Winter Nutrition for Small Ruminants: Gestation to Weaning

Proper nutrition during the winter months is crucial for maintaining the health and productivity of your ewes and does. Winter presents unique challenges, including limited access to pasture, increased energy needs, and ensuring a consistent and high-quality diet. This article explores the changing nutritional requirements of your herd/flock during these critical periods and offers practical management tips for winter care.

Nutritional Needs During Gestation

Gestation in sheep typically lasts approximately 147 days, while gestation in goats lasts approximately 150 days. Their gestation period can be divided into three trimesters. The nutritional demands of females will vary significantly throughout pregnancy:

Early to Mid-Gestation (First Two Trimesters): Nutritional needs during early gestation are modest, as the developing fetus requires minimal resources. Females should be maintained on a maintenance-level diet, which ensures they remain in good body condition without gaining excessive weight. Forages such as hay or silage often meet their nutritional requirements during this phase. Be mindful not to feed females too well with higher protein levels, as you will increase birthweight and cause potential dystocia issues during the birthing process.

Late Gestation (Last Trimester): Nutritional requirements increase during the final trimester when approximately 70% of fetal growth occurs. Females need higher energy and protein levels to support fetal development, udder growth, and preparation for lactation. Insufficient nutrition during this phase can lead to smaller and weaker newborns, increased risk of pregnancy toxemia, and reduced milk production.

A diet combining high-quality forage and a grain-based supplement can meet these increased demands. Feeding 0.5 to 1 pound of 12-14% protein grain per day (adjusted for body size and forage quality) is common with increasing quantity fed towards the end of gestation and after parturition.

Post-Pregnancy Nutrition

After parturition, a female's nutritional demands peak to support lactation, with the first six weeks being the most intensive period. High-producing females and those nursing multiples require significantly more energy and protein to maintain milk production and body condition. If these nutritional needs aren't met, the flock may face challenges such as reduced milk yield leading to lighter weaning weights or offspring death, poor body condition and a compromised immune system, and delayed rebreeding under accelerated systems.

To address these challenges, have forages analyzed so that you can balance diets to meet the nutritional needs of nursing females. As lambs/kids transition to consuming less milk, gradually reduce supplementation to align with the female's tapering needs, preparing her for weaning and the dry period. At this time, lambs or kids should have access to forage sources, such as hay or pasture, and a grain supplement if producers wish to increase their growth rate.

Tips for Winter Management

In addition to meeting nutritional requirements, mindful management practices can help maintain your animals' health and productivity during the winter:

Body Condition Scoring (BCS): Regularly monitor BCS, aiming for a score of 2.5 to 3.5 out of 5. Adjust feeding regimens to prevent body condition scores below 2.5 or above 3.5.

Shelter and Bedding: Provide a well-ventilated, draft-free shelter with ample bedding to keep young lambs and kids warm and dry. Ewes with a one-inch fleece can tolerate cold conditions and wet conditions better than does. Keeping does dry is critical. Wet or cold environments increase energy requirements and raise the risk of respiratory illnesses, particularly during rapidly fluctuating temperatures or freezing rain, which we often see in early winter/spring in Pennsylvania. Providing a dry, well-ventilated area helps maintain the health and productivity of the animals during the winter. Ventilation is just as important over the winter months as it is in the summer when it is hotter. Sheep and goats often enjoy sunny winter days, so don't be afraid to give them access to outside lots even when the air is cold.

Water Access: Water is the most essential nutrient we can give our animals. Ensure water remains unfrozen and accessible. Heated waterers or frequent ice removal can prevent dehydration.

Group Management: Separate females based on their nutritional needs, such as gestation stage or lactation. Producers can also ultrasound pregnant females to determine the expected birth type (S, TW, TR). This allows producers to sort large flocks or herds into groups based on birth types to provide proper nutrition.

Mineral Supplementation: Supply a free-choice mineral supplement formulated specifically for the species you raise, as deficiencies in critical minerals like selenium, calcium, and magnesium can affect the health of both mothers and their offspring. Selenium is crucial for preventing white muscle disease and ensuring optimal immune function. Calcium and magnesium support proper muscle function and help prevent metabolic disorders such as milk fever. Additionally, trace minerals, such as copper, zinc, and iodine, play vital roles in reproductive health and newborn vigor. Copper levels are critical for sheep because the difference between deficiency and toxicity is very small.

Parasite Management: Winter is an ideal time to assess and address internal parasites. Females in late gestation through lactation are especially vulnerable due to the stress of parturition and milk production. This can weaken their immune systems and reduce their ability to manage the parasites. Use strategic deworming practices and regularly perform FAMACHA scoring to monitor and control parasite burdens effectively during this critical period.

Monitor Feed Quality: Test hay or silage for nutrient content and balance rations accordingly. Poor-quality forage may necessitate additional grain supplementation. This can be critical if that animal is nursing multiples or is genetically inclined to produce higher amounts of milk.

Effective winter nutrition and management are foundational to maintaining healthy, productive females during gestation and post-parturition. By understanding and addressing their changing dietary needs, providing appropriate shelter, and implementing mindful management practices, producers can support the well-being of their herd/flock and optimize kidding/lambing outcomes.