Correlation between estrus onset and ovarian parameters in dairy goats / Início do estro e sua correlação com os parâmetros ovarianos em cabras leiteiras

This study assessed the effects of social dominance on the behavioral estrus and ovarian parameters of dairy goats subjected to synchronous estrus induction during the non-breeding season. Synchronous estrus was induced in 23 dairy goats allocated to collective pens. Ovarian ultrasonography was performed at 12 h intervals from device removal to ovulation. Upon estrus onset (EO) detection, the goats were immediately removed from the pens. Dominance was scored according to EO in relation to device removal in each pen, with HD - high dominants (<36 h; n = 8), MD - medium dominants (36 to 48 h; n = 10) and LD - low dominants (>48 h; n = 5). Goats in estrus underwent flexible time artificial insemination (FxTAI) according to EO. The estrus response was 100.0%. The interval to estrus was longer (P<0.05) in LD (53.7 ± 6.5 h) than in MD (37.9 ± 5.5 h) and HD goats (32.3 ± 6.6 h), while the interval from device removal to ovulation was similar (P>0.05) among all groups. The interval from EO to FxTAI was longer in HD goats compared to the other groups (P<0.05). In conclusion, although social hierarchy influenced the time of EO, the ovarian parameters, including ovulation, were not affected.

Este estudo avaliou os efeitos da dominância social sobre o comportamento do estro e os parâmetros ovarianos de cabras leiteiras submetidas à indução sincronizada do estro durante a estação não reprodutiva. A sincronização foi induzida em 23 cabras leiteira alocadas em baias coletivas. A ultrassonografia foi realizada em intervalos de 12 horas desde a remoção do dispositivo até a ovulação. Após a detecção do início do estro (EO), as cabras foram imediatamente removidas dos currais. A dominância foi pontuada de acordo com EO em relação à remoção do dispositivo, sendo: HD - alto dominante (<36 h; n = 8), MD - médio dominante (36 a 48 h; n = 10) e LD - baixo dominante (>478 h; n = 5). As cabras em estro foram inseminadas artificialmente em tempo flexível (FxTAI). O intervalo de estro foi maior (P<0,05) em LD (53,7 ± 6,5 h) do que em MD (37,9 ± 5,5 h) e cabras HD (32,3 ± 6,6 h), por sua vez, o intervalo entre a remoção do dispositivo e a ovulação foi semelhante (P> 0,05) em todos os grupos. O intervalo de EO a FxTAI foi maior em cabras HD quando comparado aos outros grupos (P<0,05). Em conclusão, embora a hierarquia social tenha influenciado o tempo de início do estro, os parâmetros ovarianos incluindo a ovulação não foram afetados.

Weight gain comparison between heifers fed colostrum or whole milk until weaning

Background: The milk-feeding phase, wherein whole milk is the natural food, is critical to calf development, health, andvitality. However, feeding milk to calves is costly in the rearing system because the milk supplied to calves is not sold. Infarms in which the average production is high, excess colostrum and transitional milk are produced that are used to feedcalves until weaning. The objective of this study was to evaluate the performance of heifers exclusively fed colostrum(including transitional milk) or raw whole milk.Materials, Methods & Results: Immediately after their birth, 83 ear-tagged healthy Holstein Friesian heifers adequatelyreceiving the initial colostrum were separated into two experimental groups. Group 1 (n = 34) was fed only fresh whole milkand group 2 (n = 49) was fed only colostrum diluted in water at a 2:1 ratio. Colostrum was removed from cows until the fifthday after birth and was stored in sanitized disposable plastic bottles, stored in a freezer at -20°C and before administration,the colostrum was thawed. Liquid diets were administered using a bottle twice a day during the first month, namely 2 L inthe morning and 2 L in the afternoon. During the second month, the heifers were fed 4 L once a day in the morning. Theheifers had access to an enclosure with fodder, in addition to concentrate specifically for heifers, which was placed in anindividual trough daily. The leftovers were weighed at the end of the afternoon. The heifers were abruptly weaned whenthey reached a daily intake of 1 kg of concentrate. The heifers were individually weighed at birth and at 30, 60, 90, 120,150, and 180 days. The average weights were 40.4, 54.1, 74.5, 95.1, 108.2, and 126.1 kg in group 1 and 45.4, 58.4, 78.2,95.9, 110.8, and 125.1 kg in group 2. The use of diluted colostrum was satisfactory...

Weight gain comparison between heifers fed colostrum or whole milk until weaning

Background: The milk-feeding phase, wherein whole milk is the natural food, is critical to calf development, health, andvitality. However, feeding milk to calves is costly in the rearing system because the milk supplied to calves is not sold. Infarms in which the average production is high, excess colostrum and transitional milk are produced that are used to feedcalves until weaning. The objective of this study was to evaluate the performance of heifers exclusively fed colostrum(including transitional milk) or raw whole milk.Materials, Methods & Results: Immediately after their birth, 83 ear-tagged healthy Holstein Friesian heifers adequatelyreceiving the initial colostrum were separated into two experimental groups. Group 1 (n = 34) was fed only fresh whole milkand group 2 (n = 49) was fed only colostrum diluted in water at a 2:1 ratio. Colostrum was removed from cows until the fifthday after birth and was stored in sanitized disposable plastic bottles, stored in a freezer at -20°C and before administration,the colostrum was thawed. Liquid diets were administered using a bottle twice a day during the first month, namely 2 L inthe morning and 2 L in the afternoon. During the second month, the heifers were fed 4 L once a day in the morning. Theheifers had access to an enclosure with fodder, in addition to concentrate specifically for heifers, which was placed in anindividual trough daily. The leftovers were weighed at the end of the afternoon. The heifers were abruptly weaned whenthey reached a daily intake of 1 kg of concentrate. The heifers were individually weighed at birth and at 30, 60, 90, 120,150, and 180 days. The average weights were 40.4, 54.1, 74.5, 95.1, 108.2, and 126.1 kg in group 1 and 45.4, 58.4, 78.2,95.9, 110.8, and 125.1 kg in group 2. The use of diluted colostrum was satisfactory...(AU)