Evaluation of closed adult nucleus multiple ovulation and embryo transfer and conventional progeny testing breeding schemes for milk production in tropical crossbred cattle

The potential benefits of closed adult nucleus multiple ovulation and embryo transfer (MOET) and conventional progeny testing (CNS) schemes, and the logistics of their integration into large-scale continuous production of crossbred cattle were studied by deterministic simulation. The latter was based on F1 (Bos taurus x Bos indicus) production using AI or natural mating and MOET, and continuous F2 production by mating of F1 animals. The gene flow and the cumulative discounted expressions (CDES) were also calculated. Both schemes had 8, 16, 32, or 64 dams with 2, 4, 8, 16, or 32 sires selected. In the MOET nucleus scheme (MNS), the test capacity was 1, 2, 8, or 16 offspring, and the number of matings per dam per year was 1, 2, or 4. A scheme of 8 sires with 64 dams and a test capacity of 4 female offspring per dam per year resulted in an annual genetic gain (in phenotypic standard deviation) of 0.324 and 0.081 for MNS and CNS, respectively. In the MNS, there was substantial genetic gain with a relatively small number of animals compared with a CNS. The F1 had the highest, and the F2 scheme the lowest CDES. However, a very large number of B. indicus females would be required in the F1 scheme. This scheme may not be practical under conditions in developing countries. The F2 scheme was logistically attractive because it produces its own replacements, and the number of B. taurus females required would be easy to attain. Accompanying technical and financial constraints of nucleus schemes should be addressed before applying them.     

Characterization of days dry for United States Holsteins

This research characterized days dry (DD) for modern US Holsteins. This included investigation of factors influencing DD, summarizing variation in herd means as well as within-herd variation, and estimation of parameters related to DD. Data consisted of records initiated before 2003 from cows first calving after 1996. A total of 459,075 records from 295,067 cows in 3527 herds were included. The overall mean DD was 60.5 d, and standard deviation among herd means was 5.8 d. Approximately 91% of all herds had mean DD between 50 and 70 d. There were 41 herds that had mean DD of < or =45 d and 2 herds with mean DD of < or =30 d. Some herds (125) had unusually long mean DD (exceeding 71 d). Variation across regions of the United States was minimal, although southwestern herds did show somewhat longer DD than other regions. Days open (DO) accounted for the most variation in DD with longer DO leading to longer dry periods. Heritability of DD was 7% and repeatability 12%. Error correlations indicated that longer dry periods benefit both milk yield and somatic cell score in the subsequent lactation. Genetic and permanent environmental correlations were large, which indicated that 1) bias would result if genetic evaluations for milk yield included an adjustment for DD, and 2) correction for cow effects is warranted in estimation of DD effects on performance. The relationship between DD and DO is due primarily to permanent cow effects. Improved fertility will enhance the feasibility of shortened dry periods.     

Milk production from Holstein half udders after concurrent thirty- and seventy-day dry periods

The objective of this study was to use a within-cow, half-udder model to compare the effect of cessation of milk removal from mammary quarters within respective half udders at either 30 or 70 d before expected calving date (ECD) on the ability of the half udders to subsequently produce milk. Pregnant Holstein cows were assigned to control (n = 14) or treatment (TRT, n = 26) groups. All mammary quarters in the udder of cows in the control group had 70-d (68 ± 9 d) dry periods, whereas in each cow of the TRT group, 1 randomly selected half udder was dried at 70 d before ECD and the other half udder continued to be milked twice daily until dried at 30 d before ECD. From 80 through 70 d before ECD, amounts of milk produced by the left and right half udders of cows in the TRT group were measured at the first-shift milking. No differences were detected in the actual or relative amounts of milk produced by the left (3.46 ± 0.2 kg; 48.8 ± 1.0%) and the right (3.63 ± 0.2 kg; 51.2 ± 1.0%) half udders. Furthermore, the actual and relative amounts of milk produced by the half udders (n = 12 left, 14 right) subsequently dry for 67 ± 7 d (3.56 ± 0.2 kg; 50.2 ± 1.0%) and the half udders (n = 14 left, 12 right) subsequently dry for 27 ± 7 d (3.54 ± 0.2 kg; 49.8 ± 1.0%) did not differ before they were dried. However, from 3 to 100 d of the subsequent lactation, the 30-d dry half udders produced 18.9% less milk than the 70-d dry half udders (16.3 vs. 20.1 ± 1.0 kg/d). In addition, relative amounts of total-udder milk produced by the 30- and 70-d dry half udders in the same cow differed (44.9 vs. 55.1 ± 0.2%, respectively). Cows in the control group produced more milk than cows in the TRT group through 80 DIM (39.5 vs. 35.2 ± 0.6 kg/d), but not from 3 through 150 DIM (39.0 vs. 36.2 ± 1.6 kg/d). Thus, half udders that produced the same actual and relative amounts of milk before being dried did not do so when given a 30-d dry period instead of a 70-d dry period. When compared with the pre-dry value (49.8%), the relative contribution of half udders dry for 30 d to the total milk yield during the first 100 DIM was decreased by 9.8%.     

Effects of dietary cation-anion difference on intake, milk yield, and blood components of the early lactation cow

Early lactation Holsteins cows (15 primiparous and 18 multiparous) were offered rations with dietary cation-anion difference, calculated as mEq (Na + K − Cl − S)/100 g of feed dry matter (DCAD:S), of 20, 35, or 50 mEq from d 0 (calving) to 42 d postpartum (August 20, 2000 to January 9, 2001) to determine the effects of increasing DCAD:S on dry matter intake (DMI), milk yield, and blood metabolites. For DCAD:S of 20, 35, and 50, DMI was 3.30, 3.38, 2.96 kg/100 kg of body weight (BW); milk yield was 25.5, 24.2, and 22.4 kg/d, respectively. No differences were observed for concentration or yield of milk fat or milk protein. Serum Ca, P, Mg, Na, K, Cl, cation-anion difference, insulin, and glucose did not differ with DCAD. Serum HCO₃⁻ was 26.07, 25.88, and 27.64 mEq/L for 20, 35, and 50 DCAD:S. Serum Ca, Mg, Na, and K concentrations were greater for primiparous cows (9.52 mg/dL, 2.35 mg/dL, 140.03 mEq/L, 4.66 mEq/L, respectively) than for multiparous cows (9.27 mg/dL, 2.12 mg/dL, 137.63 mEq/L, 4.46 mEq/ L, respectively). A DCAD:S between 23 and 33 mEq/ 100 g of dry matter (DM) appears to be adequate during cool weather for the milk yield that occurred in the present study based on DMI (kg/100 kg of BW), whereas DCAD:S of 50 mEq/100 g of DM may be excessive and could be too alkaline or unpalatable, resulting in decreased DMI (kg/100 kg of BW).     

Method for evaluation of the efficacy of antimicrobial preservatives in cosmetic wet wipes

Many cosmetic formulations are now available in the form of wet wipes packaged in sealed sachets or packets. Like the majority of cosmetic products having an aqueous phase, wipes are susceptible to microbial contamination and require the addition of preservatives. The efficacy of such preservatives can be evaluated using a standard challenge test performed on the wetting liquid but this test cannot be regarded as representative for this new type of formulation. The method presented here evaluates the efficacy of preservatives used in wet wipes kept in their original packaging. Dried inoculums were prepared by membrane filtration followed by drying in an incubator. The method is applicable to bacteria (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis), Bacillus cereus spores and fungi (Candida albicans and Aspergillus niger). These inoculated carriers were inserted between two wipes in the original package, which was then re-sealed immediately. The test requires one dry inoculum per packet and one packet for each control or test. After incubation at 22.5 degrees C for 1, 2, 7, 14 or 28 days and, for the control, immediately after insertion of the membrane (time 0), microorganism counts were performed on the germ-carrier membranes as well as on adjacent wipes, after transfer into a suitable neutralizing agent. The membranes were shaken in the presence of glass beads and microorganisms were dissociated from the wipes by means of a Stomacher. The supernatants recovered after being left to stand for 20 min are counted by pour plate method or membrane filtration. The feasibility of the method was demonstrated for each of the seven above-mentioned strains. The repeatability and reproducibility of the results obtained is similar to that obtained for preservative efficacy tests in the Pharmacopoeias. The lethal rate of microorganisms during the preparation of dry inoculums ranges from 50 to 90% depending on the strain and the test (generally, a spontaneous reduction of about 1 log up to a maximum of 2 log). The recovery rate for microorganisms from dry inoculums (on membranes) at time 0 (control = T(0)) is around 90%, regardless of the strain or the test. The number of microorganisms recovered from the wipes (W(0)) is between 2 and 10% of the number recovered from membranes (T(0)) and may be considered negligible. Application of this method to different types of wipes demonstrates that the efficacy of preservatives, expressed as the logarithmic reduction in the number of microorganisms at each time point, depends on the type of wipe and on the strain tested. The results obtained are considerably different from those found with the standard challenge tests applied to wetting liquids for wipes. The differences found confirm the need for a specific method applicable to wipes.     

食品胶协同干热处理对马铃薯淀粉理化特性的影响

为了改善马铃薯淀粉加工特性,选用瓜尔胶、羧甲基纤维素钠和黄原胶3种食品胶分别与马铃薯淀粉复配后进行干热处理,研究食品胶协同干热处理对马铃薯淀粉糊化、老化和流变特性的影响.研究发现,中3种食品胶协同干热处理均能够降低糊化温度与糊化焓,并且均能增强淀粉体系稳定性,使其呈现出弹性流体性质,不仅如此还均能提高淀粉糊热稳定性以及...     

不同橡木片处理对马瑟兰干红葡萄酒品质的影响

该试验以酿酒葡萄马瑟兰为原料,研究在葡萄酒发酵中期不同烘烤度和添加量的橡木片对葡萄酒品质的影响,通过检测酒样理化指标、酚类物质及CIELab颜色参数确定最佳处理。结果表明,橡木片烘烤度的增加对葡萄酒中酚类物质含量以及颜色优化有积极作用,而无烘烤度的橡木片对花色苷含量无积极影响,随橡木片添加量的增加有类似作用,且对颜色影响大于烘烤度的变化,其中添加2 g/L中度烘烤橡木片效果最佳,酒样的单宁、总酚、总花色苷含量分别提高38.60%、10.60%、10.28%;a*值、b*值分别提升12.02%、67.90%。     

The effect of Lolium perenne L. ploidy and Trifolium repens L. inclusion on dry matter intake and production efficiencies of spring-calving grazing dairy cows

The objective of this study was to investigate the effect of perennial ryegrass (Lolium perenne L.; PRG) ploidy and white clover (Trifolium repens L.) inclusion on milk production, dry matter intake (DMI), and milk production efficiencies. Four separate grazing treatments were evaluated: tetraploid PRG only, diploid PRG only, tetraploid PRG with white clover, and diploid PRG with white clover. Individual DMI was estimated 8 times during the study (3 times in 2015, 2 times in 2016, and 3 times in 2017) using the n-alkane technique. Cows were, on average, 64, 110, and 189 d in milk during the DMI measurement period, corresponding to spring, summer, and autumn, respectively. Measures of milk production efficiency were total DMI/100 kg of body weight (BW), milk solids (kg of fat + protein; MSo)/100 kg of BW, solids-corrected milk/100 kg of BW, and MSo/kg of total DMI. Perennial ryegrass ploidy had no effect on DMI; however, a significant increase in DMI (+0.5 kg/cow per day) was observed from cows grazing PRG-white clover swards compared with PRG-only swards. Sward white clover content influenced DMI as there was no increase in DMI in spring (9% sward white cover content), whereas DMI was greater in summer and autumn for cows grazing PRG-white clover swards (+0.8 kg/cow per day) compared with PRG-only swards (14 and 23% sward white clover content, respectively). The greater DMI of cows grazing PRG-white clover swards led to increased milk (+1.3 kg/cow per day) and MSo (+0.10 kg/cow per day) yields. Cows grazing PRG-white clover swards were also more efficient for total DMI/100 kg of BW, solids-corrected milk/100 kg of BW, and MSo/100 kg of BW compared with cows grazing PRG-only swards due to their similar BW but higher milk and MSo yields. The results highlight the potential of PRG-white clover swards to increase DMI at grazing and to improve milk production efficiency in pasture-based systems.     

谷朊粉对马铃薯热干面品质的影响

为提高马铃薯热干面的品质和稳定性,该文在分析谷朊粉基本成分与物化特性的基础上,深入研究了谷朊粉添加量对混合粉特性及对生鲜及熟制马铃薯热干面蒸煮、质构、贮藏等品质特性的影响.结果表明,随着混合粉中谷朊粉含量升高,其持水性下降,吸水膨胀性上升.随着谷朊粉添加量的增加,马铃薯热干面吸水性呈下降趋势、蒸煮损失率呈先上升后下降变...