Data/hora: 12/06/2024 17:32:44

Biblioteca(s): 	Embrapa Meio-Norte.	
Data corrente: 	31/05/1996	
Data da última atualização: 	31/05/1996	
Autoria: 	MONTEIRO, L. S.	
Título: 	The relative size of calf and dam and the frequency of calving difficulties.	
Ano de publicação: 	1969	
Fonte/Imprenta: 	Animal Production, v. 11, n. 3, p. 293-306, Aug., 1969.	
Idioma: 	Inglês	
Conteúdo: 	The frequencies of calving difficulties were computed for 458 calvingsof first and second parity Friesian, Ayrshire and Jersey dams with pure and crossbred progeny in all possible combinations. It was found that heavier breeds of dams have higher frequency of difficult calvings. For each breed of dam there is also a direct relationship between the mean birth weight of the calves and the frequency of calving difficulties associated with the breed or cross of calf. An index of calving difficulties calculated in the form of a discriminant function which combined both the birth weight of the calf and the calving weight and parity of the dam was: Z = log BW - 0.40 log DW - 0.10 P, where Z is the index of calving difficulties, BW and DW are respectively the birth and dam weight and P the parity variable with the values of one for second parity and zero for the first. To relate the values of the index with the frequencies of calving difficulties a probit transformation wasused. The mean values of the probabilities for different breeds and parities of dams obtained from the index and the probit regression have shown a good agreement with the observed frequencies of calving difficulties. The use of the index for predicting calving difficulties in experimental crosses where the birth weight of the calf is not known wasalso described. The possible methods of reducing calving difficulties and limitations in the use of the index were discussed.	
Palavras-Chave: 	Parto distocico.	
Thesagro: 	Bovino.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Meio-Norte (CPAMN)	
Exemplares: 	CPAMN - (4183-1) - ADC - SP - -- - S 10814 -  - S 10814 - DIS