Written by PJ, owner of VELD FIRST, KAROO DIREK, DIE VEEPOS and KAROO-KALAHARI VEEVOER & LOGISTIEK
Supplemental feed and licks are not complete or final solutions to nutrient deficiencies in ruminants as they do not fix the underlying challenges which gave rise in the first instance for the farmer needing to supplement.
It is fundamentally critical for the farmer to ascertain why he needs to supplement. The key reasons could include:
- Incorrect, inappropriate and/or ill-adapted bloodlines and/or breed of animal for the specific veldt type
- High-risk breeding protocols evidenced by a high inbreeding co-efficient (sub-clinical conditions will increase)
- Parasite loading and/or parasite resistance to remedial interventions
- Synthetics interfering with core physiological processes
- Poorly, un- or underdeveloped gastro-intestinal organs and rumen microbiota
- Over-grazing of veldt – carrying capacity is compromised
- Toxicity levels in the vegetation and/or within the animals
- No or very little localised body fat
- Extreme weather conditions over extended time periods
- Female animals are not given sufficient time to recover and recoup after weaning their calves and lambs.
- Average age of the herd or flock is too high (dentition is a key indicator)
What is supplemental feed?
Supplemental feed is extra nutrition given to grazing ruminants to fill nutritional gaps in their normal veldt, grass or pasture diet. These feeds can be divided into organic components (carbon-based nutrients derived from plants, animals, or synthetic processes) and inorganic components (mineral elements that do not contain carbon). The objective of supplemental feeding and the provision of mineral licks is to balance the animal’s diet when pasture or veldt quality is low or inadequate.
The purpose of supplemental feeds
- Dry seasons and droughts: Natural pastures and veldt lose protein and energy as vegetation and grass dries out or stops growing.
- Better digestion: Protein supplements feed the microbes inside the animal’s rumen, helping them break down tough, fibrous grass.
- Improved health: It prevents extreme weight loss, loss of overall condition, boosts fertility, maintains immunity levels, and increases milk or wool production
- Preparation for breeding / production: boosting of fertility, better and/or preferred sex ratios
- Recovery: from sickness, parasites, lambing/calving intervals
Main types of supplemental feed
Organic components make up the bulk of supplemental feed and provide energy, protein, and essential metabolic building blocks.
- Carbohydrates and energy supplements: the primary energy source to fuel the animal and its rumen microbes. This includes starches and sugars from grains (corn, barley, oats) and molasses, as well as digestible fibre from beet pulp or bran. These add extra calories when available pasture or veldt quantity or quality drops.
- Mineral supplements: these replace missing elements like phosphorus, calcium, and salt. (see section on licks in this paper)
- Roughage supplements: these provide extra fibre when fields are bare, for example hay and silage
- Proteins and amino acids: essential for muscle growth, milk production, reproductive and rumen microbe health. These provide nitrogen for rumen bacteria, and include cottonseed meal, soybean meal, and urea block licks, canola meal, and non-protein
nitrogen (like urea). - Lipids (fats and oils): high-density energy sources used to boost calorie intake without adding bulk. Sources include vegetable oils, tallow, and oilseeds.
- Vitamins: organic compounds required in tiny amounts for immune function and metabolism. Ruminants require dietary vitamin A, D, and E (vitamins B and K are usually synthesised by their rumen microbes).
Above: PJ (photo supplied)
WHAT IS A LICK?
A lick for ruminants is a type of supplementary feed, often supplied as a compressed block, loose meal, or liquid tub. The lick is composed of ingredients which together should provide livestock with essential nutrients missing from their regular grazing
Purpose and functions of licks
- Improves digestion and absorption: licks often contain non-protein nitrogen (like urea) and minerals that stimulate rumen microbes, helping animals break down dry, fibrous, or low-quality grass.
- Fills nutritional gaps: they supply critical elements like phosphorus, trace minerals (zinc, copper, cobalt), and proteins that veldt and pastures lack during specific seasons, such as winter or times of drought.
- Supports reproduction and growth: specialised licks help prevent weight loss, boost milk production, maintain condition and improve fertility and growth rates
Common types of licks
- Phosphate licks: given during the green grazing season to supply vital phosphorus for growth and reproduction.
- Protein / winter licks: high in protein and urea to help livestock digest dry, dormant forage when pasture quality drops.
- Production licks: richer in energy and protein, meant for animals in late pregnancy, lactation, or intensive growth phases
- Salt lick: a solid block or natural deposit of salt and essential minerals that ruminants lick to supplement their diets. A salt lick should supply missing macro-minerals like sodium, chloride, calcium, magnesium, and phosphorus, plus trace elements like zinc
and copper, and assist the animal in maintaining correct fluid balance, nerve function, and blood pH, while supporting milk production and growth.
Key constituent elements of licks
Macro- and micro (trace) minerals are vital for ruminant immunity, enzyme function, growth, and reproduction, and are provided via supplemental feeds and licks in either inorganic or organic forms.
Inorganic components
Inorganic components do not provide energy, but they are critical for structural support (bones and teeth), fluid balance, and enzyme function.
- Macro-minerals: required in relatively larger quantities.
Calcium and phosphorus: crucial for bone development and milk production (often provided via limestone or di-calcium phosphate).
Sodium and chloride: maintained via common salt blocks or mixes to regulate fluid balance and encourage water intake.
Magnesium: prevents grass tetany, a metabolic disease common in early spring pastures.
Potassium and sulphur: essential for rumen microbe function and protein synthesis. - Micro-minerals (trace elements): these minerals are bound to inorganic compounds like oxides, sulphates, chlorides, or carbonates, and are required in very small amounts but are vital for immunity and fertility. They are generally less expensive and widely used as the baseline in commercial licks. Have a lower and more variable bioavailability (often 20% to 50%), and are prone to binding with dietary antagonists in the rumen and gut (such as sulphur, iron, or phytates), which retards or even prevents absorption.
Copper sulphate, zinc oxide, iron carbonate and manganese sulphate: support skin, hoof health, and reproductive systems.
Cobalt: needed by rumen microbes to manufacture Vitamin B12.
Selenium and iodine: critical for thyroid function, temperature regulation and preventing white muscle disease in calves and lambs.
Organic components
These are minerals bound or chelated to carbon-based organic molecules like amino acids, peptides, or proteinates. Present higher bioavailability and absorption efficiency (often 40% to 80%), and are protected from negative chemical interactions with antagonists in the digestive tract. Typically more expensive, so they are targeted to high-stress, high production, or breeding stages (such as transition dairy cows or weaning calves) rather than general maintenance.
- Common organic minerals and trace elements: Zinc methionine, copper proteinate,
and selenium yeast. - Note: Proteinates are organic mineral compounds formed when a soluble mineral salt
(such as zinc, copper, or iron) bonds to an amino acids or small protein fragments.
Dangers and risks of supplemental feed and licks for ruminants
Supplemental feed and licks are not a final solution to nutrient deficiencies in ruminants because they do not fix the underlying, causative factors of the animals’ poor condition. Further, incorrectly or inappropriately dispensed, supplemental feeds and mineral licks for ruminants can cause toxicity, digestive failure, pH imbalance, dehydration and mineral disregulation. These challenges are most likely to occur if animals take in too much, or if the composition is incorrectly constituted for example in the absence of co-factors.
More common conditions include:
Urea toxicity
- Fast acting: Urea breaks down into ammonia very quickly in the rumen.
- Blood toxicity: Excess ammonia enters the bloodstream and overwhelms the liver.
- Quick death: Animals can die within hours of showing signs like staggering, heavy breathing, and tremors.
- Risk triggers: Hungry animals eating too much at once, or rain dissolving urea licks into a toxic puddle.
Grain acidosis
- pH drop: high-grain supplements cause rumen bacteria to produce too much acid.
- Tissue damage: acid burns and destroys the lining of the rumen.
- Systemic failure: animals stop eating, become bloated, develop lameness (laminitis), or die from dehydration and shock.
- Risk triggers: accidental access to feed stores or introducing high-energy grain too fast.
Mineral toxicity and imbalances
- Copper toxicity: sheep are very sensitive to copper; high levels build up in the liver and cause sudden death.
- Lockup: too much of one mineral (like sulphur or molybdenum) can block the body from absorbing another vital minerals (like copper).
- Fluorine or selenium excess: over-supplementation leads to chronic poisoning, joint stiffness, and poor growth.
Uneven intake
- Bully effect: dominant or aggressive animals push weaker animals away and eat too much supplement.
- Starvation of shy eaters: timid or young animals get no supplement at all and suffer deficiencies.
- Choking: animals can choke on hard, compressed feed blocks or coarse roughage cubes.
Gastro-intestinal challenges
- Rumen microbes starve: microbes in the rumen need degraded nitrogen and energy to break down fibre and cellulose. Licks provide extra nutrients, but if the base forage lacks basic digestibility, microbes cannot digest it faster.
- Intake remains low: animals eat less poor-quality forage when it stays in the rumen too long. Small amounts of a lick cannot speed up this slow digestion process enough to increase total energy intake.
- Substitution effect: animals may eat less of the main forage when given heavy supplements. This behaviour can cancel out the benefits of the extra nutrients the supplement was supposed to add.
- Cost and efficiency: purchasing manufactured licks or feeds is expensive. It treats the symptom of poor nutrition rather than improving the core quality of the available veldt, pasture or forage.
Conclusion
As with many intensive regimes and additives, supplemental feeds and licks have their place. Used strategically, at the correct time and with accurate application, key short to medium term objectives can be achieved. Supplementing interventions ARE NOT a ‘silver
bullet’ nor are they a solution to the underlying, causative challenges. However, if used correctly, and as a bridging and relieving short-term, selective application, they can bring about improvements and partial remediation.
Contact PJ at 072 073 6805
Relevant Agribook pages include “Animal feeds.” The Business Listings below comes from that page.
