J B Cheng

Chinese Academy of Agricultural Sciences, Peping, Beijing, China

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Publications (6)10.04 Total impact

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    ABSTRACT: Radix Bupleuri extract (RBE) has been shown to mitigate negative effects of high ambient temperature. This experiment was conducted to investigate effects of RBE supplementation on lactation performance and rumen fermentation in Holstein cows under heat stress. Forty Holstein cows (75 ± 15 d in milk, 37.5 ± 1.8 kg of milk/d, and 1.7 ± 0.4 parity) were randomly assigned to one of four groups (n = 10). One of four treatment diets, assigned randomly to one of four groups, consisted of RBE supplementation at 0, 0.25, 0.5 or 1.0 g/kg of the basal diet (concentrate and roughage) based on dry matter (DM). Cows were housed in a tie-stall barn and were individually fed the treatment diets. The experiment lasted for 10 wk in hot summer. During the experiment, average ambient temperatures and temperature-humidity indexes (THI) were respectively 27.5 ± 1.5, 29.8 ± 1.9 and 28.1 ± 1.7 °C, and 78.2 ± 2.7, 79.8 ± 3.3 and 78.3 ± 3.4 at 0600, 1400 and 2200 h. Average respiration rates (RR) with RBE at 0.25, 0.50 and 1.0 g/kg were 65.6, 60.3 and 67.4, respectively, vs. 71.4 (breaths/min) for the control (P < 0.01). Average rectal temperatures (RT) were 39.1, 39.0 and 39.1 vs. 39.3 °C for the control (P < 0.01). Moreover, cows supplemented with RBE increased dry matter intake (DMI, 22.8, 21.6 and 22.1 vs. 20.9 kg/d) (P < 0.05) and milk production (34.2, 33.4 and 32.4 vs. 31.6 kg/d) (P < 0.01) compared with control. Percentages of milk protein and fat were similar among groups, while milk protein yield increased with increasing level of RBE (0.97, 0.95 and 0.92 vs. 0.89 kg/d for the control) (P < 0.01). Milk fat yield also increased with RBE (1.13, 1.12 and 1.09 vs. 1.02 kg/d for the control) (P < 0.05). There was no treatment effect on diet apparent digestibility or volatile fatty acid (VFA) concentration among groups. Overall, supplemental RBE at 0.25 or 0.5 g/kg could mitigate the negative effects of heat stress on production in lactating Holstein cows.
    Animal Feed Science and Technology 01/2014; 187:1–8. · 1.61 Impact Factor
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    ABSTRACT: This experiment was conducted to investigate the effects of rumen-protected γ-aminobutyric acid (GABA) on performance and nutrient digestibility in heat-stressed dairy cows. Sixty Holstein dairy cows (141 ± 15 d in milk, 35.9 ± 4.3 kg of milk/d, and parity 2.0 ± 1.1) were randomly assigned to 1 of 4 treatments according to a completely randomized block design. Treatments consisted of 0 (control), 40, 80, or 120 mg of true GABA/kg of dry matter (DM). The trial lasted 10 wk. The average temperature-humidity indices at 0700, 1400, and 2200 h were 78.4, 80.2, and 78.7, respectively. Rectal temperatures decreased linearly at 0700, 1400, and 2200 h with increasing GABA concentration. Supplementation of GABA had no effect on respiration rates at any time point. Dry matter intake, energy-corrected milk, 4% fat-corrected milk, and milk fat yield tended to increase linearly with increasing GABA concentration. Supplementation of GABA affected, in a quadratic manner, milk protein and lactose concentrations, and milk protein yield, and the peak values were reached at a dose of 40 mg of GABA/kg. Milk urea nitrogen concentration responded quadratically. Total solids content increased linearly with increasing GABA concentration. Supplementation of GABA had no effect on milk yield, lactose production, total solids, milk fat concentration, somatic cell score, or feed efficiency. Apparent total-tract digestibilities of DM, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber were similar among treatments. These results indicate that rumen-protected GABA supplementation to dairy cows can alleviate heat stress by reducing rectal temperature, increase DM intake and milk production, and improve milk composition. The appropriate supplemental GABA level for heat-stressed dairy cows is 40 mg/kg of DM.
    Journal of Dairy Science. 01/2014;
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    ABSTRACT: A new antigen-release device (ARD) that can be implanted to enhance the titer of specific IgG and concentration of total IgG in milk of lactating cows was evaluated. An immunostimulating complex-based vaccine in the core of the ARD was made from the adjuvant Quil A and type XIII lipase from Pseudomonas spp. with a polylactide acid capsule that was used to control antigen release. Forty lactating Holstein dairy cows were divided into 2 groups (n = 20). All cows in the test group were implanted in the right iliac lymph node with 3 types of ARD at the same time, which were designed to release antigens on different days. The other group was used as a control with no implantation. The 3 ARD were designed to release the antigen on d 0, 14, and 28 after implantation. Specific IgG titers in whey and serum were measured by indirect ELISA, and total IgG concentrations were measured using sandwich ELISA. The results indicated that ARD implantation brought no negative effects on the health status, production performance of cows, and caused neither subclinical nor acute mastitis. The levels of specific IgG in serum (200,000 +/- 45,000 vs. 1,200 +/- 360) and whey (41,000 +/- 6,000 vs. 820 +/- 210) increased in the cows implanted with ARD. Specific IgG in whey was increased after 9 d. The dynamics of specific IgG titer demonstrated a pattern with the release of the antigen from 3 types of ARD. The average ELISA titer of test group in whey was 41,000 +/- 6,000, which suggested high efficiency of immune milk production caused by the ARD implantation. For total IgG in milk, greater concentration in the test compared with the control cows occurred from 11 to 20 d following implantation. The IgG mass was consistent with the dynamics of specific IgG titer and was higher from 15 to 30 d between test and control group (7.89 +/- 1.34 vs. 6.48 +/- 1.17 g). In conclusion, ARD implantation was effective in improving specific antibody concentration in serum and whey. Furthermore, the whey:serum ratio of specific IgG titer, the milk:serum ratio of total IgG concentration and total IgG mass in milk suggested that a transiently upregulated IgG transfer occurred after ARD implantation.
    Journal of Dairy Science 02/2009; 92(1):100-8. · 2.57 Impact Factor
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    ABSTRACT: Immunoglobulin (Ig) G1 concentrations in milk from Holstein cows was measured to determine if transfer and concentration was influenced by production factors (lactation number, stage of lactation, daily milk production), milk composition (milk fat, protein, lactose, and total solids content) or by serum IgG1 concentration. Two hundred and ninety-nine Chinese Holstein cows were randomly selected from four herds containing a total of more than 1600 lactating animals. The concentration of IgG1 in the milk and serum was determined by ELISA. Milk IgG1 concentrations varied between 0.030 and 0.614 mg/mL and significantly correlated with lactation number, stage of lactation, daily milk production and somatic cell count. The IgG1 mass was found to highly correlate with lactation number, stage of lactation, daily milk production and milk protein content. Lactation number had the highest positive direct relationship with IgG1 concentration.
    The Veterinary Journal 08/2008; 182(1):79-85. · 2.42 Impact Factor
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    ABSTRACT: The objective of this study was to evaluate the effect of implanting an Antigen Release Devices (ARD) into dairy cows during the lactation cycle to induce an immune response. Subsequently, the concentrations of lactoferrin in serum and milk were measured. Forty healthy adult Chinese Holstein cows were divided into two equal groups: a test group and a control group. Animals in the test group received ARD implants, whereas the control group animals were not treated. An even spread across the two groups was maintained with animal selection based on parity, the lactation days and milk yields. The concentrations of lactoferrin in the serum and milk of all forty animals were measured using an Enzyme-Linked Immunosorbent Assay (ELISA). The results show that the implantation of an ARD did not significantly increase the concentration of lactoferrin in the serum and milk throughout the whole experiment period except on two occasions. The levels of lactoferrin in the milk and serum significantly increased on day 7 and on day 11 after implantation (p<0.05). There was a strong correlation between milk lactoferrin and serum lactoferrin (r=0.564, P<0.01). Three separate ARDs were used releasing its antigen load on day 0, 14 and 28 to induce a primary, secondary and tertiary response respectively. As the significant increases in the lactoferrin levels were only observed after the first ARD release, the effects of lactoferrin appears to be associated with the early phase of the immune response, consistent with its role in the host's innate defense system.
    Journal of Veterinary Medical Science 08/2008; 70(8):819-24. · 0.88 Impact Factor
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    ABSTRACT: Lactoferrin (LF) concentrations in the milk with different levels of the somatic cell count score were examined using an ELISA to determine whether milk LF concentration is influenced by parity of the cow, stage of lactation, and the somatic cell count. The study animals were 198 Chinese Holstein cows randomly chosen from more than 1,600 cows in 4 dairy farms in the Beijing area. The cows had shown no sign of mastitis for 2 mo. Daily milk production was recorded, and milk samples were taken from individual cow samples. The LF concentration varied between 31.78 and 485.63 microg/mL in milk from normal animals. Lactoferrin was significantly associated with stage of lactation (r = 0.557) and daily milk production (r = -0.472). Nevertheless, there was no significant relationship with parity. Moreover, milk LF concentration tended to be correlated with the somatic cell count score (r = 0.375). This finding suggests that milk LF may be helpful as an indicator for intramammary infection in dairy cows.
    Journal of Dairy Science 04/2008; 91(3):970-6. · 2.57 Impact Factor