scholarly journals Effect of Varying Dietary Crude Protein Level on Feed Intake, Nutrient Digestibility, Milk Production, and Nitrogen Use Efficiency by Lactating Holstein-Friesian Cows

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2439
Author(s):  
Constantine Bakyusa Katongole ◽  
Tianhai Yan

The effect of dietary crude protein (CP) level on intake, digestibility, milk production, and nitrogen (N) use efficiency was studied. Twenty-four Holstein-Friesian cows (17 multiparous and seven primiparous) were grouped by parity, days in milk, milk yield, and live weight into six blocks of four, and randomly assigned to four total mixed ration (TMR) treatments, containing 141, 151, 177, or 210 g CP/kg dry matter (DM), over 28 day experimental periods. Apparent total-tract DM and fiber digestibilities and milk fat composition were similar across treatments. Milk protein and urea-N compositions, and urinary and manure N excretion increased linearly, while milk N efficiency (MNE) decreased linearly with increasing CP. DM intake was highest with the 177 diet, while CP intake increased linearly with increasing CP, peaking at 200 g/kg DM. Milk yield increased with CP intake for the three lower CP levels, peaking at 176 g CP/kg DM. The further increase in CP level from 177 to 210 g/kg DM did not result in improved milk yield, but resulted in decreased milk N secretion and increased urinary N excretion. In summary, milk protein composition increased linearly with increasing CP, accompanied by a linear decrease in MNE, resulting in a bell-shaped relationship between milk yield and dietary CP level.

Author(s):  
J A Metcalf ◽  
D Wray-Cahen ◽  
B J Bequette ◽  
F R C Backwell ◽  
D J Humphries ◽  
...  

Although milk output is known to be affected by dietary manipulation, studies have so far failed to provide sufficient information to successfully predict dietary effects on both milk protein content and yield (Thomas 1983). In a further effort to determine the metabolic control of milk protein synthesis three diets containing different levels of crude protein were fed to four Holstein-Friesian cows in early- to mid-lactation, and metabolite flow across the mammary gland was measured in relation to milk protein production.


1999 ◽  
Vol 1999 ◽  
pp. 32-32 ◽  
Author(s):  
J.D. Sutton ◽  
S.B. Cammell ◽  
D.E. Beever ◽  
R.H. Phipps ◽  
D.J. Humphries

Increasing maturity at harvest of maize silage has been shown to affect feed intake and milk production in Holstein-Friesian cows (Phipps et al., 1998). The purpose of the present experiment was to determine whether the milk production response was related to improvements in the efficiency of feed energy utilisation.Four multiparous Holstein-Friesian cows (mean live weight 620 kg) fitted with permanent cannulas in the rumen and proximal duodenum were given diets based on maize silage and grass silage (3:1 DM ratio) offered ad libitum plus 8.7 kg DM/day of a concentrate (254 g crude protein (CP)/kg DM) starting 5-10 weeks post-calving. The maize silage was harvested at four different stages of maturity as defined by DM content and ensiled without additives. The grass silage was a first-cut perennial ryegrass (260 g DM/kg, 519 g neutral detergent fibre (NDF)/kg DM, 146 g CP/kg DM).


1987 ◽  
Vol 109 (2) ◽  
pp. 375-386 ◽  
Author(s):  
J. D. Sutton ◽  
J. A. Bines ◽  
S. V. Morant ◽  
D. J. Napper ◽  
D. J. Givens

SummaryTwenty-four Friesian cows were allocated to one of four diets for weeks 3–14 of lactation following 2 weeks on a common diet. The diets (kg air-dry feed/day) were 7–2 kg hay and 10·8 kg either starchy or fibrous concentrates (60S and 60F) or 3·5 kg hay and 14·0 kg either starchy or fibrous concentrates (80S and 80F). Rumen samples were taken by stomach tube in weeks 10 and 12 of lactation and the digestibility of the diets was measured with four cows per treatment during weeks 13 and 14. The digestibility of the same feeds was also measured in sheep at maintenance.The principal carbohydrate constituents of the concentrates were barley, wheat and cassava in the starchy concentrates and citrus pulp, sugar-beet pulp and wheat feed in the fibrous concentrates. The concentrates were designed to have similar concentrations of metabolizable energy (ME) and the diets were planned to provide similar intakes of digestible energy and crude protein.Milk yield and composition were very similar for treatments 60S and 60F. With the higher proportion of starchy concentrates (80S), milk yield was about 20% greater than on 60S, fat concentration fell severely but protein and lactose concentrations were unaffected. With the higher proportion of fibrous concentrates (80F), milk yield and the protein and lactose concentration were similar to values on 60F but fat concentration was lower, though not nearly so low as on 80S. Milk energy yield was reduced by the higher proportion of concentrates but was unaffected by type of carbohydrates. Live-weight changes were small.In both the sheep, consuming at maintenance, and the lactating cows consuming at about 3 times maintenance, digestibility of dry matter, organic matter and energy was higher with the higher concentrate diets but was unaffected by type of concentrate. The digestibility of fibre was greater with the fibrous concentrates but the effect of level of concentrate inclusion was inconsistent. Digestibility coefficients were consistently lower for the lactating cows than for the sheep.The proportion of acetic acid in the rumen volatile fatty acids in the cows was higher and the proportion of propionic acid was lower with the fibrous concentrates. The differences were much greater with the higher proportion of concentrates.During weeks 15–22 of lactation the cows were reallocated to concentrate treatments and given hay ad libitum. Hay intake was about 1 kg/day higher with the fibrous concentrates but the difference was not significant. Hay intake fell by about 0·6 kg/kg concentrate intake for both concentrate types. No significant differences in milk yield or composition were established, probably because of incomplete adaptation even after 8 weeks.It is concluded that at concentrate intakes of about 10 kg/day, the source of carbohydrate in the concentrates has little effect on milk production when the concentrates are of similar ME concentration. However, at higher levels of concentrate inclusion, although the diets may have similar ME concentrations, important differences in the yields of fat, protein and lactose occur due to carbohydrate source and these can be related to differences in rumen fermentation.


1998 ◽  
Vol 7 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Jarmo Valaja ◽  
Hilkka Siljander-Rasi

A digestibility and balance trial was carried out with four intact castrated male pigs (live weight 33-82 kg) to study the effects of dietary crude protein and energy content on nutrient digestibility, nitrogen metabolism, water intake and urinary output. In a 4 x 4 Latin square design, four barley-oats-soya bean meal based diets were arranged 2x2 factorially. The corresponding factors were dietary crude protein (CP) content: high (180 g/kg CP) or low protein diet (140 g/kg CP) supplemented with free lysine, methionine and threonine; and dietary net energy content; high (1.05 feed units (FU)/kg) (feed unit=9.3 MJ net energy) or low net energy content (0.95 FU/kg). Lowering dietary CP content (mean values of 189 to 152 g/kg dry matter, respectively) by supplementation of free amino acids decreased urinary nitrogen (N) excretion by 6.9 g/day (32%) (P


1990 ◽  
Vol 30 (1) ◽  
pp. 7 ◽  
Author(s):  
SC Valentine ◽  
BD Bartsch

Milk production and composition was determined in Holstein-Friesian cows fed either 3.5 or 7.0 kg dry matter (DM) daily of lupin grain, pea grain, faba bean grain or barley grain with or without 1.5% added urea, as supplements to an oaten hay based diet. All the grains were hammermilled. Daily yields of milk (L), fat (kg) and protein (kg) were significantly (P<0.05) higher for cows fed lupin (20.0, 0.81, 0.57), pea (18.9, 0.80, 0.56) and faba bean (18.9, 0.79,0.55) grains compared with those of cows fed barley grain with (17.8, 0.73, 0.51) or without (18.0, 0.71, 0.52) urea. Yields of milk (L), fat (kg) and protein (kg) and milk protein content (g/kg) were significantly (P<0.05) higher when 7.0 kg DM (19.5, 0.80, 0.57, 29.6) compared with 3.5 kg DM (18.0,0.73,0.51,29.0) of grain was fed. There were no significant differences between treatments in hay DM intake by cows fed 3.5 kg DM of grain daily. A significantly (P<0.05) higher milk fat production per unit DM intake was recorded for cows fed legume compared with barley grain. There were generally higher returns above grain cost for cows fed legume compared with barley grain and for cows fed 4 kg compared to 8 kg daily of grain. It was concluded that it was more economical to feed 3.5 kg DM of legume grain compared with 3.5 kg DM of barley grain, with or without urea, as supplements for cows offered cereal hay in early lactation. However, the economics of feeding 7.0 kg DM of legume grain compared with 7.0 kg DM of barley grain and 7.0 kg DM compared with 3.5 kg DM of grain will depend on the costs of relative changes in hay intake associated with these practices.


2001 ◽  
Vol 44 (3) ◽  
pp. 251-262
Author(s):  
W. Richardt ◽  
H. Jeroch ◽  
J. Spilke

Abstract. Title of the paper: The impact of nutrition and non nutrition factors on milk urea concentration. I. The impact of nutrition factors on milk urea concentration The object of this study was to determine the impact of dietary crude protein / energy balance, stage of lactation parity, milk yield or milk protein yield, milk protein content, somatic cell count, season and herd on milk ureä concentration under the conditions of large herds (50–1000 dairy cows) and routine milk yield recording. From this data a model was created to predict the milk urea concentration for a single dairy cow or a feeding group For the analysis of the data a mixed linear model (proc mixed; SAS®, 1997) was used. The fixed effects (ratio of crude protein / energy, degradability of dietary crude protein, ruminal N-balance, lactation period, parity) was computed by generalized least-squares-means. The season, herd and month were used as random effects Milk yield or milk protein yield, milk protein content, somatic cell count and day in milk were included as Covariables in the model. The effect of dietary crude protein / energy balance on milk urea was significant (p < 0.0001). For diets with an optimal ratio of crude protein / energy (according to GfE, 1997) 226 mg/1 was calculated using least-squares-means. For diets with excess of crude protein this figure rose to 252 mg/1 In this study a significant difference in least-squares-means calculated urea concentration did not existed for degradability of dietary crude protein. On the other hand, a significant difference in least-squares-means calculated urea concentration existed for ruminal N-balance between 0 and 2.


Author(s):  
K. Aston ◽  
J.D. Sutton ◽  
R.D. Baker ◽  
W.J. Fisher

The response in yields of milk constituents to increases in the amounts of standard dairy concentrate (SC, 200 g crude protein (CP) per kg DM) given to cows consuming grass silage ad libitum were reported recently (Aston et al 1991; Baker et al 1991). A change of level however adjusts the supply of both energy and CP. Previous work also showed .linear responses in silage intake and milk and milk protein yields when CP was increased in a fixed ration of concentrate of constant energy value. In this trial energy and CP levels were varied Independently. The objective was to separate the effects of energy on the performance of lactating cows from those of CP.


Author(s):  
J.D Sutton ◽  
K. Aston ◽  
D.E Beever ◽  
W.J. Fisher

The importance of measuring partition between body and milk in dairy cows and identifying the factors underlying it has long been recognised. However accurate measurements of partition In the body are few because of the difficulty and expense of the techniques.The purpose of the present experiment was to measure the effects in autumn-calving Holstein-Friesian cows given grass silage ad libitum of amount of concentrate and stage of lactation on body composition by direct (Gibb et al 1992a, b) and Indirect (Kings et al 1992) techniques, adipose tissue metabolism (Walsh et al 1992) and milk production. In a related trial, energy balance was measured in other cows by Indirect calorimetry (Cammell et al 1992).This report covers silage Intake, milk production and live-weight change. Communications on the associated studies are given in the Proceedings of this Meeting.


1997 ◽  
Vol 37 (5) ◽  
pp. 505 ◽  
Author(s):  
W. K. Ehrlich ◽  
T. M. Davison

Summary. Twenty-four Holstein–Friesian cows were used in an experiment comparing milk production from cows offered rolled sorghum grain either alone at 8 or 10 kg/head. day of air-dried grain or with 4% sodium bentonite. The design was a 4 × 4 latin square with a 1 week adjustment period and a 3 week treatment period. This design was used to highlight the effects of high levels of grain feeding and changing that level of grain or grain–bentonite every 4 weeks. Cows grazed either ryegrass (Lolium multiflorum cv. Tetila) or oats (Avena sativa cv. Cluan) during the day and a mixed ration based on maize silage, lucerne hay, and meat and bone meal at night. There was no significant effect of treatments on milk yield or composition. Cows fed bentonite had a higher (P<0.05) rumen pH, tended to eat less grain sorghum and have lower concentrations of rumen ammonia and faecal starch. Faecal crude protein tended to increase with the use of bentonite indicating cows may have substituted pasture or mixed ration for grain and maintained a more stable rumen fermentation.


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