Respostas produtivas e comportamentais durante a ordenha de vacas Holandesas em início de lactação

Aiming to compare milk yield, residual milk and behavioral responses of Holstein cows during milking, fourteen experimental cows were mechanically milked twice a day, and evaluated during the first six weeks of lactation. Milk yield was measured daily, and residual milk volume weekly. Body (ribs region), udder and teat temperatures and respiratory frequency were measured twice a week. Animal behavior at the milking parlor was registered using ethograms and interviews with the milkers. During the first weeks of lactation, a higher percentage of kicks, over-steps, milking cups being knocked down, urinations and vocalizations in primiparous cows (p < 0.05) was observed, which were also considered more reactive by the parlors compared to multiparous cows. Multiparous cows produced more milk than primiparous (p < 0.05). However, there were no significant differences in residual milk percentage (p > 0.05), which suggests adaptation of both groups to the milking environment.

Analysis of culling probability in dairy buffalo using survival models

In order to contribute to the genetic breeding programs of buffaloes, this study aimed to determine the influence of environmental effects on the stayability (ST) of dairy female Murrah buffalo in the herd. Data from 1016 buffaloes were used. ST was defined as the ability of the female to remain in the herd for 1, 2, 3, 4, 5 or 6 years after the first calving. Environmental effects were studied by survival analysis, adjusted to the fixed effects of farm, year and season of birth, class of first-lactation milk yield and age at first calving. The data were analyzed using the LIFEREG procedure of the SAS program that fits parametric models to failure time data (culling or ST = 0), and estimates parameters by maximum likelihood estimation. Breeding farm, year of birth and first-lactation milk yield significantly influenced (P < 0.0001) the ST to the specific ages (1 to 6 years after the first calving). Buffaloes that were older at first calving presented higher probabilities of being culled 1 year after the first calving, without any effect on culling at older ages. Buffaloes with a higher milk yield at first calving presented a lower culling probability and remained for a longer period of time in the herd. The effects of breeding farm, year of birth and first-lactation milk yield should be included in models used for the analysis of ST in buffaloes. Copyright © The Animal Consortium 2010.

Efeito da exposição à fumaça de cigarro durante a prenhez e a lactação de ratas e sua prole sobre parâmetros séricos e morfométricos

PURPOSE: to investigate the effect of cigarette smoke exposure on body and tissue weight gain, serum parameters and milk yield during pregnancy and lactation in rats, and the impact on offspring from birth toil young adulthood. METHODS: 40 Wistar pregnant rats were randomly divided into: CG - not exposed to cigarette smoke and sacrificed at the end of pregnancy; CL - not exposed to cigarette smoke and sacrificed at the end of lactation; FG - exposed to cigarette smoke and sacrificed at the end of pregnancy; FL - exposed to cigarette smoke and sacrificed at the end of lactation. The offspring were separated by gender and divided according to their mothers' groups. Tissue weight, body weight and serum parameters were evaluated in rats and offspring. Milk yield per pup was calculated. RESULTS: body weight was decreased in FL during lactation (CL=267.0±7.2; FL=235.5±7.2 g*, *p<0.05). Adipose tissue was not detected in the CL and FL groups, and was reduced in FG compared to CG (CG=3.3±0.3; FG=2.4±0.3 g*, *p<0.05). Rats exposed to cigarette smoke had higher blood glucose levels (CG=113±17, CL=86±16, FG=177±21*, FL=178±23 mg/dL*, *p<0.05 CG versus FG e CL versus FL), CL and FL groups presented lower HDL-cholesterol with no change in total cholesterol. Finally, rats exposed to cigarette smoke had lower milk yield compared to unexposed rats (CL=6.7±0.4, FL=5.4±0.3 g*, *p<0.05). In offspring from the FG and FL groups, there was a decrease of body weight from birth to young adulthood, with no changes in gastrocnemius, liver or heart weights in any group, and adipose tissue was no detected in female offspring. There was an increase in blood glucose in offspring of both sexes from rats exposed to cigarette smoke (males: Pcg=107±10.5, Pcl=115±8.6, Pfg=148±16.8*, Pfl=172±11.2**; females: Pcg=109±27.2, Pcl=104±9.7, Pfg=134±20.0*, Pfl=126±13.3**; p<0.05 *Pcg versus Pfg and **Pcl versus Pfl). CONCLUSIONS: exposure to cigarette smoke provokes impairment of morphometric and serum parameters during pregnancy and lactation both in mothers and offspring, which is maintained during young adulthood.

Substituição dos grãos secos de milho pela silagem de grãos úmidos de milho para vacas da raça holandesa em lactação

In order to evaluate the effects of replacement of dried corn (GSM) for silage moisture corn (HMCS) on production and milk composition were used five Holstein cows, primiparous with a mean of 112 days post delivery, confined in Tie Stall, for 70 days. We used five diets according to NRC to 17.5% CP (DM) and 2.4 Mcal / kg DM, the 40:60 ratio of roughage and concentrate containing soybean meal, sugar cane silage and hay and substitution levels of the GSM HMCS the following treatments: a) 0%, 2) 25%, 3) 50%, 4) 75% and 5) 100%. Milk production and dry matter intake (DMI) were recorded daily. The animals were milked daily 6:00 and 18:00 h, and milk samples collected from consecutive milkings of each experimental period of 14 days (four days of collection). The experimental design was a 5x5 Latin square and the data analyzed by the statistical program SAS. Body weight (508 kg), milk (23.6 kg), corrected milk (22.7 kg), DMI (17.13 kg) showed no significant difference, but the intakes of neutral detergent fiber (6.67 kg), and detergent acid (3.39 kg), feed efficiency for the production of milk (milk 1.41 kg / day) urea nitrogen (17.67 mg / dL) differ, thus indicating that HMCS is more efficient than GSM in the diet of dairy cows not alter the production and milk composition.

Inbreeding depression on production and reproduction traits of buffaloes from Brazil

The objective of this study was to evaluate the influence of inbreeding depression on traits of buffaloes from Brazil. Specifically, the traits studied were body weight at 205 and 365 days of age, average daily gain from birth to 205 days (ADG_205), average daily gain between 205 and 365 days (ADG205_365) in Mediterranean buffaloes, and milk yield, lactation length, age of first calving and calving intervals in Murrah buffaloes. Inbreeding effects on the traits were determined by fitting four regression models (linear, quadratic, exponential and Michaelis-Menten) about the errors generated by the animal model. The linear model was only significant (P<0.05) for growth traits (exception of ADG205_365). The exponential and Michaelis-Menten models were significant (P<0.01) for all the studied traits while the quadratic model was not significant (P>0.05) for any of the traits. Weight at 205 and 365 days of age decreased 0.25kg and 0.39kg per 1% of increase in inbreeding, respectively. The inbred animals (F=0.25) produced less milk than non-inbred individuals: 50.4kg of milk. Moreover, calving interval increased 0.164 days per 1% of increase in inbreeding. Interestingly, inbreeding had a positive effect on age at first calving and lactation length, decreasing age of first calving and increasing lactation length. © 2012 Japanese Society of Animal Science.

Effects of a single nucleotide polymorphism in the leptin gene on the productive traits of dairy buffaloes (Bubalus bubalis)

The gene responsible for coding the leptin hormone has been associated with productive and reproductive traits in cattle. In dairy cattle, different polymorphisms found in the leptin gene have been associated with several traits of economic interest, such as energy balance, milk yield and composition, live weight, fertility and dry matter consumption. The aim of this study was to detect genetic variability in the leptin gene of buffaloes and to test possible associations with milk yield, fat and protein percentages, age at first calving and first calving interval. Three genotypes (AA, AG and GG) were identified by polymerase chain reaction-restriction fragment length polymorphism, which presented genotypic frequencies of 0.30, 0.54 and 0.16, respectively. The allele frequencies were 0.57 for the A allele and 0.43 for the G allele. No significant effects were found in the present study, but there is an indicative that leptin gene affects lipid metabolism. © 2013 Springer Science+Business Media Dordrecht.

Estimación de parámetros genéticos para producción de leche en el día de control en búfalas de primer parto

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

Diagnóstico e caracterização molecular de Giardia duodenalis e Cryptosporidium spp. em amostras fecais de bovinos e ovinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Associação genética entre produção de leite, habilidade de permanência e ocorrência de mastite em vacas da raça holandesa em condições tropicais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polimorfismo nos genes da leptina e do receptor de melatonina em búfalas (Bubalus bubalis)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Interação genótipo-ambiente para a produção de leite em bubalinos no Brasil e na Colômbia

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

Alimentos volumosos na produção de leite de cabra

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fatores que afetam a taxa de concepção após inseminação artificial ou transferência de embriões em vacas holandesas em lactação

Pós-graduação em Medicina Veterinária - FMVZ

Análise econômica parcial de dietas com farelo e a torta de girassol, na alimentação de vacas leiteiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação do teor de zinco no casco e soro sangüíneo, da produção de leite e contagem de células somáticas em bovinos leiteiros suplementados com Saccharomyces cerevisiae

Pós-graduação em Medicina Veterinária - FMVZ