Reproduction

Neonatal Lamb Management: Intraperitoneal Injection of Dextrose (Glucose)

Adapted from ‘What You Need to Know About Lambing’ presentation by Dr. Ileana Wenger.
Article, Text, and Tables provided by: Alberta Lamb Producers Factsheet
For additional information: Consult with your local veterinarian and/or additional neonatal management resources provided by Alberta Lamb Producers.

(Image Source : Farm Advisory Service)

Most lamb deaths that occur shortly after birth are due to starvation and/or hypothermia (low body temperature). These losses are most often preventable, and lambs can be saved if problems are identified and treated quickly.

Why is timing important?

  • Newborn lambs rely on reserves of brown fat as an energy source until they ingest colostrum. Ideally, lambs will nurse and receive colostrum within two hours of birth. If feeding is delayed, even by a few hours, fat stores will be depleted. Unless the lamb nurses, or receives another source of energy, it will become unconscious and die.
  • Long-term survival also depends on receiving colostrum soon after birth, as the ability to absorb antibodies in colostrum quickly decreases. Milk or milk replacer will prevent starvation but will not protect against infections.
  • The sooner an ‘at risk’ lamb is identified, the easier the treatment and the greater the chance of saving the lamb.

Continue reading Neonatal Lamb Management: Intraperitoneal Injection of Dextrose (Glucose) →

Supplement Energy to Ewes in Late Gestation

Dr. Benjamin Wenner, Assistant Professor, Department of Animal Sciences, The Ohio State University

As we approach the winter lambing season in Ohio, producers have a variety of approaches to feeding pregnant ewes. Those who believe underfeeding their ewe will decrease fetal size are partially correct (as addressed in the ASIA Sheep Production Handbook, 2002), but the likelihood of decreasing dystocia with underfeeding is nearly nil. In a 2007 review of lambing data, late gestation energy supplementation could account for increasing fetal weight by roughly ½ lb. (Gardner et al., 2007). Certainly, there are many other factors leading to dystocia that deserve consideration before a ½ lb. increase in lamb birth weight garners attention. Twinning alone can reduce birth weights (despite increasing ewe conceptus weight and energy requirement) and thus practices to achieve greater fertility in your breeding flock are a wiser pursuit than trying to nutritionally limit birth weights during gestation. Continue reading Supplement Energy to Ewes in Late Gestation →

Spider Syndrome in the Sheep Flock

Gerald Q. Fitch, Extension Sheep Specialist, Oklahoma State University
(Previously published with Oklahoma State University Extension: March, 2017)

(Image Source: Thompson and Dittmer, 2008)

Spider Syndrome is a genetic problem, common in the Suffolk breed and becoming more common in the Hampshire breed. Spider syndrome has been compared to dwarfism in beef cattle. It has been prevalent since the 1950s. Spider syndrome has also been diagnosed in commercial flocks that keep brockle-faced lambs back as replacement ewes. Those ewes are coming from Suffolk or Hampshire rams that carry the syndrome. Researchers feel certain that spider syndrome is caused by a simple, autosomal, recessive gene. If a producer has a flock of carrier ewes and breeds them to a carrier ram, one-fourth of his or her lamb crop could have spider syndrome!!!

Diagnosis
Spider lambs are affected in one of two ways: 1) lambs are abnormal at birth and will probably never be able to stand, or 2) lambs appear normal at birth, but develop into a spider lamb at two weeks to six weeks of age.

Spider lambs usually Continue reading Spider Syndrome in the Sheep Flock →

Increase Lamb Crop by Testing for Pregnancy

Geri Parsons and Cleon Kimberling, Optimal Livestock Services
Reviewed by: Jay Parsons, University of Nebraska-Lincoln and Bill DeMoss, Mountain Vet supply
(Previously published online with Agriview: September 5, 2019)

(Image Source: U.S. Lamb Resource Center)

Pregnancy detection in the ewe provides the opportunity to adjust nutritional and lambing management to save on feed and labor costs. The old adage that “one open ewe takes the profits of five producing ewes” may be true when all costs are calculated. Early determination of fetal numbers and gestational stage gives the option of sorting for nutritional demands in late pregnancy and early lactation. Without that information, the single-bearing ewe is being fed too much or the twin-bearing ewe too little. Open ewes are robbing the pregnant ewes of necessary nutrition. Grouping according to gestational stage will also save on labor and allow for better utilization of facilities and biosecurity.

The key in any type of business is producing an end product, or more simply put, production. The economic benefit of pregnancy testing in Continue reading Increase Lamb Crop by Testing for Pregnancy →

Reproductive Management of the Ewe Flock and the Ram

Mike Neary, Extension Sheep Specialist, Purdue University
(Previously published on the Purdue University Extension web page)

(Image Source: Michigan State University)

The most important factor in determining profitability of a sheep enterprise is production rate. Productivity of the ewe flock is a direct reflection of reproductive efficiency. Regardless of genetic merit, eye appeal, price, or showring placing, if a sheep will not reproduce it is worth no more than current slaughter value.

To a large extent, the goals and objectives we have for our next lamb crop are determined before and during the breeding season. Increasing ewe productivity while decreasing labor, time and facilities requirements during the lambing season can be realistic objectives.

Reproduction in sheep is influenced by numerous factors. These include: Continue reading Reproductive Management of the Ewe Flock and the Ram →

Reproductive Physiology of Sheep

Paula I. Menzies, DVM, MPVM, DECS-RHM, Ruminant Health Management Group, Department of Population Medicine, Ontario Veterinary College, University of Guelph
(Previously published in Merck Manual: Veterinary Manual: June, 2015)

(Image Source: Cornell Small Farms – Cornell University)

Ewes are seasonally polyestrous,cycling every 16–17 days during the breeding season. The major environmental factor controlling the estrous cycle is the photoperiod. Decreasing photoperiod after the summer solstice causes secretion of melatonin, which triggers the hypothalamus to produce gonadotropin-releasing hormone. Geographic location and environmental temperatures also modify the length of anestrus, as does the breed of sheep. Fine-wool breeds (eg. Rambouillet and Merino), tropical breeds, and Dorsets have a shorter anestrous period than other breeds such as the Suffolk, Hampshire, Border Leicester, and Columbia. Regardless of this breed-related variation in the length of the breeding season, all breeds are most fertile in the autumn, and anestrus is an unlikely problem associated with regular annual mating.

The duration of estrus (~30 hr.) is influenced by Continue reading Reproductive Physiology of Sheep →

Flushing Small Ruminants for a Higher Ovulation Rate

Michael Metzger, Michigan State University Extension Educator
(Previously published on MSU Extension, Sheep & Goat: August 6, 2018)

(Image Source: Sheep 101.info)

Increasing the level of nutrition for does and ewes 2-3 weeks prior to and 3 weeks into the breeding season can improve kid/lamb crop in some instances.

When managing a goat/sheep herd farmers are always looking for ways to improve their herd, increase production and raise profitability. One way that a farmer can accomplish this is to implement flushing into their breeding practices. Flushing is a temporary but purposeful increase in the level of nutrition around breeding time. This is done to boost ovulation, conception and embryo implantation rates. Flushing may also increase the proportion of females that exhibit estrus. Flushing can increase lambing and kidding rates by 10-20 percent. This is important because a flock’s lambing/kidding rate is one of the primary factors influencing profitability. Flushing works best in

Continue reading Flushing Small Ruminants for a Higher Ovulation Rate →

Nutritional Requirements of Sheep: Minerals and Vitamins

Dr. David G. Pugh, DVM, MS, MAg, DACT, DACVN, DACVM, Auburn University
(Previously published online with the Merck Manual – Veterinary Manual: January, 2014)

Minerals:
Sheep require the major minerals sodium, chlorine, calcium, phosphorus, magnesium, sulfur, potassium, and trace minerals, including cobalt, copper, iodine, iron, manganese, molybdenum, zinc, and selenium. Trace mineralized salt provides an economical way to prevent deficiencies of sodium, chlorine, iodine, manganese, cobalt, copper, iron, and zinc. Selenium should be included in rations, mineral mixtures, or other supplements in deficient areas. Sheep diets usually contain sufficient potassium, iron, magnesium, sulfur, and manganese. Of the trace minerals, iodine, cobalt, and copper status in ewes are best assessed via analysis of liver biopsy tissue. Zinc adequacy can be assessed from the careful collection of nonhemolyzed blood placed in trace element–free collection tubes. Selenium status is easily assessed by collection of whole, preferably heparinized, blood.

Salt:
In the USA, except on certain alkaline areas of the western range and along the seacoast, sheep should be provided with Continue reading Nutritional Requirements of Sheep: Minerals and Vitamins →

Breeding Soundness Examination of the Ram and Buck

David C. Van Metre, DVM, DACVIM Extension Veterinarian, Colorado State University
(Previously published online with Veterinary Extension through Colorado State University)

(Purdue Extension, Purdue University)

Veterinarians are well positioned to become valued participants in sheep flock and goat health programs through introduction of certain practices that have high potential to provide direct economic benefit to the producer. Opportune times for veterinary intervention include evaluation of the breeding flock in the fall prior to breeding, late fall / early winter pregnancy diagnosis, and lambing / kidding during the spring. To optimize the size of the following spring’s lamb or kid crop, the primary goal of the pre-breeding health program should be optimization of fertility through nutritional management and disease control measures, as well as documentation of Continue reading Breeding Soundness Examination of the Ram and Buck →