After 66 Days

Over the last two weeks, the lambs gained an average of 0.284 ± 0.286 lbs. per day. For this weigh period, the lambs in the supplemented group (n=37) had a higher ADG than the lambs in the non-supplemented (pasture) group (n=35):  0.449 ± 0.228 vs. 0.115 ± 0.239 lbs. per day.

For the 66 days of the study, ADG has ranged from 0.145 to 0.591 lbs. per day and averaged 0.386 ± .084 lbs. per day. After today's weighing, the lambs in the supplemented group surpassed the lambs in the non-supplemented group in ADG: 0.417 0.071 vs. 0.355 ± 0.085 lbs. per day. 

For the samples collected on August 17, fecal egg counts ranged from 0 to 3475 epg and averaged 371 ± 500 epg.  FAMACHA©  scores improved from August 17 until August 31, averaging 1.6 and 1.8, respectively for the supplemented and non-supplemented groups. 

Body condition scores declined an average of  0.3 points in the non-supplemented lambs. They stayed constant in the supplemented group. More lambs had positive dag scores and scours was noted in several lambs. The change in fecal consistency was attributed to the increased moisture in the forage. Rainfall has been substantially higher over the past few weeks.

Forage Quality

Forage samples have been collected from both grazing systems to determine forage quality. The samples were collected from the paddocks that the lambs were being moved to. On July 6, five samples were collected from each paddock and the averages are reported. On the other dates, a single sample was collected from each paddock. Samples were analyzed by Cumberland Valley Analytical Services.

 

 

RFV is an index used to compare the quality of forages relative to the feed value of full bloom alfalfa. It is calculated from estimates of digestible dry matter and dry matter intake.

ADG Summary, First 52 Days

While the lambs in the pasture-only group (n=36) have slighter higher ADG (0.436 vs. 0.425 lb/d) than the lambs in the supplemented group (n=37), their gains have been more considerably more erratic. During the acclimation period and before being split into their treatment groups, all the lambs gained an average of 0.543 lbs. per day. During this time, the lambs were grazing a silvopasture, consisting mostly of tall fescue and forbs.

On June 26, the lambs were split into treatment groups. During the first 10 days, the pasture group did not gain any weight, but the next two weeks, the lambs gained an average of 1 lb. per day. Gains dropped off considerably over the next two week period, but were higher the last two weeks. The supplemented group has had more steady gains. Standard deviations were large for both groups early on, but have narrowed in recent weeks.

Each group grazes a five acre system, consisting of four equal sized paddocks. They are rotated each week to the next paddock. Currently, they are grazing the paddocks for a second time. At the start of the study, the pastures were very lush, with a high clover content. It took the lambs some time to adjust to the better quality diet. Initially the lambs grazed the clover and chicory, leaving much of the grass. 

It was dry for more than a month, but recent rains have perked the pastures up.  They are lush again. Temperatures are also more favorable for grazing. The supplemented lambs are receiving 1 lb. of whole barley per head per day. So far, parasites have not been an issue. FAMACHA© scores have been good and FECs have been low.

Better grass, better gains

Recent rains have brought better grass and gains. Lambs were weighed on August 17. FAMACHA©, body condition, and dag scores were determined. Individual fecal samples were collected.

For the past two weeks (Aug 3-17), ADG ranged from -0.129 to 0.743 pounds per day and averaged 0.377 ± 0.193 lbs. per day.  The median ADG was 0.386 lbs. per day. The lambs in the supplemented group (n=37) had a higher ADG than the lambs in the pasture-only group (n=36): 0.443 ± 0.174 vs. 0.310 ± 0.190 lbs. per day.

After an 11 day acclimation period, the study was begun on June 26. For the first 52 days of the study, ADG has ranged from 0.208 to ± 0.608 and averaged 0.430 ± 0.086 lbs. per day. The median ADG is 0.432 lbs. per day. Despite being out-gained the past four weeks, the lambs in the pasture-only group still have a higher ADG than the lambs in the supplemented group: 0.436 ± 0.083 vs. 0.425 ± 0.090 lbs. per day.

FAMACHA© scores and body condition scores have not varied much during the duration of the study. No FAMACHA© scores higher than 3 have been observed. A few lambs with FAMACHA© scores of 3 have been dewormed, if they experienced weight loss. There were a lot of positive dag scores during the early part of the study, as the lambs adjusted to the clover content of the pastures. The lambs are mostly dry now. On August 17, fecals were mostly soft, not pelleted.

The lambs are rotated to a new paddock every week. There are four paddocks for each group. The lambs are grazing the paddocks for a second time. The supplemented lambs are receiving 1 lb. of whole barley per head per day.

Gains slow

Lambs were weighed on August 3. FAMACHA©, body condition and dag scores were determined. Gains slowed down as the lambs began making their second pass through their rotational grazing systems. This was particularly true of the lambs not receiving supplemental energy. The lambs are moved to a new paddock every 7 days. Each grazing system has 4 paddocks.

For the previous two weeks, the supplemented lambs had a higher ADG than the pasture-only group:  0.384 ± 0.203 lbs. vs. 0.202 ± 0.141 lbs. per day.For the first 38 days of the study, ADG has ranged from 0.211 to 0.716 lbs. per day and averaged 0.426 ± 0.114 lbs. per day. The mean ADG is 0.421 lbs. per day. No lamb remaining in the study has failed to gain weight.

So far, the lambs in the pasture-only group have a higher ADG than the lambs in the supplemented group:  0.457 ± 0.114 lbs. vs. 0.395 ± 0.107 lbs. per day. The supplemented lambs have gained more steadily, whereas the pasture-only lambs have had erratic gains, failing to gain weight for the first 10 days of the study, gaining a pound per day for the next 14 days and now gaining only two tenths of a pound for the past 14 days.

Lambs in both groups have had similar FAMACHA© and body condition scores.  One lamb was dewormed today. It had a FAMACHA© score of 3 and had lost weight. A few of the lambs had soft stools, but none had scours. Lambs that previously had positive dag scores have all dried up. Fecal samples were collected from a third of the lambs today to determine parasite loads. With improving FAMACHA© scores and dry weather, fecal egg counts are expected to be low.

Until recently, weather had been hot (above 90 degrees) and rainfall sparse. Temperatures have cooled off and rain is expected tomorrow.