2013 Pen vs. Pasture Study
2013 was the third year of the pen vs. pasture study at the University of Maryland's Western Maryland Research & Education Center. The bucks (n=30) for the study were obtained from a farm in Kansas. They were randomly allocated to two treatment groups: PEN vs. PASTURE. All of the bucks were Kiko.
As shown in the table below, the two groups were very similar in terms of their starting weights, fecal egg counts, and other traits. One of the PASTURE goats eventually had to be removed from the study due to having an abscess that tested positive for caseous lymphadenitis (CL).
Upon arrival, the goats were triple-dewormed with anthelmintics from each anthelmintic class (albendazole + moxidectin + levamisole). Even though the goats had low fecal egg counts, the triple deworming was necessary to make sure all the goats started the study equally. Because the goats were free from parasites at the start of the study, any differences measured could be attributed to treatment group.
After a 13-day adjustment period, the bucks consumed their respective diets for 84 days. The PEN goats (n=15) were fed hay and grain. A good quality mixed hay (mostly orchardgrass) was offered free choice in two 4-foot hay racks with vertical slats. Starting on May 31 grain (whole barley) was gradually introduced to the diet of the PEN goats. It was increased according to appetite. The grain was fed in 4-foot poly troughs that were hung on the side of the fence and removed after feeding. Free choice minerals were offered.
The PASTURE goats (n=15) grazed along side the goats (TEST, n=81) in the Western Maryland Pasture-Based Meat Goat Performance Test. The PASTURE goats had access to free choice minerals, but were not given any supplemental feed at any time during the adjustment period or test.
The PASTURE and TEST goats (n=96) were rotationally grazed among six, 2-acre paddocks. From May 31 until July 15, they grazed cool season grass paddocks, composed mostly of orchardgrass and tall fescue. The cool season grass paddocks had been pre-infected with infective worm larvae by untreated sheep. From July 15 until August 15, the goats grazed four acres of forage sorghum. After the sorghum pastures were depleted, the goats were returned to the cool season grass pastures (for another parasite challenge).
All of the bucks in the study and test were handled bi-weekly to determine body weights, FAMACHA© scores, body condition scores, coat condition scores, dag scores, and fecal consistency scores. Individual fecal samples were collected bi-weekly to determine fecal egg counts. Pooled fecal samples were collected every 28 days for fecal coproculture (larvae ID). During the study, the worm load consisted of 72 to 82 percent Haemonchus.
Results
The PEN goats had significantly higher rates-of-gain than the PASTURE goats. For the PEN goats, average daily gain (ADG) ranged from 0.129 to 0.452 and averaged 0.311 + 0.071 lbs. per day. For the PASTURE goats, ADG ranged from 0.005 to 0.105 and averaged 0.064 + .036 lbs. per day.
From day-14 through day-84, the PASTURE goats had significantly higher fecal egg counts than the PEN goats. If the egg counts from treated PASTURE goats were removed from the graph below, the differences would be even greater. Fecal egg counts increased significantly in both the PASTURE goats and the TEST goats from day-14 until day-42. The high fecal egg counts led to a significant clinical challenge for all of the pastured goats.
The PASTURE goats started the study with lower FAMACHA© scores than the PEN goats; however, their advantage dimished by day-28. In fact, on day-28, eight of the PASTURE goats required deworming. Twelve were dewormed on day-42. None of the PEN goats required deworming during the duration of the study.
Carcass data
On September 6, all of the study bucks were transported to Country Foods, a custom-exempt abattoir in Waynesboro (PA), for same day slaughter. Prior to slaughter, the goats were not held off feed (they had free choice hay) and the two groups of animals were mixed. This may have resulted in lower-than-expected carcass weights and dressing percentages. Dressing percentage is affected by many factors, including gut fill.
The chilled carcasses were deboned and measured four days later. A sample of the longissimus dorsi was removed from each carcass and is being analyzed for fatty acid content. The PEN goats had heavier live weights, hot carcass weights (HCW), and cold carcass weights (CCW).
Dressing percentages were determined by dividing hot carcass weights by live weights. The PEN goats had higher dressing percentages than the PASTURE goats. In the PEN goats, dressing percentage ranged from 39.2 to 46.9 and averaged 43.5 + 2.1 percent. In the PASTURE goats, dressing percentage ranged from 37.1 to 42.2 and averaged 40.3 + 1.6 percent.
All of the carcass were deboned and separated into lean, bone, and fat portions. Kidney and heart fat (KH) was weighed separately and determined as a carcass percentage. Carcass percentages of fat, bone, and lean were determined. Yield was calculated by dividing the lean weight by live weight.
The PEN goats produced fatter carcasses than the PASTURE goats, as evidenced by their percentages of kidney and heart fat and overall carcass fat. However, the carcasses from the PEN goats had a significantly higher percentage of lean and a lower percentage of bone. Their yield of boneless meat was almost 5 percent higher than the PASTURE goats.
None of the carcasses contained excessive fat. The carcasses from the PASTURE goats were especially lean, with very little trimmable fat.
Rib eye area was measured using a plastic grid (20 dots=1 square inch). The PEN goats had larger rib eye areas than the PASTURE goats (1.79 vs. 1.29 square inches). In the PEN goats, rib area ranged from 1.15 to 2.20 and averaged 1.79 + 0.28 square inches. In the PASTURE goats, rib eye area ranged from 0.75 to 1.90 and averaged 1.29 + 0.27 square inches. Ultrasound understimated rib eye area by 24 percent (0.43 square inches) in the PEN goats and 26 percent (0.34 square inches) in the PASTURE goats.
The PEN goats also had superior leg muscling. Leg circumference ranged from 30.0 to 35.6 cm in the PEN goats and averaged 33.7 + 1.47 cm. In the PASTURE goats, leg circumference ranged from 21.5 to to 35.0 cm and averaged 29.4 + 3.3 cm.
At the end of the study, each goat was graded. Most of the PEN goats were determined to be USDA Selection 1 (avg. 1.10). The PASTURE goats were determined to be a mix of USDA Selection 2 and 3 (avg. 2.5).
Economic analysis
Based on the assigned live grades, market prices at New Holland (PA) for 50-70 lb. kids (on September 9), and weights, it was estimated that the PEN goats would have been worth approximately $66 more than the PASTURE goats, if they had been commercially marketed.
The situation would have been similar for direct marketers. The PEN goats produced 6.95 lbs. more of lean (meat) than the PASTURE goats. At a value of $10/lb (of
meat). this equates to $69.60 in additional income. If the meat was sold for a higher price, the advantage would have been even greater.
Cost of production
Of course, costs must also be considered to determine which production option was more profitable. The feed cost for the PEN goats was $36.20 per head. Hay consumption average 2.4 lbs. per day and the cost of the hay was $240/ton (wow!), resulting in a per head hay cost of $24.19. Barley consumption averaged 1.1 lbs. per day and the cost of barley was $13/cwt, resulting in a grain cost of $12.01.
The PASTURE goats (n=15) shared the pasture resource with 81 bucks in the Western Maryland Pasture-Based Meat Goat Performance. Assuming a pasture rental rate of $100 per acre, the total cost of the pasture was $1250 (12.5 acres x $100/acre). The per goat cost was $13.02 ($1250 ÷ 96 goats). In the table below, Pasture A does not consider any death losses from parasites. Pasture B assumes the loss of four goats, as four goats had FAMACHA© scores of 5. In research, a goat with a FAMACHA© score of 5 is often considered a dead goat.
Discussion
This year, pen feeding was more advantageous than pasture rearing. The PEN goats grew faster, were healthier, and produced superior carcasses. Of course, the bigger question is whether it is more profitable to fatten (finish) goats in a pen or to raise them on pasture. In 2013 (in Maryland), it was more profitable to fatten goats in a pen.
The increased value of the PEN goats more than covered the cost of purchased feed. In addition, pasture-rearing is not free and has plenty of its own costs. Even when pasture gains are cheaper, substantial losses due to parasites can more than off-set the lower costs. This year pen-feeding was profitable.
Pen-feeding is most likely to be profitable when (and where) feedstuffs are more economically priced and the goats being fed have the genetic potential to perform on a moderate or high plane of nutrition. The economic advantage to pen feeding will be greater when market prices are high and when the market offers a premium for higher quality animals (Selection 1 and 2).
2013 was an extreme year. The PASTURE goats performed very poorly due to a significant parasite challenge. Persistent moisture not only favored development of worm parasites, but it also limited the dry matter intake of the goats. While pasture quantity and quality weren't lacking, most of the goats (PASTURE + TEST) were not able to consume enough dry matter to meet their nutritional requirements for growth.Market prices were also exceptionally high in 2013, and substantial price differences were observed for Selection 1, 2, and 3 kids.
Pending funding, the pen vs. pasture study will be repeated in 2014. The 2012 and 2013 studies were funed by the Maryland Grain Producers Utilization Board.
Value (live goat)
Value (meat)
Cost of production
Profitability calculations