Efficiency and performance of genetically high and low milk-producing British Friesian and Jersey cattle

Abstract

Genetic lines for high and low liquid milk production were established within the British Friesian and British Jersey breeds by random matings of experimental dams to the 'best' and 'worst' nationally available progeny-tested sires. Some Friesian dams could also be classified as either high or low for genetic potential for milk yield on the basis of previous, but less rigorously controlled, matings to highor low-production sires. The dams and their high and low potential-production female progeny were reared indoors, and given a single complete pelleted diet ad libitum from weaning until leaving the experiment after their third calving. Height at withers and width at hooks were recorded monthly, cumulate food intake and body weight fortnightly and milk yield, fat and protein concentration weekly, throughout life in the experiment. Measures of lactation production, food intake and efficiency of conversion of food to milk product during the whole calving-to-calving interval were obtained. Yields were about 0-8 times national average yields. Differences between high and low genetic lines appeared similar for the two breeds. High potential-production progeny produced more liquid milk, fat and protein but at a lower fat and protein concentration than did low-potential progeny. High-potential progeny consumed more food from calving to calving and had higher food conversion efficiencies to liquid milk, fat and protein. The response in efficiency accompanying a given change in production was close to that predicted by phenotypic regression of efficiency on yield with a 0-75% increase in efficiency for every 1% increase in yield. The likelihood of smaller returns in efficiency at higher yields is discussed. High potential-production progeny lost more body weight than did low during lactation, suggesting a greater withdrawal of energy from body reserves. High-potential progeny were neither heavier nor taller but were marginally narrower at the hooks than were low-potential progeny, suggesting the possibility of increased calving difficulties as selection for increased yield continues.Friesians produced 50% more liquid milk, 13% more milk fat and 29% more milk protein and consumed 22% more food from calving to calving than did Jerseys. As a consequence Friesians were markedly more efficient at producing liquid milk (+23%) but essentially no more efficient at producing milk energy (+2%) than were Jerseys. In terms of both biological and commercial application of the results, any biases in the experiment probably operated against the Jersey relative to the Friesian.Predictions of food intake using accepted feeding standards underestimated observed total food intake during lactation by a factor of 0-8. Linear regression indicated underestimation of maintenance requirement as a likely explanation.

Feed conversion efficiency, daily pasture intake, and milk production of primiparous Friesian and Jersey cows calved at two different liveweights

“…Bryant et al (1985) combined data from two experiments carried out at adjoining dairies, one involving J, the other F cows, and concluded that higher production from F cows (27-36, 3-7, 12-19, and 23-25% more milk, milk fat, protein, and lactose, respectively) reflected a higher FCE as opposed to higher intake. Gibson (1986) also found F cows were more efficient at producing liquid milk (+23%) but essentially no more efficient at producing milk fat, protein, or milk energy (+2%) than were J cows. In an American study, Blake et al (1986) found no comparative advantage for J cows in the conversion of nutrients to milk, in spite of their higher ratios of milk output to LW.…”

“…When corrected for the energy involved in LW gains or losses which occur during the lactation, J cows were still more efficient than F cows (P < 0.05), although the difference between breeds was smaller than with the Gross Ee calculation. This may indicate that J cows used more of their body reserves for milk energy production during lactation, especially since Gibson (1986) found that J cows lost more body weight across lactation than F cows, when expressed as a proportion of pre-calving weight (234 ± 6 versus 195 ± 7 g/kg, respectively). However, in our study J cows still gained as much LW across the lactation as a percentage of their initial LW (Table 3).…”

“…For example, Bryant et al ( 1985) concluded that higher per cow production from F cows reflected a higher FCE as opposed to higher intake. Gibson (1986) found that F cows were more efficient at producing liquid milk (+23%), but no more efficient at producing milk energy (+2%). L 'Huillier et al (1988) also found that F cows produced more milk and milk solids per cow than J cows, but this was because of their greater DMIs.…”

“…The studies of Bryant et al (1985), Gibson (1986), and L' Huillier et al (1988) showed that F cows produced more milk and milksolids per cow than J cows. The data on comparative FCE of these two breeds in these studies were equivocal.…”

Effect of Environmental Conditions in Milk Production Under Small-Scale and Semi-Extensive Conditions in Kosovo

“…It is generally accepted that the genetically correlated response in feed intake when selection is on production (rg = 0.46 -0.65; Veerkamp, 1998) is not large enough to cover the additional requirements (energy) due to increased production (Van Arendonk et al, 1989Veerkamp & Thompson, 1999). This is also so as there is little evidence for genetic variance for the rate of efficiency at converting nutrients into milk (Blake & Custodio, 1984;Gibson, 1986;Svendsen et al, 1993;Veerkamp & Emmans, 1995;Zamani et al, 2011).…”