Progut™ Info Letter 1/2007

The effects of Progut™on the performance of dairy cows.

  1. Objective

The objective of the trialswas to study the effect of Progut™on the milk production of dairy cows.

  1. Trials at HelsinkiUniversity

In the first trial a special energy supplement (Acetona™) with or without Progut™ addition was fed to dairy cows two weeks pre- and 8 weeks post-calving. The cows were getting 1 kg of Acetona daily, giving 20 grams of Progut™ per cow per day. There were 12 cows in the control group and 12 cows in the trial group (second or > calving). The addition of Progut™ in dairy cow diet increased the energy corrected milk yield (ECM kg/d) by 5.3 % during the first 8 weeks of lactation (table 1). It also increased the % fat and fat production g/day. The percentage of protein was decreased slightly but higher milk volume meant that the production of protein g/day did not change. The addition of Progut™ improved energy utilisation by 6.5%.

Table 1. The effect of the diet on the milk production of dairy cows. HelsinkiUniversity.

Weeks 1-8 / Progut - / Progut + / %
Milk, kg/d / 46.5 / 47.3
Fat % / 4.23 / 4.53
Protein % / 3.39 / 3.33
Urea g/dl / 28 / 28
Fat g/d / 1899 / 2087
Protein g/d / 1537 / 1541
ECM, kg/d / 46.8 / 49.3 / 5.3 %
ECM / DMI / 2.15 / 2.29 / 6.5 %

ECM = energy corrected milk yield, DMI = dry matter intake

In the second trial a special energy supplement with or without Progut™ addition was fed to dairy cows two weeks pre- and 8 weeks post- calving. The inclusion of Progut™ was 20 grams per cow per day two weeks pre-calving and 10 grams per cow per day 8 weeks post-calving. It should be noted however, that in this trial also the raw material composition of the energy supplement differed in the control and trial treatments. There were 12 cows in the control group and 12 cows in the trial group

The energy corrected milk yield (ECM kg/d) of the trial group was 6.9 % higher than the control (table 2). Fat and protein production was also higher but the % fat and % protein was slightly decreased. Progut™ addition improved the energy utilization in this trial, too.

Table 2. The effect of the diet on the milk production of dairy cows. HelsinkiUniversity.

Weeks 1-8 / Control / Trial / %
ECM, kg/d / 43.7 / 46.7 / 6.9 %
% fat / 4.32 / 4,23
% protein / 3.34 / 3.25
Fat g/d / 1810 / 1923
Protein g/d / 1386 / 1464
Urea g/dl / 29.2 / 28.0
ECM / DMI / 1.92 / 2.02 / 5.2 %

ECM = energy corrected milk yield, DMI = dry matter in

Effects on immunity:

In the second trial the effect of Progut™ addition on the IgA content of the colostrum and the serum of dairy cows was measured. The addition of Progut™ increased the IgA content of the colostrum by 35 - 60 % (figure 1). In the successive calf trial it was seen that the IgA content of the colostrum had a significant positive correlation with the growth of the calves (figure 2).The dams seemed to recover faster from the calving stress, which can be seen in the serum IgA “recovery” rate (figure 3). The rise started at week four and at week eight the serum IgA was already 81% of the pre-trial level, whereas in the control it was only 52% (p=0,099).

Figure 1. The effect of the diet on the colostrum IgA content of dairy cows

Figure 2. The effect of the colostrum IgA content on the growth of the calves between weeks 3 and 5

Figure 3. The effect of the diet on the serum IgA content of dairy cows around

calving

  1. Field trial at Bishopston Farm, Scotland 2005-2006

The trial was carried out at Bishopston farm in Scotland from November 2005 until May 2006 and was supervised by Dr. William V. Hutcheon. The trial continued till the cows were put out to grass on 3rd May 2006.A group of Holstein-Friesian dairy cows in lactation 2-6 was fed a Total Mixed Ration (TMR) with the addition of 200g Progut Farm (20g Progut™) per head per day from two weeks pre-calving through early lactation. Twenty-nine cows receiving Progut Farm formed the trial groups (T1-T3). These 29 cows had Progut Farm in their diet for a variable period of time, depending on when they calved (table3).

Because of the practicalities of feeding and housing in a commercial situation it was not possible to have a formal control (untreated) group of cows running concurrently with the treated groups. The best control group (C) which could be created was a group of cows calving before Progut Farm was fed. The control group of 37 cowsdid not receive Progut Farm during the dry period or the earliest part of lactation but progressively had Progut Farm during the last few weeks of the period of the lactation studied (table 3). This was because they were part of the high yielding group fed Progut Farm. The cows in groups C1 and C2 had, on average, no Progut Farm till day 91 or day 57 of lactation forming a more relevant control. Groups C3 and C4 were intermediate groups, the cows having had Progut Farm from day 30 and day 15 of lactation respectively.

Table 3. Trial groups

Group / Noof cows / Calving dates / Progut Farm in the diet(PRE = 2 weeks pre calving)
T1 / 10 / 12/05-1/06 / PRE + first 115 days of lactation
T2 / 10 / 1/06-2/06 / PRE + first 100 days of lactation
T3 / 9 / 2/06-3/06 / PRE + first 70days of lactation
C1 / 9 / 8/05-9/05 / Not before first 90 days in lactation
C2 / 9 / 9/05-10/05 / Not before first 60 days in lactation
C3 / 9 / 10/05-11/05 / Not before first 30 days in lactation
C4 / 10 / 11/05 / Not before first 15 days in lactation

The main measures of cow performance were the production of average daily milk and Fat+Protein over first 115 days (approx) of the present lactation. The actual recording day (days in milk) varies for individual cows over a 28 day span and the range used was therefore 99-130 days. Since the lactation curve for most cows is relatively flat for this part of the lactation the results should not be much affected by differences in the actual days in milk within this range.Test comparisons for a sample of the early calving groups confirmed this - i.e. the average daily yields at 100 days and 130 days were quite close. The performance measures of the present lactation were compared to respective daily averages over first 155 days (range 140-170 days) of the previous lactation.For the previous lactation, it was decided to use a more extended period as these records were readily available. Because of the need to compare previous year's milk records all heifers were excluded from the trial.

Official milk records taken every 28 days by The Cattle Information Service were used to assess cow performance. These records (mainly the Statement of Milk Records) provide very detailed independent production data and other information based on 28-day recording and milk sampling by nationally trained recorders. Records up to and including the one on 11 June 2006 were used so that all cows had records covering at least the first 100 days of lactation.

Cows in the T3 group received Progut Farm for rather less than 100 days. For this reason it was decided to use only the groups T1+ T2as the trial group. Groups C1 + C2 formed the control group and groups C3 + C4 formed the intermediate group.

Results

The main results are presented in table 4. The ratios are considered to be the most meaningful figures though the actual figures for % fat, % protein and milk yield are also shown.

Table 4. Milk yields (kg/d), % fat and % protein for present and past lactation and the ratio present:past

Milk yield (kg/day) / % Fat / % Protein
Last / Present / Ratio / Last / Present / Ratio / Last / Present / Ratio
Mean C1+C2 / 27.1 / 29.0 / 1.07 / 4.39 / 4.25 / 0.97 / 3.44 / 3.45 / 1.00
Mean C3+C4 / 29.0 / 33.0 / 1.14 / 4.20 / 3,94 / 0.94 / 3.22 / 3.21 / 1.00
Mean T1+T2 / 28.7 / 34.0 / 1.19 / 4.18 / 4.24 / 1.01 / 3.29 / 3.18 / 0.97
Mean C / 28.1 / 31.0 / 1.10 / 4.30 / 4.10 / 0.95 / 3.33 / 3.33 / 1.00
Mean T / 28.7 / 34.0 / 1.19 / 4.18 / 4.24 / 1.01 / 3.29 / 3.18 / 0.97

The average daily milk yield of the control group (C1+C2) increased by 7 % in the trial period compared to previous year (table 4). The respective improvement in the trial group (T1+T2) was 19 % and 14 % in the intermediate group (C3+C4). Comparing the results of the present lactation, trial group cows produced 17 % more milk than the control group cows and 3 % more than the intermediate group cows. The longer the period Progut™ Farm was used, the higher the improvement in milk yield seemed to be. The same results are presented in Figure 4. in graphical form. The ratio of % fat (present to previous lactation)decreased in the control and intermediate groups but remained the same in the trial group (table 2). The ratio of % protein (present to previous lactation) remained the same in the control and intermediate groups but decreased slightly in the trial group.

Figure 4. Average daily milk yields (kg/d) with different Progut™ feeding strategies

The price of milk and pricing of fat and protein varies in different countries. Using Finnish milk pricing system, 2.5 cent per % fat and 6.5 cent per % protein, the following values of milk in the present lactation were calculated for C1+C2, C3+C4 and T1+T2 respectively є9.58, є10.14 and є10.63. Compared with the previous lactation the value of milk increased most in the trial group (figure 5).

Figure 5. Value of milk with different Progut™ feeding strategies

  1. Farm trialsin Finland 2006

The effect of a half-concentrate feed containing Progut™ on the milk production of dairy cows was studied in 10 different farms in Finland during spring 2006. Half-concentrate is fed 50:50 with cereals. In all of the farms the existing half-concentrate feed was changed for the whole herd to the feed containing Progut™ and the effect on the amount of daily tank milk per cow was followed until the cows were put on pasture. For all of the cows the follow-up period was more than 100 days. The inclusion rate of Progut™ in the half concentrate was 0.2 %. The maximum recommended daily allowance of the feed was 8 kg per cow, which would mean maximum 16 g daily intake of Progut™ per cow. The average milk yield of the cows in the trial farms was around 30 kg/day. For this reason the average daily intakes of the half-concentrate and Progut™ were approximately 4 kg and 8 grams respectively.

The effect of Progut was also studied with compound feed and silage diet. This trial was one at a farm having an average yearly milk production of 10600 kg per cow. The average number of cows was 30. In this farm test the previous compound feed was changed to a feed containing Progut™ and the effect on milk production was followed through the subsequent milk recordings. The average daily compound feed intake per cow during the test period was 12 kg, which was equal to 10 grams of Progut™ per cow and day.

Results:

The average amount of tank milk per cow per day increased in 7 out of 10 farms. In three farms the milk production remained at the same level as before the feeding of Progut™ containing trial feed was started. The average improvement in the milk yield of all the 10 farms was 1.6 kg per cow per day. The composition of the milk as measured in % fat and % protein remained stable during the test period.

In the farm test in which the compound feed diet was used the addition of Progut™ in the feed increased the average daily milk yield by 1.4 kg per cow (table 5). The % fat was slightly increased, too.

Table 5. The effect of the diet on milk production of cows, farm trial in Finland 2006

Control period / Test period
Milk, kg/cow/day / 32.9 / 34.3
% fat / 4.00 / 4.24
% protein / 3.47 / 3.50
Urea g/dl / 30 / 25
  1. Major conclusions

-The tested amounts of Progut™, 8 to 20 grams per cow per day, increased the average daily milk yield of cows by 1.4 to 3.4 kg depending on the amount, lactation stage and time during which Progut™ was used

-The effects on milk production have been most pronounced with high yielding dairy cows in early lactation

-In most of the trials the % of fat has slightly increased and the % protein being stable or slightly decreased

-In the trials conducted at Helsinki University Progut™ addition improved the energy utilization (ECM/DMI) by 5-6.5%

-In these trials it was also shown that Progut™ increased the IgA content of the colostrum and seemed to fasten the dam's recovery from the calving stress

-Trials with calves showed that the IgA content of the colostrum had a significant positive correlation with the growth of the calves

-Based on the results from the performance trials and from a trial with fistulated cow (will be published in the forthcoming Info Letters), an average Progut™ dose of 10 grams (range 7 to 15 grams) can be recommended

-In the rumen simulation trials (will be published in the forthcoming Info Letters) Progut™ was shown to enhance significantly the rumen fermentation rate measured as microbial gas production, to increase the production of protein and energy by increasing significantly the number of rumen microbes and the production of short chain fatty acids, which could explain the improvements in milk production seen in the performance trials