The effect of protein content on the response of lactating cows to level of concentrate feeding

1977 ◽  
Vol 25 (2) ◽  
pp. 181-191 ◽  
Author(s):  
F. J. Gordon
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Experimental Period ◽  
Energy Output ◽  
Response Curves ◽  
Protein Levels ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Milk Output ◽  
Four Levels

SUMMARYSeventy-two lactating dairy cows were used in a 4x 3 factorial experiment to assess the effects of the protein content of concentrates on the response to concentrate feeding level. Concentrates containing 12,18 and 24% crude protein in the dry matter were given at each of four levels of feeding: 0·25, 0·36, 0·47 and 0·58 kg/kg milk for a 7-week experimental period. Milk yield, milk energy output, liveweight change and the percentage solids-not-fat and protein in the milk were significantly affected by both the level of concentrate feeding and the protein content of the concentrate. Response curves for the effect of level of concentrate feeding on milk output and liveweight change were computed for each of the three protein levels, and although there was no significant interaction between these two main factors the benefit from increased protein in the concentrate was shown to depend partly on the level of feeding at which the concentrate was used. At low feeding levels the response to an increase in protein content of the concentrate tended to be smaller than that obtained at high feeding levels. At no stage was there any marked response to protein content in the concentrate above 18%. The response curves have been used to demonstrate the interchangeability of level of concentrate feeding and protein content of the concentrate as means of supporting a given level of milk production.

The effect of crude protein content of the supplement on the response to level of supplementation for dairy cows with ad libitum access to grass silage

1989 ◽  
Vol 1989 ◽  
pp. 24-24 ◽  
Author(s):  
C. S. Mayne
Keyword(s):  
Dairy Cows ◽  
Protein Content ◽  
Crude Protein ◽  
Production Systems ◽  
Crude Protein Content ◽  
Response Curves ◽  
Grass Silage ◽  
Milk Output ◽  
Four Levels ◽  
Yield Responses

There is now a considerable volume of evidence to indicate that, with high quality, grass silage-based diets, good animal performance can be achieved by offering supplements of high crude protein content at much lower levels than would be required with conventional supplements. Given the current constraint on milk output at farm level, there is considerable interest in lower cost milk production systems and high protein supplements would appear to have a role to play in this context. However, there is little information available which enables prediction of milk yield responses to increasing levels of supplements of differing protein content. The objective of this study was to determine response curves to supplements of differing protein content, given in addition to grass silage, thereby facilitating a least-cost diet type approach to achieving a given level of milk output.Concentrates containing either 100, 220, 340 or 460 g crude protein (CP)/kg fresh weight were offered to 72 autumn-calving dairy cows from day 14 of lactation, with each concentrate offered at four levels of feeding.

Protein utilisation by the mammary gland in lactating dairy cows

1992 ◽  
Vol 1992 ◽  
pp. 1-1 ◽  
Author(s):  
J A Metcalf ◽  
D E Beever ◽  
J D Sutton ◽  
D J Humphries
Keyword(s):  
Mammary Gland ◽  
Dry Matter ◽  
Milk Composition ◽  
Protein Levels ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Milk Output ◽  
Underlying Mechanisms ◽  
Protein Supply ◽  
Friesian Cows

Milk output has been manipulated by dietary methods for many years, however the underlying mechanisms for changes in milk composition are as yet unclear. In an attempt to further understand these mechanisms we have compared the mammary uptake of metabolites on two isoenergetic diets with different protein levels expected to provide different amounts of amino acid to the mammary gland.Early- to mid-lactation Friesian cows were used to examine the effect of increased dietary protein supply on the supply of metabolites to and uptake by the mammary gland in relation to milk protein synthesis. Two barley based concentrates were formulated to contain 20.8 (Cl) or 29.1 (C2) g N/kg DM, using fishmeal (Provimi 66, high UDP) as the supplementary protein and fed with grass silage (28.3 g N/kg DM) at a total dry matter intake of 17 kg/day. In Experiment 1 these diets were fed at 50:50 (concentrate:silage) to four lactating cows fitted with rumen and duodenal cannulae in a simple crossover design.

Effect of fibre level in the diet of the dairy cow on milk yield and composition

1971 ◽  
Vol 38 (3) ◽  
pp. 381-391 ◽  
Author(s):  
F. J. Gordon ◽  
T. J. Forbes
Keyword(s):  
Energy Intake ◽  
Milk Yield ◽  
Experimental Period ◽  
Metabolizable Energy ◽  
Energy Output ◽  
Crude Fibre ◽  
Fibre Intake ◽  
Lactating Cows ◽  
Milk Output ◽  
High Fibre

SummaryThirty-six lactating cows were used in a 3×2 factorial design experiment to study the effects of level of energy and fibre intake on milk yield and composition over an 8-week experimental period. Three levels of fibre intake — 1g of crude fibre per 25, 17·5 and 10 kcal of estimated metabolizable energy (ME) requirements — were given in diets supplying both 80 and 100% of energy requirements. The level of energy intake significantly affected milk yield, milk energy output and the percentage solids-not-fat (SNF) and protein in the milk. The effects of fibre intake on both milk yield and milk energy output were marked but not significant. Fibre intake had a significant curvilinear effect on both the SNF and protein in the milk with the highest fibre intake resulting in a significant decrease in both fractions. A significant linear decrease was obtained in the lactose fraction as the fibre intake increased.The total volatile fatty acid (VFA) level in the rumen was significantly affected by both energy and fibre intake. The level of energy intake only significantly affected the proportion of propionic acid. Fibre intake significantly affected the proportion of both acetic and butyric acids resulting in mean proportions of acetic acid of 66, 70 and 72 at the low, medium and high fibre intakes. The correlations between the rumen acids and lactation efficiencies are also presented.Multiple regression analysis within each fibre level has been used to partition the ME available for production between that used for milk energy output and liveweight change. The results showed efficiencies of utilization of ME for milk output of 66, 65 and 56 on the low, medium and high fibre diets respectively.Nitrogen balance data are presented.

scholarly journals Apparent digestibility of juveniles of matrinxã Brycon amazonicus fed diets with different protein levels

2021 ◽  
Vol 43 ◽  
pp. e52236
Author(s):  
Cesar Augusto Alves Gonçalves ◽  
Jackson Pantoja-Lima ◽  
Márcia Regina Fragoso Machado-Bussons ◽  
João Paulo Ferreira Rufino
Keyword(s):  
Crude Protein ◽  
Polynomial Regression ◽  
Analysis Data ◽  
Nutrient Digestibility ◽  
Apparent Digestibility ◽  
Protein Ratio ◽  
Digestible Energy ◽  
Protein Levels ◽  
Dry Matter Digestibility ◽  
Four Levels

The objective of the present study was to determine the apparent digestibility of juveniles of matrinxã Brycon amazonicus fed diets with different levels of protein. The experimental design was completely randomized, where the treatments consisted of four levels of protein in the diets (28, 32, 36 and 40%) and five replicates (water boxes) with 10 juveniles of matrinxã each. Diets were offered four times a day, and feces were collected twice a week, along 28 days, for digestibility analysis. Data collected were subjected to polynomial regression at 5% significance. Differences (p<0.05) were observed in dry matter digestibility, with higher digestibility according to increasing levels of protein in the diets. This behavior was directly expressed in the digestibility of nutrients by juveniles of matrinxã, such as % ash, % crude protein, apparent digestible energy, % digestibility of apparent digestible energy and energy: protein ratio. However, this was not observed (p > 0.05) in the digestibility of % ether extract. Digestibility of N, P, Ca, Mg, Cu and Zn presented linear positive (p < 0.05) behavior, in which the use of these minerals increased with the increase in the level of protein in the diets. However, the digestibility of K, Fe and Mn reduced (p < 0.05) with increasing protein levels in the diets. Thus, it can be concluded that the rise in protein level in diets for juveniles of matrinxã improves nutrient digestibility. The results of this study indicated that 40% crude protein in the diets provided better results.

Statistical research on the digestibility in the cow. II. Nitrogen and ether extract

1972 ◽  
Vol 78 (1) ◽  
pp. 141-145 ◽  
Author(s):  
R. Paquay ◽  
R. de Baere ◽  
A. Lousse
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Dry Matter ◽  
Ether Extract ◽  
Crude Protein Content ◽  
Statistical Research ◽  
Lactating Cows ◽  
Hyperbolic Relation ◽  
Faecal Nitrogen ◽  
The Mean

SUMMARYThe results obtained for nitrogen and ether extract digestibility with 116 different rations fed to 242 non-pregnant dry cows and 96 lactating cows were studied.A hyperbolic relation exists between nitrogen digestibility (Y) and crude protein content (X), with the equation:Y = 88·6–(301/X)(r = – 0·928**, RSD = 4·78).Digestible protein content ( Y) is linearly related to crude protein content(X):Y = 0·90X-3·10 (r = 0·982**, RSD = 0·823).From dry-matter intake and crude protein content it is possible to estimate accurately the amount of digestible nitrogen. With all the experimental rations the mean metabolic faecal nitrogen was 496 mg/100 g of ingested dry matter, and the true nitrogen digestibility was conspicuously constant up to 90%.Digestibility of ether extract depends on the nature of the feeds. When the concentrate percentage of the ration is high, the digestibility of ether extract obeys the same laws as that of nitrogen.

The effect of protein content of wheat grain on its nutritive value in pig diets

1974 ◽  
Vol 14 (68) ◽  
pp. 286 ◽  
Author(s):  
KC Williams ◽  
RM Beames
Keyword(s):  
Protein Content ◽  
Soybean Meal ◽  
Crude Protein ◽  
Nutritive Value ◽  
Amino Acid Content ◽  
Backfat Thickness ◽  
Wheat Grain ◽  
Feed Conversion ◽  
Four Levels ◽  
Essential Amino Acid Content

In two experiments pigs were individually and restrictively fed from approximately 24 to 83 kg liveweight. The diets consisted of wheats of varying protein content supplemented with four levels of soybean meal. In experiment 1, wheats of 19.2 per cent and 11.5 per cent crude protein were compared and in experiment 2, the per cent crude protein content of the wheats was 14.9 and 13.1. Average daily gains, feed conversion ratios and carcase characteristics were not significantly affected by source of wheat in experiment 1, whereas in experiment 2, the 14.9 per cent protein wheat resulted in average daily gains and feed conversion ratios significantly superior to the 13.1 per cent protein wheat. Average daily gains and feed conversion ratios in both experiments and carcase quality in experiment 2 improved with increasing level of soybean meal supplementation. The interaction of wheat source x soybean meal level was significant only for backfat thickness in experiment 2. The level of soybean meal at which backfat thickness significantly increased was 6 per cent and 3 per cent with wheats of 14.9 per cent and 13.1 per cent protein respectively. The observed growth performance and carcase quality between the wheats fed appeared to be unrelated to the determined essential amino acid content of the wheat.

Effects of supplementing low-protein diets with sodium dichloroacetate and glucose on growth performance, carcass traits and meat quality of growing-finishing pigs

2021 ◽  
Author(s):  
Yetong Xu ◽  
Huiyuan Chen ◽  
Ke Wan ◽  
Kaifeng Zhou ◽  
Yongsheng Wang ◽  
...  
Keyword(s):  
Growth Performance ◽  
Protein Content ◽  
Meat Quality ◽  
Carcass Traits ◽  
Experimental Period ◽  
Finishing Pigs ◽  
Protein Levels ◽  
Low Protein ◽  
Protein Diets

Abstract The objective of this study was to evaluate the effects of supplementing low-protein diets with sodium dichloroacetate (DCA) and glucose on growth performance, carcass traits, and meat quality of growing-finishing pigs. A total of 80 crossbred (Duroc × Landrace × Large White) growing barrows (27 ± 0.4 kg body weight) were allocated randomly to one of the five treatments during three successive 4-week periods. There were five diets in each phase. Diet 1 was the control diet with normal protein levels (CON) where protein levels in the three phases were 18%, 16.5%, and 15.5%, respectively. The dietary protein levels of Diets 2, 3, 4, and 5 (the low-protein diets, LP) were decreased by 4.5% compared to Diet 1. Additionally, Diets 3 and 4 were supplemented with an extra 120 mg/kg DCA (LP + DCA) or 1.8% glucose (LP + GLUC), respectively. Diet 5 was further supplemented with an extra 120 mg/kg DCA and 1.8% glucose (LP + DCA + GLUC). The LP + DCA diet increased the average daily weight gain of pigs compared to the CON and LP diet in phase 3 and the overall experimental period (P &lt; 0.001). The LP diet reduced the gain:feed ratios of the pigs compared to the CON, LP + DCA, and LP + DCA + GLUC diets in phase 1 and the overall experimental period (P &lt; 0.001). Furthermore, gain:feed ratios in LP + DCA and LP + DCA + GLUC groups did not differ from that of the CON group (P &gt; 0.10). Pigs fed the LP + DCA diet had higher pH values of meat at 24 h post-mortem than the CON group (P &lt; 0.05). The LP + DCA + GLUC diet increased the total protein content in the longissimus dorsi (LD) muscle of pigs, compared to the other dietary treatments (P &lt; 0.05), and increased the Arg and Leu contents in the LD muscle compared to the LP + DCA diet (P &lt; 0.05). Moreover, the LP + DCA diet induced a higher C18:1n9t percentage in the LD muscle of pigs compared to other groups (P &lt; 0.05). In conclusion, an LP diet reduced the feed efficiency in pigs and barely affected meat quality, whereas 120 mg/kg DCA supplementation in an LP diet improved the growth performance of growing-finishing pigs, showed modest effects on carcass traits, and improved the muscle protein content with the addition of glucose.

The effects of the protein content of the diet on the performance of lactating cows

1973 ◽  
Vol 40 (1) ◽  
pp. 93-103 ◽  
Author(s):  
R. Paquay ◽  
J. M. Godeau ◽  
R. De Baere ◽  
A. Lousse
Keyword(s):  
Protein Content ◽  
Milk Production ◽  
Crude Protein ◽  
Milk Composition ◽  
Crude Protein Content ◽  
Lactating Cows ◽  
Stage Of Lactation ◽  
Daily Milk Production ◽  
D 12 ◽  
Limiting Value

SummaryFour experiments were carried out with Friesian cows in different stages of lactation to determine the influence of the crude-protein content of the diet on the digestibility and utilization of dietary constituents and on the cow's performance and milk composition.The rations were composed so that they met the energy requirements of the cows, but crude-protein content was widely variable.Our findings on the digestibility of the dietary constituents were in agreement with the data given in the literature.The utilization of dietary N for milk secretion was influenced by the level of N intake only when the crude-protein content of the diet was lower than a limiting value, which varied according to stage of lactation. When this value was not attained the daily milk production was affected, but not the protein content of the milk.The optimal crude-protein content of the diet was 15–16% (dry-matter basis) when milk production exceeded 20 kg/d, 12–13% for a production of 15–17 kg/d and 11–12% for cows giving less than 10 kg of milk daily.

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