The Effects of Dietary Fat on the Yield and Relative Proportions of Different Milk Protein Fractions From Dairy Cows

Author(s):  
J.M. Moorby ◽  
R.J. Dewhurst ◽  
S. Marsden

The inclusion of supplementary fat in the dairy cow diet is an effective and cheap method of increasing its metabolisable energy (ME) density. However, an increase in the fat content of the diet frequently causes a decrease in the protein concentration of milk, which, when the market requires an increase in the protein:fat ratio of milk, is not a desireable effect. This experiment was designed to compare die effect of dietary fat on die yield and concentrations of milk proteins in comparison to a carbohydrate ME source.Twelve multiparous mid-lactation Holstein-Friesian cows were used in a 3x3 Latin square changeover experiment with 3 four-week periods. Cows were allocated to squares on the basis of their mean milk yield over the 7 days prior to the experiment. Within squares, treatments were randomly allocated to each cow. The first 21 days of each experimental period were used for adjustment, and the last 7 for sample collection.

Author(s):  
J.M. Moorby ◽  
R.J. Dewhurst

The urinary excretion of allantoin and uric acid (collectively purine derivatives, or PD) provides an estimate of the yield of microbial protein (MP) from the rumen. The technique is useful for estimating rumen efficiency of dairy cows, but due to the problems associated with urine collection, its use is limited on the large scale. Measuring PD in milk would allow more routine assessments to be carried out on a practical level.Twelve multiparous mid-lactation Holstein/Friesian cows were used in a 3x3 Latin square changeover experiment with 3 four-week periods. Cows were allocated to squares on the basis of their mean milk yield of the 7 days prior to the trial. Within squares, treatments were randomly allocated to each cow. The first 25 days of each experimental period were used for adjustment, and the last 3 for the collection of milk and urine samples.


Author(s):  
C. A. Huckle ◽  
A. J. Rook ◽  
R. J. Wilkins

Clements, Huckle and Wilkins (1991) reported that milk yield did not differ significantly between cows grazing grass-clover swards with compressed sward heights maintained at either 4.5 or 6 cm in early season. However, cows grazing the shorter sward produced milk with a lower protein concentration. The feeding of 4 kg concentrates/day resulted in an increase in milk yield at both sward heights but there was no effect on milk constituent concentrations. The present experiment was designed to investigate the effect of a wider range of sward heights and their interaction with concentrate supplementation.Forty eight, multiparous, Holstein Friesian cows with a mean calving date of 21 March were continuously stocked on mixed grass-clover swards. The cows were blocked by calving date, parity and milk yield and randomly allocated to one of six treatments, 0 (U) or 4 kg concentrate supplementation (S) with swards maintained at 4, 6 or 8 cm compressed sward height. Sward heights were maintained by adjusting the grazed area. The swards were permanent pastures which had received no fertilizer nitrogen.


1993 ◽  
Vol 73 (3) ◽  
pp. 547-557 ◽  
Author(s):  
H. Ben Salem ◽  
R. Krzeminski ◽  
A. Ferlay ◽  
M. Doreau

Four Holstein × Friesian cows with rumen and duodenal cannulae were assigned to a 4 × 4 Latin square design consisting of four experimental diets differing in the nature of forage and the presence or absence of rapeseed oil supplement. Dietary treatments were composed of 60% grassland hay and 40% production concentrate (diet H), and of 65% corn silage, 28% production concentrate and 7% soybean meal (diet S). Each diet was also supplied with 7% rapeseed oil. These supplemented diets are designated respectively HO and SO. Digestibility of organic matter was 69.0, 67.5, 73.6 and 70.0% for diets H, HO, S and SO, respectively. The differences were mainly due to variations in NDF digestibility: 55.0, 50.4, 56.9 and 46.9% for diets H, HO, S and SO, respectively. These results are consistent with variations in VFA concentration and composition. However, differences among diets in in situ cellulose degradation were lower than expected. Starch and nitrogen degradation measured in situ, and ruminal outflow rate of liquid and solids were not modified by lipid supply. Hydrogenation of linoleic and linolenic acids was high (mean 88.9 and 89.5%, respectively) and did not depend on the diet. Key words: Cow, digestion, rumen, lipid supply


Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 961
Author(s):  
Ignacio E. Beltran ◽  
Pablo Gregorini ◽  
José Daza ◽  
Oscar A. Balocchi ◽  
Alvaro Morales ◽  
...  

The objective of this work was to evaluate whether changes in time of herbage allocation and herbage mass (HM) (low (L) or medium (M)) modify the diurnal pattern of urinary nitrogen (N) concentration and ruminal ammonia (NH3) of lactating dairy cows. Four Holstein-Friesian cows fitted with rumen cannula were randomly allocated to one of four treatments: 1) low herbage mass in the morning (L-AM) (Access to new herbage allocation after morning milking with a herbage mass (HM) of 2000 kg DM/ha); 2) low herbage mass in the afternoon (L-PM) (Access to new herbage allocation after afternoon milking with a HM of 2000 kg DM/ha); 3) medium herbage mass in the morning (M-AM) (Access to new herbage allocation after morning milking with a HM of 3000 kg DM/ha); and 4) medium herbage mass in the afternoon (M-PM) (Access to new herbage allocation after afternoon milking with a HM of 3000 kg DM/ha). A four by four Latin Square design with four treatments, four cows, and four experimental periods was used to evaluate treatment effects. Rumen NH3 concentration was greater for L-AM compared to L-PM and M-PM at 13:00 and 16:00 h. Urine urea and N concentrations were lower for M-AM compared to L-AM. Urine N concentration was greater for L-AM than other treatments at 10:00 hours and greater for M-PM compared to M-AM at 16:00 hours. Results suggest that maintaining the cows in the holding pen at the milking parlor for two hours after morning grass silage supplementation for L-AM and for two hours after afternoon grass silage supplementation for M-PM, could allow collection of urine from cows at the holding pen and storage of urine in the slurry pit during the time of peak N concentration, returning cows to the pasture at a time of day when urinary N concentration is decreased.


2013 ◽  
Vol 56 (1) ◽  
pp. 178-190 ◽  
Author(s):  
K. Puppel ◽  
T. Nałęcz-Tarwacka ◽  
B. Kuczyńska ◽  
M. Gołębiewski ◽  
M. Kordyasz

Abstract. This study examined the effect of different fat supplements on the antioxidants of cow’s milk. Thirty five Polish Holstein Friesian cows at 180±20 day of lactation and averaging 17.71±2.26 kg/d of milk were divided into five equal groups. There were five treatments groups: 300 g/d of fish oil, 500 g/d of Opal linseed, 500 g/d of Szafir linseed, 150 g/d of fish oil + 250 g/d of Opal linseed, 150 g/d of fish oil + 250 g/d Szafir linseed. Milk samples were collected five times during the 21 day of supplementation period: at the 1st, 14th and 21th day of the experimental period, and also at the 14th and 21st day after the supplement withdrawal. Diet supplementation with the Szafir linseed improved the chemical composition and milk yield at the 21st day of experiment. The highest level of malondialdehyde was recorded in fish oil, Opal linseed, fish oil + Opal linseed, and fish oil + Szafir linseed groups, and the lowest in the Szafir linseed group. After the 21st day of supplementation the concentration of α-retinol was significantly increased in all groups by 23 to 183 %. The highest level of α-tocopherol was found in fish oil + Opal linseed group at the 21st day of supplementation. Total antioxidative status increased in all experimental groups; however, the highest peak was recorded in fish oil + Szafir linseed and Szafir linseed group. The experiment confirmed that manipulation in cows’ diet may improve antioxidative capacity of milk.


1996 ◽  
Vol 1996 ◽  
pp. 85-85 ◽  
Author(s):  
R.J. Dewhurst ◽  
D.W.R. Davies ◽  
W.J. Fisher ◽  
K. Aston

Previous studies (Moorby et al, 1994) have shown increased yields of protein and lactose in the subsequent lactation as a consequence of feeding additional undegradable dietary protein (UDP) and restricting energy intake during the dry period. This experiment was undertaken to investigate the effect of supplementary UDP in the dry period diet of Holstein-Friesian cows given unrestricted access to grass silage and 1.5 kg of barley per day.Sixty-one cows received diets based on ad libitum access to grass silage with either (a) 1.5 kg barley / day or (b) 1.0 kg barley and 0.5 kg Maize Gluten Meal / day. After calving, cows had ad libitum access to grass silage (Metabolisable Energy (ME)=11.3 MJ/kg DM; crude protein (CP)=181 g/kg DM) and received 5 kg/day of concentrates (ME=13.0 MJ/kg DM; CP=250g/kg DM).


Author(s):  
N. Iqbal ◽  
J.D. Leaver

Cereal straw is the most abundant of crop residues and is an important feed resource especially in tropical countries. The limitations to its use arise from its high cellulose and lignin and low nitrogen content. The objectives of this research were to investigate the use of urea for the treatment of wheat straw and incorporation of the forage into dairy cow diets.In Experiment 1, 8 lactating Holstein Friesian cows were used in two 4 x 4 Latin Squares with three week periods. The treatments were; A - red clover silage (CS) ad libitum. B - 5kg DM/day CS + urea treated straw (TST) ad libitum. C - as for B but using untreated straw (UST), D - as for C but the straw was wetted at feeding to produce the same DM as TST (WST 600 g DM/kg). TST was treated with 5% urea (DM basis) and stored for 4-13 weeks. All cows were fed 6.4 kg DM/day of molassed sugarbeet pulp (MSBP) and o.6 kg DM/day of cottonseed meal (CSM).In Experiment 2, 10 Holstein Friesian cows were used in an incomplete Latin Square design of four 3 week periods. The treatments were; E - CS, F - 25% UST + 75% CS, G - 50% UST + 50% CS, H - 25% TST + 75% CS, I - 50% TST + 50% CS. All forages were offered ad libitum, arid in F to I pairs of forages were mixed. The urea was applied to TST at a rate of 7.5% (DM basis). The concentrate was 4.7 kg DM/day of MSBP and 2.3 kg DM/day of soya meal.


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.


2004 ◽  
Vol 20 (3-4) ◽  
pp. 1-4
Author(s):  
I. Bencsik ◽  
N. Pacala ◽  
T. Theilen ◽  
Jana Stanculet ◽  
Alena Bencsik

In our study the behavior of dairy cows was studied during the first three months of lactation. The experiments were done on 25 cows raised in free-stalls on slatted floor in 25.5-31.5 m 2 boxes. In the experimental period the cows were fed grass, silage and hay. The concentrates were used for feeding during the milking time and the quantity depended on milk production of each cow. The dairy cows were monitored every 10 minutes in 24 hours period for several days. We have observed that the primiparous and secundiparous cows are resting 1-2 hours less than the older cows. The time needed to ingest the forages is longer at primiparous and secundiparous. During 24 hours, cows are spending 12-14 hours on rest, so it is necessary to build comfortable and spacious pens. Cows are spending 5-6 hours on feeding, so we must provide a larger feeding area for each cow.


1996 ◽  
Vol 1996 ◽  
pp. 85-85
Author(s):  
R.J. Dewhurst ◽  
D.W.R. Davies ◽  
W.J. Fisher ◽  
K. Aston

Previous studies (Moorby et al, 1994) have shown increased yields of protein and lactose in the subsequent lactation as a consequence of feeding additional undegradable dietary protein (UDP) and restricting energy intake during the dry period. This experiment was undertaken to investigate the effect of supplementary UDP in the dry period diet of Holstein-Friesian cows given unrestricted access to grass silage and 1.5 kg of barley per day.Sixty-one cows received diets based on ad libitum access to grass silage with either (a) 1.5 kg barley / day or (b) 1.0 kg barley and 0.5 kg Maize Gluten Meal / day. After calving, cows had ad libitum access to grass silage (Metabolisable Energy (ME)=11.3 MJ/kg DM; crude protein (CP)=181 g/kg DM) and received 5 kg/day of concentrates (ME=13.0 MJ/kg DM; CP=250g/kg DM).


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