Production effects of extruded soybean meal replacing canola meal in the diet of lactating dairy cows.

This study investigated the effects of extruded soybean meal (ESBM) in comparison with canola meal (CM) fed on an equivalent crude protein (CP) basis on lactational performance and ruminal fermentation of dairy cows. Following a 2-wk covariate period, 48 Holstein cows averaging (±SD): 146 ± 46 d in milk (DIM) and 43 ± 7 kg/d milk yield (MY) were assigned 1 of 2 treatment diets in a randomized complete block design experiment, which included a 2-wk period for dietary treatment adaptation before experimental data were collected. Following the adaptation period, samples and experimental data were collected for a total of 7 wk. Cows were blocked based on parity, DIM, and MY. Treatment diets contained 15.8% CM (containing 41.2% CP) or 13.2% ESBM (with 48.7% CP) of total mixed ration dry matter (DM), with similar inclusion of other feed ingredients. The CM diet was supplemented with canola oil, whereas the ESBM diet was supplemented with soybean hulls to achieve similar ether extract and neutral detergent fiber contents between the diets. Urea and rumen-protected Met and Lys were added to both diets to meet or exceed cow recommendations. Whole-ruminal digesta samples were collected from 10 (5 per treatment) ruminally cannulated cows. Eight cannulated cows were removed during the last week of the experiment to participate in another study. Treatment did not affect DM intake and MY or energy-corrected MY of the cows. Energy-corrected MY, apart from experimental wk 5, was similar between treatments. Apart from experimental wk 3 and 7, milk fat concentration and yield were greater for cows fed ESBM compared with CM. In multiparous cows only, milk true protein yield was greater for cows fed CM compared with ESBM. Ruminal concentration of total volatile fatty acids and the molar proportion of acetate were greater for ESBM, and propionate and valerate were greater in cows fed CM. Acetate to propionate ratio was greater for cows fed ESBM versus CM diet. Compared with the CM diet, the ESBM diet increased plasma concentrations of Ile, Leu, and Phe but not the sum of essential AA. Apparent total-tract digestibility of acid detergent fiber was greater in cows fed ESBM relative to CM. In this experiment, CM and ESBM included on an equal CP basis in the diet of dairy cows, resulted in similar DM intake, MY, and feed efficiency.

Lactational performance, enteric gas emissions, and plasma amino acid profile of dairy cows fed diets with soybean or canola meals included on an equal protein basis.

This study investigated the effects of feeding solvent-extracted canola meal (CM), extruded soybean meal (ESBM), or solvent-extracted soybean meal (SSBM) on an equivalent crude protein basis on performance, plasma AA profiles, enteric gas emissions, milk fatty acids, and nutrient digestibility in lactating dairy cows. Fifteen Holstein cows (95 ± 20 d in milk) were used in a replicated 3 × 3 Latin square design experiment with 3 periods of 28 d each. Treatments were 3 diets containing 17.1% CM, 14.2% ESBM, or 13.6% SSBM (dry matter basis). Vegetable oil was added (canola oil for CM or soybean oil for SSBM) to equalize the ether extract concentration of the diets. Rumen-protected Met was supplemented targeting digestible Met supply of 2.2% of metabolizable protein in all diets. Canola meal increased dry matter intake (DMI) by 5.9 and 8.9% in comparison with ESBM and SSBM, respectively. Milk urea nitrogen was lowest in CM, followed by SSBM, and was highest for ESBM. No differences were observed in feed efficiency, energy-corrected milk yield, and milk composition or component yields among treatments. Cows fed CM emitted less enteric CH4 per kg of DMI compared with both ESBM and SSBM, but CH4 emission intensity (CH4 per kg of energy-corrected milk) was similar among treatments. In summary, replacement of ESBM or SSBM with CM, on an equal crude protein basis, in the diet of lactating dairy cows enhanced DMI, but yields of energy-corrected milk and milk components and feed efficiency were similar among treatments.

Production effects of feeding extruded soybean meal to early-lactation dairy cows.

The objective of this experiment was to evaluate productive and reproductive effects of replacing solvent-extracted soybean meal (SSBM) with extruded soybean meal (ESBM) in a total mixed ration for early-lactation dairy cows. Thirty-four Holstein cows (12 primiparous and 22 multiparous) were used in a randomized complete block design experiment with 17 cows per treatment. Feeding was ad libitum for 5 to 10% refusals. A fresh-cow diet was fed the first 21 d in milk followed by a lactation diet from 22 to 60 d in milk. Milk and dry matter intake data were collected throughout the experiment, and samples were collected for blood chemistry and amino acid profile, nutrient digestibility, nitrogen utilization, and enteric methane emission using the GreenFeed system (C-Lock Inc., Rapid City, SD). Dry matter intake, milk yield, and feed efficiency were not different between SSBM and ESBM. Energy-corrected milk yield and efficiency were also not different between diets. Diet had no effect on milk composition, except that milk true protein yield was decreased by ESBM. Enteric methane emission, yield, and intensity were not different between SSBM and ESBM. Because of its greater fat content, ESBM triggered expected changes in milk fatty acid (FA) profile: decreased sum of C16, saturated, and odd- and branched-chain FA and increased sum of preformed FA, polyunsaturated, and trans FA. The ESBM diet increased or tended to increase some essential amino acids in plasma. In this study, ESBM did not affect dry matter intake and did not improve lactational performance or onset of ovarian function in early-lactation dairy cows, and it decreased milk protein yield, possibly due to greater unsaturated FA intake compared with SSBM.

Effect of high-oleic-acid soybeans on production performance, milk fatty acid composition, and enteric methane emission in dairy cows.

The objective of this study was to investigate the effect of 3 soybean sources differing in fatty acid profile and processing method on productivity, milk composition, digestibility, rumen fermentation, and enteric methane emission in lactating dairy cows. The soybean sources were conventional, high-linoleic-acid variety extruded soybean meal (ESBM; 8.7% ether extract with 15% oleic and 54% linoleic acids); extruded Plenish (DuPont Pioneer, Johnston, IA), high-oleic-acid variety soybean meal (EPSBM; 8.4% ether extract with 73% oleic and 8% linoleic acids); and whole, heated Plenish soybeans (WPSB; 20.2% ether extract). The study involved 15 Holstein cows in a replicated 3 × 3 Latin square design experiment with three 28-d periods. The inclusion rate of the soybean sources in the diet was (dry matter basis) 17.1, 17.1, and 7.4% for ESBM, EPSBM, and WPSB, respectively, which resulted in ether extract concentration of the diets of 3.99, 3.94, and 4.18%, respectively. Compared with ESBM, the Plenish diets tended to increase dry matter intake and decreased feed efficiency (but had no effect on energy-corrected milk feed efficiency). The Plenish diets increased milk fat concentration on average by 5.6% and tended to increase milk fat yield, compared with ESBM. The WPSB diet tended to increased milk true protein compared with the extruded soybean meal diets. Treatments had no effect on rumen fermentation and enteric methane or carbon dioxide emissions, except pH was higher for WPSB versus EPSBM. The Plenish diets decreased the prevalence of Ruminococcus and increased that of Eubacterium and Treponema in whole ruminal contents. Total-tract apparent digestibility of organic matter and crude protein were decreased by WPSB compared with ESBM and EPSBM. Compared with the other treatments, urinary N excretion was increased by EPSBM and fecal N excretion was greater for WPSB. Treatments had marked effects on milk fatty acid profile. Generally, the Plenish diets increased mono-unsaturated (mostly cis-9 18:1) and decreased polyunsaturated, total trans-, and conjugated linoleic fatty acids concentrations in milk fat. In this study, compared with conventional, high-linoleic-acid variety extruded soybean meal, the Plenish soybean diets increased milk fat concentration and tended to increase fat yield, decreased feed efficiency, and modified milk fatty acid profile in a manner expected from the greater concentration of oleic acid in Plenish soybean oil.

Extruded soybean meal increased feed intake and milk production in dairy cows.

The objective of this study was to assess the effects of 2 extruded soybean meals (ESBM) processed at 2 extruder temperatures, 149°C (LTM) and 171°C (HTM), on performance, nutrient digestibility, milk fatty acid and plasma amino acid profiles, and rumen fermentation in lactating dairy cows. Nine multiparous Holstein cows were included in a replicated 3×3 Latin square design experiment with three 28-d periods. The control diet contained 13% solvent-extracted soybean meal (SSBM; 53.5% crude protein with 74.1% ruminal degradability and 1.8% fat), which was replaced with equivalent amount (dry matter basis) of LTM (46.8%, 59.8%, and 10.0%) or HTM (46.9%, 41.1%, and 10.9%, respectively) ESBM in the 2 experimental diets (LTM and HTM, respectively). The diets met or exceeded the nutrient requirements of the cows for net energy of lactation and metabolizable protein. The 2 ESBM diets increased dry matter intake and milk yield compared with SSBM. Feed efficiency and milk composition were not affected by treatment. Milk protein yield tended to be increased by ESBM compared with SSBM. Milk urea N and urinary urea N excretions were increased by the ESBM diets compared with SSBM. Concentration of fatty acids with chain length of up to C17 and total saturated fatty acids in milk fat were generally decreased and that of C18 and total mono- and polyunsaturated fatty acids was increased by the ESBM diets compared with SSBM. Blood plasma concentrations of His, Leu, and Val were increased by HTM compared with LTM and SSBM. Plasma concentration of Met was decreased, whereas that of carnosine was increased by the ESBM diets. Treatments had no effect on rumen fermentation, but the proportion of Fibrobacter spp. in whole ruminal contents was increased by HTM compared with SSBM and LTM. Overall, data from this crossover experiment suggest that substituting SSBM with ESBM in the diet has a positive effect on feed intake and milk yield in dairy cows.

Effects of long-term estrogen implants in beef heifers.

Crossbred beef heifers (n = 78) were assigned randomly to one of three treatments. Heifers received either no implant, one estradiol-releasing implant (Compudose), or two estradiol-releasing implants. Heifers were implanted at birth and then reimplanted every 150 d. Calves were maintained with the cows until weaning at approximately 200 d of age. Heifers were placed in the feedlot as one group and fed a growing diet for 56 d. Following the growing phase, heifers were segregated into their respective treatment groups and fed until selected by industry buyers for harvest. Beginning at 1 yr of age and continuing every 14 d until puberty or harvest, heifers were palpated per rectum, and blood samples were collected for determination of ovarian activity and attainment of puberty. Serum progesterone of > or =1 ng/mL and(or) palpation of a detectable corpus luteum were criteria of puberty. At weaning and again at harvest, an x-ray was taken of the left front leg of six heifers selected randomly from each group. Metacarpal bones III and IV from the same animals were collected at harvest and transected for determination of epiphyseal plate closure. The x-ray scores and the actual measurements had a correlation of .94. Epiphyseal plate closure occurred in a dose-related manner, with heifers on the higher dose of estrogen having earlier plate closure than heifers on the lower dose. At harvest, reproductive tissues and carcass data were collected for all heifers. Eighteen of 25 untreated control heifers (P < .05), 6 of 26 heifers treated with one implant, and 2 of 26 heifers treated with two implants attained puberty by the end of the experiment. No differences (P > .10) were detected among treatment groups for carcass traits. These data suggest that early and continuous treatment of heifers with estradiol implants can retard reproductive function.

Milk yield by Dorset ewes as affected by sibling status, sex and age of lamb, and measurement.

Milk intake (sucking-test weight) by 55 Dorset lambs and milk production (oxytocin-hand milking) by 41 Dorset ewes were measured at 2-wk intervals during the first 8 wk of lactation. Each method indicated that milk yield by ewes was greater at 2 and 4 wk of lactation than at 6 and 8 wk. Daily milk intake by a set of twins (suckling-test weight) was similar to 24-h milk production of their dam (oxytocin-hand milking) when lambs were 2, 4, 6, and 8 wk of age. At 2, 4, and 6 wk postpartum, milk production by ewes nursing single lambs was 200 to 400 g greater than milk intake by lambs due to a larger residual milk. Stage of lactation had a significant effect on protein and fat content of milk but not on lactose. Sex of offspring had no effect on milk yield or protein, fat, and lactose content of milk. Lactose was one percentage unit greater in milk of ewes nursing single lambs; however, the amount of lactose secreted daily was similar for ewes nursing single or twin lambs. Twenty-four-hour milk production by the ewe as determined by the oxytocin-hand milking method was correlated with lamb growth (.67 to .86), with milk intake, as determined by the suckling-test weight method, the next most important variable. Milk composition contributed little toward modeling lamb growth.

Effect of docking on health, blood cells and metabolites and growth of Dorset lambs.

Docking by knife or elastrator had no sustained effect on growth of lambs 0 to 8 wk postpartum. However, during the 2 wk period postdocking, growth of lambs was limited or depressed, regardless of whether lambs were docked by knife at 14, 28 or 42 d of age. Blood hematocrit and hemoglobin were decreased (P less than .01) 1 d after docking by knife and 14 d after docking by elastrator. Neither method of docking proved superior. Regardless of whether lambs were docked by knife or elastrator, tail tissue was destroyed and became necrotic. Numbers of white blood cells increased (P less than .01) in response to docking. This necessitates that lambs be observed often through 2 wk postdocking and that medical treatment be administered when needed.