Changes

*'''Growth''': Energy requirements for newborn puppies and kittens are estimated at 25 kcal/100g BW and 20-25 kcal/100g BW, respectively, until weaning.7 After weaning puppies and kittens should be fed approximately 2*MER until they reach 40-50% of expected adult weight, this should be decreased to  1.6*MER until 80% of their expected adult weight is reached, and then further decreased to 1.2*MER until they are fully grown. At maturity food intake should be adjusted to maintain an optimal body condition. Rate of growth and time to reach each change will vary with breed and individual requirements.

*'''Growth''': Energy requirements for newborn puppies and kittens are estimated at 25 kcal/100g BW and 20-25 kcal/100g BW, respectively, until weaning.7 After weaning puppies and kittens should be fed approximately 2*MER until they reach 40-50% of expected adult weight, this should be decreased to  1.6*MER until 80% of their expected adult weight is reached, and then further decreased to 1.2*MER until they are fully grown. At maturity food intake should be adjusted to maintain an optimal body condition. Rate of growth and time to reach each change will vary with breed and individual requirements.

*'''Gestation''':  

*'''Gestation''':  

#'''Dogs''': Most foetal weight gain occurs after day 40 of gestation. Until that time, maternal energy requirements do not change significantly. After day 40, energy demand increases and bitches should be allowed free access to food.

:*'''Dogs''': Most foetal weight gain occurs after day 40 of gestation. Until that time, maternal energy requirements do not change significantly. After day 40, energy demand increases and bitches should be allowed free access to food.

#'''Cats''': Energy requirements for queens do not change significantly during gestation, but they will lose 40-50% of their body weight during lactation. During the last half of gestation queens should be fed 140*BWkg0.67 in anticipation of this extreme weight loss.8

:*'''Cats''': Energy requirements for queens do not change significantly during gestation, but they will lose 40-50% of their body weight during lactation. During the last half of gestation queens should be fed 140*BWkg0.67 in anticipation of this extreme weight loss.8

*'''Lactation''':

*'''Lactation''':

#'''Dogs''': Typically lasts 6 - 8 weeks, and energy demand will vary depending on litter size and breed. Peak lactation occurs around week 4 post-partum, when weaning typically starts. The energy requirement for milk production is estimated to be 24 kcal/BWkg of bitch per puppy for litters of for 1-4 puppies; and  12 kcal/BWkg of bitch per puppy for additional puppies i.e 5 or more. The energy requirements to support lactation are added to maternal MER.7  

:*'''Dogs''': Typically lasts 6 - 8 weeks, and energy demand will vary depending on litter size and breed. Peak lactation occurs around week 4 post-partum, when weaning typically starts. The energy requirement for milk production is estimated to be 24 kcal/BWkg of bitch per puppy for litters of for 1-4 puppies; and  12 kcal/BWkg of bitch per puppy for additional puppies i.e 5 or more. The energy requirements to support lactation are added to maternal MER.7  

#'''Cats''': Typically lasts 7-9 weeks. Queens experience a net loss of body mass during lactation and should be fed at 2*MER.  

:*'''Cats''': Typically lasts 7-9 weeks. Queens experience a net loss of body mass during lactation and should be fed at 2*MER.  

*'''Athletes''':

*'''Athletes''':

#'''Dogs''': Energy intake should be adjusted to environment and condition and will vary with the activity.4,7 Racing sled dogs may have a daily energy requirement of 6-10*MER depending on temperature, pack weight, and distance covered; whereas a  racing greyhound (sprint races) may have a daily requirement of 2*MER during training and racing.

:*'''Dogs''': Energy intake should be adjusted to environment and condition and will vary with the activity.4,7 Racing sled dogs may have a daily energy requirement of 6-10*MER depending on temperature, pack weight, and distance covered; whereas a  racing greyhound (sprint races) may have a daily requirement of 2*MER during training and racing.

*'''Neutering''':

*'''Neutering''':

#Neutering can influence energy requirements due to changes in activity, and/or  in ghrelin levels in response to changes in sex hormone concentrations.9-11.  

:*Neutering can influence energy requirements due to changes in activity, and/or  in ghrelin levels in response to changes in sex hormone concentrations.9-11.  

*'''Age''':

*'''Age''':

#Digestive efficiency decreases with age, and older dogs and cats may need to  increase energy intake to offset changes in digestive efficiency and maintain optimal body weight.4,12

:*Digestive efficiency decreases with age, and older dogs and cats may need to  increase energy intake to offset changes in digestive efficiency and maintain optimal body weight.4,12

==Consequences of Energy Deficiency==

==Consequences of Energy Deficiency==