scholarly journals Effects of and interactions between the extent of silage fermentation and protein supplementation in lactating dairy cows

1998 ◽  
Vol 7 (3) ◽  
pp. 329-343 ◽  
Author(s):  
Terttu Heikkilä ◽  
Vesa Toivonen ◽  
Pekka Huhtanen
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Protein Supplementation ◽  
Plasma Urea ◽  
Silage Fermentation ◽  
Milk Protein Content ◽  
Fat Yield ◽  
Glucose Plasma ◽  
Dietary Treatments

Twelve Ayrshire cows were used to study the effects of and interactions between extent of silage fermentation and level of protein supplementation on silage intake and milk production. Experimental design was a cyclic change-over with six dietary treatments, with two replicate blocks of six cows and four 3-week periods. Dietary treatments in a 2 x 3 factorial arrangement consisted of two wilted silages treated with either a formic acid-based (FA) 5 l/t or a bacterial inoculant additive (I) and three levels of protein supplementation obtained by fish meal (FM) inclusion (0, 60 and 120 g/kg concentrate). Grass silage was given ad libitum and concentrates were offered at a rate of 10 kg/d. Both silages were well-preserved but I-silage was more extensively fermented than FA-silage. Feeding FA-silage decreased diet organic matter digestibility, particularly that of neutral detergent fibre, compared with I-silage. Inclusion of FM increased the digestibility of all dietary constituents. Dry matter (DM) intake of I-silage was lower than that of FA-silage but milk yield was not significantly affected. Restricting silage fermentation increased milk fat content, fat yield and energy corrected milk yield. FM inclusion increased silage DM intake, milk yield, milk protein content and yield. FM120 inclusion increased milk fat yield more with FA-silage than with I-silage, whereas the response in milk protein yield was greater with I-silage. Plasma glucose, plasma urea and milk urea concentrations were lower and blood β-hydroxybutyrate higher in cows given FA-diets than those given I-diets.

Production responses of dairy cows grazing well-managed kikuyu (Pennisetum clandestinum) pastures to energy and protein supplementation

1996 ◽  
Vol 36 (7) ◽  
pp. 763 ◽  
Author(s):  
M Reeves ◽  
WJ Fulkerson ◽  
RC Kellaway
Keyword(s):  
Milk Production ◽  
Milk Fat ◽  
Milk Protein ◽  
Protein Supplementation ◽  
Control Group ◽  
Plasma Urea ◽  
Pennisetum Clandestinum ◽  
Cereal Grain ◽  
Metabolisable Energy ◽  
Production Response

Three studies were conducted to examine the production response of Friesian cows grazing well-managed lukuyu (Pennisetum clandestinum) pasture to supplementation with a cereal grain concentrate, with and without the inclusion of formaldehyde-treated protein meal. Mean (¦ s.e.) levels of nutrients in the pasture (g/kg DM) on offer were: 205 ¦ 3 crude protein; 683 ¦ 7 in vitro organic matter digestibility; 239 ¦ 2 acid detergent fibre; 615 ¦ 8 neutral detergent fibre and 4.47 ¦ 0.16, 2.51 ¦ 0.06, 31.96 ¦ 0.98, 0.39 ¦ 0.03 and 3.18 ¦ 0.09 of calcium, phosphorus, potassium, sodium and magnesium, respectively. Study 1 was a 3-farmlet study conducted over 45 days (March-April 1993) involving cows 5-6 months into lactation, which compared 3 levels of concentrate feeding at 0 (R0), 3 (R3) or 6 (R6) kg crushed barley/cow.day. Study 2 was an 18-day extension of study 1 with animals in the seventh month of lactation. The concentrate fed was 72% barley and 24% formaldehyde-treated sunflower meal. Pasture intake of individual cows was determined using an alkane technique. Mean milk yields (L/cow. day) in study 1 were 14.2, 18.3 and 18.0, and in study 2 were 12.5, 18.5 and 17.4 for treatments R0, R3 and R6, respectively. Milk fat (3.77 v. 3.26%), but not milk protein, content of the Ro cows was significantly higher than R6 cows in study 1 only. In study 2, the apparent whole-diet digestibility remained constant as concentrate level rose, indicating a negative effect of concentrate fed on forage digestibility in the absence of buffers. Study 3 was a 3 x 4 factorial design plus a 'control' group (0.5 kg barley/cow.day used as a carrier for minerals) to examine the milk production response to 3 levels of concentrate feeding (3, 6 and 9 kg/cow.day) with 4 levels of formaldehyde-treated canola meal (FTCM; 0, 20, 40 and 60% of concentrate). Rations were iso-energetic within levels of concentrates fed. The control group had significantly lower milk production (17.2 L/cow.day), as well as milk protein (2.90%), plasma urea (PU) (5.90 mmol/L) and P-hydroxybutyrate (G-OHB) (0.525 mmo1L) than other treatment groups. The mean milk production response of 0.6 L milk/kg concentrate fed in study 3 at the 3 kg/day level of feeding was lower than observed in studies 1 and 2 (1.4 and 2.0 L/kg concentrate, respectively). The level of metabolisable energy in the concentrate in study 3 had a significant influence on milk production, milk fat and milk protein levels. Plasma glucose and G-OHB levels significantly increased with the incorporation of FTCM into the concentrate. Nonesterified fatty acid levels dropped significantly below levels of other treatments at the lowest level of inclusion of FTCM. PU levels generally increased in response to increasing metabolisable energy and inclusion of FTCM in the concentrate, with an interaction between them. Milk urea (MU) levels (mmol/L) showed a significant linear (P<0.001; r2 = 0.44) relationship to PU levels (mmol/L) as follows: MU = 0.167 + 0.272PU.

scholarly journals The chemical composition and technological properties of milk obtained from the morning and evening milking

2008 ◽  
Vol 56 (5) ◽  
pp. 187-198 ◽  
Author(s):  
Martin Skýpala ◽  
Gustav Chládek
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Protein Production ◽  
Milk Protein ◽  
Fat Content ◽  
Total Solids ◽  
Milk Protein Content ◽  
Solids Content ◽  
Morning Milk

Milk yield varies during lactation, following what is termed a lactation curve. ŽIŽLAVSKÝ and MIKŠÍK (1988) recorded changes in milk yield within a day, too. TEPLÝ et al. (1979) a KOUŘIMSKÁ et al. (2007) published variation within a day ± 1.10 kg in milk yield, ± 0.75 % in milk fat content and ± 0.20 % in milk protein content. Milk yield of cows can be expressed in many different ways, for instance, in kilograms per lactation or in kilograms per day. A practical parameter describing milk production is milk yield (kg) per milking.The object of experiment were 12 cows of Holstein cattle on the first lactation from the 100-day of lactation to 200-day of lactation. The samples of milk were collected from January to May 2007, once a month from the morning and evening milking (milking interval 12 h ± 15 min.). The following parameters were monitored: milk production – milk yield (kg), milk protein production (kg), milk fat production (kg); milk composition – milk protein content (%), milk fat content (%), lactose content (%), milk solids-not-fat content (%), milk total solids content (%); technological properties of milk – ti­tra­tab­le acidity (SH), active acidity (pH), rennet coagulation time (s), quality of curd (class) and somatic cell count as a parameter of udder health.Highly significant differences were found (P < 0.01) between morning milk yield (15.7 kg) and evening milk yield (13.8 kg), between morning milk protein production (0.51 kg) and evening milk protein production (0.45 kg) and between evening milk fat content (4.41 %) and morning milk fat content (3.95 %). A significant difference (P < 0.05) was found between morning milk total solids content (12.62 %) and evening milk total solids content (12.07 %). No significant differences were found between morning (M) and evening (E) values of the remaining parameters: milk fat production (M 0.62 kg; E 0.60 kg), milk protein content (M 3.24 %; E 3.27 %), milk lactose content (M 4.78 %; E 4.86 %), milk solids-not-fat content (M 7.69 %; E 7.71 %), somatic cell count (M 80 000/1 mL; E 101 000/1 mL), titratable aci­di­ty (M 7.75 SH; E 7.64 SH), active acidity (M pH 6.58; E pH 6.61), rennet coagulation time (M 189 s.; E 191 s.), quality of curd (M 1.60 class; E 1.57 class).

MILK PRODUCTIVITY OF BLACK-AND-WHITE CATTLE WITH DIFFERENT GENOTYPES OF PROLACTIN AND SOMATOTROPIN

2021 ◽  
pp. 21-25
Author(s):  
Л.Р. ЗАГИДУЛЛИН ◽  
Р.Р. ШАЙДУЛЛИН ◽  
Т.М. АХМЕТОВ ◽  
С.В. ТЮЛЬКИН ◽  
А.Б. МОСКВИЧЕВА
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Milk Productivity ◽  
Black And White ◽  
Gh Gene ◽  
White Cattle ◽  
Fat Yield ◽  
Prl Gene

Изучена взаимосвязь аллельных вариантов генов пролактина и соматотропина с показателями молочной продуктивности коров черно-пестрой породы по 1 и 3 лактации. У первотелок, как и у полновозрастных животных,  наиболее высокий удой (4642 и 6240 кг), количество молочного жира (174,1 и 215,0 кг) и молочного белка (149,0 и 182,5 кг) достигнуты в группе с генотипом PRL АА. По массовой доле жира и белка в молоке коровы с генотипом PRL ВВ достоверно превосходили животных с генотипом PRL АА на 0,12% (Р<0,05) и 0,05% (Р<0,05) соответственно. По гену соматотропина наибольший уровень молочной продуктивности выявлен у коров с генотипом GH LL при достоверном преимуществе над GH VV у первотелок по удою на 439 кг (Р<0,01), выходу молочного жира — на 13,6 кг (Р<0,001), выходу молочного белка — на 15,3 кг (Р<0,01). У полновозрастных коров превышение над остальными группами было только по удою — на 219—548 кг (Р<0,05). Наибольшая жирномолочность характерна животным с генотипом GH VV по 1 лактации — 3,83% и по 3 лактации — 3,82%, а лучшая белковомолочность — коровам, имеющим аллель V гена GH:  3,21 и 3,23% соответственно. Полученные данные свидетельствуют о более высоком уровне молочной продуктивности у коров с генотипом PRL АА и GH LL, но лучшая жирномолочность и белковомолочность отмечены у особей, имеющих в своем генотипе аллели В гена PRL и V гена GH. The interrelation of allelic variants of prolactin and somatotropin genes with indicators of milk productivity of black-and-white cows for the 1st and 3rd lactation was studied. The highest milk yield (4642 and 6240 kg) amount of milk fat (174.1 and 215.0 kg) and milk protein (149.0 and 182.5 kg) were in the group with the PRL AA genotype in first-calf heifers as well as in full-age animals. In terms of the mass fraction of fat and protein of milk, the cows with the PRL BB genotype significantly exceeded animals with the PRL AA genotype by 0.12% (P<0.05) and 0.05% (P<0.05), respectively. According to the somatotropin gene, the highest level of milk productivity was revealed in cows with the GH LL genotype with a significant advantage over GH VV in first-calf heifers in milk yield by 439 kg (P<0.01), milk fat yield by 13.6 kg (P<0.001), milk protein yield by 15.3 kg (P<0.01). The excess over the other groups in full-age cows was only in terms of milk yield that was by 219-548 kg (P<0.05). The highest protein content of milk is a characteristic of animals with the GH VV genotype, 3.83% is for the 1st lactation and 3.82% is for the 3rd lactation, and the best protein content of milk in cows with V allele of the GH gene is 3.21 and 3.23%, respectively. The obtained data  indicated a higher level of milk productivity in cows with the PRL AA and GH LL genotypes but the best fat and milk content was noted in cows with alleles B of the PRL gene and V of the GH gene in their genotype.

scholarly journals Betaine Improves Milk Yield in Grazing Dairy Cows Supplemented with Concentrates at High Temperatures

Animals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 57 ◽  
Author(s):  
Frank Dunshea ◽  
Kehinde Oluboyede ◽  
Kristy DiGiacomo ◽  
Brian Leury ◽  
Jeremy Cottrell
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
The Mean ◽  
Fat Yield ◽  
Grazing Dairy Cows ◽  
Daily Milk Yield ◽  
Betaine Supplementation ◽  
Daily Milk

Betaine is an organic osmolyte sourced from sugar beet that accumulates in plant cells undergoing osmotic stress. Since the accumulation of betaine lowers the energy requirements of animals and, therefore, metabolic heat production, the aim of this experiment was to investigate if betaine supplementation improved milk yield in grazing dairy cows in summer. One hundred and eighteen Friesian × Holstein cows were paired on days in milk and, within each pair, randomly allocated to a containing treatment of either 0 or 2 g/kg natural betaine in their concentrate ration for approximately 3 weeks during February/March 2015 (summer in Australia). The mean maximum February temperature was 30 °C. Cows were allocated approximately 14 kg dry matter pasture and 7.5 kg of concentrate pellets (fed in the milking shed) per cow per day and were milked through an automatic milking system three times per day. Betaine supplementation increased average daily milk yield by over 6% (22.0 vs. 23.4 kg/day, p < 0.001) with the response increasing as the study progressed as indicated by the interaction (p < 0.001) between betaine and day. Milk fat % (p = 0.87), milk protein % (p = 0.90), and milk somatic cell count (p = 0.81) were unchanged by dietary betaine. However, betaine supplementation increased milk protein yield (677 vs. 719 g/day, p < 0.001) and fat yield (874 vs. 922 g/day, p < 0.001) with responses again being more pronounced as the study progressed. In conclusion, dietary betaine supplementation increased milk and component yield during summer in grazing dairy cows.

The relationship between milk progesterone and milk traits during estrus in dairy Cows

2018 ◽  
Author(s):  
A Gavelis ◽  
V. Þilaitis ◽  
A Juozaitis ◽  
V. Juozaitienë ◽  
G. Urbonavièius ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Milk Traits ◽  
Subclinical Ketosis ◽  
Yield Level ◽  
Milk Protein Content ◽  
The Relationship

The aim of this study was to evaluate relationship between milk progesterone concentration (P4) and milk traits at the start of estrus time and 12h after start of the estrus in dairy cows. The 96 milk samples of 48 Lithuanian dairy cows without reproduction disorders and 90–100 days after calving were evaluated. Cows were classified into two groups based on milk yield per day: less than 30 kg (n=20) and e”30 kg (n=28). Data were categorized by milk fat and protein content at the start estrus and 12h after start of estrus to evaluate relationship between P4 and milk traits examined. P4 at estrus time in dairy cows was significantly positively correlated with milk yield (P less than 0.001), whereas it was negatively correlated with milk protein (P less than 0.05-P less than 0.01) and fat at 12h after start of estrus. Dairy cows with F/P from 1.0 to 1.5 had the lowest P4 in milk. Results of the pregnancy in dairy cows were related with lower P4 and milk yield level (P less than 0.001), higher milk fat (P less than 0.05) and milk protein content (P less than 0.001). These cows had 1.90 times lower prevalence of the signs of subclinical ketosis (P less than 0.05) at estrus time when compared with non-pregnant cows. As a result, it was clearly demonstrated that P4 in dairy cows can help to evaluate and improve the reproductive properties of cows.

The effect of distillery by-products and molassed sugar beet feed on feed intake and milk production of dairy cows fed a maize silage based total mixed ration

1998 ◽  
Vol 1998 ◽  
pp. 201-201
Author(s):  
R. H. Phipps ◽  
A. K. Jones ◽  
J.G. Perrot
Keyword(s):  
Sugar Beet ◽  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Distillers Grains ◽  
Maize Silage ◽  
Total Mixed Ration ◽  
Protein Supplements ◽  
Milk Protein Content

An earlier study conducted at the Centre for Dairy Research (Phipps et al. 1996) using a total mixed ration (TMR) based on maize silage, showed that when distillers grains wheat and molassed sugar beet feed (MSBF) replaced cereal and protein supplements, milk yield and dry matter (DM) intake were maintained but there was a large and significant reduction in milk fat and a small but significant reduction in milk protein. This depression in milk protein was attributed to the high oil content of distillers grains, which would have reduced fermentable metabolisable energy intake which in turn may have adversely affected microbial protein synthesis and reduced milk protein content. The aim of the current study was to devise a nutritional regime using distillers grains maize (DGM) and MSBF in a TMR which would allow milk fat content to be substantially reduced without compromising either DM intake, milk yield or milk protein content.

Accuracy of alternative methods of estimating weekly yields of milk fat and protein

1984 ◽  
Vol 24 (127) ◽  
pp. 464 ◽  
Author(s):  
T Clarke ◽  
A McGowan
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Low Frequency ◽  
Sampling Frequency ◽  
Alternative Methods ◽  
Stage Of Lactation ◽  
Fat Yield ◽  
Daily Milk Yield ◽  
Daily Milk

Thirty-four procedures were used to estimate the weekly yields of milk, milk fat and milk protein of 19 grazing cows on five occasions between the third and eighth months of lactation. The standard deviation of daily milk yield, fat and protein percentage of individual cows averaged 1 .3 litres, 0.58% fat and 0 - 10% protein, respectively. The four factors involved were: sampling frequency, sampling distribution, basis of compositing subsamples for compositional analyses, and the use of total weekly yields or milk yields on day(s) of sampling, for estimating yields of fat and protein. There were no substantial interactions between the 34 procedures and stage of lactation. The average difference between the estimate of weekly milk yield from any one day's yield and the true weekly milk yield (accuracy) was 7.2 litres/week. The equivalent values for fat and protein yields were 0.59 and 0.22 kg/week. When sampling frequency and measurement of milk yield was increased from one to six days per week, the accuracy of the weekly estimate of milk yield (MY) improved by 5.7 litres/week and that of fat yield (FY) by 0.49 kg/week. If total weekly milk yield was used to estimate fat yield, instead of using milk yield on days of testing only, the improvement in accuracy ranged from 0. 15 to 0.03 kg/week for one and six samplings, respectively. Two equally spaced sampling days gave a marginally better (0.74 litres/week) estimate of milk yield than two consecutive days but a marginally poorer (0.10 kg/week) estimate of fat yield. Yield weighting of subsamples for fat or protein analyses did not improve the estimate of fat yield. As the day to day variation in level of protein in the milk was low, frequency and method of sampling for protein analysis was not important but the accuracy of estimating milk yield had a large effect on estimated weekly protein yield.

Feeding concentrates based on individual cow requirements improves the yield of milk solids in dairy cows grazing restricted pasture

2007 ◽  
Vol 47 (5) ◽  
pp. 502 ◽  
Author(s):  
S. C. García ◽  
M. Pedernera ◽  
W. J. Fulkerson ◽  
A. Horadagoda ◽  
K. Nandra
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Milk Protein ◽  
Nutrient Balance ◽  
Maize Silage ◽  
Fixed Rate ◽  
Milk Protein Content ◽  
Holstein Friesian ◽  
Fat Yield ◽  
Milk Solids

A grazing experiment involving 50 lactating Holstein–Friesian dairy cows was conducted to test the hypothesis that feeding concentrates (range 3–7 kg as fed/cow.day; average 5 kg/cow.day) to grazing cows based on individual (I) cow requirements would increase milk solids yield in comparison to fixed rate (F) allocation to the whole herd (average 5 kg/cow.day for all cows). The experiment comprised two sequential periods that differed only in the way maize silage was offered to cows (either 100% on a feed pad at night or 75% on a feed pad at night, with 25% in a paddock in the morning). Intake of individual cows was estimated using the 13C and n-alkanes method. The rumen degradability of the feeds (lucerne pasture, maize silage and commercial dairy pellets) was measured in parallel, using six rumen-fistulated sheep. Compared with cows in the F group, milk yield and milk fat yield for the I cows increased (P < 0.05) by 3.0 and 11.1%, respectively. As neither milk protein content nor milk protein yield was affected (P > 0.05) by treatment, total milk solids yield (milk fat plus milk protein) was 7.0% higher (P < 0.05) for I cows than for F cows. The increase in milk fat yield was presumably associated with an improved diet nutrient balance in the I cows, as indicated by a significant correlation between fibre intake and milk fat yield for cows in the I group but not for cows in the F group. This is also supported by the results of the rumen degradability of the feeds. In this study, higher-producing cows compensated for their higher requirements by increasing intake of maize silage, rather than pasture, as the former was the less restricted feed on offer. This highlights the importance of offering at least one feed to cows in a less restricted way, in order to enable high-producing cows in the herd to compensate for their higher intake requirements. In conclusion, under the conditions of the present study, feeding concentrates to cows based on individual cow requirements increased milk solids yield at no extra cost.

scholarly journals Effect of Soybean Oil Supplementation on Milk Production, Digestibility, and Metabolism in Dairy Goats under Thermoneutral and Heat Stress Conditions

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 350
Author(s):  
Soufiane Hamzaoui ◽  
Gerardo Caja ◽  
Xavier Such ◽  
Elena Albanell ◽  
Ahmed A. K. Salama
Keyword(s):  
Body Weight ◽  
Heat Stress ◽  
Linoleic Acid ◽  
Soybean Oil ◽  
Milk Yield ◽  
Feed Intake ◽  
Milk Fat ◽  
Milk Protein ◽  
Dairy Goats ◽  
Milk Protein Content

In a previous work, we observed that heat-stressed goats suffer reductions in milk yield and its contents of fat and protein. Supplementation with soybean oil (SBO) may be a useful strategy to enhance milk quality. In total, eight multiparous Murciano–Granadina dairy goats (42.8 ± 1.3 kg body weight; 99 ± 1 days of lactation) were used in a replicated 4 × 4 Latin square design with four periods; 21 d each (14 d adaptation, 5 d for measurements and 2 d transition between periods). Goats were allocated to one of four treatments in a 2 × 2 factorial arrangement. Factors were no oil (CON) or 4% of soybean oil (SBO), and controlled thermal neutral (TN; 15 to 20 °C) or heat stress (HS; 12 h/d at 37 °C and 12 h/d at 30 °C) conditions. This resulted in four treatment combinations: TN-CON, TN-SBO, HS-CON, and HS-SBO. Compared to TN, HS goats experienced lower (p < 0.05) feed intake, body weight, N retention, milk yield, and milk protein and lactose contents. However, goats in HS conditions had greater (p < 0.05) digestibility coefficients (+5.1, +5.2, +4.6, +7.0, and +8.9 points for dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber, respectively) than TN goats. The response to SBO had the same magnitude in TN and HS conditions. Supplementation with SBO had no effects on feed intake, milk yield, or milk protein content. However, SBO supplementation increased (p < 0.05) blood non-esterified fatty acids by 50%, milk fat by 29%, and conjugated linoleic acid by 360%. In conclusion, feeding 4% SBO to dairy goats was a useful strategy to increase milk fat and conjugated linoleic acid without any negative effects on intake, milk yield, or milk protein content. These beneficial effects were obtained regardless goats were in TN or HS conditions.

scholarly journals Effects of physical treatment of barley and rapeseed meal in dairy cows given grass silage-based diets

1996 ◽  
Vol 5 (4) ◽  
pp. 399-412 ◽  
Author(s):  
Pekka Huhtanen ◽  
Terttu Heikkilä
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Protein ◽  
Rapeseed Meal ◽  
Protein Supplementation ◽  
Physical Treatment ◽  
Heat Moisture Treatment ◽  
Grass Silage ◽  
Milk Protein Content ◽  
Moisture Treatment

Twenty-four Ayrshire cows were used to study the effects of physical treatment of barley, rapeseed meal (RSM) supplementation and heat-moisture treatment of RSM on silage intake and milk production. Experimental design was a cyclic change-over with six dietary treatments. The treatments in a 2 x 3 factorial arrangement consisted of either untreated (UB) or heat-moisture treated barley (TB), given without protein supplementation (control) or with untreated or heat-moisture treated RSM. Grass silage was given ad libitum and the concentrates at a rate of 10 kg/d. For the RSM diets, 2 kg/d of the basal concentrate was replaced with either untreated or treated RSM. Treatment of barley decreased silage intake, the effect being greater when the supplement did not contain RSM. There was no effect on milk yield, but due to the lower milk fat content, energy corrected milk yield was lower in cows given TB than in those given UB. Feeding the TB diets was also associated with lower milk urea content, and with increased milk protein content but not protein yield. Faster initial rate of gas production in vitro suggested that the treatment of barley increased the rate of fermentation. Compared with the control diets, RSM supplementation significantly increased silage intake, milk yield, milk protein content and yields of all milk constituents. Heat-moisture treatment of RSM did not produce any further production response.

Sign in / Sign up

Export Citation Format

Share Document