The objective was to evaluate the ingestive behavior of ovine fed Marandu grass silage with dehydrated brewery residue added. The experiment had a completely randomized design with five treatments and four repetitions, with the treatments levels of inclusion being of 0, 10, 20, 30, and 40% natural matter of naturally dehydrated brewery residue for 36 hours to the marandu grass silage. 20 ovines were used and the experimental period was 21 days, 15 being for adaptation to diets. The use of brewery byproduct promoted quadratic effect (
The need to intensify ovine meat production system in Mato Grosso, Brazil, has been attributed to the search for alternatives that enable better combinations of food and diet costs reduction. However, the physical and chemical properties of byproducts differ from foraging plants, which makes their degradation and passage by the gastrointestinal tract different and may affect the ingestive behavior, which is influenced by the physical structure and chemical composition of diets [
In such context, among the alternatives for yielding of industrial byproducts animal feeding shows great potential [
Ovine behavior varies according to the type of food. For animals kept in the field, long feeding periods are characteristics, according to the capacity of selection for each species [
However, knowledge about the animals’ ingestive behavior that receives byproducts as part of their diet will contribute to food preparation, besides solving problem DM related to consumption diminishing. The presence of eventual antinutritional substances on food may alter time spent in feeding and, consequently, in rumination and rest periods [
Under such aspect, studies that assess the inclusion of brewery residue in adequate levels for ovines and its influence over the ovine ingestive behavior that receive diets containing such byproduct are still short, justifying the conducting of this research.
In this context, this experiment was conducted to evaluate ingestive behavior of ovine fed with marandu grass silage added with naturally dehydrated brewery residue.
The experiment was conducted in the forage crops sector experimental area in the Department of Animal Science, Federal University of Mato Grosso, Rondonópolis, Brazil, at geographical coordinates 16°28′S and 50°34′W.
The climate is of Aw tropical type by Köppen classification, with well-defined wet and dry seasons; hot and humid summers; and cold and dry winters. The mean annual temperature is 27.5°C, oscillating between respective minimum and maximum means of 17°C and 38°C. The mean relative humidity of the air is 60% and the mean annual precipitation is 1240 mm.
The researched forage species was
Following that, the storage in silos was performed, with 200 liters of capacity; the silo was opened after 45 days. The experimental lining was entirely random, with five treatments and four repetitions, with the treatments levels of inclusion being of 0, 10, 20, 30 and 40% natural matter of naturally dehydrated brewery residue for 36 hours to the marandu grass silage to feed the sheep.
The evaluation period had a total duration of 21 days, with 15 days for adaptation to the diets and six for data collection. In the first phase, feed was provided
The quantity of silage provided to each animal in the collection phase was 10% greater than the mean consumption observed in the preliminary phase, in order to enable leftovers. The consumption of silage was measured daily by measuring the weight difference between the feed offered and the leftover feed. Composite samples of provided and leftover feed was later placed in plastic wrap, identified, and stored in a freezer for laboratory analyses.
When the silos opened, subsamples were collected of approximately 25 g for pH analysis, to which 100 mL water was added, and, after a two-hour rest, the pH assessment was performed using a potentiometer. To another 25 g subsample, 200 mL of a H2SO4 solution and 0.2 N were added, remaining at rest for 48 hours and then being filtered in a Whatman 54 type filter. This filtered byproduct was stored in a refrigerator for further n-ammoniacal analysis.
The buffering capacity analysis was determined in frozen samples, according to the technique described by [
The soluble carbohydrates were extracted by percolation with 80% ethanol, in the reaction with acid solution prepared with anthrone and in the following reading in spectrophotometer using the glucose solution for the standard curve preparation. The total digestible nutrients (TDN) were estimated according to [
Collection samples of the silage were dried in a forced air oven at 65°C for 48 hours and then ground in a Wiley mill, equipped with sieve mesh of 1 mm, according to the recommendations of [
To the tubes, 40 mL of McDougall solution (artificial saliva) and 10 mL innocuous rumen of animals grazing marandu grass were added.
Ground samples were stored in polyethylene containers for further analysis of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEM), ethereal extract (EE), and crude ash (CA) according to methodology described by (AOAC, 2005).
The total digestible nutrient (TDN) values were estimated according to [
The chemical composition, pH, and N-NH3 of marandu grass silage added by different levels of dehydrated brewery residue are presented in Table
Chemical composition, pH, and N-NH3 of marandu grass silage with dehydrated brewery residue added.
Variable | DBR |
Dehydrated brewery residue (%) | ||||
---|---|---|---|---|---|---|
0 | 10 | 20 | 30 | 40 | ||
pH | — | 4.28 | 4.19 | 4.13 | 4.12 | 4.09 |
N-NH3 1 | — | 7.61 | 7.03 | 6.45 | 5.89 | 5.29 |
Dry matter1 | 89.96 | 24.13 | 27.91 | 31.02 | 39.5 | 43.9 |
Nitrogen2 | 3.89 | 1.15 | 1.80 | 2.02 | 2.16 | 2.35 |
Soluble carboydrates2 | — | 4.06 | 4.09 | 4.12 | 4.15 | 4.19 |
Ether extract | 6,52 | 3.52 | 5.08 | 5.19 | 5.29 | 5.42 |
Total digestible nutrient2 | — | 33.27 | 39.06 | 44.85 | 50.60 | 56.40 |
Neutral detergent fiber2 | 60.75 | 73.63 | 64.06 | 61.25 | 61.60 | 60.50 |
Acid detergent fiber2 | 30.09 | 29,45 | 33.28 | 30.96 | 32.30 | 34.50 |
Hemicellulose2 | 30.66 | 44.18 | 33.78 | 30.29 | 29.30 | 26.00 |
Lignin2 | 5,48 | 6.89 | 6.48 | 6.40 | 6.32 | 6.18 |
Crude ash2 | 8.89 | 6.31 | 7.13 | 7.02 | 6.52 | 6.55 |
|
64.35 | 60.93 | 64.37 | 65.10 | 65.60 | 66.10 |
2Percentage of dry matter.
Animals’ feeding behavior was determined in the last five days of the experimental period by quantifying the time intervals, for 24 hours [
The variables DM g and NDF/bolus were obtained by dividing individual average consumption of each fraction by the number of ruminated boluses per day (within 24 hours). The efficiency of feeding and rumination, expressed in g DM/hour and g NDF/hour, was obtained by dividing the average daily intake of DM and NDF in the total time spent feeding and/or rumination in 24 hours, respectively.
This and other variables, such as the number of ruminated boluses per day (NBR), time of total chewing (TMT), and the number of cud chews per day (MMND), were obtained through methodology described by [
The number of feeding periods, rumination, and rest were calculated by the number of activity sequences observed in the note sheet. The average daily duration of these activity periods was calculated dividing the total duration of each activity (feeding, rumination, and rest in min/day) by its respective number of described periods.
The remaining data were statistically analyzed: feeding behavior, the choice being based on the significance of the regression parameters, tested by Tukey (
Taking into account Figure
Ingestion time, rest, and rumination in hours, during the daily period (24 hours) of ovine fed with marandu grass silage.
There was no effect (
The use of brewery byproduct promoted quadratic effect (
An indicator of this improvement was observed in the silage containing dehydrated brewery residue, which showed appropriate and pleasant odor and color, although silage only with marandu grass had shown good fermentation, due to the fact that it was ensiled with approximately 25% dry matter, with recommended average level being of 30 to 35% dry matter, according to [
References [
Crescent linear behavior was observed (
Dry matter (kg/day) and neutral detergent fiber (NDF/kg/day) consumption in 24 hours, number of ruminated boluses per day (number of boluses per day), average time (sec) spent in chewing per bolus (boluses per sec), and total time chew (min/day) of ovine fed with marandu grass silage.
Variable | Dehydrated brewery residue (%) | Equation regression |
CV (%) |
|
||||
---|---|---|---|---|---|---|---|---|
0 | 10 | 20 | 30 | 40 | ||||
Dry matter | 0.744 | 0.820 | 0.864 | 0.875 | 0.852 |
|
8.13 | 86.20 |
NDF | 0.282 | 0.302 | 0.332 | 0.480 | 0.482 |
|
20.31 | 87.32 |
Number of boluses per day | 652.6 | 638.1 | 623.6 | 609.1 | 594.6 |
|
11.01 | 81.10 |
Chews | 44.63 | 49.48 | 52.20 | 52.81 | 51.29 |
|
8.02 | 81.76 |
Total time chew | 18966 | 22246 | 23402 | 22434 | 19342 |
|
15.36 | 86.66 |
Feeding efficiency (g DM and NDF/hour), rumination efficiency (g DM and NDF/hour), cud chews, and number of meal periods, rumination, and rest (number/day) of ovine fed with marandu grass silage.
Variable | Dehydrated brewery residue (%) | Equation regression |
CV (%) |
|
||||
---|---|---|---|---|---|---|---|---|
0 | 10 | 20 | 30 | 40 | ||||
Ingestion efficiency (g DM and NDF/hour) | ||||||||
DM | 162.0 | 169.3 | 176.6 | 184.0 | 185.3 |
|
17.02 | 89.14 |
NDF | 65.38 | 59.49 | 65.55 | 103.1 | 113.9 |
|
20.89 | 90.55 |
|
||||||||
Rumination efficiency (g DM and NDF/hours) | ||||||||
DM | 85.23 | 101.2 | 107.7 | 104.7 | 92.26 |
|
12.98 | 96.72 |
NDF | 32.15 | 38.12 | 44.09 | 50.05 | 56.02 |
|
20.46 | 86.63 |
|
||||||||
Cud chewing | ||||||||
Hours (day) | 13.47 | 13.46 | 13.40 | 13.59 | 13.94 | 14.172 | — | — |
Number of boluses per day | 67.62 | 72.35 | 74.15 | 73.02 | 68.97 |
|
10.88 | 86.35 |
Number/day | 48535 | 43739 | 41624 | 42191 | 45439 |
|
16.32 | 74.79 |
|
||||||||
Ingestion period, rumination, and rest (number/day) | ||||||||
Ingestion | 27.92 | 30.75 | 31.70 | 30.77 | 27.97 |
|
17.08 | 85.13 |
Rumination | 52.95 | 49.43 | 48.72 | 50.81 | 55.81 | 51.54 | — | — |
Rest | 62.12 | 62.71 | 62.22 | 60.66 | 58.02 | 61.14 | — | — |
Neutral detergent fiber (min/kg) and time spent per ingestion period, rumination, and rest (min) of ovine fed with marandu grass silage.
Variable | Dehydrated brewery residue (%) | Equation regression |
CV (%) |
|
||||
---|---|---|---|---|---|---|---|---|
0 | 10 | 20 | 30 | 40 | ||||
DM and NDF consumption/meal (kg) | ||||||||
DM | 0.027 | 0.028 | 0.029 | 0.030 | 0.032 |
|
20.63 | 91.84 |
NDF | 0.011 | 0.010 | 0.012 | 0.015 | 0.021 |
|
22.45 | 74.93 |
|
||||||||
DM and NDF consumption (min/kg) | ||||||||
DM | 392.9 | 383.2 | 365.9 | 341.2 | 309.1 |
|
17.46 | 79.81 |
NDF | 1119 | 989,2 | 9859 | 729,1 | 599,1 |
|
22.33 | 88.37 |
|
||||||||
Time spent per ingestion period, rumination, and rest (min) | ||||||||
Ingestion | 10.64 | 10.28 | 9.97 | 9.71 | 9.51 |
|
12.02 | 91.74 |
Rumination | 9.98 | 10.04 | 10.10 | 10.17 | 10.23 | 10.10 | — | — |
Rest | 11.97 | 12.92 | 13.03 | 12.29 | 10.71 | 9.78 | — | — |
However, the number of ruminated boluses per day (number/day) showed decreasing linear behavior (
Such behavior highlights that the reduction of cud per day, with dehydrated brewery residue added, was compensated by the increase of chew time per bolus (Table
Reference [
On the other hand, the total chews number showed quadratic behavior (
Reference [
Ingestion efficiency (g DM/hour) was significant (
Thus, there was efficiency increase of NDF ingestion of 2% for each 1% dehydrated brewery residue included in grass silage. It is noteworthy that, in this study, the DM and NDF consumptions (kg/day) were reflexes of the added silage and showed average values of, respectively, 0.835 and 0.375 kg, which justifies the results obtained for the ingestion efficiencies (g DM/hour), which are directly related to consumption expressed in g/day.
For the rumination efficiency of dry matter (g DM/hour), quadratic behavior was observed for the equation (
According to [
The ingestion period (number/day) was significant (
DM and NDF consumption expressed in kg/meal and in minutes/kg were also significant (
The time spent per period (min) was not significant (
The results were concordant with the ones from [
The rumination activity, expressed in g DM and NDF/bolus, was influenced (
Time spent in rumination (g DM and NDF/bolus), rumination (min/kg DM and NDF), and total chewing (min/kg DM and NDF) of ovine fed with marandu grass silage.
Variable | Dehydrated brewery residue level (%) | Equation regression |
CV (%) |
|
||||
---|---|---|---|---|---|---|---|---|
0 | 10 | 20 | 30 | 40 | ||||
Rumination (g DM and NDF/cud) | ||||||||
DM | 1.04 | 1.39 | 1.55 | 1.52 | 1.30 |
|
13.57 | 92.97 |
NDF | 0.376 | 0.531 | 0.649 | 0.733 | 0.781 |
|
23.62 | 96.36 |
|
||||||||
Rumination (min/kg DM and NDF) | ||||||||
DM | 707.3 | 610.4 | 571.5 | 590.7 | 667.8 |
|
12.75 | 88.34 |
NDF | 1941 | 1628 | 1397 | 1249 |
|
|
20.32 | 95.81 |
|
||||||||
Total chewing (min/kg DM and NDF) | ||||||||
DM | 999.9 | 921.4 | 883.5 | 886.4 | 929.9 |
|
11.66 | 91.59 |
NDF | 2560 | 2252 | 2019 | 1863 | 1782 |
|
13.38 | 94.80 |
Such behaviors can be influenced by the NDF levels in silage, which varied with the inclusion of dehydrated brewery residue, with the maximum difference between the levels of this fraction (13.13%) in silage with 0 and 40% additive, which might have been enough to provoke alterations in the rumination activities. A factor that might have favored the presence of effect over rumination is the small size of the particles of the dehydrated brewery residue, similar to concentrated food such as grounded corn and soy bran [
Total chewing time, in min/kg of DM and NDF, was influenced quadratically (
Use of dehydrated brewery residue in the process of silage of marandu grass affects some parameters of ingestive behavior, such as ingestion time, dry matter consumption, consumption of fiber in neutral detergent, number of ruminated boluses per day, ingestion efficiency indicating the use of intermediate level of 20 to 25%.
The authors of this paper have no competing interests.
Fundação de Amparo à Pesquisa do Estado de Mato Grosso (FAPEMAT) and Fundação de Amparo à Pesquisa e Desenvolvimento Científico do Maranhão (FAPEMA) are acknowledged.