Effect of the levels of N fertilizer, grass and supplementary feeds on nitrogen composition and renneting properties of milk from cows at pasture

1994 ◽  
Vol 61 (2) ◽  
pp. 179-189 ◽  
Author(s):  
John E. Hermansen ◽  
Steen Ostersen ◽  
Ole Aaes
Keyword(s):  
Protein Concentration ◽  
Milk Protein ◽  
Relative Proportion ◽  
Protein Composition ◽  
N Fertilization ◽  
Total Protein Content ◽  
Total N ◽  
Statistical Correction ◽  
Concentrate Mixture ◽  
Supplementary Feed

SummaryIn a 2 × 2 × 3 factorial design grazing experiment we investigated the effect of fertilizer (none or 240 kg N/ha), amounts of clover grass available (low or high) and type and level of daily supplementary feed for each cow (3·5 kg barley, 3·5 kg concentrate mixture rich in protein and fat, or both, 7 kg) on the protein composition and renneting properties of their milk. The experiment was carried out in two successive grazing seasons (years) and included a total of 79 Danish Holstein cows. The effect on milk protein composition was determined in both years whereas the effect on renneting properties was determined only in the second year. Fertilization of the clover grass significantly decreased total milk protein concentration (− 1·4 g/kg; P < 0·01) and tended also to decrease the relative proportion of whey protein N. Fertilization had no effect on renneting properties. Increased availability of clover grass significantly increased milk protein concentration (1 g/kg; P < 0·05) and resulted in significantly poorer renneting properties, that is increased clotting time (P < 0·01) and decreased coagulum development. These effects seemed to be mediated through an effect on the pH of the milk (+ 0·05; P < 0·05) as the effect was markedly reduced when statistical correction was made for the actual pH. Use of the protein- and fat-rich concentrate mix (3·5 kg) significantly reduced the total protein content of the milk (P < 0·05) and increased the proportion of non-protein N (NPN) in total N compared with use of the other supplementary feeds (P < 0·05). We found no effect on renneting properties of the different supplementary feeds. Throughout the grazing season and independent of the main treatments, the NPN proportion of milk N increased at the expense of casein N. At the same time, renneting properties became poorer, especially with high clover grass availability.

Effects of dietary protein supply on caseins, whey proteins, proteolysis and renneting properties in milk from cows grazing clover or N fertilized grass

1999 ◽  
Vol 66 (2) ◽  
pp. 193-205 ◽  
Author(s):  
JOHN E. HERMANSEN ◽  
STEEN OSTERSEN ◽  
NIELS C. JUSTESEN ◽  
OLE AAES
Keyword(s):  
Whey Protein ◽  
Milk Protein ◽  
Whey Proteins ◽  
Protein Composition ◽  
Late Summer ◽  
Total N ◽  
Rye Grass ◽  
Rumen Undegradable Protein ◽  
True Protein ◽  
Supplementary Feed

The objective of this work was to examine whether variation in the amino acid supply to cows could be a reason for the reduced casein content and poorer renneting properties of milk that often occur in late summer, or whether these effects are related to proteolysis in the raw milk. In a 2×2×2 factorial design, we investigated the effects of sward (clover v. rye-grass) and supplementary feed with a high or low level of rumen-soluble N or of rumen undegradable protein on milk protein composition during the grazing season. A total of 32 Danish Holstein cows were included in the experiment. Milk protein and casein contents and the ratios casein N[ratio ]total N and casein[ratio ]true protein were at a minimum in late summer, whereas the contents of urea, non-protein N and whey protein were higher during this period. These seasonal effects were unrelated to either the type of supplementary feed or the type of sward; neither were they clearly related to proteolysis, although casein[ratio ]true protein was related to the proteose peptone content. The results indicated that whey proteins other than α-lactalbumin or β-lactoglobulin accounted for the higher proportion or concentration of whey protein in late summer. Based on a principal component analysis including variables such as citric acid, lactose and non-protein N, we suggest that the cows' energy supply during this period may be a critical factor in determining the milk protein composition, although our results were not conclusive. There was an interaction between the supplement of rumen undegradable protein and type of sward. When clover was grazed, a high supplement increased the concentrations of protein and casein in milk and the κ-casein[ratio ]total casein ratio. When rye-grass was grazed, the opposite response was found, and overall milk protein yield was not affected. The very low N content of clover in early summer reduced milk protein and casein protein during this period.

Effect of genetic potential and level of feeding on milk protein composition

2001 ◽  
Vol 68 (4) ◽  
pp. 569-577 ◽  
Author(s):  
JEAN-BAPTISTE COULON ◽  
DIDIER DUPONT ◽  
SYLVIE POCHET ◽  
PHILIPPE PRADEL ◽  
HELENE DUPLOYER
Keyword(s):  
Protein Concentration ◽  
Milk Protein ◽  
Concentration Level ◽  
Latin Square ◽  
Protein Composition ◽  
Random Order ◽  
Plasmin Activity ◽  
Total Proteins ◽  
Nutrient Supplementation ◽  
Genetic Potential

Two groups of 15 multiparous cows in mid-lactation were used in a Latin square design experiment with 4-week experimental periods. The genetic milk protein concentration level was high in the first group and low in the second. Each group of cows was given in a random order three feeding levels that covered 85, 100 and 115% of energy requirements and 90, 110 and 125% of nitrogen requirements, respectively. In both groups, increasing level of feeding induced a significant increase in milk yield (+2·4 kg/d between lowest and highest levels) and in protein concentration (+1·7 g/kg). The proportion of paracasein in total proteins was not altered by either genetics or nutrition. The proportion of casein in total proteins was slightly increased by 0·5 percentage points (P<0·05) with the intermediate level of feeding. Plasmin and plasminogen activities were not significantly modified by the genetic milk concentration level. Plasmin activity significantly increased with nutrient supplementation, but only in animals of low genetic potential (+21% between low and high levels, P<0·01). Casein composition was not significantly altered by the genetics or level of nutrition. Over the whole range of individual measurements taken (n = 90), the relationships between casein or paracasein and total protein concentrations were linear and very narrow (R2 = 0·92 and 0·95, respectively). The proportion of casein or paracasein in total proteins significantly decreased as plasmin activity increased.

EFFECTS OF NITROGEN FERTILIZATION AND STALK POSITION ON CERTAIN CHEMICAL AND PHYSICAL CHARACTERISTICS OF THREE TOBACCO GENOTYPES

1975 ◽  
Vol 55 (2) ◽  
pp. 485-490 ◽  
Author(s):  
J. L. SIMS ◽  
S. J. SHEEN ◽  
C. GRUNWALD ◽  
W. O. ATKINSON
Keyword(s):  
Nitrogen Fertilization ◽  
Protein Concentration ◽  
N Fertilization ◽  
Leaf Position ◽  
Total Volatile ◽  
Total N ◽  
Total Alkaloids ◽  
Nitrate N ◽  
Nicotiana Tabacum L ◽  
N Fractions

Burley 21 (B21), low-alkaloid Burley 21 (LA B21), and low-polyphenol Burley 21 (LP B21) tobacco (Nicotiana tabacum L.) cultivars were grown in the field at Lexington, Kentucky, under differing rates of N fertilization. The purpose of the study was to determine the influence of N fertilizer and genotype on principal N fractions of leaves, and on certain physical leaf characteristics. Concentrations of total alkaloids, individual alkaloids, total N, nitrate N, and total volatile nitrogenous bases were markedly lower for LA B21 than LP B21 or B21. In contrast, protein N was greatest in LA B21. Leaves of LA B21 were darker, thicker, held fire longer, and had greater specific volume than LP B21 or B21 leaves. Generally, all nitrogenous constituents of leaves from all cultivars increased as rate of N fertilization increased, and concentrations of most constituents, except nitrate, increased with ascending leaf position on the stalk. However, N rate × cultivar interactions for total alkaloids, protein N, and color indicated that N rate influenced total alkaloid concentration to a greater extent, and protein concentration and color to a lesser extent, in B21 than in other cultivars.

Effects of Cover Crops and Tillage on Sweet Corn Production

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 476d-476
Author(s):  
Gary R. Cline ◽  
Anthony F. Silvernail
Keyword(s):  
Cover Crops ◽  
Sweet Corn ◽  
N Fertilization ◽  
Winter Rye ◽  
No Tillage ◽  
Corn Production ◽  
Total N ◽  
No Till ◽  
Winter Cover ◽  
Winter Cover Crops

A split-plot factorial experiment examined effects of tillage and winter cover crops on sweet corn in 1997. Main plots received tillage or no tillage. Cover crops consisted of hairy vetch, winter rye, or a mix, and N treatments consisted of plus or minus N fertilization. Following watermelon not receiving inorganic N, vetch, and mix cover cropsproduced total N yields of ≈90 kg/ha that were more than four times greater than those obtained with rye. However, vetch dry weight yields (2.7 mg/ha) were only about 60% of those obtained in previous years due to winter kill. Following rye winter cover crops, addition of ammonium nitrate to corn greatly increased (P < 0.05) corn yields and foliar N concentrations compared to treatments not receiving N. Following vetch, corn yields obtained in tilled treatments without N fertilization equaled those obtained with N fertilization. However, yields obtained from unfertilized no-till treatments were significantly (P < 0.05) lower than yields of N-fertilized treatments. Available soil N was significantly (P < 0.05) greater following vetch compared to rye after corn planting. No significant effects of tillage on sweet corn plant densities or yields were detected. It was concluded that no-tillage sweet corn was successful, and N fixed by vetch was able to sustain sweet corn production in tilled treatments but not in no-till treatments.In previous years normal, higher-yielding vetch cover crops were able to sustain sweet corn in both tilled and no-till treatments.

In vitro dynamic gastric digestion of soya protein/milk protein blended beverages: influence of protein composition and co-processing

2021 ◽  
Vol 12 (6) ◽  
pp. 2605-2616
Author(s):  
Teresa Francis Wegrzyn ◽  
Alejandra Acevedo-Fani ◽  
Simon M. Loveday ◽  
Harjinder Singh
Keyword(s):  
Whey Protein ◽  
Milk Protein ◽  
Protein Composition ◽  
Soya Protein ◽  
Gastric Digestion ◽  
Heat Treated ◽  
Protein Milk

The gastric digestion behaviours of blended protein beverages containing different ratios of casein, whey protein and soya protein that were heat-treated at 60 °C or 80 °C were investigated using an in vitro dynamic human gastric simulator.

scholarly journals Denitrifying pathways dominate nitrous oxide emissions from managed grassland during drought and rewetting

2021 ◽  
Vol 7 (6) ◽  
pp. eabb7118
Author(s):  
E. Harris ◽  
E. Diaz-Pines ◽  
E. Stoll ◽  
M. Schloter ◽  
S. Schulz ◽  
...  
Keyword(s):  
Growth Rate ◽  
Nitrous Oxide ◽  
N Fertilization ◽  
High Variability ◽  
Nitrous Oxide Emissions ◽  
Severe Drought ◽  
Total N ◽  
The Past ◽  
Precipitation Changes ◽  
Isotopic Measurements

Nitrous oxide is a powerful greenhouse gas whose atmospheric growth rate has accelerated over the past decade. Most anthropogenic N2O emissions result from soil N fertilization, which is converted to N2O via oxic nitrification and anoxic denitrification pathways. Drought-affected soils are expected to be well oxygenated; however, using high-resolution isotopic measurements, we found that denitrifying pathways dominated N2O emissions during a severe drought applied to managed grassland. This was due to a reversible, drought-induced enrichment in nitrogen-bearing organic matter on soil microaggregates and suggested a strong role for chemo- or codenitrification. Throughout rewetting, denitrification dominated emissions, despite high variability in fluxes. Total N2O flux and denitrification contribution were significantly higher during rewetting than for control plots at the same soil moisture range. The observed feedbacks between precipitation changes induced by climate change and N2O emission pathways are sufficient to account for the accelerating N2O growth rate observed over the past decade.

Responses of lactating ewes, offered fresh herbage indoors and when grazing, to supplements containing differing protein concentrations

1988 ◽  
Vol 46 (3) ◽  
pp. 403-415 ◽  
Author(s):  
P. D. Penning ◽  
R. J. Orr ◽  
T. T. Treacher
Keyword(s):  
Body Condition ◽  
Protein Concentration ◽  
Milk Protein ◽  
Fish Meal ◽  
Soya Bean ◽  
Protein Supplements ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Lamb Growth ◽  
Daily Milk

ABSTRACTThe responses to supplements differing in protein concentration and degradability were measured in lactating ewes and their twin lambs when offered fresh ryegrass either cut or grazed. Housed Scottish Halfbred ewes, offered fresh-cut grass ad libitum received no supplement (N) or supplements with barley and maize starch (B); barley and soya-bean meal (S); barley, soya-bean meal and fish meal (SF) or barley and fish meal (F) in weeks 2 to 7 of lactation. By feeding supplements, herbage organic-matter (OM) intake was depressed (2·00 v. 1·74 kg/day). Mean daily milk yield was increased when protein supplements were given and, because milk protein concentration was higher for supplement F and similar for all other diets, mean daily milk protein output increased with increasing fish meal in the diet. Milk yields were N 2·55, B 2·59, S 3·17, SF 3·15 and F 3·17 kg/day. Total milk solids and fat concentrations were also higher for S, SF and F than N or B. Lambs from ewes supplemented with protein grew faster and the ewes generally lost less weight and body condition compared with unsupplemented ewes.At pasture, Masham ewes grazed at herbage allowances of either 4 (L) or 10 (H) kg OM per day and received no supplement (N) or supplements B or F, for the first 6 weeks of lactation and then, in weeks 7 to 12, grazed without supplements. For NL, BL, FL, NH, BH and FH respectively lamb growth rates from birth to 6 weeks were 235, 242, 274, 267, 286 and 302 g/day; from birth to 12 weeks were 210, 209, 249, 255, 275 and 287 g/day and losses in ewe body-condition score from birth to 12 weeks were 1·28, 1·22, 1·06, 0·97, 0·62 and 0·76.It is concluded that protein supplements increased milk yield and lamb growth rates and that the response tended to be greater with fish meal.

A multi-scale approach to identify the role of heat treatment, milk protein composition and starter culture on the gel formation and the texture defects of acid milk gel

2018 ◽  
Vol 85 ◽  
pp. 299-310 ◽  
Author(s):  
An Thi-Binh Nguyen ◽  
Michaël Nigen ◽  
Luciana Jimenez ◽  
Hassina Ait-Abderahim ◽  
Charles Cunault ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Milk Protein ◽  
Starter Culture ◽  
Protein Composition ◽  
Gel Formation ◽  
Multi Scale ◽  
Acid Milk Gel

scholarly journals Fruit yield and composition in orange trees cv. 'Lane Late' in response to nitrogen fertilization in Sandy Typic Hapludalf soil

2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Gustavo Brunetto ◽  
◽  
Cesar Cella ◽  
Alcione Miotto ◽  
Eduardo Girotto ◽  
...  
Keyword(s):  
Fruit Juice ◽  
Organic Matter Content ◽  
Titratable Acidity ◽  
N Fertilization ◽  
Fruit Yield ◽  
Soluble Solids ◽  
Total N ◽  
Total Titratable Acidity ◽  
Orange Trees ◽  
The Impact

ABSTRACT: Little is known about the impact of N fertilization on fruit production and composition in orange groves grown in soils with low or medium organic matter content in Rio Grande do Sul (RS). This study aimed to evaluate how N fertilization of orange trees cv. 'Lane Late' in a sandy soil may interfere in fruit yield and composition of fruit and juice. The experiment was conducted with orange trees cv. 'Lane Late' growing in Sandy Typic Hapludalf soil, in Rosário do Sul (RS). The plants received applications of 0, 20, 40, 60, 80, 100, 120, 140 and 160kg N ha-1. Total N in leaves, number of fruits per plant, yield, fresh weight, fruit diameter, peel thickness, percentage of fruit juice, peel color, juice color, ascorbic acid content, total soluble solids (TSS) and total titratable acidity were evaluated in 2010/2011 and 2011/2012 crops. In the first crop, especially yield, number of fruits per plant, TSS content in fruit juice and ratio decreased with increasing N rate applied. However, in the second crop, the total titratable acidity of the fruit juice prominently increased with the dose of N applied. In both crops, results were highly influenced by rainfall distribution, which affect the plant physiology, soil N dynamics and, consequently, probability of response to N applied and the loss of mineral N in the soil.

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