Life stages Requirements Flashcards
What are 3 strategies to alleviate cold stress
- Make the environment warmer (improving insulation)
- To allow the animal to increase its heat production from existing resources (metabolizing far reserves)
3.manipulating the diet
How can you influence heat production in ruminants by means of diet?
Improving the quality of the diet. Low quality forage-based diets have lower efficient ME compared to high-quality concentrate-based diets
What are the 4 categories that the horse activity/exercis can be classified by the NRC? And how can it be calculated based on MER?
Light (1-3h/week) 20% MER
Moderate (3-5h/week) 40% MER
Heavy (4-5h/week) 60% MER
Very heavy (1h/week of speed work -> 6-12h/week slow work) 90% MER
Which is the first limiting aas for pigs?
Lysine
Which is the first limiting aas for chicks?
Methionine
What wool fibres consists of?
Keratin : high content of sulphur-containing aas cystine.
The efficiency with which dietary protein is concerted into wool depends on the relative proportions of cystine and methionine
What are advantages and disadvantages of a rapid growth in cattle?
Rapid growth has the economic advantage of reducing the non-productive part of the animal’s life. With meat-producing animals, a high plane of nutrition in early life allows the selection for breeding purposes of those individuals that respond to liberal feeding most favourably in terms of growth, and which may therefore be expected to produce fast-growing offspring.
Disadvantage: excessive fat deposition. In dairy cattle, fatness in early life may prejudice the development of milk-secreting tissue, and there is also some evidence that rapid early growth reduces the useful life of cows. Overfat gilts do not mate as readily as normal animals, and during pregnancy may suffer more embryonic mortality.
What should be done in the nutritional management of female sheep to increase the expected amount of lambs?
Transfer the female from a low to a high plane nutrition 3-4 weeks prior to mating (eg. transferring from hill pastures to lowland pastures or fodder crops).
> > A high plane of nutrition promotes a greater production of insulin, which encourages the ovary’s uptake of glucose and the synthesis of steroid hormones.
After being mated, the flushing plane of nutrition should be reduced to the maintenance level (as a high plane can reduce the survival of oocytes and the embryos they become after fertilisation).
What should be done in the nutritional management of a sow to increase the litter size?
Flushing (Transfer the female from a low to high plane nutrition) the maiden gilt for ten days before mating can increase litter size.
Can high planes of nutrition improve male fertility?
There is no reliable evidence for that, however, it is recognised that underfeeding has deleterious effects. Males, however, do have a higher fasting metabolism and therefore a higher energy requirement for maintenance than do females and castrates
Which nutrient imbalances can impair fertility?
- phosphorus deficiency in grazing
ruminants - Protein deficiency, especially in ruminants, can be expected to influence reproduction
because it reduces food intake. - In pigs, short-term deprivation of protein has no effect on fertility, but a prolonged protein deficiency – especially in younger animals – leads to reproductive failure.
- High dietary intake of crude protein
seems to depress fertility in horses. - In dairy cows, feeding diets containing high levels of starch (above 160 g/kg DM)
are associated with elevated plasma insulin concentrations and an earlier resumption
of oestrus postpartum.
What can be done in dairy cows to improve the conception rate (low/high-starch diets)?
Strategies whereby high-starch diets are provided to dairy cows pre-service and low-starch diets post-service result in significant increases in conception rate compared to
animals that have been offered only high- or low-starch diets.
Which Vitamins can play a role in fertility?
Vitamin A deficiency must be prolonged if it is to affect fertility;
Vit E deficiency in pigs, dogs (decrease reproductive performance), fowls (sterility)
In non-ruminants, deficiencies of the B-group vitamins riboflavin and folic acid
have been shown to reduce embryo survival.
Which trace elements can play a role in fertility?
selenium, copper, molybdenum, iodine, manganese and zinc are important in influencing fertility
Which nutritional management should be done to laying hens in contrast to broiler-breeders (meat-type birds) during the rearing period?
Layers should be fet to appetite during rearing (egg weight is related to body weight) - thus, pullets should be reared on diets high in ME and protein
In contrast to layers, pullets being reared as broiler breeders have to be restricted in food intake, or else they grow too fast and their subsequent egg production is much reduced.
