| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.39 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
O grande foco de uma exploração leiteira é maximizar o seu lucro, sem prejuízo do
cumprimento das leis vigentes e do respeito pelo seu bem-estar animal.
O principal objetivo do presente estudo, executado no âmbito da unidade curricular
de Dissertação, Trabalho de Projeto ou estágio, do mestrado em Tecnologias em Ciência
Animal, do Instituto Politécnico de Bragança, foi comparar os efeitos da administração
de três dietas diferentes sobre o crescimento de vitelas da raça Holstein-Frísia, entre os 4
dias de idade e o desmame.
As vitelas estavam alojadas em duas explorações distintas. Entre o nascimento e o
3º dia de vida, todas elas foram alimentadas exclusivamente com colostro. A partir do 4º
dia de vida, elas passaram a ser alimentadas com diferentes tipos de leite de substituição
e de alimento concentrado comercial e feno distribuído ad libitum. Na exploração A, 10
vitelas foram alimentadas com leite de substituição à base de soro de leite e alimento
concentrado comercial starter (mistura de flocos) distribuído ad libitum – Dieta 1. A outra
metade foi alimentada com leite de substituição spray contendo 62% de leite de vaca e
dois tipos de alimentos concentrados comerciais: até aos 30 dias de idade foi administrado
um concentrado starter em farinha (com composição láctea), até perfazer um total de 6
kg/vitela, e posteriormente, até aos 90 dias de idade, um concentrado granulado, ambos
distribuídos ad libitum – Dieta Experimental. Na exploração B, metade das vitelas foram
alimentadas com leite de substituição spray contendo 60% de leite de vaca e alimento
concentrado comercial starter (mistura de flocos) distribuído ad libitum – Dieta 2. A outra
metade foi alimentada com a Dieta Experimental. O crescimento das vitelas foi avaliado
através do peso corporal e do perímetro torácico (PT). Ao 4º dia de vida, elas foram pe-
sadas e medidas pela primeira vez, antes de iniciarem a ingestão de leite de substituição.
As demais pesagens e medições foram realizadas quinzenalmente até ao desmame, ou
seja, aos 90 dias de vida.
De acordo com os resultados observados, o peso corporal das vitelas estudadas au-
mentou mais do que o dobro. O PT aumentou 1,38 vezes. O PT revelou-se um ótimo
estimador do peso vivo (PV), mas não tão bom do ganho médio diário de peso (GMD).
O crescimento das vitelas foi igual nas duas explorações. Na mesma exploração, o cres-
cimento das vitelas não variou em função do indivíduo ou do regime alimentar aplicado.
The main goal of a dairy farm is to maximize its profit while ensuring compliance with current laws and respect for animal welfare. The main objective of the present study, carried out as part of the Master´s degree in Animal Science Technologies at the Polytechnic Institute of Bragança, was to compare the effects of administering three different diets on the growth of Holstein-Friesian calves, from 4 days old until weaning. The animals were housed in two separate farms. Between birth and the 3rd day of life, they were exclusively fed with colostrum. From the 4th day of life, they were fed with different types of milk replacer and commercial starter feed, along with ad libitum hay. On farm A, 10 calves were fed a whey-based milk replacer and commercial starter feed (flake mixture) distributed ad libitum – Diet 1. The other half were fed a spray-dried milk replacer containing 62% cow's milk and two types of commercial feed: until 30 days of age, they were given a starter feed in meal form (with milk ingredients) up to a total of 6 kg per calf, and thereafter, until 90 days of age, a pelleted feed, both distributed ad libitum – Experimental Diet. On farm B, half of the calves were fed a spray-dried milk replacer containing 60% cow's milk and commercial starter feed (flake mix) distributed ad libitum – Diet 2. The other half were fed with the Experimental Diet. The growth of the calves was evaluated by measuring body weight and thoracic perimeter (TP). On the 4th day of life, they were weighed and measured for the first time, before starting the milk replacer intake. Further weighing’s and measurements were performed every two weeks until weaning, at 90 days of age. According to the observed results, the body weight of the studied calves increased more than doubled. The TP increased by 1.38 times. The TP proved to be an excellent estimator of live weight (LW), but not as good for estimating average daily weight gain (ADG). The growth of the calves was the same in both farms. Within the same farm, calf growth did not vary according to the individual or the applied feeding regime.
The main goal of a dairy farm is to maximize its profit while ensuring compliance with current laws and respect for animal welfare. The main objective of the present study, carried out as part of the Master´s degree in Animal Science Technologies at the Polytechnic Institute of Bragança, was to compare the effects of administering three different diets on the growth of Holstein-Friesian calves, from 4 days old until weaning. The animals were housed in two separate farms. Between birth and the 3rd day of life, they were exclusively fed with colostrum. From the 4th day of life, they were fed with different types of milk replacer and commercial starter feed, along with ad libitum hay. On farm A, 10 calves were fed a whey-based milk replacer and commercial starter feed (flake mixture) distributed ad libitum – Diet 1. The other half were fed a spray-dried milk replacer containing 62% cow's milk and two types of commercial feed: until 30 days of age, they were given a starter feed in meal form (with milk ingredients) up to a total of 6 kg per calf, and thereafter, until 90 days of age, a pelleted feed, both distributed ad libitum – Experimental Diet. On farm B, half of the calves were fed a spray-dried milk replacer containing 60% cow's milk and commercial starter feed (flake mix) distributed ad libitum – Diet 2. The other half were fed with the Experimental Diet. The growth of the calves was evaluated by measuring body weight and thoracic perimeter (TP). On the 4th day of life, they were weighed and measured for the first time, before starting the milk replacer intake. Further weighing’s and measurements were performed every two weeks until weaning, at 90 days of age. According to the observed results, the body weight of the studied calves increased more than doubled. The TP increased by 1.38 times. The TP proved to be an excellent estimator of live weight (LW), but not as good for estimating average daily weight gain (ADG). The growth of the calves was the same in both farms. Within the same farm, calf growth did not vary according to the individual or the applied feeding regime.
Description
Keywords
Vitelas de substituição Crescimento Peso corporal Perímetro torácico