Farmers must prioritise the next generation of milking cows by ensuring that the target weights of their replacement heifers are realised over the coming months.

With this in mind, heifers should reach 30% of their mature bodyweight at six months of age and achieve 60% of mature weight when bred at 15 months.

Over the next few months, optimal average daily gain may be difficult to maintain when grass growth/quality declines and grazing conditions become more challenging. So it is important to consider where your replacement heifers are in relation to targets (% of mature weight) currently.

By weighing heifers in early autumn as opposed to weighing at the point of housing, farmers can identify which animals are behind target. The best advice is to group accordingly and make alternative plans for heifers below their target weights.

Underweight heifers are considered to be those that are 5% or more below target bodyweight. Therefore, the regular weighing of heifers can help farmers to keep track of performance through the season.

Heifers that are lighter than this should be separated and given priority access to the highest quality grass and be re-introduced to concentrates depending on their weight relative to the herd’s target.

Higher weight gains can be achieved from grass rather than from winter/silage diets and a good response to autumn supplementation can be achieved. Should grass be in short supply and quality or when conditions are deteriorating, under-target replacement heifers should be fed a supplement until housing time to maintain weight. To increase growth rates, 1-2kg of concentrate/head/day should be sufficient.

Research shows that youngstock at grass in summer can achieve a weight gain of 0.85kg/day on grass alone. Come the autumn, where 1kg of concentrate plus high-quality grass are offered, average daily gains of 1kg/head/day can be achieved.

For more information, contact your local Agritech Sales Advisor here.

Calves born over the next few weeks will calve down in February 2026, and become the mature stalwart cows of 2029, and the influence we have on the beginning of their lives will be long felt regarding longevity, milk production and the herd’s overall health and wellbeing.

Colostrum is (still) King

Year-on-year we discuss, read and write about 3-2-1 rules, and how important receiving adequate colostrum is. Yet conversations still arise around how best to avoid scour in calf sheds, anti-scour remedies and as we face into another spring, a back to basics approach needs to be taken with colostrum.

It is important to remember that the calf’s first opportunity for infection is through its navel or mouth. Therefore, teats, the cow’s underbelly, and contact with the calving pen bedding become a source of infection for a new-born calf. Prolonged time spent in the calving areas are often a key issue with disease transfer in herds.

All feed equipment must be disinfected before colostrum is collected/fed. Dirt contamination of colostrum is known to have a negative effect on passive transfer and therefore cleanliness of the collection process is vital.

Storage is also important – it’s an all-too-common sight to see buckets of colostrum in the parlour/dairy – and where ambient conditions arise, bacterial counts can double every 20 minutes.

A dam-to-calf system is obviously the ideal. However, during a compact calving period this can sometimes be difficult to obtain in every instance. It’s very important to remember that colostrum quality can vary dramatically between cows. Where pooling occurs, at the very least, colostrum must be brix tested prior to pooling to avoid dilution with poor colostrum.

Factors that affect colostrum quality are short dry periods, parity, high yielders (dilution effect) and poor dry cow nutrition. Vaccination of the dam is also a key consideration on farm to help avoid scour outbreaks. However, passive transfer from the vaccine only occurs from dam-calf via colostrum and transition milk so all of the above still applies.

Research has shown where passive transfer is 100% successful in herds mortality rates of <5% are achievable, in stark comparison where passive transfer of just 85-90% is achieved, calf mortality rates can increase to ~8%.  Treat colostrum with the respect and attention it deserves.

For further advice, contact your local Agritech Sales Advisor.

Hitting target weights at certain milestones is crucial to ensure replacement heifers are on course to achieve the main goal of being 60% of their mature weight when bred at 15 months.

Meal feeding at grass

Transitioning calves from a milk-based diet to a grass-based diet can be tricky. Spring born calves that are weaned and now at grass, should be offered supplementary concentrates in the diet for 4-6 weeks minimum, to ease with the transition onto a grass-based diet.

Where 102kgs concentrate is offered at grass for the first number of weeks, this reduces the total amount of fresh grazed grass in the diet and avoids hungry calves over-indulging on lush low fibre, high N grass; resulting in what is often referred to as ‘summer scour’.

Alongside offering concentrates, fibre sources can also be offered in the diet (e.g., straw/hay/roughage) through this transition, as well as turning calves into slightly heavier covers. We must remember young calves are not fully developed ruminants yet and high quality lush grass may not be the best forage for supporting rumen development.

Target weights

Weighing scales are by far one of the most under-utilised management tools on farm. Timing of weighing can also be beneficial. By weighing in the weeks pre-housing, compared to weighing at the point of housing, allows farmers to identify heifers that are behind target. The best advice is to group accordingly and make alternative plans for those heifers under target weights.

The threshold figure for 2023 spring born weanling heifers is approximately 200kg in mid-September (33% of an assumed mature weight of 600kg). Heifers that are lighter than this should be separated and given priority access to the highest quality grass and re-introduce concentrates depending on their weight relative to the herds target.

Further information: 

For more information, contact your local Sales Advisor.

Silage harvesting is a major cost on Irish farms, therefore it is most important that the desired level of quality is achieved.

Dry Matter Digestibility (DMD) indicates the feeding value of a forage crop. In grass silage, it refers to the percentage of grass dry matter that an animal can digest to support their feed requirements. To make high DMD silage, the grass sward needs to contain a high leaf content. DMD is also linked to harvest date, with research showing that a crop harvested on June 2nd versus a harvest date of May 20^th, resulted in a DMD drop of as much as 5%.

Key considerations
Weather will be the main dictating factor with silage harvesting. However, during periods of broken weather, where a window of opportunity appears, avoid delaying harvest. Delaying first cut will cause a large drop in quality and reduce second cut yields significantly.

Grass sugars are the main consideration for crop preservation (Sugar being the food required for fermentation bacteria). The target for good preservation is 3%. Cutting time (early afternoon) and cutting conditions will have the greatest impact on sugar content in grass.

Grass nitrates can affect preservation by increasing buffering capacity. A grass crop will on average use up 2 units of N per day for first cut. Nonetheless, this is only a general rule and should not delay cutting date. Wilting silage to approximately ˃28% will help decrease nitrates.

Wilting is very beneficial to silage preservation where sugars are marginal and/or nitrates remain elevated. The aim should be to increase crop dry matter to 25-30% with pit silage and 30-35% with baled silage. Over wilting can cause issues when feeding out silage, such as heat loss/secondary fermentation.

Using a silage additive

The application of a proven silage additive, such as Agritech’s GrasZyme Sugarboost, at ensiling is a very important part of securing as much of the quality in the winter forage as possible – speeding up preservation and retaining more of the feed value within the pit, alongside less waste/losses.

From a total of 19 independent trials, GrasZyme Sugarboost has proven to deliver:

• + 1 litre of milk per cow per day and .09% milk protein increase
• + 110g daily live-weight gain in beef animals
• 1% reduction in dry matter losses

For further information, contact your local Agritech Sales Advisor.