Composition Of Cows Research Articles

Effect of Dietary Condition on Milk Production and Composition of Cows and Buffaloes During One Lactation

AbstractIn the present investigation the effects of feeding concentrate mixture (25.6% C.P.) and groundnut cake (45.6% C.P.) to four groups of Kankrej cows and Surti buffaloes have been reported. There were three animals per group. Milk yield and composition were higher for concentrate fed groups in comparison to that for the groundnut (GN)‐cake fed groups. Green grass supplementation alongwith the major feed excercised positive effect on the milk production and 4% FCM.

Effect of intravenous supplements of L-methionine on milk yield and composition in cows given silage-cereal diets.

Eight cows in mid lactation and receiving a diet of perennial ryegrass silage and barley (70:30 on a DM basis) were given intravenous supplements of L-methionine (8 g/d). The methionine treatment had no significant effect on milk yield, protein content or lactose content, but increased milk fat content and yield by approximately 10% (P less than 0.05).

The effects of protein degradability and food intake on milk yield and composition in cows in early lactation.

1. In two experiments measurements were made of food intake, live-weight change, milk yield and milk composition in early lactation when dairy cows were given diets containing varying proportions of protein as fish meal (low rumen degradability) or as groundnut meal (high rumen degradability). In a preliminary trial measurements were also made with cows given supplements of either fish meal or barley and fed at a restricted level of feeding. 2. When metabolizable energy (ME) intake exceeded 160 MJ/d there was no evidence of responses to changes in protein degradability, ut at ME intakes below 135 MJ/d increases in the supply of undegradable protein led to increases in fat-corrected milk yield, protein content and live-weight loss. 3. The interaction between energy intake and protein degradability is unexpected because net protein:net energy requirement increases as milk yield increases, but may be explained in terms of differential effects of changing rumen outflow rates on degradabilities.

Effect of protected casein supplements on pasture intake, milk yield and composition of cows in early lactation

Thirty dairy cows in early lactation were individually fed in stalls on high quality pasture (Lolium peuenne, Dactylis glomerata and Trifoliium repens) and given either formaldehyde-treated casein or untreated casein at 1000 g/day. Nitrogen content and apparent digestibility of herbage nitrogen was 2.8 and 70.4% respectively. Treated casein significantly increased the yield of milk by 13 % and milk protein by 15 % although neither supplement affected milk composition. High-producing cows showed a greater response to formaldehyde-treated casein, with increases in milk yield of 0.5 �0.14 kg per kg increase in level of milk production. Increases in milk synthesis were associated with increased efficiency in utilization of nutrients and not with changes in pasture intake. The results support the hypothesis that formaldehyde-treated casein provided more protein for duodenal digestion and thereby increased the supply of essential amino acids which were limiting milk production. It is concluded that milk synthesis in cows fed solely on high quality pasture in early lactation is limited by the amount of protein absorbed post-ruminally.

Yield and Protein Composition in Cows Milked Prepartum

Fifteen cows in various lactations were milked for an average of 14 days prepartum. Most cows were stimulated for increased secretion 2 or 3 days before parturition. Prepartum milking resulted in an earlier peak of milk secretion in all cows so treated as well as a 10% increase in milk yield in the first 100 days of lactation. The protein contained 60% immunoglobulins 14 days before parturition. This percent decreased rapidly from the 4th day before parturition to 25% on the day of parturition and 3.3% of the protein 2 days later. Caseins increased from 28% of the protein on the 4th day prepartum to 64% on the 2nd day postpartum. Edema was only slightly reduced by prepartum milking.

The effects of nutritional level on milk yield and milk composition in cows and heifers

SummaryThe effects of diets high in concentrates and low in roughage on the yield of milk and milk constituents were studied in 32 cows and heifers throughout lactation. A high level of concentrates in the ration caused an increase in milk yield, a decrease in fat percentage but not in total fat yield, and an increase in protein production.Milk produced under such feeding conditions is capable of yielding greater quantities of curd than would be expected from its fat content, and should be evaluated accordingly. Feed requirements of the cows should be assessed not solely on the basis of the fat content of their milk but also in accordance with the protein content.

The Effect of Ethanol and Acetic Acid on Milk Yield and Milk Composition of Cows Given Rations High in Concentrates

(1970). The Effect of Ethanol and Acetic Acid on Milk Yield and Milk Composition of Cows Given Rations High in Concentrates. Acta Agriculturae Scandinavica: Vol. 20, No. 1, pp. 17-24.

Ryegrass varieties in relation to dairy cattle performance

The effects of cows grazing short and long pastures of ‘Grasslands Ruanui’ perennial ryegrass on the yield and composition of the milk were compared in two experiments. The cows grazing short pasture produced significantly more milk in both experiments than those grazing long pasture. The butterfat percentage in the milk from the two groups did not differ, and the solids-not-fat percentage was depressed by the short pasture in the first experiment and by the long pasture in the second. The depression in the solids-not-fat percentage caused by the short pasture in experiment 1 may have been associated with the chemical composition of the pasture, but the depression caused by the long pasture was probably associated with a lowered intake of digestible energy. The effect on milk yield and composition of cows grazing Ruanui ryegrass pastures which had received high and low levels of nitrogen fertiliser was also examined. The milk yields of cows grazing pasture which had received high levels of nitrog...

Ammonium salts of fatty acids for milk production 2. The effect of feeding a salt solution containing ammonium acetate on the yield and fatty acid composition of Jersey milk fat

SUMMARY1. The effect of feeding a salt solution containing ammonium acetate on the yield and fatty acid composition of cows' milk fat has been studied.2. The trials involved eighteen lactating Jersey cows. In the first trial one group of 5 cows was fed the treatment diet throughout an experimental period of 10 weeks and another group of 5 cows acted as controls. In the second trial which extended over four 28-day periods, two groups of 4 cows spent alternate periods on treatment or control diets. The overall results of the two trials were in agreement.3. The outputs of C4-C14acids and of palmitic acid per kg of milk yielded were greater than the intakes. The output of C18acids was less than the intake per kg of milk yielded. These observations were noted on both treatment and control.4. Treatment resulted in an increased secretion of C4-C14acids and of palmitic acid and a decreased secretion of C18acids per kg of milk yielded.5. The results have been discussed in the light of present knowledge concerning the synthesis of fat in the mammary gland.

Composition of Cows’ Milk. I. Environmental and Managerial Influences

Means and standard deviations for 4,664 age-adjusted 305-day lactational records on 3,472 Holstein-Friesian cows were milk 6,820 ±1,384kg; fat, 3.67±.41% and 245±50kg; solids-not-fat, 8.51±.37% and 560±112kg. Age at calving accounted for 10.0–14.3% of the total variance in milk, fat, and solids-not-fat yields, and days milked for 14.0–18.0%. Month of calving accounted for 0.5–5.8%, days carried calf for 0.1–1.2%, and body weight for zero to 0.8% of the total variance in yields. Age at calving and days carried calf affected solids-non-fat per cent significantly and accounted for 12.4 and 0.4%, respectively, of the total variance. Fat per cent was not affected significantly by any of the factors.Lactational records of milk, fat, and solids-not-fat yields before comparing with one another or for use in genetic analyses should be adjusted for age at calving, number of days milked, and month or season of calving.

The effect of growth hormone on the yield and composition of cows' milk.

SUMMARY Using a single injection technique, a study has been made of the effect of growth hormone (GH) on the yield and composition of cows' milk. Six lactating cows comprising three sets of identical twins each received six different injection levels during a 78-day period. Quantities of GH injected ranged from 6·25 to 200 mg in geometric progression, and responses were measured for milk yield (lb.), fat percentage, and solids-not-fat percentage, together with the derivatives of these three. Quantities of food consumed by the animals were calculated from the weights of food offered and refused, and total dry-matter intakes were derived from dry-matter estimates obtained on every 3rd day. Results from this experiment show that there is a highly significant linear relationship between log weight of GH injected (mg) and the increase in milk yield (lb.) obtained. Significant linear relationships have also been found between log weight of GH injected (mg) and the degree of change obtained in each of the following milk components: water (1b.); fat (1b.); and solids-not-fat (lb.). Further analysis of the data has shown that by increasing the quantity of GH injected, significant increases are produced in the yield of fat (lb.) relative to the yield of non-fatty-solids (lb.). This is attributed to a significant negative relationship between log weight of GH injected (mg) and the extent of the change in the solids-not-fat percentage. Administration of GH produces increases in the efficiency of conversion of food dry matter to milk and the extent of these changes is closely related to those of milk yield. The results are discussed in relation to previously published findings, and possible explanations for some of the phenomena noted are advanced.

442. Variations in composition of cows' milk during a period of 12 weeks

The milk from twelve individual cows in a mixed herd in Shropshire was sampled twice weekly over a period of 12 weeks, which covered the transition from winter to summer conditions of feeding. Detailed analytical results are tabulated, and certain figures presented in graphical form. In addition, bulk samples of both morning's and evening's milk were obtained and tested for fat and solids-not-fat.On the whole the results show great individual consistency of composition, but an appreciable rise in the crude protein content of the milk from all cows took place in late April and in May, this effect being attributed to the change-over in feeding to an all-grass diet. From a consideration of the figures obtained, it is deduced that:(1) The average composition of mid-lactation milk may differ markedly from cow to cow, but appears to be unchanged by minor alterations in the winter rations, provided these are reasonably satisfactory to begin with. There is, however, a marked increase in total protein resulting from the introduction of spring-grass feeding.(2) The results show that a herd, although well-fed and efficiently managed, may produce milk in the late winter months, and even in the early spring, which is below the legal standard of 8·50% in s.n.f.

Œstrogens in Grass and their Possible Effects on Milk Secretion

STUDIES of variations in the composition of cows' milk1,2 have revealed a progressive decline in the non-fatty solids content during the winter months, followed by a substantial and immediate rise When the cows are turned out to grass in the spring. Also it is widely recognized that on ‘going out to grass' cows often show an increase in milk yield, greater than the amount ascribable to the extra nutrients ingested.

The composition of cows' milk in the Sudan

The composition of cows' milk in the Sudan

Variation in the Composition of Cows' Milk

The object of the present communication is to collect together and compare the data obtained in the principal investigations which have been carried out in this country during the past five years into the variations in composition of the milk of the cow. The results of many of these experiments have been published only in annual reports or as special bulletins with limited and more or less exclusively local circulation.

LVI.—The composition of cows' milk in health and disease

LVI.—The composition of cows' milk in health and disease