Bull Management: Getting Your Ratios and Health Right
Bull management involves ensuring the right number of healthy bulls for your herd, minimising stress and reducing injury risks.
It’s essential to maintain BCS targets, as too thin or too fat cows can negatively affect reproductive performance. Regularly track feed and nutrition to avoid excessive BCS loss. Also, it’s crucial to score the condition at key times in the year, allowing you to monitor trends and act accordingly.
For effective herd reproduction, you should implement a strategy for BCS assessment, considering feed budgets, milking frequency and plans for drying off. Remember, balance feed supply and demand to keep your cows well fed.
Effective management of body condition over the whole season improves herd reproductive performance, cow health and milksolids production.
Most New Zealand herds have some cows that are too thin at calving. They may also have some cows that are too fat at calving and lose too much body condition in early lactation. Both are problems that reduce reproductive performance.
Hitting BCS targets is important
Cows calving in body condition score (BCS) 5.0 for mature cows, and 5.5 for first and second calvers, have substantially better reproductive performance than cows in lower body condition.
Losses of one body condition score can be expected in early lactation, and cows calving at BCS 5.0 and 5.5 targets will likely be condition score 4.0-4.5 at mating start date.
Cows that calve in low condition score (4.0-4.5) may lose less condition but end up at condition score less than 4.0 at mating. They produce less milksolids, take longer to start cycling and their reproductive performance suffers.
Excessive losses of condition score (1.5 scores or more) can occur when cows calve in body condition score above 5.5, reducing their reproductive performance. First calvers are at risk of losing more than one condition score, but if they calved early, and are gaining condition prior to mating start date (MSD), they have every chance of getting back in calf early.
Managing body condition score is all about managing your herd’s nutrition and lactation programme. Condition scoring at critical times throughout the year lets you know if you need to consider changing herd nutrition or shortening lactation of some cows.
Herd managers need to regularly track against budget all aspects of feed and nutritional management. This allows you to anticipate and detect problems early and take action to avoid excessive loss of condition and reduced reproductive performance.
A sound BCS programme allows you to meet herd targets
- Not more than 15% of mature cows are below body condition score 5.0 at calving and not more than 15% of mature cows are above body condition 5.0 at calving
- Not more than 15% of first and second calvers are below body condition score 5.5 of first and second calvers are above body condition score 5.5 at calving.
- The average decrease in body condition score for the herd between calving and mating is not more than 1.0
- Not more than 15% of cows are below body condition score 4.0 at mating; and
- Cows maintain or gain body condition from the commencement of mating.
Article - DairyNZ
