Bovine somatotropin and rumen-undegradable protein effects in prepubertal dairy heifers: effects on body composition and organ and tissue weights

The objectives of this study were to determine the effect of recombinant bovine somatotropin (bST) and added dietary rumen undegradable protein (RUP) on organ and tissue weights and body composition in growing dairy heifers. Thirty-two Holstein heifers were in the experiment, 8 killed initially at 3 mo of age, with the remaining 24 Holstein heifers randomly assigned to treatments (n = 6) consisting of 0.1 mg/kg of body weight per day of bST and 2% added dietary RUP (dry matter basis) applied in a 2 x2 factorial design. A total of 6 heifers per treatment group (3 each at 5 and 10 mo of age), were slaughtered to determine body composition and organ masses. Feed intake measured from group intakes were increased by 0.25 and 0.35 kg/d with bST and RUP, respectively. Administration of bST tended to increase the weights of visceral organs including heart, kidney, and spleen by 16, 16, and 38%, respectively. At 10 mo of age, there was a trend for increased empty body weights (EBW) and non-carcass components for heifers treated with bST, but there were no effects of RUP. Body components and organ weights, expressed as a percentage of BW were not affected by RUP or bST. Somatotropin increased ash weight at 10 mo without affecting amounts of protein, fat, and energy. Rates of ash deposition between 3 and 10 mo of age were increased 7 and 4 g/d by bST and RUP, respectively. There were no treatment effects on rates of body fat, protein, and energy deposition. Bovine somatotropin and RUP altered the metabolism of growing heifers in a manner that was consistent with increased rates of skeletal growth. This suggests that nutritional and endocrine manipulations could increase growth rates of skeletal tissues without increasing fat deposition in prepubertal dairy heifers.     

Effect of dietary rumen-protected choline in lactating dairy cows

Two experiments were conducted to test the effects of graded amounts of rumen-protected choline on milk yield and composition in lactating dairy cows fed 40% corn silage and 60% concentrate diets (DM basis). In Experiment 1, 48 Holstein cows were fed 0, .078, .156, and .234% rumen-protected choline (choline chloride basis) from wk 5 to 21 postpartum. Increasing choline had no effect on DMI and tended to increase milk yield only from 1 to 2.2 kg/d. Milk fat percentage was reduced in the .078% choline treatment and increased to control levels thereafter with .156 and .234% choline. In Experiment 2, 16 Holstein cows in midlactation were assigned randomly to either 13.0 or 16.5% dietary CP (DM basis). Within CP concentration, cows were fed 0, .08, .16, and .24% rumen-protected choline in a replicated 4 x 4 Latin square design. Dietary protein had no effect on milk yield, although milk protein percentage and yield were increased .25 percentage units and 63 g/d, respectively, by increased dietary CP. Increasing dietary choline to .24% linearly increased milk yield 2.6 kg/d, although it had no consistent effects on milk fat or protein percentage. There was only a slight tendency for greater responses in milk yield to dietary choline with lower dietary CP. Data from these experiments confirm earlier results with postruminal choline infusions, suggesting that choline may be a limiting nutrient for milk production.     

In vitro degradation of choline from selected feedstuffs and choline supplements

The objective of this experiment was to determine the extent of in vitro degradation of choline from barley, corn, corn gluten meal, cottonseed meal, fish meal, soybean meal, alfalfa hay, timothy hay, choline chloride, and choline stearate. During four individual fermentation runs, samples were incubated in vitro for .25, 1, 3, 6, 12, 18, 24, 36, and 48 h with an inoculum mixture containing rumen fluid obtained from a rumen-fistulated dairy cow fed 17.5% corn silage and 28.7% grass silage and 53.8% concentrate diet. Because of their low choline content (less than .68 mg/g) corn, corn gluten meal, alfalfa hay, and timothy hay gave erratic values for choline disappearance for different fermentation runs and times of incubation although disappearance tended to increase with time. Data for the rest of the feeds and choline supplements were analyzed using nonlinear regression procedure to obtain estimates of potentially degradable choline, rapidly degradable choline, and the rate of choline degradation in vitro. The mean estimates of rumen degradable choline (%) were 79.4, 84.7, 82.9, 83.8, 98.0, and 98.6 for barley, cottonseed meal, fish meal, soybean meal, choline stearate, and choline chloride, respectively. The results suggest that incorporating choline-rich feedstuffs in diets can only marginally increase the postruminal flow of choline in dairy cows.     

α-Tocopherol,but Not γ-Tocopherol,Attenuates the Expression of Selective Tumor Necrosis Factor-Alpha-Induced Genes in Primary Human Aortic Cell Lines

Of the antioxidant vitamin E isoforms, α-tocopherol (αT) and γ-tocopherol (γT) are the most abundant in the human diet, and αT is consumed from both natural and synthetic sources. αT and γT may differentially impact inflammation and influence cardiovascular outcomes, in part by modulating gene expression. The goal of this study was to compare the effects of natural αT, synthetic αT, and γT on gene expression in two human cell lines. Human aortic smooth muscle cells (HASMC) and endothelial cells (HAEC) were either: (1) treated with 25 μM tocopherols alone, or (2) pretreated with tocopherols prior to a pro-inflammatory cytokine (tumor necrosis factor-alpha, TNF-α) stimulation. The expression of atherosclerosis-related genes was measured using RT² Profiler PCR arrays. Tocopherol treatments alone did not significantly modulate the expression of genes in unstimulated HASMC or HAEC. TNF-α stimulation significantly upregulated genes involved with apoptosis and stress response in both cell lines. Pretreating cells with tocopherols did not normalize the gene expression changes induced by TNF-α. However, αT pretreatments, but not γT pretreatments, attenuated TNF expression in both HASMC and HAEC. These findings suggest that under stimulated conditions, αT modestly modulates the expression of selective genes and that αT may be more anti-inflammatory than γT.     

The winged bean as an oil and protein source: A review

Despite high protein contents in its ripe seeds, tubers and fresh leaves (ranging from 29.3–39.0%, 3.0–15.0% and 5.0–7.6% respectively) and the high quality of that protein, the winged bean (Psophocarpus tetragonolobus) remained an obscure food source until about 10 years ago. Recently, this legume has received increasing attention from scientists because of its potential multiple uses as a food protein source in the humid tropics. This article reviews the utilization and nutrition literature of winged bean published during the last 10 years. The following aspects are covered: classification of winged bean proteins, nutritional properties and antinutritional components of the protein, protein quality, functional properties, and protein-based food products. The oil content of winged bean seeds ranges from 15.0–20.4%, and use of the winged bean as a potential oilseed crop is discussed. Areas of needed research are identified and described. Presented at the 74th Annual Meeting of American Oil Chemists’ Society, Chicago, May 8–12, 1983.     

Program solves N-job, M-machine sequencing problem

The objective of this program is to find a schedule that minimizes the completion time (make-span) of all jobs, and in so doing it also minimizes the idle time on the last machine in a flow shop problem.     

Effects of silage pH on voluntary intake of corn silage

We evaluated effects of silage pH on corn silage intake. Sixteen Holstein heifers (292 kg) were fed control corn silage during a 2-wk preliminary period. This was followed by an 8-wk experimental period in which animals were fed silage neutralized with 0, 2, 4, or 6% sodium bicarbonate (dry matter) added prior to feeding with corresponding pH's 3.72, 4.46, 5.62, and 8.05. Organic matter intake was increased 1.0 and 1.2 kg/day by addition of 2 and 4% sodium bicarbonate versus controls whereas 6% sodium bicarbonate reduced intake .7 kg/day. An equation developed to predict organic matter intake from silage pH was: Y = 3.20 + 3.92 (pH) -.35 (pH)2 with coefficient of determination .66. This equation predicted maximum organic matter intake at pH 5.6. It appears that silage pH is a factor that affects voluntary consumption of corn silage and that pH 5 to 6 is optimum, whereas silage pH above and below may reduce intake.     

Effects of long daily photoperiod and bovine somatotropin (Trobest) on milk yield in cows.

Bovine somatotropin (bST) and exposure to long daily photoperiod increase milk yield of dairy cattle. We tested the hypothesis that long daily photoperiod and bST treatment would increase milk yield in an additive manner in lactating cows. At winter solstice, 40 lactating cows were started on a 140-d experiment; cows were greater than 70 d in milk (DIM) and were balanced for uniformity of DIM and milk yield within parity. Cows were randomly assigned to one of four treatments (10/treatment): 1) natural photoperiod, 2) natural photoperiod + bST (14 mg/d Trobest i.m.), 3) long daily photoperiod (18 h of light and 6 h of darkness/d), or 4) long daily photoperiod + bST. Long daily photoperiod increased fat-corrected milk (FCM) yield 1.9 kg/d versus natural photoperiod. Treatment with bST increased FCM 5.7 kg/d versus natural photoperiod, and long daily photoperiod + bST increased FCM 5.8 kg/d versus long daily photoperiod. Long daily photoperiod + bST was additive, increasing FCM 7.7 kg/d versus natural photoperiod. Serum somatotropin increased with bST, but not photoperiod, and bST increased serum insulin-like growth factor-I. Long daily photoperiod tended to increase prolactin; bST had no effect. Long daily photoperiod + bST increased dry matter intake (DMI) relative to natural photoperiod and natural photoperiod + bST; long daily photoperiod increased DMI relative to natural photoperiod + bST. Photoperiod had no effect on net energy balance; however, bST decreased net energy balance. Generally, body weight and milk composition did not differ among treatments. In conclusion, combination of bST with long-daily photoperiod tended to amplify the increases in milk yield observed with either treatment individually.     

Milk fat responses to dietary supplementation of short- and medium-chain fatty acids in lactating dairy cows

Short-and medium-chain fatty acids (SMCFA), which are synthesized de novo in the mammary gland, are reduced to a much greater extent than the long-chain fatty acids during diet-induced milk fat depression. Our hypothesis was that SMCFA are limiting for milk fat synthesis even under conditions when milk fat is not depressed. Our objective was to test the potential limitation of SMCFA on milk fat synthesis via dietary supplementation. Sixteen lactating Holstein cows (107±18d in milk) were fed a corn silage-based total mixed ration. Cows were randomly assigned to groups of 4 per pen and supplemented with 1 of 4 dietary fat supplements (600g/d) supplied in a 4×4 Latin square design with 21-d experimental periods. Treatments consisted of fat supplements containing mixtures of calcium salts of long-chain fatty acids (Megalac; Church & Dwight Co. Inc., Princeton, NJ) and an SMCFA mixture (S; 3.3% C8, 7.6% C10, 9.85% C12, 32.12% C14, and 47.11% C16) that contained 0, 200, 400, and 600g/d of S substituted for Megalac (S0, S200, S400, and S600, respectively). No treatment effects were observed for dry matter and fat-corrected milk. However, milk yield was decreased with S600. Milk fat increased linearly by 0.17, 0.25, and 0.33 percentage units for the respective S treatments. However, fat yield peaked at S200 and milk protein concentration and yield was significantly decreased at the higher S levels because of a linear trend toward decreased milk yield in the S600 treatment. In conclusion, SMCFA supplementation linearly increased milk fat concentration but decreased milk production at the higher levels of supplementation. The dietary inclusion of SMCFA had no effects on total milk fat yield.