The research team, led by Rabia Arslan together with Necmettin Ünal and Akın Yakan of Ankara University’s Faculty of Veterinary Medicine, worked with 36 healthy male Lalahan lambs, all born as singletons during the same lambing season and weaned at about 90 days of age. The lambs were randomly divided into three groups and fed intensively until each group reached an average live weight of 35, 40, or 45 kilograms. Six lambs from each group, those closest to the group mean, were then selected for slaughter, giving the team 18 carcasses to dissect, weigh, and analyze joint by joint. Every animal received the same treatment before the experiment began: raised alongside their mothers under identical herd management, with ewes that had given birth at least twice, ensuring the lambs genuinely represented the Lalahan genotype.

The feeding regime was carefully standardized. Fattening started with 400 grams of concentrate per lamb per day plus 300 grams of alfalfa hay, after which the lambs were individually fed concentrate ad libitum with the same limited hay ration. Feeders were weighed morning and evening, leftovers collected and deducted, and body weights recorded every 14 days before feeding. Each lamb enjoyed 2 square meters of space, 50 centimeters of feeder length, and unlimited drinking water. From these meticulous measurements the researchers calculated the two numbers that matter most in fattening economics: daily weight gain and feed conversion rate, the kilograms of concentrate needed to produce one kilogram of body weight.

The growth numbers tell a story of steady, efficient performance. Average daily weight gains were 241.50, 243.33, and 235.45 grams in the 35, 40, and 45 kilogram groups respectively, figures that sit comfortably within the 230 to 265 gram range reported for intensively fattened Kıvırcık lambs, the breed from which Lalahan sheep largely descend. More impressive was the feed conversion. The Lalahan lambs needed just 3.590, 3.958, and 4.392 kilograms of concentrate per kilogram of gain in the three groups, substantially better than the 5.29 to 6.14 kilograms reported for Kıvırcık lambs in comparable intensive systems. In plain terms, these crossbred lambs turned feed into meat considerably more cheaply than one of their parent breeds, a trait with obvious economic value for producers operating on thin margins.

As expected, feed conversion worsened as the lambs grew heavier, because larger animals devote more of each meal to maintenance rather than growth. The jump from 3.590 to 4.392 kilograms of feed per kilogram of gain between the lightest and heaviest groups illustrates the classic diminishing returns of extended fattening. Yet the daily gain barely budged across the three groups, hovering around 240 grams regardless of target weight. That combination, flat growth rate but rising feed cost, is precisely why the question of when to stop fattening is so consequential, and why the carcass data that followed would prove decisive.

Slaughter characteristics were assessed both against pre-slaughter body weight and against empty-body weight, a refinement that accounts for the variable fullness of the digestive tract. Hot dressing percentages, the proportion of live weight that becomes a fresh carcass, were 46.22, 45.49, and 47.05 percent across the three groups, with cold dressing percentages of 45.26, 44.66, and 46.11 percent after 24 hours of chilling at 4 degrees Celsius. None of these differences reached statistical significance, though there was a slight upward trend with weight, likely reflecting greater muscle and fat deposition in heavier animals. The researchers also tracked how individual body components shifted with weight: feet and empty rumen proportions fell, while omental and mesenteric fat depots and testicle proportions rose, the latter a sign that the longer-fattened lambs were approaching puberty.

The carcass dissection delivered the study’s most consequential findings. Lean meat content was 61.82 percent in the 35 kilogram group and 61.04 percent in the 40 kilogram group, but dropped significantly to 57.53 percent at 45 kilograms. Fat told the mirror-image story: 13.57 and 14.05 percent in the two lighter groups, then a statistically significant leap to 19.46 percent in the heaviest lambs. Bone percentages stayed essentially constant at around 18 percent. The lean-to-fat ratio, a key index of carcass quality, was 4.56 and 4.35 in the 35 and 40 kilogram groups but collapsed to 2.98 at 45 kilograms. Notably, the lean percentages exceeded those reported for most Turkish native breeds, while the fat percentages were lower, an advantage the authors highlight as particularly important for modern consumers who increasingly prefer leaner carcasses.

Prime cuts shifted with weight as well. The hind leg, the most valuable joint, accounted for 31.57, 30.04, and 28.41 percent of the carcass in the three groups, a significant decline, while the loin fell from 8.41 to 7.19 percent. The back cut bucked the trend, rising from 13.39 to 14.72 percent. Meanwhile, the cross-sectional area of the longissimus dorsi muscle, the prized eye muscle running along the spine, grew steadily and significantly with slaughter weight, from 14.29 to 16.16 to 17.73 square centimeters, outperforming values reported for Kıvırcık lambs at comparable weights. Back fat depth also climbed, from 1.13 to 1.57 to 2.43 millimeters, though it remained generally lower than in other native breeds. The fact that muscle area expanded faster than fat thickness is, the authors argue, a genuine strength of the genotype.

Placing all the evidence side by side, the case for 40 kilograms becomes compelling. At that weight the lambs achieved their highest average daily gain, maintained a lean percentage above 61 percent, kept carcass fat near 14 percent, and avoided the steep feed conversion penalty that sets in beyond it. The 45 kilogram lambs delivered bigger eye muscles but paid for them with nearly a fifth of the carcass as fat and the worst feed efficiency of the trial. The 35 kilogram lambs were lean and efficient but left growth potential unrealized. The authors note that their recommendation aligns with international literature suggesting that around 38 to 42 kilograms represents the optimal balance between muscle development and fat deposition in medium-sized native and crossbred genotypes, even as European meat-type breeds are pushed to heavier weights.

Beyond the headline number, the study carries broader significance for Turkish agriculture, where sheep meat accounts for only 9.1 percent of red meat production despite growing demand for high-protein foods. The Lalahan genotype was bred for exactly this gap: an animal with good herding instinct, easy management, adequate fertility, and the hardiness to prosper on steppe pastures. Previous work had documented the breed’s reproductive performance, including estrus rates near 99 percent and twin births at just over 25 percent, but its meat traits had never been systematically measured. This first comprehensive assessment shows the Lalahan lamb matching or exceeding its Kıvırcık parentage in fattening performance, slaughter yield, and carcass composition, with a muscle-to-fat balance that suits contemporary market preferences. For a country seeking to raise its lamb output under challenging climatic conditions, a genotype that converts feed efficiently, deposits fat sparingly, and hits its peak value at a well-defined weight offers producers something rare: a clear, evidence-based target for profitability.

Subject of Research: Fattening performance, slaughter traits, and carcass characteristics of Lalahan-genotype lambs at different slaughter weights in Türkiye

Article Title: Meat production traits of Lalahan sheep: fattening, slaughter, and carcass characteristics of lambs

Article References: Arslan, R., Ünal, N., & Yakan, A. (2026). Meat production traits of Lalahan sheep: fattening, slaughter, and carcass characteristics of lambs. Archives Animal Breeding, 69(3), 431-439. https://doi.org/10.5194/aab-69-431-2026

Image Credits: AI Generated

DOI: 10.5194/aab-69-431-2026

Keywords: Lalahan sheep, lamb meat production, slaughter weight, carcass characteristics, feed conversion rate, daily weight gain, Kıvırcık, Akkaraman, crossbreeding, Türkiye, steppe conditions, animal breeding

The trial involved 300 one-day-old male Cobb 500 broiler chicks, randomly assigned to five dietary treatments with four replicate pens of 15 birds each. One group received a standard corn–soybean meal control diet, while the others were fed diets supplemented with either 0.75 percent or 1.5 percent Prangos ferulacea powder, or with 750 or 1500 milligrams per kilogram of the plant’s aqueous extract. All diets were formulated to be isocaloric and isonitrogenous, meaning they delivered equivalent levels of energy and protein, so any differences between groups could be attributed to the plant material itself rather than to nutritional imbalances. The birds were monitored over a full 43-day production cycle spanning starter, grower, and finisher phases.

The plant material itself carried considerable biochemical promise. Prangos ferulacea is native to West Asia and is rich in monoterpenes, coumarins, and phenolic compounds — classes of molecules frequently associated with antioxidant, antimicrobial, and smooth-muscle-modulating activity. The researchers harvested mature aerial parts of the plant from the rangelands of Divandareh County in Kurdistan Province, shade-dried them, and milled them into powder. To prepare the aqueous extract, ten kilograms of powder were macerated in thirty liters of distilled water for twenty-four hours, filtered, and concentrated at sixty to seventy degrees Celsius, yielding roughly 10.8 percent of the starting weight as dried extract. Botanical identity was confirmed by a qualified botanist, and a voucher specimen was deposited in the university herbarium, lending the study a level of taxonomic rigor that is not always present in phytogenic feed research.

When it came to the bottom line of broiler production — body weight gain and feed conversion ratio — the results were sobering. Across the entire 43-day period, cumulative body weight gain and feed efficiency did not differ significantly among the five dietary groups. Body weights at eleven, twenty-three, and forty-three days of age were statistically indistinguishable. There was, however, a phase-specific wrinkle: during the finisher period from days twenty-four to forty-three, body weight gain was significantly reduced in the supplemented groups compared with the control, a pattern the authors suggest could relate to effects on feed intake or palatability, though the underlying cause was not directly measured. Feed intake during the grower phase was actually higher in all supplemented groups, yet this did not translate into better growth, and overall feed intake across the trial was unaffected.

Carcass characteristics told a similarly restrained story. Carcass yield and the relative weights of the heart, liver, spleen, pancreas, and bursa of Fabricius were comparable across treatments. One exception stood out: birds fed the lower dose of the powder, 0.75 percent of the diet, showed a significantly heavier gizzard relative to their body weight than both extract-fed groups and the control. The authors speculate that the fibrous, structural nature of the powdered plant material may have stimulated gizzard development, a phenomenon previously reported with coarse or fiber-rich feed components, but they caution that because particle size was not measured, this interpretation remains speculative.

Blood chemistry offered a few more points of interest. Serum triglycerides were significantly lower in birds receiving 0.75 percent powder, while very-low-density lipoprotein levels were unchanged, suggesting the plant does not exert a broad effect on lipid metabolism. Serum cholesterol was significantly lower in birds receiving both forms of supplementation compared with controls, and markers of kidney function — urea, creatinine, and uric acid — were unaffected, indicating the treatments were not harming the birds. Total protein, albumin, and globulin concentrations also remained stable, painting a picture of animals whose basic metabolic health was intact regardless of diet.

The most intriguing and, frankly, most puzzling findings emerged from the antioxidant measurements. Birds receiving the highest dose of aqueous extract, 1500 milligrams per kilogram, showed a significant increase in serum total antioxidant capacity, a measure of the blood’s non-enzymatic antioxidant potential. That might sound like a win for the plant. But the same group also exhibited significantly elevated serum malondialdehyde, a well-established marker of lipid peroxidation and oxidative damage, alongside significantly reduced glutathione peroxidase activity in the liver, one of the body’s key antioxidant enzymes. In fact, all four supplemented groups showed reduced hepatic glutathione peroxidase activity compared with controls, while liver superoxide dismutase showed only a trend toward reduction and red blood cell enzyme activities were unchanged.

This pattern — higher total antioxidant capacity coexisting with more lipid damage and less enzymatic defense — does not add up to an unequivocal antioxidant benefit, and the authors are careful to say so. Rather, they argue, it points to a complex and potentially pro-oxidant response at the highest extract dose, consistent with the dose-dependent or biphasic effects that phytochemicals sometimes display. It also underscores a broader lesson for the field: antioxidant biomarkers should be interpreted collectively rather than in isolation, and a shift in any single indicator does not necessarily signal improved health. Notably, none of the biochemical changes translated into better growth, feed efficiency, or carcass yield, reinforcing a growing consensus that modulating redox biomarkers under low-stress conditions may not produce tangible production benefits.

The study has honest limitations that shape how its findings should be read. With only four replicate pens per treatment and one bird per pen sampled for biochemical analyses, statistical power to detect subtle effects was limited. The experimental diets were formulated on calculated rather than chemically analyzed nutrient values, and the phytochemical characterization relied on spectrophotometric assays of total phenolics, flavonoids, and coumarins rather than chromatographic identification of individual compounds — meaning the differences between powder and extract cannot be tied to specific active constituents or their bioavailability. The authors also note that under the non-stressed conditions of a well-managed research facility, the birds’ endogenous antioxidant systems may already have been operating near optimal levels, leaving little room for a phytogenic additive to demonstrate measurable gains.

Where does this leave Prangos ferulacea on the crowded shelf of candidate antibiotic alternatives? The study contributes to mounting evidence that phytogenic feed additives can shift oxidative status without necessarily improving performance, particularly in animals that are not under environmental or metabolic stress. The authors chart a clear path forward: comprehensive phytochemical profiling of the plant, formal dose–response studies, investigation of molecular mechanisms such as redox-sensitive signaling pathways like Nrf2, and — perhaps most importantly — testing under oxidative-stress challenge models that better mirror the realities of commercial poultry production. Until then, the mountain herb remains a biochemical curiosity with demonstrated biological activity but, at the doses and conditions tested, no proven ticket to faster-growing, healthier chickens. For an industry under pressure to eliminate antibiotics, that distinction between biochemical activity and production benefit is exactly the kind of hard evidence that keeps the search honest.

Subject of Research: Effects of dietary Prangos ferulacea powder and aqueous extract on growth performance, carcass traits, and antioxidant status in broiler chickens

Article Title: Effects of different levels of Prangos ferulacea (L.) Lindl. (Apiaceae) powder and extract on performance, carcass characteristics, and antioxidant status in broiler chickens

Article References: Janfadah, A., Sadeghi, A. A., & Karimi, A. (2026). Effects of different levels of Prangos ferulacea (L.) Lindl. (Apiaceae) powder and extract on performance, carcass characteristics, and antioxidant status in broiler chickens. Discover Animals, 3(1), Article 98. https://doi.org/10.1007/s44338-026-00250-7

Image Credits: AI Generated

DOI: 10.1007/s44338-026-00250-7

Keywords: Prangos ferulacea, broiler chickens, phytogenic feed additives, antioxidant status, total antioxidant capacity, malondialdehyde, glutathione peroxidase, feed conversion ratio, carcass characteristics, poultry nutrition, antibiotic alternatives, oxidative stress