The German government’s decision to phase out the culling of male chicks has put pressure on German laying hen farms and hatcheries. The latter are obliged to pass on hatched male chicks to rearing farmers immediately after hatching.

No specific data is available on the number of male chicks reared in Germany, as no nationwide records have been kept to date. However, it can be assumed that the majority of male chicks are reared in other European countries. When rearing male chicks abroad, it is difficult to monitor the rearing conditions, and the chicks usually face longer transport journeys. However, farms rearing male chicks under the KAT system (Association for Controlled Alternative Animal Husbandry) must also comply with the relevant guidelines when operating abroad.

Following the ban on the culling of male day-old chicks, the rearing of male chicks became the dominant alternative in Germany. However, due to technological advances and the resulting fall in costs, in-egg sexing has become increasingly important and now represents the main alternative. The German government’s decision to permit sex determination from 1 January 2024 until the 12th day of incubation – rather than, as originally planned, only until the 6th day of incubation – is fuelling this trend. Furthermore, technological progress is causing the selection costs per egg to fall steadily, meaning that in-ovo selection is also becoming increasingly economically viable. This is usually not financed solely by the proceeds from the sale of the meat, but predominantly through cross-subsidisation via a 2 to 4 cent higher egg price for the ‘sister hens’.

The number of brother roosters is therefore likely to continue to fall; however, it should be borne in mind that roosters will still be produced as a result of misidentification during in-ovo selection. Furthermore, most organic associations fundamentally reject sex determination in the egg and regard the rearing of brother roosters as a transitional form towards dual-purpose chickens.

The rearing of male chicks is a relatively new area of production and presents farmers with new challenges. To date, legal requirements for their rearing exist only in the context of organic farming, as set out in Implementing Regulation (EU) 2020/464 to Regulation 2018/848, the so-called EU Organic Regulation.
In the conventional sector, Lower Saxony alone has defined specific minimum requirements for the rearing of brother cocks. In both cases, the rearing guidelines are closely aligned with those for pullets.  At present, from a legal perspective, brother cocks are still classified as broiler chickens. However, due to their different behaviours (e.g. increased perching, pecking order fights, agility) and biological performance, they are more similar to their sisters, the pullets. For this reason, the birds can theoretically also be reared in mixed-sex groups, thereby avoiding the need for sex determination after hatching. However, due to a different vaccination programme for male and female birds, rearing them together is significantly more expensive than rearing them separately. Most of the eggs produced in Germany come from farms with KAT certification. With the new rearing guidelines, the association has decided that, from January 2022, only KAT pullets may be housed if the rearing of brother cocks also complies with KAT requirements.

In Germany, former duck and broiler chicken houses are usually converted for the rearing of male chicks. Feeding and watering troughs from broiler chickens can continue to be used for rearing the male chicks. However, these must be fitted with a wire rope as a perch guard or reinforced to prevent them from being used as perches. The house must be well-structured overall to accommodate the animals’ more active behaviour and to prevent pecking, feather-picking and cannibalism. To this end, perches or raised platforms and enrichment materials (e.g. hay bales, dust-bathing facilities) should be provided as early as possible. Access to a cold-weather area and outdoor run can offer the animals additional incentives.

There is currently still disagreement regarding space requirements. Whilst KAT requires a maximum of 18 birds per m² of usable floor space from 1 July 2024, practical experience shows that a lower stocking density of 13 to 15 birds per m² is more favourable for preventing aggressive behaviour. An advantage for rearing is the significantly longer rearing period of 10 to 22 weeks, compared to broiler rearing, which accordingly involves fewer service periods. There is a tendency towards lower antibiotic use and lower mortality rates in young cocks. Due to the longer rearing period, an adapted vaccination programme should be considered.

Feed consumption in broiler cocks is approximately twice that of broiler hybrids. When reared under conventional conditions up to 1.5 kg live weight, the feed conversion ratio is approximately 1:3.0–3.5. With extended rearing, feed conversion efficiency deteriorates further. However, brother cocks have the potential to achieve satisfactory performance with a lower protein intake. In particular, the heavier brown breeds can achieve final fattening weights comparable to those achieved with a standard fattening feed when fed an adapted extensive diet. The birds must have unlimited access to feed in order to compensate for the lower protein content through increased feed intake. Furthermore, the energy content can be reduced to prevent earlier sexual maturity and the associated cockfighting.