scholarly journals Effects of Dietary Starch and Crude Protein Levels on Milk Production and Composition of Dairy Cows Fed High Concentrate Diet

Author(s):  
Mustafa Güçlü Sucak ◽  
Uğur Serbester ◽  
Murat Görgülü

Effects of two dietary levels of starch and crude protein on performance of dairy cow fed low roughage level (70:30 concentrate to roughage) were investigated. Twenty eight Holstein cows were randomly assigned to one of four dietary treatments in a 2 x 2 factorial arrangement. Factors were two dietary level of starch (14% and 22%) and crude protein (15% and 18%). Wheat straw was used as sole roughage source. The study was continued 6 weeks. Dry matter intake was not affected (P>0.05) by the dietary treatments in the study. Milk and protein yield (kg/d) were higher (P

1999 ◽  
Vol 39 (8) ◽  
pp. 923 ◽  
Author(s):  
P. J. Moate ◽  
D. E. Dalley ◽  
J. R. Roche ◽  
C. Grainger

Summary. The effect of herbage allowance (20, 30, 40, 50, 60 and 70 kg DM/cow. day) on the consumption of nutrients from herbage and milk production by cows in early lactation, was examined. The experiment was conducted on rainfed perennial ryegrass pastures in September and October 1997 in south-eastern Victoria, Australia. The herbage on offer comprised 64% perennial ryegrass, 21% other grasses, 1% white clover, 5% weeds and 9% dead material on a dry matter (DM) basis. The average pregrazing herbage height was 13 cm, at an estimated pregrazing herbage mass of 3.6 t DM/ha. The herbage on offer was of high quality containing 11.6 MJ metabolisable energy/kg DM, 202 g crude protein/kg DM and 525 g neutral detergent fibre/kg DM. Concentrations of calcium, magnesium, sodium, potassium, phosphorus, sulfur and chloride were 4.4, 2.2, 4.4, 31.2, 3.5, 2.7 and 11.4 g/kg DM, respectively. As daily herbage allowance per cow increased, dry matter intake increased curvilinearly (P<0.01) from 11.2 to 18.7 kg DM/cow. day. This was associated with a decrease in utilisation of herbage from 54 to 26% and an increase in milk production from 25.9 to 29.1 kg/cow. day. The cows on all treatments grazed for less than 8.7 h/day. The increase in intake was achieved by an increase in the rate of herbage intake from 1.5 to 2.2 kg DM/h for herbage allowances of 20 and 70 kg/cow.day, respectively. Irrespective of herbage allowance, cows selected a diet that was approximately 10% higher in in vitro dry matter digestibility and 30% higher in crude protein than that in the herbage on offer. The neutral detergent fibre content of the herbage selected was lower (P<0.05) than that on offer. The herbage consumed contained more (P<0.05) magnesium, potassium and sulfur, the same amount of calcium and phosphorus and less (P<0.05) sodium and chloride than the herbage on offer. For rainfed perennial pastures in spring, herbage allowance is an important factor in determining voluntary feed intake and production of dairy cows. To achieve 30 L from herbage, without supplementation, high herbage allowances are required. The increase in herbage intake, with increasing herbage allowance, resulted from an increase in rate of dry matter intake and not an increase in grazing time. No relationship was evident between herbage allowance and the selection differentials for in vitro dry matter digestibility, crude protein and neutral detergent fibre. Selection differentials for rainfed perennial pastures in spring are similar to those reported for irrigated perennial pastures in northern Victoria in spring and autumn. When determining nutrient requirements it is important to consider the interaction between herbage intake and nutrient concentration in the herbage.


Author(s):  
T. W. J. Keady ◽  
J. J. Murphy

In general cows have higher intakes and higher milk yields when outdoors grazing pasture compared to indoors consuming grass silage. However, this observation is not valid as a direct comparison of grass and silage due to the following reasons. Firstly, the cows consuming the silage and grass are usually at different stages of lactation and secondly the silage has not been produced from the herbage being grazed. There is little information available in the literature comparing the intakes of grass and silage harvested from the same sward at the same stage of maturity when fed to lactating dairy animals at similar stages of lactation. The present study was initiated as part of a series of studies at this Institute, to evaluate factors affecting silage intake. The main aims of this study were to determine the actual effect which ensiling “per se” had firstly on dry matter intake and secondly on animal performance by the lactating dairy cow.


1999 ◽  
Vol 133 (4) ◽  
pp. 419-425 ◽  
Author(s):  
Y. UNAL ◽  
P. C. GARNSWORTHY

Dry matter intake is one of the major factors limiting milk production in dairy cows, although the quantity of food consumed by an individual cow when housed and fed as part of a group is rarely known. Such information would permit more precise ration formulation, concentrate allocation and selection of cows according to efficiency of milk production. Alkanes have been used with sheep and cattle to estimate feed intake under grazing conditions and could provide a technique for measuring intake in housed dairy cows. The purpose of this study was to examine alkanes C32 and C36, in combination with alkane C33, as indigestible markers for estimating intake of housed dairy cows fed on different diets under experimental and commercial conditions. Three experiments were conducted with hay-based diets (Expt 1), silage only diets (Expt 2) and a diet consisting of a silage-based basal ration plus concentrates (Expt 3). Animals were dosed once daily with C32 and C36, either on filter papers (Expts 1 and 2) or as part of a specially prepared concentrate (Expt 3). Faecal recoveries of alkanes ranged from 0·88 to 0·99. Over the range of intakes found in the three experiments (6–24 kg DM/d), the r2 values for estimated versus actual dry matter intakes ranged from 0·81 to 0·99. It is concluded that alkanes could provide a useful technique for estimating intake in dairy cows housed and fed in groups.


1983 ◽  
Vol 37 (1) ◽  
pp. 105-112
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
D. Drori ◽  
Y. Folman

ABSTRACTWheat straw treated with 35 g NaOH per kg was offered to male calves at three levels: 300 (A), 500 (B), and 700 (C) g/kg diet, in a metabolism trial and in a feeding trial. In the former the wheat straw was offered either neutralized with HC1 (N) or unneutralized (U), in six subtreatments (AN, BN, CN, AU, BU and CU) in a 3 × 2 factorial design to a total of 24 calves. Dry-matter intake per kg W0·73was 123, 108, 104, 122, 105 and 91 g/day, and the digestibility of the organic matter of the straw was 0·388, 0·616, 0·629, 0·385, 0·528 and 0·544 respectively. The apparent digestibility of the crude protein of the straw was negative. Nitrogen retention per kg W0·73was 0·91, 0·58, 0·52, 0·97, 0·57 and 0·50 g/day, respectively.In the feeding trial, unneutralized, NaOH-treated wheat straw was offered to a total of 84 calves for 100 days at the above three levels with two protein levels: standard, 120 g/kg (S) and high, 140 g/kg (H), in six subtreatments (AS, BS, CS, AH, BH and CH) in a 3 × 2 factorial design. The concentrates were pelleted. From day 101 to slaughter all the calves were offered one finishing diet.Level of protein had no effect on performance. Increasing the levels of straw in the first 100 days sharply reduced average daily gains; these were 1 074, 825 and 583 g, respectively. However, the respective average daily gains on the finishing diet were 1 131, 1 272 and 1 316 g, indicating a considerable amount of compensatory growth.


Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 925
Author(s):  
Zhao ◽  
Min ◽  
Zheng ◽  
Wang

Heat stress negatively impacts the health and milk production of dairy cows, and ruminal microbial populations play an important role in dairy cattle’s milk production. Currently there are no available studies that investigate heat stress-associated changes in the rumen microbiome of lactating dairy cattle. Improved understanding of the link between heat stress and the ruminal microbiome may be beneficial in developing strategies for relieving the influence of heat stress on ruminants by manipulating ruminal microbial composition. In this study, we investigated the ruminal bacterial composition and metabolites in heat stressed and non-heat stressed dairy cows. Eighteen lactating dairy cows were divided into two treatment groups, one with heat stress and one without heat stress. Dry matter intake was measured and rumen fluid from all cows in both groups was collected. The bacterial 16S rRNA genes in the ruminal fluid were sequenced, and the rumen pH and the lactate and acetate of the bacterial metabolites were quantified. Heat stress was associated with significantly decreased dry matter intake and milk production. Rumen pH and rumen acetate concentrations were significantly decreased in the heat stressed group, while ruminal lactate concentration increased. The influence of heat stress on the microbial bacterial community structure was minor. However, heat stress was associated with an increase in lactate producing bacteria (e.g., Streptococcus and unclassified Enterobacteriaceae), and with an increase in Ruminobacter, Treponema, and unclassified Bacteroidaceae, all of which utilize soluble carbohydrates as an energy source. The relative abundance of acetate-producing bacterium Acetobacter decreased during heat stress. We concluded that heat stress is associated with changes in ruminal bacterial composition and metabolites, with more lactate and less acetate-producing species in the population, which potentially negatively affects milk production.


Sign in / Sign up

Export Citation Format

Share Document