The research team, led by Lasna Sahib, applied the Cornell Net Carbohydrate and Protein System, or CNCPS, to thirteen concentrate ingredients routinely used in feed mills across India. Rather than reporting only crude protein and crude fibre, the CNCPS partitions every feed into fractions defined by how fast they degrade in the rumen. Carbohydrates are split into rapidly fermentable sugars and organic acids (CA), intermediately degradable starch and pectins (CB1), slowly fermentable available cell wall (CB2), and lignin-bound cell wall that is essentially indigestible (CC). Proteins are similarly divided into non-protein nitrogen (PA), rapidly, intermediately and slowly degradable true protein (PB1, PB2 and PB3), and acid detergent-insoluble protein that no enzyme in the animal can reach (PC).

The biological logic behind this framework is what gives it its predictive power. Rumen microbes, the organisms that actually convert feed into meat and milk, need fermentable energy and degradable nitrogen to arrive at roughly the same time. When they do, microbial protein synthesis is maximised and the animal receives a steady supply of high-quality protein downstream. When they do not, nitrogen is wasted as ammonia and excreted in urine, or energy is lost as heat and gas. The CNCPS was designed to capture exactly this synchronisation problem, and when its inputs have been properly measured it has explained around 90 per cent of the variation in individual cow milk production with a bias of only 1.3 per cent.

Despite that track record, the system’s standard feed library was built largely from temperate feedstuffs. Comprehensive fractionation data for the concentrates that dominate South Asian rations, including regionally distinctive by-products such as tapioca starch waste, black gram husk and alfalfa residue, have been scattered across small studies or missing altogether. To fill the gap, the Kerala team procured six independent consignments of each of the thirteen ingredients from commercial suppliers, analysed every sample in duplicate, and expressed the results as means with standard errors. The protein concentrates included alfalfa residue, coconut oil cake, sesame oil cake, groundnut cake, soybean meal, sunflower cake and corn gluten feed; the energy concentrates were maize, de-oiled rice bran, wheat bran, rice polish, tapioca starch waste and black gram husk.

The carbohydrate results expose how misleading a single number can be. Maize, the region’s staple energy feed, was dominated by the intermediately degradable starch fraction, with CB1 accounting for 71.53 per cent of its total carbohydrate, confirming its role as the primary fermentable energy source for ruminants. Rice polish, by contrast, carried a staggering 67.43 per cent of its carbohydrate in the unavailable CC fraction, meaning nearly two-thirds of the carbohydrate it contains can never be digested by the animal, no matter what the total carbohydrate figure suggests. Coconut oil cake and sesame oil cake fared similarly, with CC fractions of 58.42 and 52.70 per cent respectively, driven by their high lignin contents of 27.13 and 38.99 per cent of neutral detergent fibre.

Those lignin-bound fractions have direct practical consequences. Oilcakes that look respectable on a proximate analysis sheet may contribute far less fermentable energy than their composition implies, and rations that lean on them heavily must be supplemented with more fermentable sources to keep rumen microbes working. On the other side of the ledger, alfalfa residue and corn gluten feed carried high slowly fermentable fibre fractions, 63.22 and 58.54 per cent of carbohydrate respectively, the kind of structural carbohydrate that stabilises rumen pH and sustains microbial protein synthesis without the acidosis risk that comes with rapidly fermentable starch-heavy diets. Black gram husk and tapioca starch waste, both cheap milling by-products, turned out to supply readily fermentable energy, with fast-degrading CA fractions of 33.87 and 25.47 per cent of carbohydrate.

The protein picture was equally revealing. Soybean meal, the benchmark protein supplement, was dominated by the intermediately degradable true protein fraction PB2 at 78.91 per cent of crude protein, closely matching European data. Alfalfa residue, which in this study refers to the leaf-derived protein concentrate left after chlorophyll extraction rather than ordinary alfalfa hay, was dominated by the slowly degradable PB3 fraction at 75.08 per cent of crude protein, making it a natural source of protein that escapes rumen breakdown. Groundnut cake released nitrogen quickly, with 44.48 per cent of its crude protein in the rapidly degradable PB1 pool, while corn gluten feed was extraordinary in a different way: 68.47 per cent of its crude protein was non-protein nitrogen, with 98.56 per cent of its soluble protein consisting of NPN, a signature of wet milling processes that break true protein down into ammonia and peptides.

That corn gluten feed profile carries a warning. High non-protein nitrogen supply without synchronously available fermentable carbohydrate drives ammonia accumulation and urinary nitrogen losses, so the PA-to-CB1 balance becomes critical when the ingredient is included in a ration. Pairing it with a high-starch energy source such as maize is precisely the kind of matching the CNCPS is built to guide. Another cautionary figure came from tapioca starch waste, where 45.73 per cent of crude protein sat in the heat-damaged PC fraction, bound in Maillard reaction products that neither rumen microbes nor the animal can use. The authors note that because the ingredient contains only 2.61 per cent crude protein to begin with, the absolute amount of damaged protein is nutritionally negligible, but the same PC logic cautions against overestimating the metabolisable protein contribution of black gram husk and de-oiled rice bran, whose PC fractions were 11.95 and 7.71 per cent of crude protein.

When the team converted the protein fractions into rumen-degradable and rumen-undegradable protein using degradation and passage rate equations, the thirteen feeds spanned a nutritionally actionable spectrum. Corn gluten feed delivered the highest rumen-degradable protein at 74 per cent of crude protein, making it best suited to rations where maximising microbial protein synthesis is the goal, particularly alongside high-CB1 energy sources. Coconut oil cake sat at the opposite extreme, with 64 per cent of its protein escaping rumen degradation, making it most valuable where post-ruminal amino acid supply is the limiting factor, as in early lactation or high-producing cattle whose metabolisable protein requirements exceed what microbes alone can supply. Soybean meal and alfalfa residue occupied an adaptable middle ground.

None of these distinctions are visible in a conventional feed tag, which is precisely the point the authors emphasise. Poor nutritional management rooted in poor-quality feeds is identified as the primary on-farm constraint limiting milk yield on smallholder tropical dairy farms, frequently pushing animals into negative energy and protein balance. By publishing a consistent, regionally grounded CNCPS reference dataset for thirteen ingredients analysed in a single run, the Kerala team has given South Asian nutritionists the raw material to formulate diets around ruminal degradation kinetics rather than proximate composition alone. The researchers frame the work as a starting point: wider sampling across different agro-climatic zones and supply chains will be needed to expand it into a comprehensive regional feed library, and future studies should progressively adopt the updated CNCPS v6.5 fractionation framework, with careful attention to how the older fraction definitions map onto the newer pool structure.

Subject of Research: CNCPS-based carbohydrate and protein fractionation of tropical ruminant concentrate feed ingredients for precision diet formulation

Article Title: CNCPS-based carbohydrate and protein fractionation of feed ingredients commonly used in tropical ruminant diet formulation

Article References: Sahib, L., Kulangara, A., Kalarikkal Subramanian, A., Chacko, B., Gopalakrishnan, R., & Kundukulam Sunny, A. (2026). CNCPS-based carbohydrate and protein fractionation of feed ingredients commonly used in tropical ruminant diet formulation. Discover Animals, 3(1), Article 100. https://doi.org/10.1007/s44338-026-00245-4

Image Credits: AI Generated

DOI: 10.1007/s44338-026-00245-4

Keywords: CNCPS, feed fractionation, tropical ruminants, rumen degradability, concentrate ingredients, South Asia, precision feeding, dairy nutrition, protein fractions, carbohydrate fractions, RDP RUP, livestock

The research team, led by scientists from Mengniu Dairy’s Ambient Product Research and Development Centres, purchased sixteen commercial UHT whole milk products from the Chinese e-commerce platform Jingdong Mall. Six samples were produced in China, five in Western Europe, drawn from the Netherlands, Germany, Austria, Ireland, and Spain, and five from Australia and New Zealand. Imported products explicitly labeled as grass-fed or pasture were preferentially selected to maximize the likelihood that they represented grazing-based production systems, although the authors caution that label claims do not guarantee the annual diet of any herd. All samples contained only raw milk or organic raw milk with no additives, and all were packed in aseptic cartons.

The analytical arsenal deployed on these sixteen cartons was formidable. Gross composition, including fat, protein, lactose, solid-non-fat, and total solids, was measured by mid-infrared spectroscopy. Fatty acids were quantified by gas chromatography with flame ionization detection according to the Chinese national standard GB 5009.168. Fat-soluble vitamins A and E were determined by high-performance liquid chromatography with diode-array detection, while riboflavin was measured by HPLC with UV/visible detection. Niacin, pantothenic acid, and folic acid were assessed with commercial assay kits, choline by ion chromatography, and a panel of minerals, including calcium, potassium, sodium, magnesium, zinc, selenium, and iodine, by inductively coupled plasma mass spectrometry. Phosphorus was determined spectrophotometrically. This breadth matters because single-nutrient comparisons can be misleading; milk quality is a multivariate property.

The macronutrient results revealed a subtle but telling pattern. Measured fat and lactose levels of the domestic samples were significantly higher than those of the imported milks, and the domestic products showed the highest fat, vitamin E, vitamin B3, zinc, and iodine content, while milk from Australia and New Zealand had the lowest levels of fat, solids, and vitamin A. Interestingly, the measured fat and protein values for domestic milk exceeded typical raw-milk averages reported for China, pointing to standardization practices in dairy processing, particularly for domestic products claiming 3.6 grams of protein per 100 milliliters. Minerals tied to casein micelles, such as calcium, phosphorus, and magnesium, showed no significant regional differences, likely because protein standardization counteracts the feed-driven variation that previous studies have documented for grazing versus total mixed ration systems.

The vitamin findings may be the study’s most counterintuitive result. Fresh and ensiled grass is an excellent source of fat-soluble vitamins, so one might expect pasture-fed European and Oceanian milk to contain more vitamin A and vitamin E. The opposite was observed. The researchers attribute this to the harsher thermal reality of imported UHT milk: longer transportation distances demand longer shelf lives and higher heat loads, and quality reports cited in the paper show imported UHT milk carried markedly higher heat-load indicators such as furosine and lactulose between 2021 and 2023. Vitamin A degrades through isomerization of its unsaturated isoprenoid side chain during thermal processing, and vitamin E loss increases with temperature and holding time. Degradation continues even under refrigeration, with losses of roughly 8 percent for vitamin A and 11 percent for vitamin E after thirty days of storage. In contrast, water-soluble vitamin B2 was higher in imported milk, consistent with its origin in green leafy forage, while vitamin B3, derived mainly from cereal grains, was higher in domestic milk, matching expectations for grain-heavy total mixed rations.

The fatty acid analysis produced perhaps the clearest separation between regions. Total saturated and monounsaturated fatty acids did not differ significantly, but the polyunsaturated fatty acid picture split sharply along the n-3 and n-6 families. Domestic Chinese milk was richer in n-6 fatty acids, including C18:2n-6c, C18:3n-6, C20:3n-6, and C20:4n-6, whereas imported milks carried higher levels of n-3 fatty acids such as C18:3n-3, C20:3n-3, and C20:5n-3. The imported samples achieved an n-3/n-6 ratio of approximately 0.31 to 0.32, compared with only 0.12 for Chinese milk. The biochemistry behind this split is well understood: pasture is rich in alpha-linolenic acid, an omega-3 precursor, while maize silage, cereals, and oilseeds in mixed rations supply abundant linoleic acid, an omega-6. These dietary fatty acids are then elongated and desaturated in the mammary gland, amplifying the regional differences in long-chain polyunsaturates.

Shorter-chain fatty acids told the same story from a different angle. Imported milk contained significantly higher levels of C4, C6, C12, and C14, reflecting the fact that high-fiber pasture diets stimulate de novo fatty acid synthesis in the udder, whereas the high-starch rations of confined systems lower ruminal pH and suppress this synthesis. Odd-chain fatty acids, C11, C15, C17, and C21, were also significantly elevated in imported milk, and these compounds are recognized biomarkers of pasture-based feeding because they arise from rumen microbial fermentation of forage. The paper notes that omega-3 fatty acids are associated with reduced risk of cardiovascular disease, diabetes, cancer, and mental disorders, and that the dietary n-3/n-6 ratio of Chinese consumers is suboptimal. However, the authors are careful to add a crucial caveat: milk products account for only about 2.3 percent of Chinese food intake and roughly 1 percent of daily milk fat consumption, so switching to imported milk alone cannot transform the overall dietary fatty acid profile. Pairing milk with omega-3-rich foods such as deep-sea fish, nuts, and flaxseeds remains essential.

Sensory evaluation added a human dimension to the chemistry. Eight trained, certified assessors evaluated the samples in duplicate on a nine-point hedonic scale after a structured three-day training program. Imported milks scored significantly higher for cowy and tea flavors and for astringency, while domestic samples appeared brighter in color and sweeter. The yellow-cream hue of grass-based milk reflects high carotenoid and riboflavin levels in forage, whereas total-mixed-ration milk tends toward white. The cowy note is linked to compounds such as p-cresol, a consistent marker of pasture diets, and the higher sweetness scores for domestic milk align with its higher measured lactose content. Notably, despite the heavier heat treatment of imported products, no significant difference in cooked flavor emerged between groups. The authors candidly acknowledge a limitation: Chinese assessors unfamiliar with imported milk may score attributes differently from their Western counterparts, and previous cross-cultural work has shown Irish and Chinese panelists interpreting the same pasture-milk attributes in opposing ways.

Principal component analysis wove all these threads together into a single picture. Two principal components explained 56.7 and 18.2 percent of the variance respectively, and the first component cleanly separated domestic from imported milk. Domestic samples clustered tightly, characterized by higher vitamin E, fat, and n-6 fatty acids, while the imported samples scattered more widely, positively correlated with vitamin B2, n-3 fatty acids, short- and medium-chain fatty acids, long-chain fatty acids, astringency, and tea flavor. That dispersion, the researchers suggest, reflects the diversity of feeding systems, processing technologies, and storage conditions across Western European and Oceanian countries, in contrast to the large-scale standardized farming and industrial production that dominates the Chinese dairy sector.

The study concludes with practical recommendations that extend beyond shopping advice. Because average dairy intake among Chinese adults was only 27.6 grams per day in 2018, less than a tenth of the 300 grams recommended in the national dietary guidelines, the authors argue that even meeting the current recommendation would not fully satisfy needs for calcium, selenium, and vitamin B2, and they suggest that intake above 500 grams per day of milk and dairy products may be needed. They also call for exogenous vitamin A fortification, better retention of vitamins during storage and transport, and regulation of grass-fed and pasture label claims in the Chinese market, including nutrient indicators such as n-3 fatty acid content. The work was funded by the China government guides local funds for scientific and technological development under grant number 2024ZY0146, and the authors declare no competing interests. For consumers, the takeaway is refreshingly even-handed: neither domestic nor imported milk is simply better. They are products of two different agricultural philosophies, and understanding that difference is the first step toward an informed choice.

Subject of Research: Comparative nutritional composition, fatty acid profiles, and sensory characteristics of commercial UHT bovine milk from China, Western Europe, and Australia/New Zealand sold in the Chinese market

Article Title: Nutritional composition, fatty acid profiles, and sensory characteristics of commercial bovine milk from different global production regions in the Chinese market

Article References: Yang, J., Wang, M., Hu, P., Li, S., Qian, W., & Li, H. (2026). Nutritional composition, fatty acid profiles, and sensory characteristics of commercial bovine milk from different global production regions in the Chinese market. Food Science of Animal Resources, 46(1), Article 80. https://doi.org/10.1007/s44463-026-00086-5

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00086-5

Keywords: UHT milk, dairy nutrition, fatty acids, pasture feeding, total mixed ration, vitamins, sensory analysis, China dairy market, omega-3, food science, milk composition, principal component analysis