Effects of winter and spring housing on growth performance and blood metabolites of Pengbo semi-wool sheep in Tibet

The Effects of Housing on Growth, Immune Function and Antioxidant Status of Young Female Lambs in Cold Conditions

Cold conditions in northern China during winter may reduce sheep growth and affect their health, especially if they are young, unless housing is provided. We allocated 45 two-month-old female lambs to be housed in an enclosed building, a polytunnel, or kept outdoors, for 28 days. The daily weight gain and scalp and ear skin temperature of outdoor lambs were less than those of lambs that were housed in either a house or polytunnel; however, rectal temperature was unaffected by treatment. There was a progressive change in blood composition over time, and by the end of the experiment, outdoor lambs had reduced total antioxidant capacity (T-AOC), catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) and increased malondialdehyde compared to those in the house or polytunnel. In relation to immune responses in the lambs' serum, in the polytunnel, immunoglobulin A (IgA), tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) were higher and immunoglobulin G (IgG) lower compared with the concentrations in lambs that were outdoors. Over the course of the experiment, genes expressing heat shock proteins and antioxidant enzymes increased in lambs in the outdoor treatment, whereas they decreased in lambs in the indoor treatments. It is concluded that although there were no treatment effects on core body temperature, the trends for progressive changes in blood composition and gene expression indicate that the outdoor lambs were not physiologically stable; hence, they should not be kept outdoors in these environmental conditions for long periods.

Effects of Allium mongolicum Regel supplementation on the digestibility, methane production, and antioxidant capacity of Simmental calves in northwest China

This study evaluated the effects of Allium mongolicum Regel (AM) supplementation on nitrogen (N) balance, ruminal fermentation, and antioxidant properties. Sixteen male calves were assigned randomly to four groups, and the four were added with 0 (CON), 200 mg/kg (body weight; BW) (Low AM; LA), 400 mg/kg (BW) (Middle AM; MA), or 800 mg/kg (BW) (High AM; HA) per day for each individual. AM was added on dry matter (DM) basis. The experiment lasted for 58 days. Supplementation of AM could significantly increase average daily gain, DM digestibility, acid detergent fiber digestibility, and retained N/Intake N. N digestibility and molar proportion of propionate in the MA and HA treatments were higher than that in the CON treatment (p < .05), respectively. AM supplementation significantly increased the molar concentration of total volatile fatty acid in the rumen fluid (p < .05). The ratio of acetate to propionate in the MA and HA groups was lower than that in the CON treatment (p < .05). Furthermore, AM supplementation significantly reduced methane (CH₄ ) (p < .05) emissions. AM supplementation significantly increased the activities of superoxide dismutase. The MA group could significantly increase the activities of glutathione peroxidase and decrease the content of malondialdehyde. Our results indicated that AM supplementation could affect the nutrient digestibility, CH₄ emission, and antioxidant capacity of Simmental calves.

Optimising grazing for livestock production and environmental benefits in Chinese grasslands

Overgrazing has extensively degraded Chinese grasslands. A reduction in stocking rate of 30–50% below the district averages is required to increase the profitability of livestock production and protect vital ecosystem services such as mitigation of greenhouse gases (GHG). Grazing experiments located in the desert steppe, typical steppe and alpine meadow verified the influence of stocking rate and grazing management on livestock production, grassland composition and associated ecosystem services. The desert steppe experiment found lower stocking rates of ~150 SE (where SE is sheep equivalent, which is a 50kg animal) grazing days ha–1 (1 SE ha–1 over 150 days) enhanced botanical composition, maintained profitable lamb growth rates and reduced GHG emissions intensity. The typical steppe experiment found moderate grazing pressure of ~400 SE grazing days ha–1 (4 SE ha–1 over 100 days) maintained higher lamb growth rates, an average herbage mass &gt;0.5t DM ha–1 that maintained the content of Leymus chinensis above 70% and Artemisia frigida below 10% of the grassland and had the highest level of net carbon sequestration. In the alpine meadow experiment the district average stocking rate of ~16 SE ha–1 (1440 SE grazing days ha–1 over 90 days) was not too high, but extending grazing into the non-growing season had no benefit. The findings of these experiments highlight that many of the benefits to ecosystem services can be achieved with reduced stocking rates which also generate profitable levels of livestock production. In both the desert and typical steppe experiments, the results were optimal when the stocking rates were adjusted to maintain average herbage mass over summer above ~0.5t DM ha–1, whereas herbage mass was higher with the local, conservative stocking rates in the alpine meadow.

Variations in serum metabolites in response to season, cyclicity, and pregnancy in estrus-synchronized Damascus goats

The current study was carried out to determine the changes in serum electrolytes, liver enzymes, and hormones during breeding and non-breeding seasons in estrus-synchronized goats. Forty goats (n = 40) were synchronized by inserting the sponges intravaginally for 12 days; PMSG and PGF₂α were injected on day of sponge removal. Blood samples were collected from the goats at the time of sponges insertion (day -12), estrus day (day 0), and at 15 day after sponge withdrawal (day 15). The blood samples were analyzed for glucose, cholesterol (CHO), aspartate aminotransferase (AST), alanine aminotransferase (ALT), thyroid stimulating hormone (TSH), triiodothyronine (T₃), thyroxine (T₄) and progesterone (P₄), calcium (Ca), phosphate (PO₄), magnesium (Mg), sodium (Na), potassium (K), and chlorine (Cl) levels. Repeated measurements ANOVA of general linear model were used as statistical model. The results showed that seasons have an effect (p < 0.05) on glucose, Ca, Na, K, Cl, CHO, T₃, and T₄ levels. There was an effect (p < 0.05) of cyclicity only on P₄ level. Whereas, nonpregnant, or goats carrying singlet and twin fetuses have shown variation (p < 0.05) in glucose, Ca, and P₄ levels. Although, the correlations existed between different serum metabolites but strong correlations (p < 0.05) were observed either between Ca and Na or T₃ and T₄. In conclusion, the serum electrolytes and liver enzymes are correlated with hormones during the different seasons, pregnancy status, and fecundity. In recommendation, the results of the study could be as managemental tool to monitor the reproductive activity across seasons and to maintain pregnancy carrying twining in goat breeds.