Sunday, October 26, 2008

Artificial Lighting Increases Milk Yield in Dairy Ewes

I hope I'm not boring you with scientific or technical articles, in this case an abstract. I have feeds for these things and when I see something interesting, I want to share it. This study was with dairy sheep, but they certainly are similar to dairy goats.


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Artificial Lighting During Winter Increases Milk Yield in Dairy Ewes

A. D. Morrissey, A. W. N. Cameron and A. J. Tilbrook1

Department of Physiology, Monash University, Clayton, Victoria, 3800, Australia

1 Corresponding author: alan.tilbrook@med.monash.edu.au

In Australia, the supply of sheep milk is reduced during the winter. Housing dairy animals under lights during winter is a simple technique to increase milk yield; however, it is difficult to predict the magnitude of this increase in dairy ewes, because there are few corroborating data. We studied 220 East Friesian crossbred ewes (50 primiparous and 170 multiparous ewes, respectively) that lambed in April to May 2007 (late autumn, southern hemisphere) and were weaned from their lambs within 24 h of parturition and milked exclusively by machine. These ewes were ranked according to their milk production, and ewes producing ≥1,000 mL/d of milk were allocated to 1 of 2 groups. One group of ewes was kept indoors under a long-day photoperiod (16 h of light), whereas the other group was kept indoors under a naturally declining day length. Ewes were maintained under these conditions for 8 wk. Milk yield was measured twice weekly, and ewe weight and condition were measured at weekly intervals. From a subset of ewes (n = 20 per group), milk samples were collected twice weekly at the morning milking to measure milk lipid, protein, and lactose, and blood samples were collected once a week to measure plasma prolactin concentrations. Mean daily milk yield was analyzed as a percentage of preexperimental milk yield because the milk yield of ewes housed under the long photoperiod was lower than that of ewes under a declining day length when the treatments began. Thus, the ewes under a long photoperiod yielded 91.7% of their starting yield by wk 8 of treatment, whereas ewes under a declining day length yielded 76.25% of their initial value (LSD = 5.1), and this divergence in milk yield was apparent by wk 2 of treatment. Mean plasma prolactin levels were greater in ewes housed under the long-day photoperiod (n = 20) compared with control ewes (n = 20) at wk 6 (168 ± 27 vs. 72 ± 19 ng/mL, respectively), wk 7 (125 ± 28 vs. 37 ± 7 ng/mL, respectively), and wk 8 of the experiment (132 ± 35 vs. 31 ± 7 ng/mL, respectively). The composition of the milk was similar between the groups at each time point, and milk from these ewes (n = 20 per group) contained, on average, 6.1 ± 0.05% lipid, 4.8 ± 0.02% protein, and 5.4 ± 0.01% lactose (n = 309 samples). We concluded that ewes increase milk production in response to being housed under a long-day photoperiod during winter.

J. Dairy Sci. 2008. 91:4238-4243. doi:10.3168/jds.2007-0918
© 2008 American Dairy Science Association ®




Friday, October 24, 2008

OBA Picture Calendars available


Jillian announced this on OberhasliTalk today:

tervherd@yahoo.com writes:

Hello Everyone,

I'm pleased to announce that the 2009 OBA Photo calendar is available
for purchase.

Sneak peek images of the calendar are available in the files section
of OberhasliTalk under OBA Fundraising.

_http://tech.http://tech.http://techttp://tech.<Whttp://techttp://tech.http://tech.groups.yahoo.com/group/OberhasliTalk/files/OBA%20Fundraising/)

make PAYPAL payment to:
_secretary@oberhaslisecr_ (mailto:secretary@oberhasli.net) for the total
amount.

These beautiful professionally printed calendars sport full color
photos of lovely Oberhasli. The photo titles are humorous and
creative. Each calendar is only $17.25 and that includes shipping by
first class mail. We can even send them to friends on your behalf.



If you are following this blog and are bit by the Oberhasli bug or if you know someone who might like this, say a 4H leader, please use the email address above or me at lm12oliver@hotmail.com and we'll make sure you get one or more. They may be available at the NAILLE show in Louisville, KY next month as well.

Monday, October 20, 2008

SGCH Willow Run Hassida *M


This is three time national champion, Willow Run Hassida. Not only is she quite a show girl, she was a top ten milker.

This doe is related to my foundation buck, FDF-Pleasant Fields Solaris. Sol's dam is Hassida's grand dam, specifically GCH Destiny Farm Souvenir, two time Reserve Natl GCH.

Hassida was the national champion once again in 2008 with Heaven's Hollow Shotsi, my new buck's dam, in Reserve. Both of these does classified 92 the highest scores in the Oberhasli breed.

Laboratory Determination of Fat in Milk

The following is straight from my college nutrition lab book. Please leave comments if you have questions and cannot find answer on internet. I'll try to help.

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Milk is a colloidal dispersion and contains water-soluble solutes as well as insoluble material. Fatty compounds are generally insoluble in water but soluble in organic solvents like hexane, chloroform, etc. The determination of fat in milk will require extraction of fat in an organic solvent. Direct treatment of such an organic solvent generally produces an emulsion at the junction pf twp solvents (water from milk and organic solvent.)

The problem can be solved in various ways. One of the simple methods is to first precipitate the proteins and then filter them out. Proteins can be precipitated out by trichloroacetic acid, acetic acid (vinegar), and heavy metals or by adding large amount of salt.

REQUIREMENTS: Milk sample to be analyzed, suitable reagent for precipitation of proteins, organic solvent to extract fatty compounds, filter equipment or a centrifuge, evaporating dish or beaker, separatory funnel, balance (scale).

PROCEDURE:

1. Weight a 250 ml size beaker. Place 100 ml of milk sample in it and record the total weight. From these weights find out the weight of milk.

2. Add 40% solution of trichloroacetic acid (be careful) solution or acetic acid solution (vinegar from a supermarket) whichever is provided to you. Stir continuously and continue the addition of a reagent until the precipitation is complete. If a pH meter is available check the pH of the milk sample. You may use pH paper. The pH should be 4.0 or less than 4.0. The pH of normal milk sample is generally close to neutral pH (i.e., pH 7.0).

3. If a centrifuge is available, centrifuge the sample carefully in the pre-weighed centrifuge tubes for 25 minutes at 4000 rpm.

Pour the supernatant into a clean beaker. If a centrifuge is not available, filter the ppt (precipitate) using pre-weighed Whatman 52 or fine grade filter paper.

4. Now add approximately 20 ml of hexane or petroleum ether or the solvent recommended by your instructor to the filtrate or the supernatant (liquid separated after centrifugation).

Stir well and pour the contents into a separatory flask. Allow the two liquid layers to separate as clearly as possible. You may add approximately 4 ml of methanol if you see emulsion or scum like cloudy or milky interface.

5. Separate the organic layer. Depending on the density of the solvent used, the organic solvent will be either upper or lower layer. Collect the organic layer in weighed evaporating dish or a small beaker.

6. The water layer should be treated with 20 ml of the fresh organic solvent for the extraction of fat. Then separate clear organic solvent.

7. Repeat the extraction two more times. Collect all the extracted fat solutions in the same container.

8. If air current is available dry over such air jets and weigh the beaker/evaporating dish. Otherwise, dry it over a boiling water bath.

CALCULATIONS:

Weight of beaker:

Weight of milk and beaker:

WEight of milk used: (in other words, net weight)

WEight of dish:

Weight of dish plus dried fat:

Weight of fat: (in other words, net weight)

% fat content = [weight of fat X100]/Weight of milk sample

%fat content = [weight of fat X 100]/Weight of milk used

SAMPLE CALCULATIONS:

Wt. of beaker: 25.5 g
Wt of beaker + milk: 115.0 g
Wt. of milk = 115.0 - 25.5 = 89.5 g
Wt of dish:35.8 g
Wt of dish and dried fat: 39.8 g
Wt of fat= 39.8 g - 35.8 g = 4.0 g
% fat content = [4.0 g X 100]/89.5 g = 400/89.5 = 4.47%. This might be a homogenized milk sample.

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"Laboratory Manual for Introductory Course in Nutrition," by Kris Dhawale, Professor of Chemistry, IU East, Richmond, IN. 2003The following is straight from my college nutrition lab book. Please leave comments if you have questions and cannot find answer on internet. I'll try to help.

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Sunday, October 12, 2008

DAIRY MANAGEMENT: EVERY SECOND COUNTS

THE FOLLOWING WAS WRITTEN WITH COW DAIRIES IN MIND BUT I FOUND IT VERY HELPFUL FOR GOAT DAIRY MANAGEMENT AS WELL.


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Dairy Management: Every Second Counts

The little things we do during milking time have a profound effect on udder health and milk quality. It is important to remember that every quarter of every cow must be prepped for milking the same way by every milker at every milking.

Specifics of milking procedures may vary from farm to farm. For example, one farm may prep cows in sets of 4 cows, while the next farm preps in sets of 6. However, the basics of timing should ideally be the same or similar on every farm.

The first important time frame to remember relates to contact time of the teat dip being used as pre-dip. The contact time of teat dips applied before milking need to be on the teat skin for a minimum of 30 seconds to have adequate killing effect. During this time, the quarters can be stripped, but the dip needs to remain on the teat skin for the full 30 seconds prior to wiping.

In addition to contact time, we must ensure that the “prep-lagtime” has an average length of 90 seconds from start of tactile stimulation. Prep-Lag-Time by definition is the time from the start of either stripping, massaging or wiping the teats with a towel, whichever comes first, to unit attachment. On some farms this is stripping and others it is wiping, depending on the order of your preparation procedures. If we attach the units prior to the 60-second mark, we have not given adequate time for oxytocin to reach a useful concentration in the udder. On the flip side, we need to ensure units are attached within 90 seconds of stimulation to make maximum use of the letdown effect. I encourage you to take a stop-watch to the parlor, check your timing of milking procedures and make necessary adjustments to your routine until you are within these time frames.

One suggested protocol would include prepping cows in blocks of 4 or 5. Begin with the first cow by removing lose debris with a towel, then stripping each quarter and examine the milk for signs of mastitis. This would be repeated for the remaining cows in that block. Start back at the first cow of the block (do not weave back through the cows in reverse order) and apply the predip ensuring at least half of the teat is covered. Once the entire block has been predipped, begin wiping the first cow of the block with a single-use towel.

At this point, you should be able to also attach the unit before wiping the second cow of the block. However, check your timing and make sure a full 60 seconds have elapsed from the time that cow was stripped. If you are shy of the 60-second mark, continue wiping the remaining cows in the block and then return to attach the units, starting at the first cow.

Once you have a routine established, you will need to monitor the routine monthly to ensure the time frames are being met. Proper milking procedures will help to lower somatic cell count, increase pounds in the tank and decrease milk out time.


By Christina Petersson-Wolfe (Extension Dairy Scientist, Milk Quality & Milking Management)
Dairy Pipeline newsletter - Virginia Cooperative Extension



Published 10/10/2008

Source: Virginia Cooperative Extension Dairy Pipeline