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Doran MJ, Mulligan FJ, Lynch MB, Fahey AG, Ryan NJ, McDonnell C, McCabe S, Pierce KM. Effect of supplement crude protein concentration on milk production over the main grazing season and on nitrogen excretion in late-lactation grazing dairy cows. J Dairy Sci 2021; 105:347-360. [PMID: 34635358 DOI: 10.3168/jds.2021-20743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/24/2021] [Indexed: 11/19/2022]
Abstract
The objectives of this study are to evaluate the effects of (1) a potential interaction between supplement crude protein (CP) concentration and differing cow genotypes on milk production, (2) differing cow genotypes on milk production, and (3) decreasing the supplement CP concentration on milk production and N excretion during the main grazing season within a spring-calving herd. A 2 × 2 factorial arrangement experiment, with 2 feeding strategies [14%; n = 30 (lower CP; LCP) and 18%; n = 28 (higher CP; HCP) CP concentrate supplements] offered at varying levels according to pasture availability and days in milk (DIM) was conducted over the main grazing season from April 3 to September 3, 2019, at University College Dublin Lyons Farm. Cows were also grouped into 2 genotype groups: lower milk genotype; n = 30 [LM; milk kg predicted transmitting ability (PTA): 45 ± 68.6 (mean ± SD); fat kg PTA: 10 ± 4.9; and protein kg PTA: 7 ± 2.3] and higher milk genotype; n = 28 [HM; milk kg PTA: 203 ± 55.0; fat kg PTA: 13 ± 3.8; and protein kg PTA: 10 ± 2.4]. A total of 46 multiparous and 12 primiparous (total; 58) Holstein Friesian dairy cows were blocked on parity and balanced on DIM, body condition score, and Economic Breeding Index. Cows were offered a basal diet of grazed perennial ryegrass pasture. The N partitioning study took place from August 25 to 30, 2019 (187 ± 15.2 DIM). No interactions were observed for any milk production or milk composition parameter. No effect of supplement CP concentration was observed for any total accumulated milk production, daily milk production, or milk composition parameter measured. The HM cows had increased daily milk yield (+1.9 kg), fat and protein (+0.15 kg), and energy-corrected milk (+1.7 kg), compared with the LM cows. Furthermore, HM cows had decreased milk protein concentration (-0.1%) compared with LM cows. For the N partitioning study, cows offered LCP had increased pasture dry matter intake (PDMI; +0.9 kg/d), dietary N intake (+0.022 kg/d), feces N excretion (+0.016 kg/d), and decreased N partitioning to milk (-2%), and N utilization efficiency (-2.3%). In conclusion, offering cows LCP had no negative influence on milk production or milk composition over the main grazing season where high pasture quality was maintained. However, any potential negative effects of offering LCP on milk production may have been offset by the increased PDMI. Furthermore, offering cows LCP decreased N utilization efficiency due to the higher PDMI and feed N intake associated with cows on this treatment in our study.s.
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Affiliation(s)
- M J Doran
- School of Agriculture and Food Science, University College Dublin Lyons Research Farm, Celbridge, Naas, Co. Kildare, Ireland, W23 ENY2.
| | - F J Mulligan
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland, D04 V1W8
| | - M B Lynch
- School of Agriculture and Food Science, University College Dublin Lyons Research Farm, Celbridge, Naas, Co. Kildare, Ireland, W23 ENY2; Teagasc Environment Research Centre, Johnstown Castle, Wexford, Ireland, Y35 Y521
| | - A G Fahey
- School of Agriculture and Food Science, University College Dublin Lyons Research Farm, Celbridge, Naas, Co. Kildare, Ireland, W23 ENY2
| | - N J Ryan
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland, D04 V1W8
| | - C McDonnell
- School of Agriculture and Food Science, University College Dublin Lyons Research Farm, Celbridge, Naas, Co. Kildare, Ireland, W23 ENY2
| | - S McCabe
- School of Agriculture and Food Science, University College Dublin Lyons Research Farm, Celbridge, Naas, Co. Kildare, Ireland, W23 ENY2
| | - K M Pierce
- School of Agriculture and Food Science, University College Dublin Lyons Research Farm, Celbridge, Naas, Co. Kildare, Ireland, W23 ENY2
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Oliveira Junior GA, Schenkel FS, Alcantara L, Houlahan K, Lynch C, Baes CF. Estimated genetic parameters for all genetically evaluated traits in Canadian Holsteins. J Dairy Sci 2021; 104:9002-9015. [PMID: 33934872 DOI: 10.3168/jds.2021-20227] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/25/2021] [Indexed: 12/12/2022]
Abstract
Genetic improvement is a crucial tool to deal with the increasing demand for high quality, sustainably produced dairy. Breeding programs are based on genetic parameters, such as heritability and genetic correlations, for economically important traits in a population. In this study, we estimated population genetic parameters and genetic trends for 67 traits evaluated on heifers and first-lactation Canadian Holstein cows. The data consisted of approximately 500,000 records with pedigree information collected from 1980 to 2019. Genetic parameters were estimated using bivariate linear animal models under a Bayesian approach. Analyses for the 67 traits resulted in 2,211 bivariate combinations, from which the estimated genetic parameters are reported here. The most highly heritable traits were fat percent (0.66) and protein percent (0.69), followed by stature (0.47). Lowest heritabilities (0.01) were observed for disease-related traits, such as lameness and toe ulcer, and calf survival. The genetic correlations between gestation length, calf size, and calving ease measured on both heifer and cows were close to unity. On the other hand, traits such as body condition score and pin width, cystic ovaries and sole ulcer, rear teat placement, and toe ulcer were genetically unrelated. This study reports genetic parameters that have not been previously published for Canadian Holstein cows, and provides updates of those previously estimated. These estimates are useful for building new indexes, updating existing selection indexes, and for predicting correlated responses due to inclusion of novel traits in the breeding programs.
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Affiliation(s)
- G A Oliveira Junior
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - F S Schenkel
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - L Alcantara
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - K Houlahan
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - C Lynch
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - C F Baes
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada; Institute of Genetics, Department of Clinical Research and Veterinary Public Health, University of Bern, Bern, 3001, Switzerland
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Ornelas LTC, Silva DC, Tomich TR, Campos MM, Machado FS, Ferreira AL, Maurício RM, Pereira LGR. Differences in methane production, yield and intensity and its effects on metabolism of dairy heifers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 689:1133-1140. [PMID: 31466153 DOI: 10.1016/j.scitotenv.2019.06.489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 06/10/2023]
Abstract
The effects of divergent phenotypic classification in crossbreed Holstein × Gyr dairy heifers for methane emissions in relation to performance, digestibility, energy and nitrogen partition, blood metabolites and temperature of body surface were evaluated. Thirty-five heifers were classified as high and low emission for CH4 production (g/day), yield (g/kg dry matter intake) and intensity (g/kg average daily gain). Digestibility was evaluated by total collection of feces and urine. Gas exchanges were obtained in open-circuit respiratory chambers. A completely randomized design was used and divergent groups were compared by Fisher's test. No differences were found in intake traits between groups of CH4 production and intensity. The low yield group had higher intake. For digestibility and temperature at different body sites were no differences between variables. High production group had higher energy losses as methane and heat production. Low intensity group had higher digestible energy, energy balance and ratio between metabolizable and digestible energy. Urinary nitrogen was 14.3% lower for low production group. There was a difference between methane yield divergent groups for nitrogen intake, digestible and retained. Energy and nitrogen partitioning traits are correlated to the animals divergent for methane production and yield. The low production group presented lower blood insulin concentration. It was not possible to identify divergent animals for CH4 emission using the infrared thermography technique.
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Affiliation(s)
- L T C Ornelas
- Department of Animal Science, State University of Southwestern Bahia (UESB), Bahia 45700-000, Brazil
| | - D C Silva
- Department of Animal Science, State University of Southwestern Bahia (UESB), Bahia 45700-000, Brazil
| | - T R Tomich
- Embrapa Dairy Cattle, Minas Gerais 36038-330, Brazil
| | - M M Campos
- Embrapa Dairy Cattle, Minas Gerais 36038-330, Brazil
| | - F S Machado
- Embrapa Dairy Cattle, Minas Gerais 36038-330, Brazil
| | - A L Ferreira
- Department of Agricultural Science, Federal University of São João del-Rei (UFSJ), Minas Gerais 36307-352, Brazil
| | - R M Maurício
- Department of Agricultural Science, Federal University of São João del-Rei (UFSJ), Minas Gerais 36307-352, Brazil
| | - L G R Pereira
- Embrapa Dairy Cattle, Minas Gerais 36038-330, Brazil.
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Saavedra-Jiménez LA, Ramírez-Valverde R, Núñez-Domínguez R, Ruíz-Flores A, García-Muñiz JG. Genetic parameters for nitrogen fractions content in Mexican Brown Swiss cattle milk. Trop Anim Health Prod 2019; 51:2235-2241. [DOI: 10.1007/s11250-019-01926-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 03/28/2019] [Accepted: 05/15/2019] [Indexed: 10/26/2022]
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