THE Weatherbys Return of Mares is an indispensable resource for pedigree buffs and professionals, featuring breeding records for every broodmare in Britain and Ireland in the past year. It details the identity of the mares’ foals and coverings in that season, as well as current and historical statistics on breeding activity in the two countries.

The book also provides an essential guide to the popularity of sires, the latest news on top mares and crucial clues to the health of the bloodstock business. As a taster for the recently published 2025 edition – which is available to buy on the Weatherbys Shop through (www.weatherbysshop.ie) – here are five key pieces of information contained within its pages.

Affinisea tops

Affinisea has regained his title as the busiest sire, covering 314 mares in the last breeding season. The son of Sea The Stars also topped the table in 2021 and 2022. His smaller earlier crops, numbering 72 seven-year-olds and 67 six-year-olds, produced Cheltenham Festival Grade 1 runners-up Affordale Fury and Only By Night and Grade 2-winning hurdler Sixmilebridge.

He also proved to be a dab hand with four-year-old point-to-pointers. His best representative in the past 12 months was Hernando De Soto, who bolted up on debut for Ellmarie Holden at Monksgrange and sold for £230,000 at the Goffs UK Aintree Sale four days later.

Affinisea’s continued popularity pays tribute to late Whytemount Stud owner Ronnie O’Neill, who built up a loyal following of breeders. It also shows that O’Neill’s legacy is safe in the hands of his son John.

Rounding out the top 10 most active sires in 2025 were Poet’s Word (298), Sioux Nation (282), Maxios (281), Starman (267), Luxembourg (261), Mehmas (257), Harzand (255), Order Of St George (234) and Hurricane Lane (216).

New boys

Luxembourg was the most in-demand new recruit to the stallion ranks, thanks to 261 mares sent to him at The Beeches Stud. He was a brilliant talent on the track, winning the Futurity Trophy at two, the Irish Champion Stakes at three, the Tattersalls Gold Cup at four and the Coronation Cup at five. He is also by Camelot, whose sire Montjeu was such a force for good in the National Hunt realm.

Luxembourg’s introductory book of mares included Christmas Hurdle heroine Verdana Blue and the dams of Grey Dawning, Mister Fisher, Nick Rockett, Poniros, Romeo Coolio and Yorkhill. The next most popular new sires were Auguste Rodin (205), Look De Vega (195), City Of Troy (175), Henry Longfellow (172), Mill Stream (170), Arrest (163), Vandeek (161), Big Evs (159) and King Of Steel (153).

Starman surge

Starman was the subject of one of the biggest increases in book size between 2024 and 2025. The son of Dutch Art served 267 mares at Tally-Ho this year, up from 104. He was surely inundated with mares after his first runner, Lady Iman, bolted up on debut at Dundalk in March, and when more of his two-year-olds hit the headlines at the breeze-ups.

Starman, set to be champion first-season sire, was sent the dams of Eqtiraan, Forever In Dreams, Gaga Mate, Gear Up, Katla, Lusail, Moss Tucker, New Providence, Patrick Sarsfield and Shumookhi this year.

Australia benefited from a price cut to €10,000 and covered 154 mares at Coolmore this season, up from 60 in 2024. His supporters must have been thrilled when he later supplied dual Derby winner Lambourn, Coronation Stakes heroine Cercene and Irish Oaks runner-up Wemightakedlongway.

Perfect Power is another sire whose book size surged on the back of a reduction in fee, going from covering 58 mares at £10,000 in 2024 to 134 mares at £7,500.

Star mares

Night Of Thunder looks likely to secure a first British and Irish champion sire title, with the exploits of Desert Flower, Gewan and Ombudsman putting him some £700,000 clear of Wootton Bassett.

The star-studded nature of the son of Dubawi’s book at Kildangan this season, covered at a career high fee of €150,000, confirms his status among European breeding’s elite.

He covered 169 mares, including Group/Grade 1 winners Audarya, Queen’s Trust, Sea La Rosa, Seal Of Approval, Sheikha Reika, Skitter Scatter, Sunny Queen and With You, and the dams of Group 1 winners Battaash, El Cordobes, Kalpana, Look De Vega, Mill Stream and Tarnawa. Dar Re Mi falls into both categories, having produced Too Darn Hot.

Several mares who have already clicked with Night Of Thunder returned to him, including the dams of Desert Flower, Dynamic Pricing, Economics, Estrange, More Thunder, Ombudsman, Thunder Kiss and Vespertilio.

Final book

Wootton Bassett looks odds-on to be crowned champion sire at some point in the future. The son of Iffraaj covered 206 mares at Coolmore, including high-class racemares Acapulco, Al Husn, Blowout, Blue Rose Cen, Bubbling, Chicquita, Curvy, Empress Josephine, Fairy Godmother, Grateful, In Italian, Jannah Rose, Lady Bowthorpe, Magic Wand, Nazeef, Opera Singer, Playful Act, Polydream, Quadrilateral, Ramatuelle, Relief Rally, Search For A Song, Sistercharlie, Tahiyra, Treve and Urban Fox.

His final full book included the dams of Almanzor, Al Riffa, Blackbeard, Camille Pissarro, Capri, Churchill, Latrobe, Palace Pier, Precise, Puerto Rico, Rhea Moon, Sahlan, Scandinavia, Ten Sovereigns, Twain, Unquestionable and Vandeek.

CLICK HERE TO ORDER YOUR COPY OF THE 2025 RETURN OF MARES

BUSIEST IRISH & BRITISH STALLIONS IN 2025

Sire No of mares

Affinisea 314

Poet’s Word 298

Sioux Nation 282

Maxios 281

Starman 267

Luxembourg 261

Mehmas 257

Harzand 255

Order Of St George 234

Hurricane Lane 216

Good Guess 210

Wootton Bassett 206

Auguste Rodin 205

Look De Vega 195

Walk In The Park 194

Frankel 192

Ghaiyyath 192

Martinborough 189

Gleneagles 188

Camelot 184

Little Big Bear 180

Golden Horn 177

Santiago 177

City Of Troy 175

New Bay 175

Blue Point 172

Henry Longfellow 172

Too Darn Hot 171

Mill Stream 170

Dark Angel 169

Night Of Thunder 169

Success Days 169

Baaeed 165

Space Blues 165

Arrest 163

Kingman 163

Vandeek 161

Big Evs 159

Jukebox Jury 157

Australia 154

Jeu St Eloi 153

King Of Steel 153

No Nay Never 151

Chaldean 150

Dragon Symbol 150

Arrest 149

Blackbeard 145

Havana Grey 145

Mirage Dancer 141

Sea The Stars 140

Paddington 137