The nutritive value of non-milk proteins for the preruminant calf. The effect of replacement of milk protein by soy-bean flour or fish-protein concentrate

Organic Nitrogen Supplementation Increases Vegetative and Reproductive Biomass in a Versatile White Rot Fungus

The Black Poplar Mushroom Cyclocybe aegerita (syn. Agrocybe aegerita) is a white-rot fungus that naturally fruits from woody substrates, including buried wood. It is known for its substrate versatility and is equipped with a respective carbohydrate-active enzyme repertoire being intermediate between typical white-rot fungi and plant litter decomposers. Given relative nitrogen scarcity in wood, mobilization of nitrogen from surrounding litter is known as a way to meet nitrogen requirements for cellular homeostasis and reproduction of wood decay fungi. However, the effect of added nitrogen on vegetative and reproductive biomass has not yet been studied in a uniform minimalistic laboratory setup. For C. aegerita, such a growth and fruiting setup has been developed. In the present study, this white-rot fungus has been grown with and without additional β-adenosine, an organic nitrogen source present in plant litter. Elevated β-adenosine levels increased aerial mycelium weight by 30% (1 × β-adenosine) and 55% (10 × β-adenosine), reproductive biomass by 75% (1 × β-adenosine) and by 100% (10 × β-adenosine), number of primordia by 127% (10 × β-adenosine) and accelerated primordium formation by 1.6 days (10 × β-adenosine), compared to the control treatment. These findings imply that C. aegerita invests additional organic nitrogen resources into direct vegetative and reproductive biomass build-up at the same time. Colonization of niches with accessory nitrogen sources, like buried wood, which is near the plant litter layer, may thus provide an evolutionary fitness advantage. Globally anthropogenically altered nitrogen dynamics may affect hyphal-driven processes as well as fruit body-driven food webs.

Voluntary food intake in the young pig

During the 1st week of life the energy contained in the body of the average piglet increases by a factor between four and five. To achieve this increase the piglet must ingest metabolizable energy (ME) at a rate which is about four times its maintenance requirement. Well over half the ME supplied in the milk of the sow is in the form of emulsified fat. Whilst the piglet is being suckled, its intake is controlled by litter size, availability of teats and productiveness of the mammary gland. At 3 weeks of age the normal piglet requires about 7.8 MJ digestible energy to sustain a live growth rate of 280 g/day. At this stage the growth comprises about 40 g protein and about 68 g fat. This means that the required intake for a newly weaned piglet on a typical starter diet should be about 475 g/day. In practice such intakes are rarely achieved for several days, therefore weaning causes severe disruption of intake and of the growth curve and there are other factors involved including social disturbance and stress. Further problems are caused by the provision of diets which are unsuited to the physiology of the piglet's immature digestive tract. The sudden loss of the IgA component and indeed other protective factors contained in the dam's milk can be extremely serious, and the reduction in food intake is effectively a defence strategy by the piglet to cope with its new circumstances and try to maintain physiological homoeostasis. In some circumstances the use of antibacterial agents, organic acids or probiotics may be beneficial, but the approach is less reliable than careful formulation of the diet to avoid provocative ingredients such as soya-bean and rapeseed meal.

Supplementation of milk replacers containing soy protein with threonine, methionine, and lysine in the diets of calves

An attempt was made to improve the protein quality supplied in milk replacers containing soy protein by supplementing Thr, Met, and Lys to the milk replacers fed to calves. Six Holstein x indigenous male calves were fitted with single cannulas at the end of the ileum. Calves were fed milk replacers containing skim milk (86%) and whey (14%) proteins or skim (43%), whey (14%), and soy (43%) proteins either with or without amino acid (AA) supplementation according to a double 3 x 3 Latin square design. Average daily gain, N retention, and ileal digestibilities of dry matter, N, and AA were significantly higher for calves fed the milk replacer containing skim milk protein than for calves fed the milk replacer containing soy protein. Average daily gain, N retention, and ileal digestibilities of dry matter, N, and AA were significantly higher for calves fed the milk replacer containing soy protein plus AA supplementation than for calves fed the milk replacer containing the soy protein without AA supplementation. Therefore, supplementation of a milk replacer containing the soy protein without AA supplementation. Therefore, supplementation of a milk replacer containing soy protein with limiting AA that correspond to the AA found in milk protein can considerably improve the protein quality of that milk replacer for the preruminant calf.

Detection and quantitation of pea and soy-derived proteins in calf milk replacers

Preruminant calves on several farms had diarrhea nonresponsive to treatment and were doing poorly, despite being fed a high quality calf milk replacer. Because these reconstituted milk replacers always had a sediment, they were suspected of containing insoluble nonmilk-derived proteins. Microscopic examination of the milk replacer, however, did not show any evidence of starch granules. We therefore analyzed the samples by SDS PAGE. We were able to identify and quantitate pea protein in calf milk replacers in which all the protein was supposedly milk-derived. We were also able to differentiate polypeptides derived from pea and soy. We concluded that PAGE is a sensitive technique for detecting nonmilk-derived proteins in calf milk replacers.

Replacement of skimmed milk with hydrolyzed fish protein and Nixtamal in milk substitutes for dairy calves

Two experiments were conducted with 3- to 5-d-old Holstein male calves. In Experiment 1, 15 calves were assigned to three dietary treatments. The control diet was based on sodium caseinate, lard, and cerelose. In the other diets, either 50% or all carbohydrates were replaced by lime-treated corn flour (Nixtamal). In Experiment 2, 35 calves were assigned to dietary treatments in which 0, 50, or 67% low heat skimmed milk protein was replaced by hydrolyzed fish protein; for the replacement diets, Nixtamal was incorporated at 25 or 35% of the dry matter. Control diet protein was entirely from skimmed milk. Milk substitutes provided the only feed during the 8-wk experiment. In Experiment 1, body weight gain and feed efficiency declined when Nixtamal completely replaced skimmed milk but remained unchanged at 50% substitution. Substitution of Nixtamal for skimmed milk powder decreased nitrogen and carbohydrate digestibility; but digestibility improved with age. In Experiment 2, replacing up to 67% of skimmed milk protein with partially hydrolyzed fish protein concentrate had no effect on body weight gain but decreased feed efficiency linearly at 8 wk and reduced dry matter, nitrogen, and fat digestibility. Nixtamal can replace up to 50% of skimmed milk carbohydrates without detrimental effect on growth rate, feed efficiency, and diarrhea, but digestibility might be reduced. Concurrent replacement of up to 67% of skimmed milk protein with partially hydrolysed fish protein concentrate would be feasible for newborn calves gaining 450 g/d, despite lower nitrogen digestibility.

Digestion of milk, fish and soya-bean protein in the preruminant calf: flow of digesta, apparent digestibility at the end of the ileum and amino acid composition of ileal digesta

1. Digesta were collected from eleven preruminant calves fitted with re-entrant (four calves in Expt 1 and three in Expt 2) or single cannulas (four calves in Expt 1) in the terminal ileum. Collection periods lasted 24 h (Expt 1) or 96 h (Expt 2). 2. Two milk-substitutes (fish and soya bean) and a control diet were given to the calves. In the control diet, protein was entirely provided by skim-milk powder. In the other two diets, protein was provided mainly by a partially hydrolysed white-fish protein concentrate or a soya-bean protein concentrate prepared by extracting soya-bean meal with hot aqueous ethanol. 3. In Expt 1, flow rates of fresh matter, dry matter, nitrogen and ash exhibited two maxima between 6 and 8 h after the morning meal and between 4 and 6 h (control and soya-bean diets) or 6 and 8 h (fish diet) after the evening meal. Minimum pH values were observed at times of maximum flow rate. Variations observed in the flow rates and pH values were larger with fish and especially soya-bean diets than with the control diet. 4. The apparent digestibility of the three diets in the terminal ileum was significantly higher in Expt 2 than in Expt 1: for N, the values were 0.92, 0.83 and 0.75 (Expt 1), and 0.94, 0.87 and 0.88 (Expt 2) with the control, fish and soya-bean diets respectively. 5. The amount of N apparently absorbed in the terminal ileum represented 90-96% of the amount that disappeared from the whole digestive tract in Expt 1 and 95-99% in Expt 2. 6. In Expt 1 the amino acid (AA) composition of digesta changed little with the flow rate when the calves were given the control diet (from 158 to 179 g glutamic acid/kg AA). With the fish and soya-bean diets the AA composition was similar to that observed with the control diet when the flow rate was minimum, but differences became apparent as the flow rate increased (281 and 161 g glutamic acid/kg AA for the soya-bean and control diets respectively with maximum flow rate). In Expt 2, the mean compositions of the digesta were very similar to the means obtained in Expt 1. 7. Different comparisons with dietary, endogenous and bacterial proteins indicated that for the three diets a common mixture containing approximately 65% endogenous and 35% bacterial proteins reached the terminal ileum.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of protein source in calf milk replacers on morphology and absorptive ability of small intestine

Holstein calves were fed milk or one of four milk replacers with one-third of the total protein supplied by casein, soy protein concentrate, soy flour, or fish protein concentrate. The remainder of the protein in each replacer was from milk sources. Milk and milk replacers (13% solids) were fed at 10% of body weight daily. No dry feed or bedding was provided. Absorptive ability of small intestine was evaluated by xylose absorption test at 2-wk intervals. With calves under general anesthesia, a biopsy of small intestine was taken after each xylose test to examine morphological changes in mucosa by scanning electron microscopy. Villi were long, tapering, and uniform in calves fed milk. Calves fed casein had greater variation in size and conformation of villi. Gradual deterioration in villous integrity was seen in calves fed soy proteins. Calves fed fish protein concentrate performed poorly and had abnormal villi. Diets were changed to milk to test for reversal of effects after marked alterations in intestinal structure had been observed. Atrophy was reversed as villi returned toward normal size and shape within 2 wk after milk feeding began. The surgical procedure apparently did not cause harmful effects of villi. Absorption of xylose and daily gain were greater, and feces firmer, in calves fed milk than in those fed milk replacers.

Digestion, absorption and utilization of single-cell protein by the preruminant calf. The true digestibility of milk and bacterial protein and the apparent digestibility and utilization of their constituent amino acids

Two experiments of Latin square design were made, each with four Friesian bull calves fitted with re-entrant duodenal and ileal cannulas at 4-10 d of age. The calves were used to study the effect of giving milk-substitutes containing 0, 300, 500 and 700 g bacterial protein (Pruteen)/kg total protein on apparent digestibility of nitrogen fractions and amino acids and true digestibility of 3H-labelled milk protein and 35S-labelled bacterial protein in the small intestine. A third experiment of Latin square design with four intact Friesian calves was used to measure apparent digestibility of nutrients throughout the alimentary tract and retention of N, calcium and phosphorus. At the duodenum, volume of outflow, its pH, and outflow of total-N(TN), protein-N (PN) and non-protein-N (NPN) decreased with time after feeding. At the ileum, volume of outflow and TN outflow were unaffected by time after feeding but PN outflow decreased; NPN outflow at the ileum increased to a maximum 6 h after feeding and then declined. Increased inclusion of Pruteen did not affect the volume of outflow at the duodenum or ileum, but duodenal PN outflow increased. At the ileum, pH values were lower and TN, PN and NPN outflows were higher with increasing concentration of Pruteen in the diet. Apparent digestibility in the small intestine tended to decrease with greater amounts of Pruteen, but was only significant for NPN. Apparent digestibility from mouth to ileum significantly decreased for TN and PN as Pruteen inclusion increased. Amino acid concentration in duodenal outflow, with the exception of that of arginine, reflected intake. The total amount of each amino acid in ileal outflow increased and the apparent digestibility of most amino acids decreased with greater amounts of Pruteen in the diet. Apparent digestibility of nucleic acid-N from Pruteen was very high. True digestibility in the small intestine and between mouth and ileum of 3H-labelled milk protein was high and did not differ between dietary treatments. True digestibility of 35S-labelled Pruteen was low for the milk-protein diet and tended to increase linearly as more dietary Pruteen was included. Dry matter concentration in faeces and a high apparent digestibility throughout the whole alimentary tract of carbohydrates did not differ between treatments.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of kidney bean (Phaseolus vulgaris) toxin on tissue weight and composition and some metabolic functions of rats

Inclusion of raw kidney bean (Phaseolus vulgaris) proteins in the diet for rats was shown to affect the weight of some internal organs. Of these, in addition to the well-known hypertrophy of the pancreas attributable to dietary trypsin inhibitors, the observed atrophy of the thymus and the doubling in weight of the small intestine are related to the protein or lectin content of the bean diet, or both. Changes in tissue composition of the small intestine were also recorded. Its protein content increased by about 40-50% and carbohydrate content doubled suggesting the occurrence of increased mucinous glycoprotein secretion. Increased DNA content (by about 30-40%) however also indicated mucosal hyperplasia. Changes were also observed in mineral content, urea concentration and some enzyme activities in sera and urine, possibly as a result of disturbances in systemic metabolism or hormone levels, or both. The results gave further support to previous suggestions that the oral toxicity of kidney-bean lectins involves local reactions in the small intestine in combination with their effects on the systemic immune system and general metabolism.

Dietary fibers and supplementary iron in a milk replacer for veal calves

Thirty 1-wk-old male Holstein calves were allotted randomly to six groups into a 3 X 2 factorial design. The control diet was skim milk, whey, tallow, vitamins, and minerals. Either Alpha-Floc or pectin was added at 5% dry matter. Supplementary iron was added at 30 and 50 ppm (dry basis). The six diets were fed for 14 wk. Calves without supplementary iron were mildly anemic at 6 wk and severely at 14 wk (7 and 5 g/dl hemoglobin). At 14 wk, both fibers had decreased blood hemoglobin in calves given supplementary iron. Feed refusal began at 8 wk with the appearance of anemia for calves unsupplemented with iron, but both Alpha-Floc and pectin decreased feed refusal. Supplementary iron practically eliminated feed refusal. Supplementary iron improved average daily gain and feed conversion, but dietary fibers had no effect. Adding Alpha-Floc and pectin to the diets reduced frequency of diarrheic feces. Mean carcass weight of calves fed supplementary iron was 11.6% higher than that of unsupplemented calves. Supplementary iron decreased liver lipids and increased glutamic oxaloacetic transaminase activity in blood plasma.

Performance and digestion by calves from limestone added to milk replacers containing soy protein concentrate

Sixteen male Holstein calves were fed milk replacers containing milk protein or 50% of the protein from soy protein concentrate for study of limestone as a buffer in the small intestine. Experimental diets were: A) 19% of crude protein as milk protein; B) same as A but containing .8% limestone; C) 19% crude protein, 9.5% milk protein, and 9.5% soy protein; and D) same as C but containing .8% limestone. Milk replacers were reconstituted with water to 14% solids and fed at 8, 9, 10, 11, 12, and 12% body weight from 1 to 6 wk of age. Calves were fed twice daily, and clean fresh water was available at all times. Soy protein concentrate in the replacer resulted in 20% lower weight gains, lower dry matter and protein digestibilities. Apparent crude protein retention also was reduced, but intake of nutrients, feed efficiencies, fecal scores, and rectal temperatures were not different between protein sources. Limestone did not change any of these measurements. Xylose absorption tests at 3 and 6 wk of age showed differences from age but not treatment. Analysis of digesta from different sections of the gut of 6-wk-old calves sacrificed 6 h after feeding revealed that pH throughout the small intestine was above 6 for both proteins, which may explain the ineffectiveness of added limestone. Compared to milk protein, soy protein concentrate produced a lower pH in the large intestine and feces.

Enzymatic hydrolysate of fish, spray-dried fish solubles, and soybean protein concentrate in milk replacers for calves

Holstein calves (120) were fed milk replacers as the only nutrients from 4 to 46 days of age. All milk replacers contained 20% crude protein and differed in protein source: 1) 100% milk protein; 2) 67% milk protein, 33% soybean protein concentrate; 3) 67% milk protein, 33% enzymatic hydrolysate of fish; 4) 67% milk protein, 16.5% soybean protein concentrate, 16.5% enzymatic hydrolysate of fish; 5) 67% milk protein, 16.5% soybean protein concentrate, 16.5% spray-dried fish solubles; 6) 67% milk protein, 24.75% soybean protein concentrate, 8.25% spray-dried fish solubles. Substitution up to 33% of dietary protein with soybean protein concentrate or combinations of soybean, enzymatic hydrolysate of fish, or spray-dried fish solubles produced 14% lower weight gains than all milk protein, but 33% replacement with enzymatic hydrolysate of fish produced 27% lower weight gains. Feed consumed per kilogram of gain was least for all milk, most for 33% fish hydrolysate, and intermediate for other rations. Scour scores did not differ between diets.

The amino acid requirements of the preruminant calf

1. Ten calves (50--58 kg live weight) were given a diet consisting of diluted whole milk, wheat gluten and supplemented with appropriate nutrients including amino acids but deficient in lysine. The lysine reequirements of these calves, which were growing at approximately 0.25 kg/d, were estimated from responses to lysine supplementation of this diet. From plasma urea, plasma lysine, nitrogen retention and apparent digestibility of N responses the estimated lysine requirements were 8.5, 7.5, 7.2 and 7.6 g/d respectively. 2. From the mean lysine requirement (7.8 g/d) and the ratio, lysine: otheressential amino acids in carcasses of similar calves the estimated requirements were (g/d): methionine 2.1, cystine 1.6, threonine 4.9, valine 4.8, isoleucine 3.4, leucine 8.4, tyrosine 3.0, phenylalanine 4.4, histidine 3.0, arginine 8.5, tryptophan 1.0.