H.M. Saturnino

Effects of milk replacer feeding strategies on performance, ruminal development, and metabolism of dairy calves

Performance, rumen development, and metabolism of male Holstein calves (n=54) were evaluated according to 1 of 3 liquid feeding strategies: 4 L of milk replacer (MR)/d until 60 d old (4 L-60 d), 6L of MR/d until 29 d old and 4 L/d from 30 to 60 d (6L-29 d/4 L-60 d), or 6L of MR/day until 60 d old (60 d-6L). Water and starter were provided ad libitum. Intakes of MR and starter were monitored daily and body weight (BW) weekly. Blood samples for glucose and insulin concentrations and ruminal content samples for volatile fatty acids and ruminal ammonia concentrations were collected at 15, 30, 45, 60, 75, and 90 d of age. Six calves on each treatment were euthanized at 30, 60, and 90 d of age. Empty weights of forestomach and abomasum, papillae length, and mitotic index were measured. Average MR intake/d (expressed as a percent of BW) was greater for calves receiving 6L/d than for those receiving 4 L/d until 30 d of age. Calves on the 6 L-29 d/4 L-60 d had the smallest MR intake from 30 to 60 d old, followed by the 4 L-60 d and 6L-60 d treatments. Starter intake (kg of dry matter/day) did not differ between groups. It increased from 0.065 kg/d in the first month to 0.386 kg/d in the second month, and to 2.065 kg/d after weaning. Weight gain was greater for calves fed more MR in the first month, but no difference was observed during the second month. After weaning, 6L-60 d calves had greater rate of weight gain than others and were heavier at 30, 60, and 90 d of age. Weight of empty forestomachs, ruminal pH, and ammoniac nitrogen concentration were not different among groups. Propionate concentration was lower for 6 L-60 d calves, but acetate and butyrate concentrations were not influenced by MR feeding strategy. Calves fed more MR until d 30 had greater ruminal epithelium mitotic index. The different MR feeding strategies did not influence papillae length or ruminal epithelium thickness. Lesions such as ruminal parakeratosis or hyperkeratosis were not observed. The MR feeding strategy did not affect glucose concentration, but insulin was higher in 6L-60 d calves than in the other groups. Glucose concentration increased with age, whereas insulin decreased until 45 d old, and then started to increase until 90 d. In conclusion, MR feeding strategy did not influence ruminal development. Feeding calves 6 L of MR/d over 60 d resulted in greater rate of weight gain without negative effects on starter intake or forestomach development. The weight advantage that 6L-60 d calves obtained preweaning was maintained until 90 d of age.

Desempenho de bezerros alimentados com dietas líquidas à base de leite integral ou soro de leite

Quinze bezerros da raca Holandesa, desaleitados aos 30 dias de idade, foram utilizados para avaliar os efeitos da inclusao de fontes proteicas alternativas, em substituicao as proteinas do leite integral, na formulacao de sucedâneos do leite. Os animais foram divididos em tres grupos: o grupo controle (C) - recebeu leite em po integral reconstituido; o grupo sucedâneo SL (soro/leite) recebeu 41,6% da proteina bruta (PB) vinda do concentrado proteico de soro (CPS), 23,1% do soro de leite e 35,3% do leite em po integral; e o grupo sucedâneo S (soro) recebeu 68% da PB vinda do CPS e 32% do soro de leite. O consumo de concentrado, feno, sal mineral e agua foi mensurado diariamente, enquanto o ganho de peso foi avaliado semanalmente. Nao houve diferenca (P>0,05) para o consumo de concentrado, sal mineral e agua entre os grupos, nos periodos avaliados. O consumo de feno e o ganho de peso foram inferiores nos animais do grupo S (P<0,05). A substituicao de 100% do leite integral por CPS e soro de leite influenciou negativamente o desempenho.

Efeito da substituição do feno de Tifton 85 pelo caroço de algodão como fonte de fibra na dieta de bezerros

Para avaliar a substituicao do feno Tifton 85 pelo caroco de algodao como fonte de fibra na dieta foram utilizados 24 bezerros da raca Holandesa, distribuidos em dois grupos. O grupo-feno recebeu feno e concentrado separados, fornecidos a vontade, e o grupo- algodao recebeu caroco de algodao incorporado ao concentrado (13,5%), a vontade. O consumo de alimentos, o peso, as alturas da cernelha e do ileo, as circunferencias toracica e abdominal, a concentracao de glicose sanguinea, as concentracoes de acetato, propionato e butirato, o pH do fluido ruminal e os pesos dos compartimentos do estomago foram mensurados. O consumo de alimentos, o desenvolvimento ponderal dos animais, as concentracoes de acetato, propionato e butirato, o pH do fluido ruminal, as concentracoes de glicose sanguineas e o peso dos compartimentos do estomago foram semelhantes entre os tratamentos (P>0,05). A necropsia, nao foram observadas alteracoes sugestivas de intoxicacao por gossipol. Concluiu-se que o caroco de algodao substituiu, sem prejuizos, o feno como fonte de fibra na dieta de bezerros.

Taxa de gestação em fêmeas da raça Holandesa confinadas em free stall, no verão e inverno

The gestation rate was used to evaluate the reproductive performance of dairy cows and heifers confined in a free stall barn during the winter and summer seasons of 1993, 1994 and 1995. The temperature (T) and relative humidity (RH) were monitored daily during the summer (December, January, February and March) and winter (June, July and August). The rectal temperature (RT) and respiration rate (RR) were measured weekly at 9AM and 3 and 9PM, in each season, in 50% of the animals randomly selected and sorted in four groups based on their milk production. The averages of T and the temperature and humidity index (THI) were higher in the summer (25.6oC e 75.8) than in the winter (19.0oC e 65.3), while the RH were the same in both seasons (80.0%). The averages of RT and RR were always higher in the summer and at 3PM when compared to 9AM RT and RR (39.47oC and 64.76 mov/min vs 38.89oC and 44.21 mov/min). Gestation rate for milking cows was smaller in summer than in the winter. Conversely 85.4% of heifers became pregnant during the summer and 78.5% during the winter season.

Avaliação da incidência e fatores de risco da retenção de placenta em vacas mestiças leiteiras

The incidence rate, risk factors and impact of retained placenta on the reproductive and productive performance of crossbred dairy cows was evaluated. The frequency distribution of retained placenta and also a Poisson multivariate analysis were developed for the following variables: year, calving season, lactation order, body condition score, gestation length, type of delivery, number and sex of calves. First calf heifers and multiparous cows, with and without retained placenta, during the rainy and dry season, had their average results compared in the following items: days from calving to first service, number of semen doses per conception, milk production up to 305 days and lactation peak. The incidence rate of retained placenta was 12.8%. The risk factors were: rainy calving season, 2nd, 3rd and above 4th lactation orders, body scores below 3.5 and greater than 4.0, abortion, stillbirth, premature birth, assisted birth and multiple birth. An increase of 51.2 and 27.5 days in the average interval between calving and first service, and of 1.2 and 0.6 in the average number of semen doses was observed in multiparous cows with retained placenta, giving birth during the rainy and dry seasons, respectively (P<0.05).

Produção e composição do leite de vacas alimentadas com dietas com diferentes proporções de forragem e teores de lipídeos

Milk yield and composition of Holstein dairy cows fed different forage to concentrate ratio as well as different lipid contents in the diets were studied. Eight cows with 58±9 days in milk and average production of 28±4 kg/day were assigned in a double Latin square design 4 x 4, in a 2 x 2 factorial arrangement. Treatments were diets with high forage and low lipid levels, high forage and high lipid levels, low forage and low lipid levels and low forage and high lipid levels. Milk yield and fat corrected milk yield (3.5%) were not affected by treatments (P>0.05). The reduction on forage ratio in the diet decreased milk fat percentage and production (P<0.05). The increase in lipid levels in the diets reduced total milk solids as well as milk urea nitrogen concentrations (P<0.05).

Infestação de Tunga penetrans siphonaptera: Tungidae em cascos de vacas leiteiras F1 Holandês-Zebu

Tunga penetrans rate of infestation in hooves of confined F1 Holstein-Zebu cows during the dry season was recorded. First parturition cows showed an infestation rate of 90.5% in the thorax and 96.9 in the pelvic members, second parturition cows showed an infestation rate of 95.3% in the thorax and 100% in the pelvic members while third parturition cows showed rate of infestation of 100% for both members.

Silagens de girassol e de milho em dietas de vacas leiteiras: consumo e digestibilidade aparente

The intake and the apparent digestibility of dry matter, organic matter, neutral detergent fiber, acid detergent fiber and the intake of crude protein were evaluated in lactating Holstein cows fed sunflower silage (SS) in replacement of corn silage (CS) in their diets. Five ruminal cannulated cows, 60 to 82 days in milk, were arranged in a 5 x 5 latin square design. The treatments werethe following: 100% corn silage (100CS) and concentrate; 34% sunflower silage plus 66% corn silage (34SS) and concentrate; 66% sunflower silage plus 34% corn silage (66SS) and concentrate; 100% sunflower silage (100SS) and concentrate;and 100% corn silage plus whole cotton seed (CS-WCS) and concentrate. Dry matter (17.86kg for 100SS and 21.62kg for 100CS) and organic matter intake (17.5kg for 100SS and 20.2kg for 100CS), intake and apparent digestibility of neutral detergent fiber and acid detergent fiber were lower for 100SS compared to 100CS (P<0.05). Apparent digestibility of organic matter for treatment 100SS was the lowest (54.8%). Increasing levels of corn silage in the diets increased the dry matter intake, the organic matter intake and the apparent digestibility. Parcial replacement of the corn silage with sunflower silage could be a viable option for lactating cows diets.

Degradabilidade in situ da silagem de quatro genótipos de sorgo com e sem tanino: II - Fibra detergente neutro, fibra detergente ácido, hemicelulose e celulose

The in situ procedure was used to evaluate the disappearance of neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicelulose and celulose of four sorghum genotypes with (CMS XS 210 and BR 701) or without (CMS XS 214 and BR 007) tannin in a completely randomized block design experiment with three replicates (animals), in a split plot arrangement. The four genotypes were allotted to the plots and the time of disappearance to the split plot. The BR 701 showed higher NDF and ADF degradation up to 24h of incubation and hemicelulose up to 48h, been the values similar after those times. No differences concerning the disappearance values of cellulose among genotypes and times were observed.

Degradabilidade in situ da silagem de quatro genótipos de sorgo com e sem tanino: I - Matéria seca e proteína bruta

The in situ procedure was used to evaluate the disappearance of dry matter (DM) and crude protein (CP) of four sorghum genotypes with (CMS XS 210 and BR 701) or without (CMS XS 214 and BR 007) tannin in a completely randomized block design experiment with three replicates (animals), in a split plot arrangement. The four genotypes were allotted to the plots and the time of disappearance to the split plot. The DM of CMS XS210 was less degraded when compared to the others and sorghums with tannin showed lower CP degradability when compared to the sorghums without tannin.