Rearing Dairy Herd Replacements

Roy, J. H. B.

doi:10.1111/j.1471-0307.1978.tb01384.x

Cited by 9 publications

(6 citation statements)

References 13 publications

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“…Most of the research involved overconditioning or liberal feeding of heifers; however, some work suggested that heifers raised on low or medium nutrition produced slightly more milk than heifers raised on high nutrition. Since then objectives of several studies (8,62,68,74) have concerned a rate of development that allows for calving at 24 mo, efficient use of feed during rearing, delivery of a healthy, vigorous calf, few calving problems, production at maximum genetic potential in first lactation, resistance to metabolic problems and infections, enough size successfully to compete for feed, and longevity.…”

Section: Rearing Rates Of Heifersmentioning

confidence: 99%

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Advances in Nutrition and Management of Calves and Heifers

Otterby

Linn

1981

Journal of Dairy Science

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Strides have been significant in the knowledge of calf and heifer rearing during the last 25 yr. Much information has been gathered on digestive enzymes, development of the digestive system, and metabolism. Investigations have clarified further the role of colostrum in immunity and nutrition of the young calf. Several sources of nutrients have been tested for their suitability in formulation of acceptable milk replacers and calf starters. Once-a-day feeding of milk, colostrum, or milk replacer and early weaning are practical management procedures. Labor and cost efficient methods of feeding and caring for young calves have developed. Extensive work on rearing rates and methods of rearing was published during these 25 yr.Successful schemes have evolved for feeding heifers to freshen at an optimal age and to occupy a respectful position in the milking line. Developments in housing have been phenomenal -from the calf hutch to environmentally controlled nurseries for calves. Heifer housing has ranged from relatively simple, but laborefficient housing, to complete confinement systems. Herd health programs have developed to minimize many disease problems that can be particularly disastrous in large herds. Contract rearing of herd replacements has become a more frequently chosen option in this period. Budgets for rearing calves from birth to freshening have appeared in recommendations for raising heifers.

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Section: Rearing Rates Of Heifersmentioning

confidence: 99%

“…First estrus occurs earlier and at lower weights for small breeds than for large breeds. If heifers are fed to gain .9 to 1.0 kg/day, first estrus may be as early as 6 to 8 mo for Holsteins (62). Swanson (73)has predicted puberty at 10 mo with .82 kg gain/day, 11 mo with .68 kg gain/day, and 14 mo with .54 kg gain/day.…”

Section: Rearing Rates Of Heifersmentioning

confidence: 99%

Advances in Nutrition and Management of Calves and Heifers

Otterby

Linn

1981

Journal of Dairy Science

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“…Only 005 of heifers had condition scores outside this range, and only 001 of heifers were both infertile and in an extreme body condition category. The evidence reviewed by Roy (1978) also indicates that heifers need to be growing at rates of approximately 0-7 kg/day if they are to attain live weights necessary for satisfactory reproduction and subsequent performance. Mulvany (1977) found that, for dairy cows inseminated in early lactation, there was an association between body condition score and pregnancy rate.…”

Section: Discussionmentioning

confidence: 99%

“…Kilkenny and Herbert (1976) and Roy (1978) concluded that heifers need to grow at an average rate of at least 0-6 kg/day if they are to attain the necessary live weight at service and pre-calving necessary for satisfactory fertility and subsequent milk production. Kilkenny and Herbert (1976) and Roy (1978) concluded that heifers need to grow at an average rate of at least 0-6 kg/day if they are to attain the necessary live weight at service and pre-calving necessary for satisfactory fertility and subsequent milk production.…”

Section: Introductionmentioning

confidence: 99%

The effect of change and level of nutrition on the reproductive performance of group-fed dairy heifers

Ducker¹,

Yarrow²,

Morant³

1982

Anim. Sci.

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Link to this article: http://journals.cambridge.org/abstract_S0003356100000684How to cite this article: M. J. Ducker, N. Yarrow and S. V. Morant (1982). The effect of change and level of nutrition on the reproductive performance of group-fed dairy heifers. ABSTRACTOne hundred and sixty Friesian heifers were allocated to two groups 8 or 9 weeks before artificial insemination and group-fed to gain live weight at 0-8 or 0-3 kg/day. Half the heifers of each group were moved to the other group 2 weeks before first insemination. All heifers received two intramuscular injections of prostaglandin (cloprostenol) 11 days apart, followed by inseminations at 72 and 96 h after the second injection.The feeding regimes applied did not significantly affect the fertility of groups of heifers as measured by pregnancy rates to fixed-time or all inseminations. There were significant differences between pregnant and nonpregnant heifers within groups where changes in feeding levels were imposed (P <0001), the overall pregnancy rates were not significantly different.

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“…A greater availability of heifers also enables dairy producers to aggressively cull poor-performing heifers, as well as those with lower genetic merit (Roy 2007).…”

Section: Introductionmentioning

confidence: 99%

Fertility in Holstein × Gyr cows in a subtropical environment after insemination with Gyr sex-sorted semen

Mellado

Coronel

Estrada

et al. 2010

Trop Anim Health Prod

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Breeding records, including 649 inseminations during fall and winter at a dairy farm in a subtropical area of Western Mexico (24 masculine N; 24 degrees C, mean annual temperature 24 degrees C) were analyzed to document effects of sex-sorted semen from commercial Gyr bullls, estrus synchronization protocol, inseminator, sire and environmental conditions on fertility of crossbred cows (Holstein x Gyr). Percentage of services resulting in pregnancies decreased sharply when sex-sorted semen was used (22.7 vs. 37.7%; P < 0.01). Although statistically not significant (P = 0.31), cows whose first insemination was in November experienced a numerically greater reduction (21 percentage points) in pregnancy rate compared to cows whose first insemination occurred in December. Substantial increases in services per pregnancy (4.71 +/- 1.35 vs. 2.13-2.43; P < 0.01) were associated with the warmer month of the study period, November, compared to other winter months. Pregnancy rates of cows regardless of semen category (33%) were not affected by sire, temperature-humidity index and estrus synchronization protocol. Cows inseminated by one inseminator had higher pregnancy rates (P < 0.01) than cows inseminated by other two technicians. The sorted sperm produced 91% (142/156) female offspring. It was concluded that, under the field conditions of the present study, pregnancy rate with sexed semen was 15 percentage points lower than pregnancy rates using conventional semen, with 91% of female calves derived from sexed sperm.

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Rearing Dairy Herd Replacements

Cited by 9 publications

References 13 publications

Advances in Nutrition and Management of Calves and Heifers

Advances in Nutrition and Management of Calves and Heifers

The effect of change and level of nutrition on the reproductive performance of group-fed dairy heifers

Fertility in Holstein × Gyr cows in a subtropical environment after insemination with Gyr sex-sorted semen

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