Effect of age on spermiogram of Holstein Friesian × Sahiwal crossbred bulls

Abstract Background Hot-iron disbudding is a common management procedure to prevent horn growth in calves. The study objective was to examine effect of age, breed and sex on horn bud size of dairy-bred and suckler-bred calves at time of disbudding. Results The left and right horn bud size (diameter and height in mm) of 279 calves, including dairy-bred Holstein-Friesian (Male (M) = 88) and 191 suckler-bred (86 Charolais, CH; (M = 39, Female (F) = 47), 67 Limousin, LM; (M = 32, F = 35) and 38 Simmental, SI; (M = 22, F = 16) sired)) was measured using a digital calliper at time of disbudding. Calves were retrospectively assigned to two age categories at time of disbudding: 1), 14 to 28 days (d) old and 2), 29 to 60 d old. Holstein-Friesian M calves had a greater horn bud diameter (16.97 v.14.45 mm) and height (7.79 v. 5.00 mm) compared to suckler-bred M calves (P < 0.01), with no difference (P > 0.05) among the suckler-bred calves. Suckler-bred M calves had a greater horn bud diameter (14.46 vs 13.29 mm) and height (5.01 vs 3.88 mm) compared to suckler-bred F calves (P < 0.05). The slopes of the lines of best fit show that horn bud diameter and height increased with age (P < 0.05) for HF, SI male and CH female calves while there was no relationship with age (P > 0.05) for CH and LM male calves, or for SI and LM female calves. Linear regression of age with diameter and with height for each breed and sex showed high variability in the data as indicated by R-squared values ranging from 0.003–0.41 indicating that in the case of the diameter and the height, the weight of the fitting effect was poor. Conclusions Calf age is not a good predictor of horn bud size and recommendations for the disbudding of calves should be based on horn bud size and not on age. The implications of these findings are that calves should be disbudded while horn development is still at the bud stage and when the bud is large enough to be easily palpable/visible, but not so large that disbudding could lead to severe tissue trauma.

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Effect of Age at First Calving on First Lactation Milk Yield, Lifetime Milk Production And Longevity of Cows

Annals of Animal Science ◽

10.2478/aoas-2018-0044 ◽

2019 ◽

Vol 19 (1) ◽

pp. 189-200

Author(s):

Anna Sawa ◽

Kamil Siatka ◽

Sylwia Krężel-Czopek

Keyword(s):

Dairy Cows ◽

Milk Production ◽

Milk Yield ◽

Considerable Decrease ◽

Age At First Calving ◽

Productive Life ◽

Active Population ◽

Holstein Friesian ◽

Effect Of Age ◽

Friesian Cows

AbstractThe objective of the study was to analyse the effect of age at first calving (AFC) on first lactation milk yield, lifetime milk production and longevity of dairy cows. The study used SYMLEK data on the milk yield and culling of 111 857 Polish Holstein-Friesian cows from the active population in Pomerania and Kujawy, Poland. The cows first calved during 2000–2009 and were used or removed from the herds until the end of 2015. For each cow, calculations were made of first lactation milk yield, lifetime milk production, first lactation milk yield per milking day, lifetime milk production per day, as well as the lifespan (length of productive life, duration of rearing) and number of calvings. Based on the age at first calving (duration of the rearing period), the cows were grouped as follows: ≤22, 22.1–24.0, 24.1–26.0, 26.1–28.0, 28.1–30.0, 30.1–32.0 and >32 months. The GLM, CORR PEARSON and FREQ procedures from the SAS package were used in the statistical calculations. Considering first lactation milk yield, lifetime milk production and longevity, it is recommended that the cows should be first milked between 22.1 and 26.0 months of age. This is supported by the approximately 24% higher lifetime milk production in relation to the latest calving cows (P<0.01). Late commencement of the first milking (especially after 28 months) causes a considerable decrease in the first lactation milk yield and lifetime milk production, shortens the productive period, reduces the number of calvings, and increases culling rate due to low milk yield and udder diseases.

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A large-scale study on the effect of age at first calving, dam parity, and birth and calving month on first-lactation milk yield in Holstein Friesian dairy cattle

Journal of Dairy Science ◽

10.3168/jds.2020-18431 ◽

2020 ◽

Vol 103 (12) ◽

pp. 11515-11523

Author(s):

M. Van Eetvelde ◽

G. de Jong ◽

K. Verdru ◽

M.L. van Pelt ◽

M. Meesters ◽

...

Keyword(s):

Dairy Cattle ◽

Milk Yield ◽

Large Scale ◽

Age At First Calving ◽

Large Scale Study ◽

Holstein Friesian ◽

Effect Of Age

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Effect of age on energy utilization of early-weaned growing calves weighing less than 100 kg

Animal Production ◽

10.1017/s0003356100003809 ◽

1989 ◽

Vol 48 (1) ◽

pp. 75-79 ◽

Cited By ~ 1

Author(s):

J. Sekine ◽

R. Oura ◽

S. Morita ◽

T. Morooka ◽

Y. Asahida

Keyword(s):

Energy Balance ◽

Metabolizable Energy ◽

Energy Utilization ◽

Regression Analyses ◽

Holstein Friesian ◽

Age Regression ◽

Energy Retention ◽

Balance Trials ◽

Effect Of Age

ABSTRACTTo study, after weaning at 6 weeks of age, the effect of age on energy utilization of growing calves and to estimate the requirements of metabolizable energy (ME) for calves weighing less than 100 kg, 243 energy balance trials were conducted using 68 Holstein-Friesian castrated male calves at 7, 9 and 13 weeks of age. Regression analyses of energy retention (ER, kj/kg M0·75) on intakes of ME (kJ/kg M0·75) gave the following equations at the respective age: ER = 0·479 (s.e. 0·070) ME — 197, for 7 weeks, ER = 0·521 (s.e. 0·052) ME - 216 for 9 weeks and ER = 0·523 (s.e. 0·043) ME - 236, for 13 weeks. Amounts of ME for maintenance (MEm) calculatedas ER = 0 were 413, 415 and 451 kJ/kg M0·75 for calves at 7, 9 and 13 weeks of age, respectively. The efficiency of utilization of ME for growth was not significantly different among the ages and was 0·500 (s.e. 0023). ME required for growth was estimated to be 510 kJ/kg M0·75 for each kg gain in weight, irrespective of age. The requirements of ME of calves weighing less than 100 kg were lower than those estimated by extrapolation of British and American standards.

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