Funções de covariância para produção de leite no dia do controle em bovinos Gir leiteiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise das relações da curva de crescimento e eficiência produtiva de vacas da raça Holandesa

O objetivo neste trabalho foi analisar as relações entre parâmetros da curva de crescimento (peso à maturidade e taxa de maturação) e medidas da eficiência produtiva de 333 vacas da raça Holandesa nascidas de 1992 a 2002. Dados de idade ao primeiro parto, produção de leite e duração da primeira lactação, primeiro intervalo de partos e produção de leite por dia de intervalo de partos foram analisados por meio de um modelo linear generalizado com o efeito fixo de grupo contemporâneo (ano-estação de nascimento), os efeitos aleatórios de pai da vaca e erro e os efeitos lineares e quadráticos do peso à maturidade e da taxa de maturação. Nas análises de longevidade e de duração da vida útil, incluiu-se o efeito fixo de motivo de descarte da vaca. Houve efeitos linear e quadrático da taxa de maturação sobre a maioria das características, exceto o primeiro intervalo de partos e a produção de leite por dia de intervalo de partos. As estimativas das taxas de maturação ótimas variaram de 0,0896 a 0,1187 kg/kg de peso vivo/mês. O peso à maturidade influenciou a longevidade de forma linear e quadrática. A combinação ótima foi de 701 kg de peso à maturidade e 0,0934 kg/kg de peso vivo/mês de taxa de maturação. O peso à maturidade correlacionou-se de forma desfavorável com a duração da primeira lactação (-0,11). Coeficientes de correlação significativos foram obtidos entre taxa de maturação e idade ao primeiro parto (-0,22), produção de leite na primeira lactação (0,18), duração da primeira lactação (0,18) e longevidade (0,14), o que confirma a hipótese de que vacas com taxas de maturação mais rápidas apresentam maior eficiência produtiva.

Time-dependent alterations of soluble and cellular components in human milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hazards in non-pasteurized milk on retail sale in Brazil: prevalence of Salmonella spp, Listeria monocytogenes and chemical residues

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on Prototheca zopfii strains isolated from bovine milk

Prototheca zopfii has been considered one of the most important causes of environmental mastitis in Brazil. These algae are refractory to conventional therapy and cause great damage to the mammary gland. The present study evaluated the in vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on 27 P. zopfii strains isolated from the milk of cattle. Low concentrations of sodium hypochlorite (0.0390625-0.15625%) and iodine (0.15625-0.625%) were effective against the isolates. These antiseptics may be recommended for hygiene routines, pre and postdipping and cauterization of bovine mammary glands infected by P. zopfii. (C) 2009 Elsevier Ltd. All rights reserved.

Factors potentially affecting fertility of lactating dairy cow recipients

Objectives of this study were to evaluate factors that could affect pregnancy rate after embryo transfer (ET) in lactating dairy cow recipients. The trial was conducted at a dairy farm located in Descalvado, SP, Brazil from October 2003 to September 2004. From 1037 cows with CL that were treated with an injection of PGF(2 alpha), 43.3% were detected in heat; 263 were previously assigned at day of PGF(2 alpha) injection for AI and 186 for ET. Ovulation rate was 85.7% (385/449). Pregnancy rate for cows with CL for AI and embryo transfer recipients were 36.5% (84/230) and 58.7% (91/155) at day 25 and 33.0% (76/230) and 45.8% (71/155) at day 46, respectively. Embryonic loss were 9.5% (8/84) for the AI group and 21.9% (20/91) for the ET group. Average milk production was 31.4 L/day/cow. Average daily milk production from 7 days before PGFZ injection to 7 days after ET tended (P < 0.10) to influence pregnancy rate on days 25 and 46. Average daily milk production from the day of embryo transfer to 7 days after influenced embryonic loss (P < 0.05). Cows with higher milk production had lower probability of pregnancy and higher probability of embryonic loss. Cows with higher days in milk had higher probability of pregnancy. Cows with higher rectal body temperature had lower probability of pregnancy and higher probability of embryonic loss. The influence of high milk yield and body temperature on fertility in lactating dairy cow recipients suggests that these effects can occur also after embryo reaches the blastocyst stage. (c) 2005 Elsevier B.V. All rights reserved.

Desempenho de vacas leiteiras em pastagem de alfafa suplementada com silagem de milho e concentrado e viabilidade econômica do sistema

Avaliou-se o efeito da substituição parcial de silagem de milho por pastagem de alfafa no desempenho de vacas leiteiras e na viabilidade econômica do sistema. Utilizaram-se 24 vacas da raça Holandesa, em estádio médio de lactação, em delineamento em blocos ao acaso. Os tratamentos foram: dieta à base de silagem de milho em confinamento, silagem de milho substituída parcialmente por pastejo restrito (PR) e pastejo irrestrito (PI) de alfafa. O sistema de pastejo foi rotacionado, e a quantidade de concentrado igual em todos os tratamentos. A massa de forragem foi de 2.338 e de 1.878kg de MS/ha, e a oferta de 1,8 e 4,2kg de MS/100kg de peso vivo, nos tratamentos PR e PI, respectivamente. A produção de leite não diferiu entre os tratamentos, cujas médias foram de 25,9; 25,8 e 25,2 litros por vaca por dia no confinamento, no PR e no PI, respectivamente. A produção diária de leite por área foi de 59,3L/ha no PR e de 63,0L/ha no PI, enquanto no confinamento foi de 45,7L/ha. A substituição parcial de silagem de milho por alfafa em pastejo não limitou o desempenho produtivo dos animais e mostrou-se economicamente vantajosa em relação ao confinamento.

Effects of intravenous glucose infusion and nutritional balance on serum concentrations of nonesterified fatty acids, glucose, insulin, and progesterone in nonlactating dairy cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Progesterone-based estrous synchronization protocols in non-suckled and suckled primiparous Bos indicus beef cows

In Experiment 1, effects of an intravaginal progesterone insert (CIDR) for synchronization of estrus in non-suckled cycling primiparous Bos indicus beef cows were evaluated. Cows received either no treatment (Control), prostaglandin F(2 alpha) (PGF), or CIDR (6 d)+prostaglandin F(2 alpha) (CIDR+PGF). There were greater (P<0.05) percentages of cows inseminated and pregnant in 4 d of breeding season in CIDR+PGF (81.6%; 48.7%) than in PGF (53.8%; 32.5%) and Control cows (14.6%; 8.5%). In Experiment 2, efficacy of a treatment with CIDR (6 d)+prostaglandin F(2 alpha)+48 h temporary weaning (CIDR+PGF+TW) associated or not with equine chorionic gonadotropin (eCG) for synchronization of estrus in suckled primiparous B. indicus beef cows was evaluated. Cows were assigned to receive either no treatment (Control), CIDR+PGF+TW, CIDR+PGF+TW+200 IU of eCG, or CIDR+PGF+IW+400 IU of eCG. There were greater (P<0.05) percentages of insemination and pregnancy in 4 d of breeding season in treatment groups (47.0%; 27.5%) than in Control cows(4.5%; 3.0%) and in cows treated with eCG (50.9%; 29.4%) than in cows treated only with CIDR+PGF+TW (39.4%: 23.7%). No effects of eCG dosage were detected. The percentage of cows inseminated and pregnant in a 30 d breeding season were greater (P<0.05) in cows assigned to synchronization treatments (53.3%; 37.2%) than in Control cows (35.3%; 21.4%). In the beginning of the BS, non-suckled primiparous cows treated with CIDR+PGF with estrous cycles having been initiated following calving had greater estrous detection and pregnancy rates than PGF and Control cows, and suckled primiparous cows had improved estrous detection and pregnancy rates when eCG was associated with CIDR+PGF+TW. (C) 2009 Elsevier B.V. All rights reserved.

Elevated progesterone concentrations enhance prostaglandin F-2 alpha synthesis in dairy cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Concentrations of Progesterone and Insulin in Serum of Nonlactating Dairy Cows in Response to Carbohydrate Source and processing

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of temperament on pregnancy rates to fixed-timed AI in Bos indicus beef cows

The objective of the present experiment was to assess the effects of temperament on pregnancy rates to fixed-time AI (FTAI) in Bos indicus beef cows. A total of 761 multiparous lactating Nelore cows, originated from 4 different commercial cow-calf ranches, were evaluated for BCS and temperament at the time of FTAI (day 0). Temperament was assessed by chute score and exit velocity. Further, individual exit score was calculated by dividing exit velocity results into quintiles and assigning cows with a score from 1 to 5 (exit score: 1 = slowest cows; 5 = fastest cow). Temperament scores were calculated by averaging cow chute score and exit score. Cows were also classified for temperament type according to temperament score (<= 3 = adequate temperament, >3 = excitable temperament). Pregnancy status was verified by detecting a viable conceptus with rectal ultrasonography approximately 40 days after FTAI. Chute score, exit velocity, and temperament score were not correlated to BCS (P>0.31). Hence, BCS did not differ (P=0.30) according to temperament type (4.13 vs. 4.09 for cows with excitable and adequate temperament, respectively; SEM = 0.070). Pregnancy rates to FTAI tended to be negatively affected by temperament score (P=0.08), whereas the probability of cows becoming pregnant to FTAI was negatively associated with temperament score (linear effect, P<0.01). Accordingly, pregnancy rates were reduced (P=0.05) in cows with excitable temperament compared to cows with adequate temperament (35.3 vs. 42.8% of pregnant cows/total cows, respectively; SEM = 2.85). Pregnancy rates to FTAI were not affected by chute score (P=0.25), although the probability of cows becoming pregnant to FTAI tended to be negatively associated with chute score (linear effect, P=0.07). Pregnancy rates to FTAI were negatively affected by exit score (P=0.05), and the probability of cows becoming pregnant to FTAI was negatively associated with exit score and with actual exit velocity (linear effects, P<0.01). Results from this experiment indicate that excitable temperament is detrimental to pregnancy rates of B. indicus cows assigned to an estrus synchronization + FTAI protocol. Published by Elsevier B.V.

Composição físico-química e produção do leite de búfalas da raça Mediterrâneo no oeste do Estado de São Paulo

O objetivo do presente trabalho foi avaliar os componentes físico-químicos e a produção do leite de búfalas da raça Mediterrâneo criadas no Oeste do Estado de São Paulo. Utilizaram-se 1438 controles provenientes de 152 lactações, controladas no período de 1985 a 1995, na Estação Experimental de Zootecnia de Andradina. Os dados foram analisados por meio do procedimento GLM do Programa SAS. O modelo estatístico para produção de leite teve como fontes de variação (FV) os efeitos fixos de mês do controle e lactação. Para as demais características, usou-se o mesmo modelo, acrescido da produção de leite como covariável. Todas as fontes de variação do modelo foram significativas. As médias ajustadas foram 4,52 kg, 4,13%, 6,59%, 17,01%, 10,47% e 18,98°D, respectivamente, para produção de leite, porcentagens de proteína totais, gordura, extrato seco total, extrato seco desengordurado e acidez. Verificou-se elevado teor de nutrientes no leite, evidenciando a boa qualidade do produto.

Evaluation of fermented milk containing probiotic on dental enamel and biofilm: In situ study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Synchronization of ovulation in beef cows (Bos indicus) using GnRH, PGF2 alpha and estradiol benzoate

The objective of this study was to evaluate protocols for synchronizing ovulation in beef cattle. In Experiment 1, Nelore cows (Bos indicus) at random stages of the estrous cycle were assigned to 1 of the following treatments: Group GP controls (nonlactating, n=7) received GnRH agonist (Day 0) and PGF2 alpha (Day 7); while Groups GPG (nonlactating, n=8) and GPG-L (lactating, n=9) cows were given GnRH (Day 0), PGF2a (Day 7) and GnRH again (Day 8, 30 h after PGF2 alpha). A new follicular wave was observed 1.79+/-0.34 d after GnRH in 19/24 cows. After PGF2a, ovulation occurred in 19/24 cows (6/7 GP, 6/8 GPG, 7/9 GPG-L). Most cows (83.3%) exhibited a dominant follicle just before PGF2a, and 17/19 ovulatory follicles were from a new follicular wave. There was a more precise synchrony of ovulation (within 12 h) in cows that received a second dose of GnRH (GPG and GPG-L) than controls (GP, ovulation within 48 h; P<0.01). In Experiment 2, lactating Nelore cows with a visible corpus luteum (CL) by ultrasonography were allocated to 2 treatments: Group GPE (n=10) received GnRH agonist (Day 0), PGF2a (Day 7) and estradiol benzoate (EB; Day 8, 24 h after PGF2 alpha); while Group EPE (n=11), received EB (Day 0), PGF2a (Day 9) and EB (Day 10, 24 h after PGF2a). Emergence of a new follicular wave was observed 1.6+/-0.31 d after GnRH (Group GPE). After EB injection (Day 8) ovulation was observed at 45.38+/-2.03 h in 7/10 cows within 12 h. In Group EPE the emergence of a new follicular wave was observed later (4.36+/-0.31 d) than in Group GEP (1.6+/-0.31 d; P<0.001). After the second EB injection (Day 10) ovulation was observed at 44.16+/-2.21 h within 12 (7/11 cows) or 18 h (8/11 cows). All 3 treatments were effective in synchronizing ovulation in beef cows. However, GPE and, particularly EPE treatments offer a promising alternative to the GPG protocol in timed artificial insemination of beef cattle, due to the low cost of EB compared with GnRH agonists. (C) 2000 by Elsevier B.V.