Effect of Continuous Suckling/”Ewe-rearing” on Growth and Level of Parasitism of Lambs and on Productivity and Profitability of Lamb Operations

Effect of Continuous Suckling/”Ewe-rearing” on Growth and Level of Parasitism of Lambs and on Productivity and Profitability of Lamb Operations

Summary

The purpose of this project is to evaluate the effect of continuous suckling/“ewe-rearing” on growth, intestinal parasitism, and productivity and profitability of sheep production in Appalachia. Weaning at approximately 3-4 months of age is routinely practiced by most lamb producers. One reason weaning is practiced is so that lambs can be placed into feedlots and grown and fattened to reach market weight and condition. However, weaning prior to slaughter may not be necessary as there is an increasing demand for younger lambs at lighter slaughter weights with minimal finish.

Weaning has been associated with psychological and nutritional stress on the lamb that might compromise the growth, immune function, and welfare of the young animal resulting in an overall decline in productivity. In some studies, continuous suckling has been shown to lower susceptibility to parasitism and increase pre-slaughter growth rates of lambs. Worm burden has been shown to be reduced in young lambs consuming milk compared to their counterparts on dry-feed. Higher growth rates have been observed in late-weaned and un-weaned lambs. The proposed study will further examine the impact of continuous suckling on growth rate and potential interactions with type of diet.

An increase in the demand and price for lighter (< 100 lbs) market lambs in the Northeastern United States, suggests that market weights can potentially be achieved by 3-5 months of age. Lambs for this market can be finished on pasture while still suckling their dam and in so doing avoid the stress of weaning and subsequent effects on the health and growth of the lambs. If successful, the results of this study will lead to the development and adoption of a low-cost, simple management strategy that can enhance agriculture sustainability by increasing productivity and profitability of sheep enterprises while improving the health and welfare of lambs.

Objectives/Performance Targets

The overall objective of the proposed project is to investigate the potential benefit of continuous suckling/“ewe rearing” on the productivity of sheep enterprises. The specific objectives include:

1. To determine the effect of continuous suckling/“ewe-rearing” with and without supplementation on growth rate of lambs

The project commenced in June, when the spring born lambs were at the proper age(about 3 months). They were divided into 4 groups: suckling, supplemented (SS); suckling, no supplement (SU); weaned, supplemented (WS); and weaned, no supplement (WU). The lambs were weighed every two weeks for three (3) months.

2. To determine the effect of continuous suckling/“ewe-rearing” with and without supplementation on degree of parasitism of lambs

Within the four groups: SS, SU, WS, and WU, 10 lambs were randomly chosen from which to take fecal samples and 6 lambs from each of the groups were randomly chosen from which to collect blood samples . The fecal samples were collected at initiation and once a month thereafter. Fecal samples were processed using McMaster’s solution and fecal eggs were counted. The blood samples were used to assess packed cell volume (PCV). This data is in the process of being analyzed.

3. To determine the effect of continuous suckling/“ewe-rearing” on weight and body condition changes of ewes

The dams of the lambs were assigned a body condition score and weighed initially then once a month following initiation of the study. Data is currently being analyzed.

4. To compare the economic benefit of continuous suckling/“ewe-rearing” of lambs to market to the traditional practice of weaning lambs and fattening to market

The lambs were sold at the end of the study in order to assess the potential economic benefit. We have yet to analyze the economic impact of this project as of yet. We are scheduled to do this in January.

Accomplishments/Milestones

Lambing records were obtained and animals were identified for the project. The project was initiated a bit later that anticipated due to when the lambs were born. The lambs were broken into the four random groups, weighed, and blood and fecal samples collected. The ewes were assigned a body condition score (BCS) and weighed. All of the animals were evaluated for parasite load using the FAMACHA system; lambs and ewes were treated with anthelmintic, if necessary. The lambs were weighed approximately every two weeks and the fecal and blood samples were collected every other time they were weighed (once a month). The ewes were assigned BCS and weighed once a month.
After collection, fecal samples were processed within 7 days using McMasters solution, and fecal egg counts were determined. Blood collected was used to determine Packed Cell Volume (PCV).
We have collected quite a bit of data that we are working on analyzing. Preliminary analysis has suggested that suckling lambs have a greater growth rate than weaned lambs, regardless of supplementation; however, this data needs further analysis.

Impacts and Contributions/Outcomes

The results of the proposed study have direct implications on the management practices that producers might employ to enhance the productivity and profitability of small-scale sheep operations in the Northeastern United States. As soon as the data is completely analyzed, a bulletin will be written for the West Virginia Small Ruminant Producers (WVSRP). The results will also be presented to producers at the Annual Short-course held by the WVSRP, which has had an average attendance of over fifty producers and eight extension agents. We also intend to present the results at one of the Animal Science meeting in the coming year. Finally, we intend to discuss our results with all of the producers with which we routinely work.

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