A blend of animal and cereal protein or fish meal as partial replacement for soybean meal in the diets of lactating Holstein cows

Effects of different polyunsaturated fatty acid supplementations during the postpartum periods of early lactating dairy cows on milk yield, metabolic responses, and reproductive performances

In spite of the difficulties in delivering PUFA to ruminants, studies have generally indicated that the PUFA of the omega-6 (linoleic acid) and omega-3 [α-linolenic acid; eicosapentaenoic (EPA), C20:5 omega-3; docosahexaenoic (DHA), C22:6 omega-3] families are the most beneficial to improving reproduction in cows. The objectives were to determine if a diet enriched in α-linolenic acid (omega-3) or linoleic acid (omega-6) would influence milk production and composition, metabolic status, and reproductive performance in lactating dairy cows. High-yielding multiparous Holstein dairy cows (n = 120) with no overt clinical illnesses were blocked according to calving date and parity. Cows were assigned randomly to be fed 1) soybean whole roast (Soy, omega-6, n = 40) or 2) linseed (Lin, omega-3, n = 40) or 3) palm oil as a source of SFA (PO, n = 40) from calving until first heat after 40 d postpartum (dpp), and then half of the cows in each treatment group were switched to receive either Lin or SFA (PO) from first heat after d 40 to 120 dpp. Blood was collected from a subsample of cows. Blood was collected at 14 d intervals for 12 wk, starting on the day of calving. Results showed milk yield and DMI were not affected. Milk compositions were similar (P > 0.08) among diets, except concentration and yield of milk fat percentage, which was less in cows fed Lin (P < 0.05). Uterine involution in cows fed Soy occurred earlier (P < 0.05). Diets affected day to first estrus and day to first insemination in cows (P < 0.05). There were no differences among treatments for percent heat detection, percent pregnancy per first insemination, and percent conception per AI at estrus. Also, there is a trend of pregnancy by 120 d, which is 66.7% for the Lin group vs. 50.91% for the PO group (P < 0.08). Of the 4 pregnancy losses, 2 occurred in PO-PO group and 2 occurred in Soy-PO group, and none occurred in the other 4 treatments. In conclusion, our study showed feeding omega-6 fatty acids during 40 dpp could be a good treatment for early postpartum periods, and a shift to omega-3 fatty acids until 40 d after AI can be considered as a strategy for improving fertility in lactating dairy cows.

Ruminal degradability and lysine bioavailability of soybean meals and effects on performance of dairy cows

Evaluations of 4 soybean meal (SBM) products were conducted in 3 experiments. The 4 products were 1) solvent SBM (SSBM), 2) SSBM treated with 0.05% baker's yeast and toasted at 100 degrees C (YSBM), 3) expeller SBM (ESBM), and 4) lignosulfonate-treated SBM (LSBM). Multiparous Holstein cows (n = 32; 152 +/- 63 d in milk; body weight = 708 +/- 77 kg; producing 41 +/- 7 kg/d of milk at the beginning of the study) were used in a 4 x 4 Latin square design with 28-d periods to investigate cow responsiveness to supplemental ruminally undegradable protein (RUP) from the SBM products. Dietary treatments were formulated by substituting all of the SSBM and part of the ground corn with YSBM, ESBM, or LSBM to yield isonitrogenous diets. Diets were formulated to provide adequate ruminally degradable protein, but deficient RUP and metabolizable protein supplies. No differences among dietary treatments were observed for dry matter intake, body weight gain, milk and component yields, or efficiency of milk production. The lack of response to changes in SBM source was likely due to an adequate RUP and metabolizable protein supply by all the diets. In situ ruminal degradations of YSBM and LSBM were slower than those of SSBM or ESBM; thus, RUP contents of YSBM and LSBM were greater than those of SSBM or ESBM. The RUP of all SBM products had similar small intestinal digestibility. Available Lys contents, estimated chemically or by using a chick growth assay, were less for YSBM and LSBM than for SSBM or ESBM, suggesting deleterious effects of processing on Lys availability in YSBM and LSBM.

Effects of Feeding Fish Meal and n-3 Fatty Acids on Milk Yield and Metabolic Responses in Early Lactating Dairy Cows

The study was designed to test the effects of feeding fish meal (FM) and specific n-3 fatty acids on milk yield and composition, dry matter intake, plasma concentrations of metabolic hormones and metabolites, and liver triglyceride accumulation in early lactating cows. From 5 to 50 d in milk (DIM), cows were fed diets that were isonitrogenous, isoenergetic, and isolipidic containing none (control), 1.25, 2.5, or 5% menhaden FM or 2.3% Ca salts of fish oil fatty acids (CaFOFA). Milk yield (48.2, 49.8, 48.6, 53.5, and 52.2 +/- 1.0 kg/d, respectively) and dry matter intake (22.7, 22.8, 23.0, 23.8, and 24.7 +/- 0.5 kg/d, respectively) differed among diets. Average daily plasma glucose concentration (53.4, 55.3, 51.1, 57.6, and 57.3 +/- 1.3 mg/dL, respectively) was also affected by diet, and plasma insulin concentration was increased by 5% FM and 2.3% Ca-FOFA. At 25 and 50 DIM, blood was collected before feeding and hourly for 11 h after feeding. Plasma glucose concentrations in cows during the day were similar among diets at 25 DIM, but differed at 50 DIM (54.6, 54.4, 52.4, 60.5, and 58.3 +/- 1.4 mg/dL for 0, 1.25, 2.5, and 5% FM or 2.3% CaFOFA, respectively). Plasma insulin was increased in cows fed 5% FM and 2.3% CaFOFA at 25 DIM and was similar among diets at 50 DIM. Dietary treatments had no significant effect on milk composition, energy balance, or on daily plasma concentrations of nonesterified fatty acids, beta-hydroxybutyrate, and urea. Plasma aspartate aminotransferase and hepatic triglyceride concentration in cows did not differ among diets at 21 DIM. Results from this experiment demonstrate that dietary supplementation with FM or n-3 polyunsaturated fatty acids in early lactating dairy cows significantly increased milk yield and DMI with no change in milk composition.

Impacts of the source and amount of crude protein on the intestinal supply of nitrogen fractions and performance of dairy cows

The objective of this article was to review and summarize the significance of the amount and source of dietary crude protein supplements on the supply of nitrogen fractions passing to the small intestine and the performance of lactating dairy cows. A meta-analysis was used to evaluate 2 data sets, one for nitrogen flow to the small intestine and one for performance of cows. The response of dairy cows to rumen-undegradable protein supplements is variable. A portion of this variable response from research trials is explained by the source of crude protein in the control diet, the proportion and source of rumen-undegradable protein in the experimental diet, the effect of rumen-undegradable protein on microbial protein outflow from the rumen, the degradability and amino acid content of the rumen-undegradable protein, and the crude protein percentage of the diet. Compared with soybean meal, the mean milk production responses to feeding rumen-undegradable protein supplements ranged from -2.5 to +2.75%. Because of the large variation and small magnitude of response when rumen-undegradable protein supplements are fed compared with soybean meal, efficiency of nitrogen utilization and the cost to benefit ratio for these crude protein supplements may determine the source and amount of crude protein to feed to dairy cows in the future.

Effects of inclusion of a blended protein product in 35 dairy herds in five regions of the country

We assessed the change in milk production in 35 dairy herds located in eight states when a blended animal-marine protein product was included in diets at 2 (22 herds) to 4% (13 herds) of dry matter. Average 305-d production across herds was 8844.1 kg (SEM = 153.7 kg) of milk, with a range of 6876.9 to 11,293.2 kg. The mean days in milk for all herds at initiation of the trial was 118.8 d (SEM = 3.7, herd mean range of 68.8 to 160.0 d), and the average daily milk production was 32.6 kg (SEM = 0.6 kg, range 24.2 to 39.6 kg). The animal-marine protein blend was included in herd rations for 30 d, beginning immediately after a DHI herd test month and ending immediately after the next DHI sample test. Cow milk records were collected for 1 to 2 mo before the protein blend was included and for 2 to 3 mo after the protein was removed. Sample days were assigned a dummy variable to indicate months off or on the animal-marine protein blend. A total of 33,190 milk records from 7135 cows were analyzed. The numbers within herd ranged from 35 to 2012 cows. Of the 35 herds, 19 were classed as having increased milk yield, 12 herds as having no change, and 4 herds as having decreased milk yield when the animal-marine protein blend was included in the diet. The population mean for change in milk yield with the inclusion of the animal-marine protein blend was 1.24 kg/d of milk (SEM = 0.05 kg). There was no significant effect of parity on mean response. Milk protein content was not influenced by animal-marine protein blend inclusion. Fat content was lower for the month on which the animal-marine protein blend was fed (3.51%) compared with the month prior (3.63%) and the month after (3.70%), respectively (SEM = 0.032). Stage of lactation influenced the method for calculating the production response and the actual response to the animal-marine protein blend.

Evaluation of ruminally protected methionine and lysine or blood meal and fish meal as protein sources for lactating Holsteins

Forty lactating Holstein cows averaging 55 days in milk were used in a randomized block designed experiment to evaluate the effectiveness of ruminally protected Met and Lys compared with that of ruminally undegradable protein for supporting lactation. Cows were fed total mixed diets for 15 wk. Diets were formulated to be isonitrogenous with the same base ingredients resulting in base crude protein percentage of 15.5. Supplemental crude protein supplied by urea, soybean meal, or a 50:50 (wt/wt) mixture of fish and blood meal increased total dietary nitrogen to 18.0% of diet DM. Two additional diets consisted of the basal diets soybean meal and urea, which were supplemented with ruminally protected DL-Met and Lys-HCL at 10 and 25 g/d, respectively (soybean meal + amino acids (AA), urea + AA). Mean measures of dry matter intake, milk yield, milk protein percentage, and milk fat percentage were not affected by protein supplement. Milk protein yield, milk fat yield, casein yield, and casein percentage also were not affected by source of supplemental protein. Results indicate that at the level of crude protein intake relative to milk production in this experiment, the source of protein did not affect lactational performance.

Effects of rumen-undegradable protein on dairy cow performance: a 12-year literature review

In order to integrate and analyze knowledge on the use of protein supplements and protein nutrition of lactating dairy cows, we compiled a review of 108 studies published throughout the world, but principally in the Journal of Dairy Science between 1985 and 1997. In 29 comparisons from 15 metabolism trials, soybean meal was replaced by high amounts of rumen undegradable protein (RUP) as a supplement; the benefits were not consistently observed for flow to the duodenum, essential amino acids, or lysine and methionine. High RUP diets resulted in decreased microbial protein synthesis in 76% of the comparisons. However, fish meal provided a good balance of lysine and methionine when calculated as a percentage of total essential amino acids. In 127 comparisons from 88 lactation trials that were published from 1985 to 1997, researchers studied the effects of replacing soybean meal with high RUP sources, such as heated and chemically treated soybean meal, corn gluten meal, distillers grains, brewers grains, blood meal, meat and bone meal, feather meal, or blends of these sources; milk yield was significantly higher in only 17% of the comparisons. Fish meal and treated soybean meal accounted for most of the positive effects on milk yield from RUP; corn gluten meal resulted in mostly negative results. The percentage of fat in milk was depressed more by fish meal than by other RUP sources. Protein percentage was decreased in 28 comparisons and increased in only 6 comparisons, probably reflecting the decrease in microbial protein synthesis, as was observed for diets high in RUP. The data strongly suggest that increased RUP per se in dairy cow diets, which often results in a decrease in RDP and a change in absorbed AA profiles, does not consistently improve lactational performance.