AN INFLUENCE OF DRIED BREWER’S YEAST (SACCHAROMYCES CEREVISIAE) ADDITION BEFORE AND AFTER CALVING ON YIELD AND CHEMICAL COMPOSITION OF MILK AND BIOCHEMICAL INDICES OF BLOOD IN THE FIRST 100 DAYS OF LACTATION

Marian Kuczaj¹, Aleksander Dobicki¹, Jerzy Preś², Andrzej Zachwieja¹, Wiesław Jakus^3
1 Institute of Animal Breeding, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Science, Poland
² Department of Animal Nutrition and Feed Management, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Science, Poland
³ Cattle Farm Malerzowice Małe, PRU Kłos RLLLP, Poland

ABSTRACT

The aim of the study was an assessment of an influence of dried brewer's yeasts addition on yield and chemical composition of milk of Polish Holstein-Friesian breed cows fed with PMR system, in the first 100 days of lactation, allowing of some biochemical parameters of blood. The experiment was conducted on 50  Polish Holstein-Friesian cows (Red-White variety) maintained in tied stalls. The cows calved in summer season randomly entered one of the two groups: experimental (n=25 heads) and control one (n=25 heads). An application of a preparation of dried brewer's yeasts (200 g/head/day) in dairy cows feeding 3 weeks before calving and in the first 100 days of lactation caused slightly higher fat content in milk, and statistically significant (p ≤ 0.05) increase in FCM milk yield (of 2.27 kg) as compared to cows from the control group that were not given such a feed supplement. Clearly decreased (however insignificant statistically) somatic cells count was observed in milk of cows that were given an addition of dried brewer's yeasts as compared to the control group. Proper values of biochemical indices of blood in both groups of cows demonstrate an appropriate energy-protein ratio of feeding doses used in an experimental period. An addition of dried brewer's yeasts given to cows before calving statistically significantly influenced the level of total protein and magnesium in blood, and content of urea, albumins, globulins and magnesium after calving. An application of an addition of dried brewer's yeasts should be recommended in high-yielding cows feeding, since it profitably influences an increase in FCM milk yield and some biochemical indices of blood.

Key words: cows, brewer’s yeasts, yield and chemical composition of milk, biochemical parameters of blood.

INTRODUCTION

An interest of scientists in an application of brewer's yeasts (Saccharomyces cerevisiae) in farm animals feeding has been increasing for more than ten years. Live yeasts cells (cultures) or so called active yeasts have been used the most often. The study concerning an activity of dried brewer's yeasts are almost not found.

A mechanism of brewer's yeasts activity in ruminants is not fully recognised [12]. Expending lots of oxygen, yeasts stimulate a development of anaerobic bacteria, however their development in rumen is limited. One of the theories says that yeasts stimulate a development of ruminal bacteria by growth factors, vitamins and microcomponents that are present in them. Another theory, the main activity of yeasts in rumen sees in lowering of lactic acid amount and increasing of content pH. The in vitro and in vivo study conducted last years [2,13] does not fully confirm that hypothesis. A maintenance of higher rumen pH stimulates a development of celulolytic bacteria that increases fibre digestion and influences an increase in fodder intake, especially during an early lactation [4,15,17,25].

The other theory emphasises an influence of brewer's yeasts cultures on higher protein decomposition, better ammonia nitrogen utilisation and higher bacterial protein production. Moreover, amino acid profiles of bacterial proteins are subject of a profitable change [3,7,12,15]. It results in a better transfer of the most important for dairy cows amino acids to a duodenum.

According to numerous authors [7,8,11,12,22], the mechanism of live yeasts cells activity depends on an increase in bacteria number, stimulation of celulolytic and proteolytic bacteria development, increase in NDF (neutral detergent fibre) and ADF (acidic detergent fibre) decomposition ratio, and increase in propionic acid amount. The study on an influence of brewer's yeasts cultures addition in cows in a period of 3 weeks before calving and in the first month after calving, poses a separate issue. Fodder intake, amount and chemical composition of milk were main factors determined. The results of above study are not fully unequivocal. A positive influence of yeasts cultures or active dried yeasts on analysed parameters was observed in numerous experiments [4,9,14,15,17,20,25]. Some authors in turn, did not confirm a significant influence of that treatment [16,19,21].

Piva et al. [14] suggest that an influence of brewer's yeasts depends on factors like lactation period, kind of bulky feed, feeding manner and nutritive fodders contribution. Another authors [4,17] observed lower energy intake from reserve fat, and a higher one from fodder in cows in early lactation that were given yeasts cultures, comparing to the control group. Moreover, an activity of brewer's yeasts in an immunomodulation range was compared. A stimulation of a level of acute-phase proteins was observed when supplementing brewer's yeasts (live cells) to beef cattle [6]. The content of haptoglobin, liposaccharides binding proteins, and amylases A of serum increased significantly. An addition of yeasts cultures resulted thus in symptoms similar to subtle inflammatory state.

The aim of the study was an assessment of dried brewer's yeasts addition influence on yield and chemical composition of milk of Polish HF breed cows (Red-White variety) fed with PMR system, in the first 100 days of lactation, allowing of chosen biochemical parameters of blood.

MATERIAL AND METHODS

The experiment was conducted on cattle farm in Malerzowice Male, on 50 cows of Polish HF breed (Red-White variety) of an average body mass on a level of about 580 kg, kept in tying stalls. Cows calving in summer season randomly entered one of the two groups: experimental (n=25 heads) and control (n=25 heads). A register of the experiment was kept in a cow-house for all the cows.

Cows from the experimental group (I) were given an addition of a preparation of dried brewer's yeasts (Saccharomyces cerevisiae) of Leiber BT company in a dose of 200 g/head/day starting from the end of drying off (3 weeks before calving) and after calving until 100^th day of lactation. Leiber BT yeasts were carefully mixed in a proper ratio with nutritive fodder (premixe) and given "by hand" to cows from group I. Cows from control group (II) were fed with a feeding dose without yeasts addition.

Both groups were fed with a feeding dose balanced according to INRA standards. Dry animals were given an all-mash TMR fodder with straw addition, and milked cows were given a basic, partly mixed (PMR) dose, standardised for a yield of 16 kg of milk per day. Animals had ad libitum access to water and salt licks. An average milk yield per cow on a farm was about 7 000 kg. Cow-house was under a constant veterinary supervision, free of infectious diseases – contagious and invasive ones.

A dose for dry cows included: corn silage (whole plants) – 25 kg, silage from withered grass – 15 kg, fresh spent grains – 5 kg, fodder straw (an average intake about 2 kg/head/day), own nutritive mixture – 2kg (corn meal – 25%, rapeseed meal – 25%, wheat bran – 25%, barley meal – 25%) and 100 g of mineral-vitamin mixture B 7-tan.

Milk cows of a yield up to 16 kg of milk per day were given 25 kg of corn silage (whole plants), 15 kg of silage from withered grass (ryegrass), 5 kg of fresh spent brewer's grain , 2 kg of fodder straw, 2 kg of nutritive mixture of own production (corn meal – 25%, rapeseed meal – 25%, wheat bran – 25%, barley meal), an addition during period of increasing milk yield after calving: – 0.5 kg of soybean meal, 1.0 kg of rapeseed meal, 150 g of mineral-vitamin mixture B 7-tan (Therabio Comeron – Francja).

Feeding of cows and nutritive value of a given feeding dose used to be assessed once a month. The content of basic nutrients was determined in samples of fodders using conventional methods in a laboratory of Department of Animal Nutrition and Feed Management, Wroclaw University of Environmental and Life Sciences. Calcium content was determined using atomic absorption spectrometry (AAS) method, and  phosphorus using colorimetric method.

Nutritive value of PMR dose adjusted to daily yield on a level of 16 dcm³ was as follows: 28.82% D.M., 12.0% total protein, 20.1% fibre, 19.7% starch, 6.5% ash, 0.44% Ca and 0.32% P. Energy amount in 1 kg of D.M was assessed as 0.85 JPM or 1.4 Mcal NEL. Higher milk yield was awarded with an addition of a nutritive mixture (1 kg of fodder on 2 kg of milk) of a following nutritive value (1 kg): 6.53 MJ NEL, 174 total protein, 2.15 g Ca and 7.06 g P.

Concentration of components in Leiber BT feed supplement (containing 40% of brewer's yeasts) was as follows in 1 kg f dry matter (in %): crude protein 25.0, crude fat 3.0, crude fibre 0.5 and crude ash 4.0; amino acids (in %): lysine 1.8, methionine 0.6, cystine 0.6, tryptophan 1.6, treonine 1.15; mineral components (in mg/100 g): Ca 230.8, P 1038.4, Mg 53.5, Fe 7.95, Mn 0.45, Zn 10.5, Cu 0.9, Na 25.0.

Chemical composition of 1 kg of mineral-vitamin mixture B7 – tan (Therabio Comeron – France) was as follows: P 70 g, Ca 210 g, Mg 40 g, NaCI 80 g, Mn 4000 mg, Zn 6000 mg, Cu 800 mg, vitamin. A 500 thousands I.U., vitamin D₃ 80 thousands I.U., vitamin E 1 thousands I.U., vitamin B 100 mg, Co 20 mg, J 40 mg, Se 20 mg, + oils lowering protein decomposition in rumen.

A control of milk performance was conducted once a month (official control). Routine analysis of chemical composition of milk were done in Laboratory of Milk Analysis in Opole. The content of main elements, including urea using Combi Foss apparatus (Foss Electric Company, Denmark) was determined in milk samples. Somatic cells count (SCC) in milk was assessed fortnightly on Somacount-120 apparatus of Bentley Company (Laboratory of Milk Assessment and Analysis, Wroclaw University of Environmental and Life Sciences).

Blood for analysis was collected from 8 cows in a group from jugular vein 2 hours after morning feeding of cows. Biochemical parameters of blood of cows were determined on biochemical analyser Pentra 400 of Horiba ABX Company in Department of Animal Hygiene and Ichtiology, Wroclaw University of Environmental and Life Sciences.

Numerical data were worked out using GLM procedure (SAS, 1999), using east squares method according to the model:

Y_ijk = µ + a_i + b_j + e_ijk

where: µ – total mean, a_i – subsequent lactation influence (1, 2, 3+further), b_j – influence of the first control milking yield (kg of milk), e_ijk – experimental error. Signifcance of differences between groups of cows was determined using Scheff's test [18].

RESULTS AND DISCUSSION

Differences in milk yield between groups in subsequent sample milkings after calving (p<0.05) were not confirmed statistically (Table 1). Mean yield of cows that were given an addition of dried brewer's yeasts during the experiment was higher of 1.24 kg of milk comparing to the control group. FCM milk yield, due to higher fat content in milk of cows receiving an addition of dried yeasts (group I), was significantly higher (of 2.27kg FCM) as compared to the control group (II).

Significant increase in amount of milk produced by cows, but similarly without any changes in its composition, with an addition of dried yeasts cultures was observed by Piva et al. [14]. Distinct increase in milk performance of cows was noted by Korniewicz et al. [9] who used an addition of preparation with active brewer's yeasts (Diamond V). Applying cultures of S.c. yeasts before and after calving, Soder and Holden [21] obtained an increase in milk production of 2.5 to 3.5 kg; however it was not confirmed statistically.

Table 1. Milk yield of cows in the experiment (n=50, , sd)

Lactation period	Group
	I – experimental		II – control
		sd		sd
1 month	29.41	5.11	28.42	4.31
2 month	30.00	4.30	28.39	5.33
3 month	30.11	4.81	29.01	4.81
In total	29.84	4.80	28.60	4.82
FCM	32.09a	4.97	29.82b	4.97

a, b – values in rows marked with various letters differ significantly with p<0.05

Robinson and Garret [17] administered active dried brewer's yeasts in amount of 56 g/head/day from 23 days before calving to 56^th day of lactation. They did not observe any influence on fodder intake in a period before calving. After calving however, they obtained higher fodder intake, higher yield (of about 2 kg), and lower body mass loss, thus better energy utilization (yield in 56^th day on a level of 25.4 vs 27.8 kg/day in a group of primiparous cows; in multiparus cows 38.6 vs 40.4 kg/day). Any distinct changes in milk composition were noted.

Fig. 1. Yield of cows in a period of the first six months of lactation

Analysing yield of cows under the experiment it should be stated that faster and more significant yield decrease in subsequent months of lactation (from 4th to 6th) was observed in the control group (Fig. 1). Cows that were given an addition of dried yeasts were characterised by more even milk yield in that period. An increase was observed in the first three months, and a regular decrease, that was little bit over 3 kg, and almost 5 kg in the case of the control group, in subsequent ones. That proves a profitable influence of used yeasts addition on milk yield during the whole period of lactation. It was also demonstrated in previous experiments [5].

Any statistically significant differences in a range of chemical composition of milk, except an increase in dry matter and fat content in subsequent months of lactation, were observed in milk of cows that were given an addition of dried yeasts (group I) (Table 2).

Table 2. Chemical composition of milk in 3 subsequent sample milkings

Group	Month	Milk components
		Dry matter		Fat		Protein		Lactose
			sd		sd		sd		sd
I experimental	3	12.64b	0.81	4.00b	0.73	3.11	0.25	4.85	0.08
	2	12.52b	0.78	4.06b	0.79	2.94	0.21	4.82	0.12
	1	13.50a	1.39	4.82a	1.18	3.16	0.40	4.79	0.11
	In total	12.87	1.09	4.30	0.98	3.07	0.33	4.82	0.11
II control	3	12.79	1.00	4.15	0.94	3.12	0.37	4.84	0.10
	2	12.57	0.99	4.01	0.98	3.05	0.22	4.83	0.09
	1	13.18	0.82	4.39	0.66	3.32	0.35	4.78	0.15
	In total	12.84	0.96	4.18	0.87	3.16	0.30	4.81	0.12

a, b – values in columns marked with various letters differ significantly with p<0.05

A significant increase in a level of dry matter and fat was obtained in milk of cows from group I in the first month, comparing to the two subsequent sample milkings.

Skórko-Sajko et al. [20] noted higher milk yield and higher fat and protein level while giving an addition of yeast cultures. The results of study conducted so far connected with an application of brewer's yeasts in dairy cows feeding in a form of preparations containing, besides live yeasts cells, also other components [4,23] point an increase in fodder intake, increase in milk yield in a period of the first 100 days of lactation, increase in fat content in milk, higher decomposition of organic matter and protein in rumen, and higher N bacteria contribution in duodenum. The effects were better with higher NDF content in a dose. Any influence was however noted with respect to milk composition and somatic cells count [4].

The results of the study by Robinson [16], where an addition of dried active yeasts (Diamond) was used in amount of 57 g/day before and after calving, do not confirm their influence on a degree of fodder intake. Better energy utilization after calving was in turn observed in cows of hf breed (33.11 vs 31.51 Mcal EN), and better BCS index. Better utilisation of dose energy after calving by cows that were given an addition of brewer's yeasts cultures was demonstrated in another paper [4].

Schwartz et al. [19] conducted the study on an addition of live S.c. cells in the first 120 days of lactation on 7 farms of hf breed cows. Any differences in yield of cows and SCC in milk were stated. Wohlt et al. [25] using an addition of S.c. yeasts cultures before and after calving, obtained  a significant increase in fodder intake (of 1 kg DM), and yield (of 1.5–2.0 kg) after calving. Cows that were given yeasts before calving, reacted poorer on that addition applied after calving. Any distinct improvement in dry matter of a dose intake was obtained in all experiments with an addition of S.c. yeasts cultures before calving.

Somatic cells count in milk was on a relatively high level (Table 3).

Table 3. Somatic cells count and urea level in milk of cows (n=50)

Specification	Month	Group
		I – experimental		II – control
			sd		sd
SCCx1000	1	333.41	633.00	732.50	1006.31
	2	268.01	386.50	639.42	1262.09
	3	370.20	701.20	518.60	653.59
	In total	322.52	578.32	620.19	994.49
Urea (mg·l-1)	1	314.02	90.59	296.12	74.29
	2	259.01	69.79	268.89	96.21
	3	243.69	104.61	213.41	64.22
	In total	272.39	92.81	259.40	85.49

SCC in milk of cows of group I was on a level more than twice higher comparing to group II in the first and second month of the experiment; differences appeared to be insignificant statistically (p<0.05). Observed somatic cells count in milk of cows that were given dried yeasts (group I) was within the range of values for extra-class milk in a purchase for the whole experimental period. Urea content in milk of cows of both groups was similar and on an average physiological level. Differences between mean values of urea in milk of both groups were insignificant statistically, and the values are a confirmation of a proper energy to protein ratio in feeding dose.

Barkema et al. [1] on a basis of a study conducted in Holland (300 farms of dairy cows), reveal that low values of SCC were characteristic for herds led by young, well-educated farmers who work slowly but accurately. Other authors examining an influence of yeasts cultures did not observe any changes in SCC in milk of cows [4,17,19]. Only Dobicki et al. [5] give in their work that an addition of dried brewer's yeasts significantly decreased somatic cells count in milk of cows.

Biochemical indices of cows' blood in a period of 7–10 days before calving are presented in Table 4. An enrichment of feeding dose of cows in a preparation of dried brewer's yeasts (group I) caused a significant decrease in urea content (of 0.59 mmol·l^-1), in a content of total protein (of 9.60 g·l^-1) and magnesium (of 0.11 mmol·l^-1) in blood (p ≤ 0.01). The differences between the groups in the content of albumins, globulins, glucose, and in Ca and P concentration appeared to be insignificant statistically.

Since albumins level in blood of cows from both groups was similar, an increase in total protein content resulted from an increase in globulins contribution, that in the experimental group was on a level of about 55 g·l^-1 (recognised as acceptable one).

Table 4. Biochemical indices of blood of cows in a period of 7–10 days before calving (n=16, , ±sd)

Specification	Group
	I-experimental		II-control
		sd		sd
Urea, mmol·l-1	3.90b	0.47	4.49a	0.68
Total protein, g·l-1	84.20A	5.03	74.60B	5.71
Albumins, g·l-1	29.12	1.49	28.72	0.55
Globulins, g·l-1	55.07	4.01	47.81	3.97
Glucose, mmol·l-1	2.42	0.63	2.66	0.40
P, mmol·l-1	2.32	0.55	2.23	0.16
Mg, mmol·l-1	1.15A	0.09	1.04B	0.06
Ca, mmol·l-1	1.81	0.14	1.83	0.08

A, B – values in rows marked with various letters differ significantly with p<0.01

An increase in globulins concentration in a final pregnancy period is a physiological phenomenon. The analysis of total protein level in blood is of a some significance with respect to feeding analysis. The feeding analysis basing on urea determination alone is not sufficient. Determination of that element together with protein in milk enables an assessment of protein-energy ratio of feeding dose for cows. Albumins are synthesised in liver, and their increased concentration in blood attests to malnutrition of cows. Globulins do not have a big significance in feeding assessment, but are used in liver and kidneys diseases diagnosis.

Table 5 presents biochemical indices of blood of cows in 5–6 week of lactation. An addition of dried yeasts to feeding dose of cows caused statistically significant (p ≤ 0.01) increase in urea concentration (of 1.32 mmol·l^-1), and a decrease in albumins (of 1.33 g·l^-1) and magnesium content (of 0.08 mmol·l^-1). Also differences in globulins content appeared to be significant statistically (p ≤ 0.05). Any statistically significant differences were found in levels of other biochemical indices.

Table 5. Biochemical indices of blood of cows, 5-6 week of lactation (n=16, , ±sd)

Specification	Group
	I-experimental		II-control
		sd		sd
Urea, mmol·l-1	5.34A	0.57	4.02B	0.61
Total protein, g·l-1	71.72	2.62	74.45	5.62
Albumins, g·l-1	28.49A	0.69	29.82B	1.34
Globulins, g·l-1	43.39a	1.98	44.63b	2.99
Glucose, mmol·l-1	3.01	0.25	3.14	0.36
P, mmol·l-1	2.53	0.24	2.61	0.31
Mg, mmol·l-1	1.01A	0.04	1.09B	0.04
Ca, mmol·l-1	2.81	0.09	2.78	0.16

A, B – differences significant with p<0.01, a, b – differences significant with p<0.05

Piva et al. [14] demonstrated an increase in amount of protein (globulins and albumins) and decrease in urea content in blood of dairy cows that were given an addition of brewer's yeasts cultures. The level of macroelements in turn, was not subjected to any changes. Lack of changes in a level of glucose and urea with an addition of yeasts to cows was observed by Putnam et al. An increase in urea level in a study on cows in an early lactation was demonstrated by Wohlt et al. [25]. Mineral components of blood, except magnesium, were not changed significantly, similarly like in the study by Piva et al. [14].

The level of urea increased in both analysed groups, however it was still within standards. Level of protein, globulins and glucose was slightly higher in cows fed with an addition of dried yeasts, that corresponds to the study by Piva et al. [14]. Another biochemical indices were similar in both groups and were within standard range [24]. Values of biochemical indices of cows' blood obtained in the present study are similar to values observed by Lach (1999) for cows of phf breed (Black-and-White variety) from cattle farm in Osięciny. A positive influence of brewer's yeasts addition was observed in cows before calving.

SUMARY AND CONCLUSIONS

1. An application of a preparation of dried brewer's yeasts (200 g/head/day) in dairy cows feeding in the first 100 days of lactation caused slightly higher content of fat in milk and statistically significant (p ≤ 0.05) increase in FCM milk yield (of 2.27 kg) comparing to cows that were not given such a preparation.

2. Clearly lowered (however insignificant statistically) somatic cells count was observed in milk of cows that received an addition of dried brewer's yeasts comparing to the control group.

3. Proper values of biochemical indices of blood in both groups of cows demonstrate an appropriate energy-protein ratio of used feeding doses in an experimental period.

4. An addition of dried brewer's yeasts given to cows before calving statistically significantly influence the level of total protein and magnesium in blood, and content of urea, albumins, globulins and magnesium after calving.

5. An application of an addition of dried brewer's yeasts should be recommended in feeding of high-yielding cows, since it profitably influences an increase in FCM milk yield and some biochemical indices of blood.

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Accepted for print: 16.08.2010

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Marian Kuczaj
Institute of Animal Breeding, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Science, Poland
Chełmońskiego 38 C
51-630 Wrocław, Poland
Phone +48 71 32-05-860
fax: +48 71 32-05-764
email: marian.kuczaj@up.wroc.pl

Aleksander Dobicki
Institute of Animal Breeding, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Science, Poland
Chełmońskiego 38 C, 51-630 Wrocław, Poland

Jerzy Preś
Department of Animal Nutrition and Feed Management, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Science, Poland
Chełmońskiego 38 C
51-630 Wrocław, Poland
Phone +48 71 32-05-839
fax: +48 71 32-05-845

Andrzej Zachwieja
Institute of Animal Breeding, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Science, Poland
Chełmońskiego 38 C
51-630 Wrocław, Poland
Phone +48 71 32-05-765
fax: +48 71 32-05-765
email: andrzej.zachwieja@up.wroc.pl

Wiesław Jakus
Cattle Farm Malerzowice Małe, PRU Kłos RLLLP, Poland
Malerzowice 13, 48-385 Otmuchów, Poland

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