A positive phenotypic correlation between milk protein percentage and reproductive performance in dairy cattle, especially during early lactation has been recently reported. The objective of this study was to quantify the relationship between milk protein percentage and different measures of fertility in Irish, seasonal calving, dairy cattle using data from experiments comparing strains of Holstein-Friesian cows under different feeding systems. The relationships between body condition score, milk production and fertility were also investigated. The data used in this study consisted of 584 lactation records over a 5-yr period. Principal component analysis and logistic regression was used to study the relationship between milk protein percentage and fertility performance of the cow. Greater milk protein percentage during the first 60 days post-calving was associated with better reproductive performance. The probability of a cow being submitted in the first 21 days of the breeding season increased with increased milk protein percentage during early lactation. Similarly, the probability of a cow becoming pregnant to its first service or to the whole breeding season also increased. Cows were classified as either high or low milk protein percentage based on their protein percentage over the whole lactation. Cows in the high milk protein group had a 7% greater conception rate compared to cows in the low protein percentage group. In conclusion, cows with higher protein percentage, especially during early lactation are submitted earlier in the breeding season, and have a higher conception rate. Physiologically, the shortage of glucose caused by negative energy balance restricts the synthesis of milk protein in the udder. On the other side, negative energy balance also causes the reduction of IGF-I, LH and oestradiol, which consequently delay the ovarian follicular development and finally reduces fertility. Therefore, there is a biological explanation for the association between milk protein percentage and fertility performance.

Univ., Diss.--Kiel, 2003.

Originally presented as the author's Thesis (doctoral)--Johan Wolfgang von Goethe-Universität Frankfurt am Main, 1976. / Includes bibliographical references (p. 275-280).

The aim is to assess the relationship between disease hooves of dairy cows and milk production traits selected, evaluation limbs according to the Methodology linear description and evaluation zavnějšku Holsteins and assess the impact of fathers on the hoof diseases.

The diploma thesis is focused on reproduction and milk yield of a herd of Czech Fleckvieh and Red Holstein cattle on Velká Chyška farm. Milk yield together with the reproduction makes a basement of every breeding and its analysing is very useful for the breeder. The aim of the thesis was to split the herd according to the lactation into four groups (1, 2, 3, 4 and more lactations) and according to the percentage of blood of Czech Fleckvieh and Red Holstein cattle into three groups (C1- C 75-100 %, C2- C 51-74 % and R- R 51-100 %). To observe the indicators of milk yield and especially to observe yield in standardized lactation, index of persistence of the lactation line and whole-life yield of these cows. Next, to focus on the reproductive indicators: the insemination interval, the service period and the interval itself. Gathered information was recorded into tables and then statistically evaluated. Also, all groups were mutually compared. Needed information was gathered from GEA Dairy plan program and the milk cow cards. Milk cows, which started the lactation in period from 10. 10. 2014 to 30. 2. 2015, were included into the analyzed group. Generally, 155 pieces of livestock participated here. The milk yield indicators were evaluated as excellent. The groups of cows C1 and C2 cows with dominant percentage of blood of Czech Fleckvieh breed, showed significantly better-than-average results when compared with the yield check. The group with dominant percentage of blood of Red Holstein breed (R) exceeded the results from the yield check of the Czech republic as well, but not as in such extent as in case of C1 and C2 groups. In comparison of the groups together, no statistically important results were found. Statistically, only influence of lactation order to the yield in standardized lactation and also influence of lactation order to the index of persistence of lactation line was proved. Reproductive indicators were different in comparison from the yield; they were on very low levels. The service period and the period itself were evaluated as unsatisfactory in all groups and a problem with reproductive management was proved. In comparison of the groups together, no statistically important differences were found as well. Based on the found results and their analysis, conclusions for the breeding practice came about.

The aim of the work was to elaborate a literary review of the characteristics, reproductive properties of Holstein cattle and influences affecting the reproduction of cattle. Another objective of the work was to evaluate the selected influences on their reproduction in a group of selected dairy cows from the monitored cattle herd. The data were processed and sorted by genotype, level of milk performance, parity, length of dry period, length of insemination interval, difficulty of calving, age of the first calving and synchronization of estrous (Ovsynch). In evaluating the effect of the genotype on reproductive parameters, there were no statistically significant differences between purebred Holstein cows (H100) and crosses (H50-88C). In addition, the effect of milk yield on lactation on reproductive performance was evaluated. The results showed that with increasing performance, the values of reproduction indicators (insemination index, insemination interval and period service) have increased. The statistically lowest insemination index (1.70) and insemination interval (96 days) were detected in cows with a yield up to 8,000 kg. The service period (122 days) was conclusively the lowest in a cow group with a yield of 8,001 to 10,000 kg lactating milk. In contrast, the highest conclusive values of the insemination index, interval and period service were detected in a group of dairy cows with a yield above 12,001 kg of milk. It is further evident from the results that the values of the pregnancy rate after the first insemination increased with the increasing level of milk performance. The lowest value (27.14%) was detected in the group with the highest milk yield (over 12,001 kg of milk). There were no significant differences between the different groups of dairy cows in the evaluation of the influence of parity on the reproduction indicators. Furthermore, the influence of length of dry period was evaluated. The average dry period in the monitored herd was 69 days. The pregnancy rate after the first insemination was better for the group with a dry period over 61 days (40.38%). On the other hand, periods of service and days open values were lower in dairy cows with a dry period less than 60 days (119 and 394 days respectively). The length of uterine involution was also monitored by the length of insemination interval. Most cows in the monitored group of dairy cows (25.29%) were first inseminated 66th - 87th day after calving. No statistically significant differences were detected in the assessment of the age of the 1st calving and the severity of births on reproductive parameters. The use of controlled reproduction methods (Ovsynch) was also monitored and applied only in the case of reproductive disorders of dairy cows. In the monitored period, Ovsynch was used in only 10 dairy cows and the average service period was 140 days.

The aim of this thesis is to evaluate chosen influences on the extent of reproduction of randomly chosen milk cows that are bred in the same conditions. The chosen influences such as breed, age of the first calving, time of year of calving and level of yield were observed within breeds of Czech Fleckvieh and Holstein cattle. Evaluation was carried out in ZOD "Podhradí" Choustník company, specifically in Budislav farm. 191 cows were chosen for the basic sample. 95 of them were Holstein cattle and 96 were Czech mottled cattle. Chosen influences were evaluated according to data gained from the set of milk yield inspections. A statistically significant difference was observed between Czech ticks and Holstein cows in the length of service period per second and first lactation where Holstein cows have a second lactation period longer than 44 days (P <0.001). Evaluation of first calving age did not show any influence on the level of reproduction neither within Czech Fleckvieh nor within Holstein cattle. During the annual evaluation, it emerged that Holstein cows calved in spring and winter have significantly bigger insemination interval compared to cows that were calved during summer or autumn. This fact was also proven by correlation analysis. This analysis also confirmed the relation between annual period and insemination interval Rxy=0,21(P<0,05). The correlation analysis also proved the relation between annual period and service period as well as interim of Czech Fleckvieh cattle Rxy= 0,327 (P<0,01). Statistically significant influence was not proven within Holstein cattle. Correlation analysis only pointed out the relation between yield and service period Rxy=0,213 (P<0,05). Unlike Holstein cattle, gradual increase of service period figures and interim depending on yield was noticed. Breeding cows milking more that 7,5 thousand kg of milk per lactation had service period of 132 days (P<0,01) and interim 407 days (P<0,01). Economical losses caused by prolonged interim during monitored herd of cattle reached 400.490 CZK in year of 2016.

This thesis deals with the evaluation of selected influences on the milk production and fertility of dairy cows in a herd of Holstein cattle. The cattle husbandry sector, in recent years, has been facing a worsening of the indicators of reproduction and longevity in dairy cows. It is primarily the requirement of constantly increasing the milk yield of dairy cows that has had an adverse impact on these indicators. The worsening of these indicators can result in a reduction of the cost-effectiveness of the production of milk and meat. The evaluation of influences on milk production and fertility in a herd of Holstein cattle was carried out at the AGRODAM Hořepník s.r.o. company. The selected influences included milk yield quantity, parity, age at first calving, calving interval, insemination index, and conception rate after first insemination. Two hundred and two Holstein dairy cows were included in the monitoring. Data on milk yield and reproduction were obtained from milk yield records and zootechnical records. The results showed that milk production of the monitored group of dairy cows was at a high level (10,025 kg of milk). The highest milk yield in kilograms of milk during first lactation was achieved by dairy cows that calved at the age of 27 to 29 months (9,335 kg of milk). According to the milk yield during the first lactation, the highest milk yield during three lactations was by dairy cows that had a milk yield exceeding 10,000 kg of milk during the first lactation (35,515 kg). When utilizing the DOUBLE OVSYNCH synchronization protocol, the average calving interval was 412 days, and a higher conception rate after first insemination (43%) was found as compared to the nationwide average in the Czech Republic (34.2%). The average number of culled dairy cows was 32%; from this the highest proportion of culled dairy cows was for other medical reasons (31%). Due to low milk yields, 25% of the dairy cows were culled.

Milk production has been evaluated not only by genetic potential but there are also a lot of indicators. The potential milk production of the herd depends on the correct link between the genetic potential and the system of selection, feeding and nutrition, reproduction and the breeding environment and health of animals. The aim of the thesis was to produce a literary overview of milk production, milk composition and influences that can influence the composition of milk. For the selected herd to evaluate the effects on the monitored indicators of the milk composition and to statistically evaluate them. For discarded dairy cows to determine the age and reason of culling and lifelong milk production.

Made available in DSpace on 2016-12-08T16:24:11Z (GMT). No. of bitstreams: 1 PGCA10MA064.pdf: 877931 bytes, checksum: ef65c09f07dc6c43c6a132d5ed45fb8b (MD5) Previous issue date: 2010-08-19 / Holstein is the dominant breed in dairy herds in southern Brazil, being known by the high milk yield, with low solids concentration, reduced fertility and longevity and high proportion of dystocia. The crossing with other specialized dairy breeds, especially Jersey, has been utilized as an option to reduce the deficiencies of the Holstein. The aim of this study was to evaluate dystocia in Holstein cows inseminated with Holstein or Jersey and performance of the calves resulted from these matings (growth, immune status and prevalence of diarrhea in the first days of life). The study was conducted at the Centro de Ciências Agroveterinárias of the Universidade do Estado de Santa Catarina (UDESC) in Lages, SC, Brazil. Forty cows and heifers were randomly inseminated with Holstein or Jersey, leading to the birth of 23 Holstein calves (11 males and 12 females) and 17 crossbred calves (7 males and 10 females). The birth were observed and a scale for calving ease from 1 (easy, unassisted) and 5 (extreme difficulty) were used. After birth, calves were housed in individual pens weight, height at withers, chest diameter and diameter and length of the head were obtained, and these measures were weekly repeated. Until one hour after birth, calves fed 2 liters of colostrum, and a second dose within 8 hours. In the following two days, they received 4 liters / day of transition milk, from the 4th day began to receive 4 liters / day of whole milk and starter concentrate. On day 42, calves were weaned and the diet was based in starter concentrate added to 20% alfalfa hay. Daily supply and plenty of concentrate were weighed and fecal score assigned on a scale from 1 (normal faeces) to 4 (fluid faeces). The samples of blood serum proceeded soon after birth, with 24 hours, 15, 30, 42, 49 and 84 days of age to assess the immunity of calves. Dystocia were observed only in Holstein calves (17.39%). The F1 Holstein x Jersey had lower weight and height at birth (35.2 kg and 72 cm) compared to the Holstein straigthbred (42.8 kg and 76.3 cm) at weaning and at the end of the experiment (84 days old), with no difference in weight gain and height growth (P> 0.05). There was no difference between genetic groups in concentrate intake and feed conversion. F1 calves have higher levels of protein and immunoglobulins in blood serum with 24 hours and 15 days of age, which may result from greater colostral absorption, indicated by increased serum gamma-glutamyl trasferase. No difference was observed between genetic groups for average fecal score, however the F1 calves required fewer treatments with antibiotics for diarrhea. We conclude that crossing Holstein cows with Jersey sires reduces dystocia due to the ix smaller size of F1 calves at birth. The performance of crossbred calves is similar to the Holstein, from birth to 84 days of age, with higher immune status and requiring fewer treatments for diarrhea / A raça Holandesa predomina nos rebanhos leiteiros do Sul do Brasil, sendo conhecida pela elevada produção de leite com baixa concentração de sólidos, reduzida fertilidade e longevidade e elevada proporção de partos distócicos. O cruzamento com outras raças leiteiras especializadas, especialmente a raça Jersey, vem sendo empregado como uma opção para reduzir as deficiências da raça Holandesa. O objetivo deste trabalho foi avaliar a facilidade de parto de vacas da raça Holandesa inseminadas com Holandês ou Jersey e o desempenho dos bezerros oriundos destes acasalamentos quanto ao desenvolvimento, status imunológico e prevalência de diarréias nos primeiros dias de vida. O estudo foi desenvolvido no Centro de Ciências Agroveterinárias da Universidade do Estado de Santa Catarina (UDESC), em Lages SC. Utilizaram-se 40 vacas e novilhas inseminando-as aleatoriamente com Holandês ou Jersey, das quais, obtiveram-se 23 bezerros Holandês (11 machos e 12 fêmeas) e 17 bezerros mestiços (7 machos e 10 fêmeas). Os partos foram observados e uma escala para facilidade de parto entre 1 (fácil, sem auxílio) e 5 (extrema dificuldade) foi adotada. Após o nascimento, os bezerros foram alojados em bezerreiro com baias individuais e avaliados quanto ao peso, altura à cernelha, diâmetro torácico e diâmetro e comprimento de cabeça, sendo estas medidas repedidas semanalmente. Até uma hora após o nascimento, os bezerros receberam 2 litros de colostro e uma segunda dose até 8 horas após. Nos 2 dias seguintes, recebiam 4 litros/dia de leite de transição e a partir do 4º dia passavam a recebem 4 litros/dia de leite integral e alimento concentrado a vontade. No 42º dia os bezerros eram desaleitados e a dieta passava a ser o concentrado inicial adicionado de 20% de feno. Diariamente a oferta e a sobra de concentrado foram pesadas e o escore fecal avaliado em uma escala de 1 (fezes normais) a 4 (fezes líquidas). As coletas de soro sanguíneo procederam-se logo após o nascimento, com 24h, 15, 30, 42, 49 e 84 dias de idade, para avaliar a imunidade dos bezerros. Partos distócicos foram observados somente em bezerros da raça Holandesa (17,39%). Os bezerros F1 Holandês x Jersey apresentaram menor peso e altura ao nascer (35,2 Kg e 72 cm) em comparação aos Holandês (42,8 Kg e 76,3 cm), ao desaleitamento e no final do experimento (84 dias de idade), sem diferença em ganho de peso e crescimento em altura (P>0,05). Também não houve diferença entre os grupamentos genéticos para consumo de concentrado e conversão alimentar. Os bezerros F1 apresentam níveis mais elevados de proteínas totais e imunoglobulinas no soro sanguíneo com 24h e 15 dias de idade, o que pode ser vii resultado de maior absorção colostral, indicado por maior concentração sérica de gama-glutamil trasferase. Não foi observada diferença entre os grupamentos genéticos para escore fecal médio, entretanto os bezerros F1 necessitaram menos tratamentos com antibióticos para diarréia. Conclui-se que o cruzamento entre Holandês e Jersey reduz a distocia em razão ao menor tamanho dos bezerros F1 ao nascimento. Os bezerros mestiços comportam-se de forma semelhante aos da raça Holandesa em relação ao desempenho do nascimento até os 84 dias de idade, apresentando status imunitário mais elevado e necessitando menos tratamentos para casos de diarréia