O gado caracu sob o sistema de retiros
Palavras-chave:
gado caracu, produção leite, período lactação, manejo alimentar, período serviçoResumo
1. Tn this work were found the following means: milk yield 779 kg.; lactation period, 319 days; service period, 222 days; dry period, 188 days;and gestation period, 284 days.
2. The length of lactation period was the principal facter affecting the milk yield. The variance in yield was reduced 25 per cent when the lactation period was held constant. The correlation between milk yield and length of lactation period was -+ .519, beeing a linear relation. Correction factors were calculated for correcting the milk yield to a standard lactation period of 305 days.
3. There was a statistically sigrificant influence of the service period on milk yield. The variance in yield was reduced 7 per cent, when the service period was held constant, The correlation coeficiente between service pe- riod and milk yield was + .201. The correlation coeficiente hetween service period and lactation period was + .622. The service period has a practical importance in milk yield only through the lactation period.
4. The interdependence among milk yield, lactation period, and service period was studied. The correlaction coeficiente between milk yield and service period when the lactation period was held constant, was-182.
5. There was an influence statistically significant of the calving month on the milk yield and lactation period. The cows calving during the dry months produced less and had a shorter lactation period than those calving in wet season.
6. The calving month had a statistically significant influen- ce on the following service period. The cows calving in the dry months had a longer service period even though the lactation period was shorter during this time.
7. The total miik yield of each month was highly affected by the dry season. The dilerence between the month ol higher and lower yield was 73 per cent.
8. In a small group of cows on a improved condition of management, was observed an increase of 43,0 per cent on milk yield over the previous milk yield, which were on the general way of management.
9. In a group ol cows receiving a light ration of concentrates was observed a shortening of 105.0 per cent in the service period when compared to the mean of the herd
Referências
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[Autor não informado] — , J. B. — III — Contribuição ao estudo da resis- tência e susceptilidade genética dos bo- vinos ao Boophilus niicrophus. Bol. Ind. Animal 4(1) 60 — 86: 194
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