Estimation of intake and digestibility of forage-based diets in group-fed dairy cows using alkanes as markers

1999 ◽  
Vol 133 (4) ◽  
pp. 419-425 ◽  
Author(s):  
Y. UNAL ◽  
P. C. GARNSWORTHY
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Once Daily ◽  
Major Factors ◽  
Filter Papers ◽  
Selection Of ◽  
Basal Ration ◽  
Food Consumed

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.

Dry matter intake, nutrient selection and milk production of dairy cows grazing rainfed perennial pastures at different herbage allowances in spring

1999 ◽  
Vol 39 (8) ◽  
pp. 923 ◽  
Author(s):  
P. J. Moate ◽  
D. E. Dalley ◽  
J. R. Roche ◽  
C. Grainger
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Neutral Detergent Fibre ◽  
Dry Matter Digestibility ◽  
Herbage Intake ◽  
Selection Differentials

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.

scholarly journals Effect of Heat Stress on Bacterial Composition and Metabolism in the Rumen of Lactating Dairy Cows

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 925
Author(s):  
Zhao ◽  
Min ◽  
Zheng ◽  
Wang
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Production ◽  
Dry Matter ◽  
16S Rrna Genes ◽  
Dry Matter Intake ◽  
Rrna Genes ◽  
Bacterial Composition ◽  
Rumen Ph ◽  
Lactating Dairy Cows

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.

An examination of the effect of type of concentrate and method of concentrate feeding on the milk production of british friesian dairy cows offered grass silage based diets

1992 ◽  
Vol 1992 ◽  
pp. 38-38
Author(s):  
K W Agnew ◽  
C S Mayne
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Animal Performance ◽  
Grass Silage ◽  
Complete Diet

In a previous study at this Institute, significant increases in total dry matter intake were obtained with first lactation animals offered grass silage and concentrates as a complete diet rather than in separate feeds. However, the increased DM intake associated with complete diet feeding was not reflected in improved animal performance. Similar results have also been reported by Phipps, Bines, Fulford and Weller (1984) and Cassel, Merrill, Milligan and Guest (1984).The aim of this experiment was to investigate the effect on animal performance of offering two types of concentrate in addition to grass silage, with concentrates offered either as a complete diet or in three feeds per day.

Hay supplements to overcome underfeeding of dairy cows. 2. Late lactation

1981 ◽  
Vol 21 (109) ◽  
pp. 157 ◽  
Author(s):  
KR King ◽  
CR Stockdale
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Body Condition ◽  
Dry Matter ◽  
Nutritive Value ◽  
Dry Matter Intake ◽  
High Quality ◽  
Stage Of Lactation ◽  
Ad Libitum ◽  
Ration Composition

The effect of hay supplementation on the performance of dairy cows on a restricted intake of paspalum-dominant perennial pasture was studied in two 21 -day periods in the eighth and ninth months of lactation. In each period, there were three groups fed pasture only at mean intakes of 15.2, 11.5 and 7.3 kg/cow day-1, two groups fed at similar pasture restriction levels and supplemented with hay ad libitum, and one further group fed an average of 7.3 kg of pasture supplemented with only 4.3 kg of hay. The data were analyzed by regression, using total dry matter intake as the dependent variable, and pseudovariables were used to examine the effects of hay feeding. The relations between total dry matter intake and milk, butterfat, protein and solids-not-fat production, and change in body condition of dairy cows were not altered by ration composition. Milk production declined linearly by 0.66 kg and 0.31 kg/cow day-1 in the eight and ninth months of lactation, respectively, for each kg reduction in total dry matter intake. Similar responses were obtained for butterfat, protein and solids-not-fat production. Gain in body condition of the cows also decreased as total intake fell, but the relation was curvilinear and not affected by stage of lactation. It was concluded that high quality hay can be used to overcome shortages of paspalum-dominant perennial pasture in autumn, and that it has similar. nutritive value to pasture in terms of milk production and body condition.

scholarly journals Effect of Post-grazing Sward Height on Ingestive Behavior, Dry Matter Intake, and Milk Production of Holstein Dairy Cows

2021 ◽  
Vol 2 ◽  
Author(s):  
Gabriel Menegazzi ◽  
Pamela Yanina Giles ◽  
Matías Oborsky ◽  
Oliver Fast ◽  
Diego Antonio Mattiauda ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Fat ◽  
Dry Matter ◽  
Ingestive Behavior ◽  
Dry Matter Intake ◽  
Management Tool ◽  
Intake Rate ◽  
Evaluation Period ◽  
Sward Height

Sward height is strongly related to the daily dry matter intake of grazing dairy cows, which consequently determines animal performance. Despite that, few studies have explored the potential to increase milk production by managing post-grazing sward height. An experiment was carried out to evaluate the effect of three defoliation intensities on a Lolium arundinaceum-based pasture on frequency and length of grazing meals and ruminating bouts, daily grazing and ruminating time, feeding stations and patches exploration, and dry matter intake and milk production of dairy cows. The treatments imposed were three different post-grazing sward heights: control (TC), medium (TM), and lax (TL), which were managed with 6, 9, and 12 cm of post-grazing sward heights during autumn and winter, and 9, 12, and 15 cm of post-grazing sward heights during spring, respectively. Thirty-six autumn-calving Holstein cows were grouped by parity (2.6 ± 0.8), body weight (618 ± 48) kg, and body condition score (2.8 ± 0.2) and randomized to the treatments. The pasture was accessed from 08:00 to 14:00 and 17:00 to 03:00 during spring and no supplement was involved during the evaluation period. Daily grazing time averaged 508 ± 15 min and was not affected by treatment. The reduction of post-grazing sward height increased the length of the first grazing session in the morning and the afternoon. The number of grazing sessions was greater on TL than on TM, with no difference in TC. The number of feeding stations (the hypothetical semi-circle in front of an animal from which the bites were taken without moving the front forefeet) visited was less on TC than on TL, and neither of them differed from TM. Dry matter (DM) intake was lesser on TC than on TM and TL (14.7 vs. 17.8 kg DM). Milk production during the evaluation period was 13.1, 16.2, and 18.7 kg/day for TC, TM, and TL, respectively. The milk fat, protein, and lactose content did not differ between treatments. The cows on TC exhibited a lower intake rate, although they were less selective, probably as a consequence of the sward structure of TC treatment. The cows on TM adopted a compensation mechanism which allowed them to achieve the same dry matter intake as cows on TL, but lower milk production. The cows on TL were more selective than TC and TM resulting in higher digestible dry matter intake and consequently higher milk production. The intensity of defoliation impacts on the animal-plant interaction, and constitutes a valuable management tool that can be used to boost forage intake and milk production. The new developments on information technology would allow researchers to link behavioral data with response variables (e.g., milk production, health, welfare, etc.) at different spatio-temporal scales and support short and long-term management decisions.

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