Wednesday, July 1, 2020

Day 0

Using the June 15 data, the lambs were sorted by weight, age, type of rearing, and FEC. Every other lamb was allocated to either group 1 or group 2. Group 1 lambs will receive a daily supplement of energy (whole barley). Group 2 lambs will graze only. Both lambs will graze similar pastures. 

After an 11 day acclimation period, the lambs (n=79) were weighed on June 26 (day 0). FAMACHA© and body condition scores were determined. Weights ranged from 40.6 to 103.4 lbs. and averaged 72.6 lbs. ± 14.2 lbs. The median weight was 73.8 lbs.

FAMACHA© scores ranged from 1 to 3 and averaged 1.8 ± 0.4. The median FAMACHA© score was 1.8. No lamb required deworming based on the criteria of the FAMACHA© system and Five Point Check©. Body condition scores ranged from 2 to 3.5 and averaged 2.8 ± 0.4. The median body condition score was 3. Fecal samples were collected from the lambs on June 15.  Fecal egg counts (FEC) ranged from 0 to 750 epg and averaged 200 ± 171 epg.

Group 1 (supplemented)
Group 2 (pasture only)

The two groups have similar starting weights, ages, FAMACHA© and body conditions scores and fecal egg counts.

Age days
Pasture only


Monday, June 15, 2020

Start of 2020 Research Program

Seventy-nine Katahdin ram lambs were delivered to the University of Maryland's Western Maryland Research & Education Center today. The lambs are from Ewe Lamb Right Farm (Dan & Jan Turner) in Shippensburg, PA. Ewe Lamb Right Farm is a pasture-based farm with approximately 250 Katahdin breeding ewes. The flock is enrolled in the National Sheep Improvement Program (NSIP) and submits data for parasite resistance (fecal egg counts).

Jan and Dan Turner (Ewe Lamb Right Farm)

The average age of the lambs is 97.1
± 14.9 days. They range in age from 75 to 120 days. The median age is 94 days. Weights ranged from 39.4 to 91.2 lbs. and averaged 66.7 ± 12.7 lbs. The median weight was 68.6 lbs. After weighing, FAMACHA© and body condition scores were determined. FAMACHA© scores ranged from 1 to 3 and averaged 1.6 ± 0.6. The median FAMACHA© score was 2. No lamb required deworming. Body condition scores ranged from 2 to 3.5 and averaged 3.0 ± 0.4. The median body condition score was 3. A fecal sample was collected from each lamb.

After handling, the lambs were put into a silvopasture area.  After an acclimation period, they will be divided into two groups for the experiment. Half of the lambs will graze only. The other half will graze similar pastures and receive a daily supplement of whole barley. The pastures are a mixture of various cool season grasses, legumes, and forbs. The lambs will be handled every two weeks to determine body weights and assess health, including the need to deworm.

Silvopasture grazing

The Five Point Check
©, including FAMACHA© will be used to make deworming decisions. Per the recommendation of the American Consortium for Small Ruminant Parasite Control (ACSRPC;, any lamb requiring deworming will be given a combination treatment of two or more dewormers. It is not known if the parasite challenge will be sufficient to determine the effect of diet supplementation on parasite resistance (fecal egg count) and resilience (FAMACHA©). Fecal samples will be collected several times during the experiment. The samples will be analyzed by Dr. Dahlia O'Brien's lab at Virginia State University.

At the end of the grazing period, fifteen or more lambs from each group will be harvested (locally) to collect carcass data. A sample will be collected from each carcass for fatty acid analysis.

Thursday, October 10, 2019

Lamb Served in Dining Halls

For the second year in a row, the lamb from our comparison study of ram, wether, and short-scrotum lambs was served in the dining halls at the University of Maryland College Park. On October 2nd, a Harvest Festival was held to promote local food, including the lamb. Sliced leg of lamb and lamb burgers were served to students, faculty, and visitors.

Results: Growth and Carcass Data

This was the second year of a 2-year study comparing the growth and carcass characteristics of (intact) ram, wether, and short-scrotum lambs from a commercial sheep dairy in Maryland.

After weaning, lambs were grazed and fed for 107-d at the University of Maryland's Western Maryland Research & Education Center in Keedysville. At the end of the study, they were harvested to collect carcass data.  Data was collected on 21 rams, 25 wethers, and 18 short-scrotum lambs. 

Ram lambs had the heaviest final weights and highest ADG. The wether lambs had the lightest final weights and lowest ADG.  Short scrotum lambs were not statistically different from ram lambs. Ram lambs had the heaviest hot and cold carcass weights. Wethers had the lightest. Short scrotum lambs were intermediate.

A 4% pencil shrink was applied to the lambs to calculate dressing percentage. Dressing percentage was determined by dividing hot carcass weight (HCW) by "shrunk" live weight. Wether lambs had the highest dressing percentage. Ram and short scrotum lambs were not statistically different.

Rib eyes (REA) from the ram carcasses were largest. Wethers had the smallest rib eyes. Short scrotum lambs were intermediate. However, when adjusted to a common weight (of 100 lbs), there were no statistical differences in rib eye area among treatment groups.

Wethers produced the fattest carcasses, as evidenced by greater back fat (BF) and yield grade (YG). Short scrotum lambs had more back fat and higher yield grades than ram lambs, but the differences were not statistically significant. At the same time, none of the lambs carried excess back fat or internal fat.

Sex did not affect body wall thickness (BWT), percent kidney and heart fat (KH), or leg conformation score (LC). Ram carcasses yielded a higher percentage of boneless closely trimmed retail cuts (BCTRC) than wether lambs. Short scrotum lambs were intermediate. BCTRC is calculated using the following formula: 49.936 - (0.0848 x HCW) - (4.376 x BF) - (3.530 x BW) + (2.456 x REA).

Due to inadequate backfat, seven ram carcasses failed to quality for the USDA Choice grade, as there is a minimum requirement of 0.08 inches. Two short scrotum carcasses failed to grade. All of the wether carcasses graded Choice or above.  Despite the leanness of the carcasses, there was evidence of quality in all the carcasses: maturity, flank streaking, and conformation.

For the second year in a row, ram and short scrotum lambs demonstrated superior growth and carcass composition compared to wether lambs.

Wednesday, August 21, 2019

Testicle Dissection

At the time of harvest, five pairs of testicles were obtained from intact rams and five were obtained from short-scrotum rams. The testicles were sent to Virginia State University for dissection by Dr. Stephan Wildeus and Dr. Dahlia O'Brien.

The short-scrotum lambs had significantly smaller testes than the ram lambs: 108.9 vs. 291.2 g. The epididmymal weight was also smaller (17.7 vs. 53.8 g) in the short-scrotum lambs, as were the ratios of parenchyma: tunica and testis: epididymis).

Organ weights
 Sex No. Total testes, g Epididymal wt, g Parenchyma:
tunica ratio
Testis: epididymis
 Ram 5 291.2 53.8 9.79 5.50
 Short scrotum 5 108.9 17.7 7.76 6.32
Probability 5 <0.0012 <0.0027 0.1204 0.2594

The testicles from the intact ram lambs were smaller than last year by about 100 g. This may have accounted for the lower ejaculate quality of the intact rams. One of the short-scrotum rams had one testicle that was significantly larger than the other. Its testicle was also considerably larger than the other short scrotum rams (by over 50 g). 

Thursday, August 15, 2019

Background Information on 2019 Lambs

Sixty-four lambs were used to compare the growth, carcass, and reproductive characteristics of intact ram (n=21), short-scrotum (SC) ram (n=18), and wether lambs (n=25) . The lambs were single-sourced from the state's only licensed sheep dairy. The breed was East Friesian x Lacaune.

The oldest lamb was born on January 26. The youngest lamb was born on March 22. Upon arrival, the lambs ranged in age from 31 to 86 days and averaged 65.1 ± 17.4 days of age. The median age was 70 days. The median date of birth was February 11. Less than 2 days separated the average age of the rams, SC, and wethers.

As it was a dairy farm, the lambs were weaned at an early age, ~30 days. After weaning, they remained in the barn/dry lot until they were transported to the University of Maryland's Western Maryland Research & Education Center on April 22.

Birth weights ranged from 5.5 to 16.0 lbs. and averaged 11.5 ± 2.2 lbs. Birth weights were similar for ram, SC, and wether lambs. Birth type ranged from 1 to 3 and averaged 1.95 ± 0.55. The  median birth type was 2 (twin). Birth type was similar across treatment groups. Most of the lambs (87.5%)  had the same sire.

The lambs were weighed upon arrival. Starting weights ranged from 28.0 to 71.0 pounds and averaged 44.5 ± 10.6 lbs. The ram lambs were a little heavier than the wether lambs: 45.1
± 10.5 vs. 43.5 ± 10.9 lbs.  The SC were intermediate: 45.1 ± 10.9 lbs. 

Castrations were performed by 10 days of age. Every third lamb was left a ram, castrated, or made a short-scrotum.

Sex No. Start age, d Birth type Birth wt, lbs. Start wt, lbs. Same sire, #
Ram 21 66.4 2.00 11.6 45.1 19
SC 18 63.7 1.79 11.6 44.4 16
Wether 25 64.2 2.00 11.2 43.5 21
All 64 65.1 1.95 11.5 44.5 56

Compared to last year, this year's lambs were younger (11 days) and lighter (11 pounds).

All of these factors will be put into the statistical model to determine if they affected the outcome of the experiment. Last year, they did not.

4-H Pelt Project

The pelts (hides, skins) from the lambs in the comparison study of ram, wether, and short-scrotum lambs are being used in a 4-H Entrepreneurship Program, under the leadership of Ashley Travis, 4-H Youth Educator in Washington County, and Dr. Jesse Ketterman, Family & Consumer Sciences Educator for the Western Maryland Cluster.

The pelts were retrieved immediately after slaughter at Old Line Custom Meat Company (in Baltimore). They were salted generously and laid on top of each other for transport. Upon arrival to the Western Maryland Research & Education Center, the pelts were lightly salted again, re-stacked, and held overnight in a cooler.

The following day, the pelts were taken to the local fairgrounds where they were stretched out on wooden pelts and re-salted (even more generously). Pelts were trimmed to removed flesh and excess body parts.The pelts will be dried for approximately 2 weeks before being transported to Bucks County Fur Products, Inc. (in Quakertown, PA) for professionally tanning. Bucks County Fur specializes in the tanning of sheep, goat, and deer hides.

Youth will sell the finished pelts, hopefully for a profit, after expenses have deducted. As part of the entrepreneurship program, youth learned how to develop their own business plans. They will give oral presentations to share their business plans. The youth are mostly 12-13 years of age.

Pelts immediately after slaughter

Initial salting of pelts in the back of a pickup truck

Stacked and ready to go

Stretched and salted for drying

Ordinarily, pelts are a waste product of lamb production, unless producers decide to tan their own hides. For innovative producers, pelts are a way to add value to a lamb and increase the profitability of sheep rearing. Professionally tanned sheep hides can fetch good prices, especially if they are from large sheep (or lambs) with long, colorful fleeces.

In the past, pelts (especially those from unshorn fine wool lambs) had a significant value and were an important source of income for lamb processors. Currently, lamb pelts are selling for a low price and many processors simply discard them. The high value of the US dollar (against international currencies) is one reason given for their low commercial value.

Weekly Lamb Pelt Price Report

Day 0

Using the June 15 data, the lambs were sorted by weight, age, type of rearing, and FEC. Every other lamb was allocated to either group 1 or ...