475,622 research outputs found
Comparative study of lactation curves and milk quality in Holstein versus Swedish Red and White-Holstein Cross Cows
The objective of this study reported in this research paper was to compare the lactation curves of the production of milk, fat, protein, percentages of fat and protein, and somatic cell score in purebred Holstein (H) cows and Swedish Red and White (SRW) - Holstein (SxH) crossbred cows in the south-central region of the province of Cordoba, Argentina. The data set consisted of 32847 herd-test records from 1244 purebred H cows and 310 SRW x H crossbred cows, from three commercial dairy farms with cows of first to fifth or more lactations. The curves were modeled using the fourth-order Legendre orthogonal polynomials. In this study, the data of production of milk, fat production, protein production, percentage of fat, percentage of protein and somatic cell score (SCS) were analyzed. Purebred H cows had significantly higher milk production, more fat production and higher protein production levels than did SxH crossbred cows. However, SxH crossbred cows produced milk that had a higher percentage of fat and a higher percentage protein than did purebred H cows. In none of the lactations did somatic cell score differ significantly between the two breed groups. The results of our study showed that, SxH crossbred cows had significantly higher percentages of fat and protein; however, purebred H cows were significantly superior to SxH crossbred cows for the production of 305-d milk, fat, and protein. Mammary health, expressed in SCS, did not differ significantly between the two breed groups. Thus, suggest that crossbreeding Holstein purebred cows with SRW bulls can improve the composition of milk solids without affecting mammary health and, in this way, compensate substantially for any potential loss in the production and/or quality of the milk of the crossbred cows compared to H purebred cows.Fil: Pipino, Diego. Agroveterinaria Pipino; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Piccardi, Mónica Belén. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Desarrollo Rural. Area de Estadística y Biometría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lembeye, Felipe. Soprole. Gerencia de Abastecimiento. Departamento Agropecuario; ChileFil: Lopez Villalobos, Nicolas. Massey University; Nueva ZelandaFil: Vazquez, Maria Isabel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Quantitative determination of fatty acids in the University of Vermont\u27s CREAM herd followed over the course of six months
Holstein and Jersey cows were used to determine how the fatty acid profile of their milk differed with regard to breed of cow and season over the course of six months. Milk was collected from each cow monthly between November 2011 and April 2012 and analyzed for components and fatty acid composition. Data were analyzed using linear mixed models with a repeated measures design with breed, month, and breed × month as the main effects. Holstein cows produced more milk than Jersey cows (79.98 vs. 50.48 lbs), and significant differences were seen between both breeds (P\u3c0.001) and months (P=0.014) of the study. Jersey cows produced more fat (5.20 vs. 3.91%, P\u3c0.001) and protein in their milk (3.83 vs. 3.12%, P\u3c0.001) when compared to Holstein cows. Jersey cows produced more saturated fatty acids than Holstein cows (72.9% vs. 70.7%, breed P=0.004, month P\u3c0.001). Vaccenic acid was produced in similar levels by both breeds, but Holsteins produced slightly higher levels (0.92%) than Jerseys (0.81%, breed P=0.0016, month P\u3c0.001). Holstein cows produced higher levels of conjugated linoleic acids in their milk (0.49%) when compared to Jersey cows (0.41%, P\u3c0.001). Holstein cows produced higher levels of linoleic acid (1.60% vs. 1.43%, P\u3c0.001, month P=0.005) when compared to Jersey cows. Linolenic acid levels produced by both breeds were similar for Holstein (0.31%) and Jersey cows (0.29%, month P=0.007). From the analysis of concentrations of both selected fatty acids as well as groups of major fatty acids, there is evidence that the fatty acid profile of milk differs with respect to both breed of cow, as well as month of the year
Exercise of tied dairy cows during the winter
The aim was to investigate whether tied dairy cows have a motivation to move per se when exercised during winter and whether they prefer to be outdoors or indoors when exercising. In the first experiment tied dairy cows were observed when exercised outdoors every day, twice a week or once a week. In the second experiment the preference of tied dairy cows for being indoors or outdoors during exercise was tested in two types of preference tests. Cows exercised at longer intervals walked and trotted more than did cows exercised at shorter intervals. The cows that were exercised once and twice a week explored the environment more during exercise than did cows that were exercised every day. The increase in movement with duration of confinement indicates that the cows’ motivation to move built up with time. An alternative explanation is that the walking and trotting was a response to the novelty of the exercise area. However, we did not observe a build-up of explorative behaviour with time. The cows did not show a preference for exercise either indoors or outdoors. Preference for being outdoors or indoors may therefore be independent of the motivation for movement. In future studies this preference may be assessed in a situation where the motivation for movement is controlled. In conclusion, tied dairy cows increased the amount of movement with increased length of indoor confinement. Also, the amount of explorative behaviour was greater for cows exercised less frequently than for cows exercised every day. Finally, tied dairy cows did not show a preference for indoor or outdoor exercise
Effect of age and nutrient restriction pre partum on beef suckler cow serum immunoglobulin concentrations, colostrum yield, composition and immunoglobulin concentration and immune status of their progeny
peer-reviewedThe effect of cow age (multiparous (MP) v. primiparous (PP)) and nutritional restriction
pre partum (grass silage ad libitum v. straw only ad libitum for the last 15 (s.d. 3.3)
days of gestation) on cow serum immunoglobulin (Ig) concentration, on colostrum yield, composition and Ig concentration and on calf serum Ig concentrations (at ~8 and 48 h post partum) using spring-calving Limousin Holstein-Friesian cows and their progeny was studied over 3 years. The method of colostrum administration (stomach tube vs. assisted suckling within 1 h post partum) on calf immune status was also investigated. When feeding colostrum the target was to give each calf 50 mL per kg birthweight via stomach tube. Colostrum yield and Ig concentration were measured
following administration of oxytocin and hand-milking of half (Experiments 1 and
2) or the complete udder (Experiment 3). Following an 8-h period after birth during
which suckling was prevented a further colostrum sample was obtained. There was no
significant difference in first milking colostrum Ig subclass concentrations between the
within-quarter fractions or between the front and rear quarters of the udder in either
MP or PP cows. Colostrum Ig subclass concentrations at second milking were 0.46 to
0.65 of that at first milking. Compared to MP cows offered silage, colostrum yield and
the mass of colostrum IgG1, IgG2, IgM, IgA and total Ig produced was lower (P < 0.001)
for PP cows and the mass of IgG1, IgM and total Ig produced was lower (P < 0.05) for MP cows offered straw. Calves from PP cows and MP cows offered straw had significantly
lower serum IgG1 and total Ig concentrations at 48 h post partum than calves
from MP cows offered silage but there was no difference (P > 0.05) between colostrum
feeding methods. In conclusion, calves from PP cows and MP cows offered straw had a
lower humoral immune status than those from MP cows offered grass silage
Behaviour of dairy cows on organic and non-organic farms
There is an increasing number of organic dairy farms in the UK. The aim of this study is to compare behaviour of dairy cows on organic and non-organic farms. Twenty organic and 20 non-organic farms throughout the UK were visited over two winters (2004/05 and 2005/06). Organic and non-organic farms were paired for housing type, herd size, milk production traits and location. The number of cows feeding was counted every fifteen minutes for 4.5 h after new feed was available post morning milking. Behaviour at the feed-face was recorded for 60 minutes and aggressive interactions between cows were quantified. Farm type had no effect on numbers of cows feeding. There were more interactions between cows feeding at open feed-faces compared to head-bale barriers. At open feed-faces, there were more interactions on organic farms than non-organic. It is possible that organic cows were hungrier than non-organic cows after the arrival of new feed
Immune response of cows fed polyunsaturated fatty acids under high ambient temperatures
The aim of the experiment was to determine the effects of 2 different fat supplementations on immune functions of dairy cows under high ambient temperatures. The experiment involved 24 Italian Friesian cows, divided into 3 groups of 8 animals, that were subjected to fat supplementations based on whole flaxseed (FS) or microencapsulated fish oil (FO). At d 0, 45, and 90 of the experiment, lymphocyte response to phytohemagglutinin (PHA) was determined in vivo on each animal by measurement of skin-fold thickness at the site of PHA injection. A humoral response to chicken egg albumin (OVA) was established following a subcutaneous injection with OVA. To assess cows' immune responses, plasma was prepared from experimental blood samples taken at d 0, 15, 30, 45, 60, 75, and 90 of the experiment. Plasma samples were measured for the presence of anti-OVA IgG, IL-1beta, IL-6, and IL-10. Results revealed greater skin-fold thickness in cows fed FS compared with the FO and the control groups, corresponding to higher mean lymphocyte proliferation following in vivo PHA injection. Cows fed FS displayed higher titers of anti-OVA IgG than the control and FO-fed cows. No effects of the diet on IL-1beta or IL-6 were found, whereas IL-10 secretion was lower in FS-fed cows than in control cows. The present study demonstrates that feed supplementation of n-3 polyunsaturated fatty acids can enhance immune responses of dairy cows exposed to high ambient temperatures
Milk production and survival of spring-calving carryover cows in New Zealand dairy herds : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Manawatu, New Zealand
Non-pregnant cows are generally culled from dairy herds and replaced with two-year-old heifers. Alternatively, non-pregnant cows can be dried-off at the end of lactation, retained for one year (carried over), before being mated and returned to a milking herd in the following year. In this study, calving interval was used as a tool to identify and define the carryover cow population in spring-calving dairy herds. Linear modelling methods were used to compare carryover cow milk production with that of heifers, lactation-matched and age-matched non-carryover cows. Lastly, the survival for second-lactation carryover cows was compared with that of two-year-old heifers and lactation-matched non-carryover cows. Results showed that annually, 2.5% of spring-calving cows had returned to a milking herd after a carryover period in the previous year. Of those carryover cows, 43% returned to a milking herd at four years old, after failing to conceive in their first lactation. Most (69%) dairy herds contained less than 5% carryover cows and 17% of dairy herds comprised of zero carryover cows. The difference between the proportion of Holstein-Friesian in the carryover cow and non-carryover cow group was minimal (2%) but statistically greater (P<0.01) for the carryover cow group. Estimated breeding values (EBVs) for milk traits (milk yield, fat yield, protein yield and somatic cell count) were greater (P<0.01), but fertility EBVs were lower (P<0.01) for the carryover cow group in the year when they failed to conceive, compared to those for the non-carryover cow group. These were reflected in greater (P<0.01) selection indices (Breeding Worth and Production Worth) for carryover cows. After the carryover period, EBVs for milk traits and fertility decreased, and Breeding Worth was lower (P<0.01) for the carryover cow group, compared to the non-carryover cow group. Carryover cow milk yield, fat yield, protein yield and somatic cell score was greater (P<0.01) than those for heifers, lactation-matched and age-matched non-carryover cows in their first carryover year. This milk production advantage was maintained for up to three carryover years, if the carryover cow maintained an annual calving pattern, but at a decreasing rate. The probability of survival (days) was lower (P<0.01) for second-lactation carryover cows when compared to heifers and lactation-matched non-carryover cows. These findings are important for the New Zealand dairy industry as they can aid on-farm culling (removal from the herd) decisions
Severity of experimental escherichia-coli mastitis in ketonemic and nonketonemic dairy-cows.
The severity of experimental Escherichia coli mastitis in relation to in vitro chemotaxis of polymorphonuclear leukocytes was investigated in cows during negative energy balance. The negative energy balance was induced by feed restriction. Cows were classified into two groups, ketonemic and nonketonemic, based on the beta-hydroxybutyrate concentration in the peripheral blood at the moment of inoculation. Bacterial growth in the inoculated quarter was used as a parameter to indicate the severity of experimental mastitis. In the nonketonemic cows, experimental mastitis ranged from moderate to severe. Severity of experimental mastitis was negatively related to preinfection chemotactic response of polymorphonuclear leukocytes. In contrast, the course of experimental mastitis in the ketonemic group was relatively severe in all cows, regardless of preinfection chemotactic response
Day-to-day dynamics of commensal Escherichia coli in Zimbabwean cows evidence temporal fluctuations within a host-specific population structure
To get insights into the temporal pattern of commensal Escherichia coli populations, we sampled the feces of four healthy cows from the same herd in the Hwange District of Zimbabwe daily over 25 days. The cows had not received antibiotic treatment during the previous 3 months. We performed viable E. coli counts and characterized the 326 isolates originating from the 98 stool samples at a clonal level, screened them for stx and eae genes, and tested them for their antibiotic susceptibilities. We observed that E. coli counts and dominant clones were different among cows, and very few clones were shared. No clone was shared by three or four cows. Clone richness and evenness were not different between cows. Within each host, the variability in the E. coli count was evidenced between days, and no clone was found to be dominant during the entire sampling period, suggesting the existence of clonal interference. Dominant clones tended to persist longer than subdominant ones and were mainly from phylogenetic groups A and B1. Five E. coli clones were found to contain both the stx1 and stx2 genes, representing 6.3% of the studied isolates. All cows harbored at least one Shiga toxin-producing E. coli (STEC) strain. Resistance to tetracycline, penicillins, trimethoprim, and sulfonamides was rare and observed in three clones that were shed at low levels in two cows. This study highlights the fact that the commensal E. coli population, including the STEC population, is host specific, is highly dynamic over a short time frame, and rarely carries antibiotic resistance determinants in the absence of antibiotic treatment. (Résumé d'auteur
Cation-anion balance in organic silage in relation to prevention of milk fever
Studies of organic farms in Norway have documented that cows in organic herds are less prone to milk fever compared to the overall average incidence of milk fever in Norway. Milk fever occurs most frequently in high-yielding cows, fat cows and older cows. On average, cows on organic farms are lower yielding, but also older. Dry cow diets relatively high in the anion chloride (Cl–) and low in the cations potassium (K+) and sodium (Na+) can prevent milk fever. In organic farming no inorganic fertilisers are used. This may result in low content of K in the plants and with that a low content of K in the fodder. Often there also is greater diversity of plants (clover, herbs, “weeds”) in an organic meadow than in a conventional meadow. Plants vary in their uptake of different elements. One can therefore expect a different composition of minerals in organically produced fodder compared to fodder from conventionally managed fields.
Therefore, the mineral content in fodder from eight organic farms and eight conventional control farms was examined to see if low frequency of milk fever is connected to the cation-anion balance (CAB) in the fodder. Seven cows were selected from each farm. Fodder given to the cows in the dry period was analysed for Na, K and Cl, and the botanical composition of the roughage were determined. The cows’ urinary pH was measured during the dry period, using pH-papers. The fodder was also analysed for other minerals (Ca, Mg, P, Mn, Fe, Cu, Zn and Mo) to get a broader picture of the ration. The cows’ body condition scores in the dry period were measured.
The mean CAB in both the organic and conventional fodder was 366 mEq kg-1 DM, and the cows’ urinary pH was around 8.5. Based on results from this project we cannot see any connection between the lower frequency of milk fever in organic milk production and CAB in organic fodder. Not unexpectedly, the organic fodder contained more Ca and Mg. There was no difference in content of Fe, Cl, Na, K, P, Mn, Zn and Cu. Several fodder samples had more then 2% K of DM. The Ca/P ratio was high, together with a relatively low content of P. Both high K content and high Ca/P ratio together with low P content are connected to increasing risk for milk fever. The results from the mineral analysis of the fodder samples indicate an unfavourable mineral composition regarding milk fever in both conventionally and organically produced fodder
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