantly lower Mg and Zn than sterilized and pasteurized milk (p < 0.05). Imported sterilized milk exhibited higher Mg (160.10 ± 31.88 mg/kg) than domestic counterparts (147.41 ± 32.47 mg/kg, p < 0.05). In terms of mineral intake contribution rates (defined as the percentage of mineral intake from dairy products relative to the Recommended Nutrient Intake (RNI), unit: %), the rates are ranked in descending order as follows: Se (11.68–25.32%) > Mg (11.11–20.76%) > Zn (5.88–16.33%) > Cu (0.62–1.81%) > Fe (0.25–1.00%). This study elucidates the mineral profiles of Henan’s dairy products, supporting residents’ dairy choices and optimisation of dairy processing technologies.