D.G. Johnson

Crossbreds of Jersey × Holstein Compared with Pure Holsteins for Production, Fertility, and Body and Udder Measurements During First Lactation

Jersey x Holstein crossbreds (JxH; n = 76) were compared with pure Holsteins (n = 73) for 305-d milk, fat, and protein production; conception rate; days open; proportion of cows pregnant within fixed intervals postpartum; and body and udder measurements during first lactation. Cows were housed at 2 research locations of the University of Minnesota and calved from September 2003 to May 2005. The JxH were mated to Montbeliarde sires, and Holstein cows were mated to Holstein sires. Best Prediction was used to determine actual production (milk, fat, and protein) for 305-d lactations with adjustment for age at calving, and records less than 305 d were projected to 305 d. The JxH (274 kg) and pure Holsteins (277 kg) were not significantly different for fat production, but JxH had significantly less milk (7,147 vs. 7,705 kg) and protein (223 vs. 238 kg) production than pure Holsteins. The JxH had significantly fewer days open than pure Holsteins (127 vs. 150 d). Also, a significantly greater proportion of JxH were pregnant at 150 and 180 d postpartum than pure Holsteins (75 vs. 59% and 77 vs. 61%, respectively). The JxH had significantly less body weight (60 kg) at calving, but significantly greater body condition (2.80 vs. 2.71). Furthermore, JxH had significantly less udder clearance from the ground to the bottom of the udder than pure Holsteins (47.7 vs. 54.6 cm), and greater distance between front teats (15.8 vs. 14.0 cm) than pure Holsteins during first lactation.

Crossbreds of Jersey × Holstein Compared with Pure Holsteins for Body Weight, Body Condition Score, Dry Matter Intake, and Feed Efficiency During the First One Hundred Fifty Days of First Lactation

Jersey x Holstein crossbred (JxH) cows (n = 24) were compared with pure Holstein cows (n = 17) for body weight, body condition score, dry matter intake (DMI), and feed efficiency during the first 150 d of first lactation. Cows were housed in the University of Minnesota dairy facility at the St. Paul campus and calved from September 2004 to January 2005. The JxH cows were mated by artificial insemination with Montbeliarde bulls, and Holstein cows were mated by artificial insemination with Holstein bulls. Cows were weighed and body condition was scored every other week. Cows were individually fed a TMR twice daily, and feed refusals were measured once daily. The DMI of cows was measured daily and averaged across 7-d periods. Milk production and milk composition were from monthly Dairy Herd Improvement records. Best Prediction was used to calculate actual production (milk, fat, protein) for each cow from the 4th to 150th day of first lactation. The JxH cows had significantly less body weight (467 vs. 500 kg) and significantly higher body condition scores (2.90 vs. 2.76) than pure Holstein cows. The JxH cows had significantly less milk production (4,388 vs. 4,644 kg) during the 4th to 150th day of lactation than did pure Holstein cows. However, fat plus protein production during the first 150 d of lactation was not significantly different for JxH (302 kg) and Holstein (309 kg) cows. The JxH and pure Holstein cows did not differ significantly for daily DMI (22.0 vs. 22.7 kg, respectively), and the JxH (4.7%) and pure Holstein (4.5%) cows consumed similar DMI based on percentage of body weight. Consequently, feed efficiency for the 4th to 150th day of lactation did not differ for JxH and pure Holstein cows.

Short communication: Jersey × Holstein crossbreds compared with pure Holsteins for production, mastitis, and body measurements during the first 3 lactations

Jersey (JE)×Holstein (HO) crossbred cows (n=76) were compared with pure HO cows (n=73) for 305-d milk, fat, and protein production, somatic cell score (SCS), clinical mastitis, lifetime production, and body measurements during their first 3 lactations. Cows were in 2 research herds at the University of Minnesota and calved from September 2003 to June 2008. Best prediction was used to determine actual production for 305-d lactations as well as lifetime production (to 1,220 d in the herd after first calving) from test-day observations. During first lactation, JE×HO cows and pure HO cows were not significantly different for fat plus protein production; however, JE×HO cows had significantly lower fat plus protein production during second (-25 kg) and third (-51 kg) lactation than pure HO cows. Nevertheless, JE×HO cows were not significantly different from pure HO cows for lifetime production or lifetime SCS. The JE×HO cows were not significantly different from pure HO cows for SCS and clinical mastitis during first and second lactations; however, JE×HO cows tended to have higher SCS (3.79) than pure HO cows (3.40), but significantly lower (-23.4%) clinical mastitis during third lactation. The JE×HO cows had significantly less hip height, smaller heart girth, less thurl width, and less pin width than pure HO cows during the first 3 lactations. Furthermore, JE×HO cows had significantly less udder clearance from the ground and significantly greater distance between the front teats than pure HO cows during their first 3 lactations.

Birth traits of pure Holstein calves versus Montbeliarde-sired crossbred calves.

Pure Holstein calves and Montbeliarde-sired crossbred calves from multiparous Holstein dams were compared for gestation length, calf weight at birth, calving difficulty, and stillbirth in 2 research herds of the University of Minnesota. The Montbeliarde-sired calves from multiparous Holstein dams had significantly longer gestation lengths (283.2 d) than Holstein-sired calves from Holstein dams (278.4 d), and Montbeliarde-sired calves from multiparous Holstein dams had significantly greater calf weight at birth (48.3kg) compared with Holstein-sired calves from Holstein dams (43.3kg). However, calves sired by Montbeliarde bulls were not significantly different from calves sired by Holstein bulls for calving difficulty and stillbirth. In addition, Jersey x Holstein crossbred cows mated to Montbeliarde artificial insemination (AI) bulls were compared with pure Holstein cows mated to Holstein AI bulls for gestation length, calf weight at birth, calving difficulty, and stillbirth at their first 3 calvings. Gestation length was significantly longer for Jersey x Holstein cows bred to Montbeliarde bulls than for pure Holstein cows bred to Holstein bulls at first calving (280.3 versus 277.7 d) and second and third calving (282.2 versus 278.6 d); however, Jeresy x Holstein cows bred to Montbeliarde AI bulls were not significantly different from pure Holstein cows bred to Holstein AI bulls for calf weight at birth, calving difficulty, and stillbirth at the first 3 calvings.

Short communication: Jersey × Holstein crossbreds compared with pure Holsteins for body weight, body condition score, fertility, and survival during the first three lactations

Crossbred cows (n=80) resulting from the use of Jersey (JE) semen on their pure Holstein (HO) dams were compared with pure HO cows (n=77) for body weight, body condition score, fertility, and survival during their first 3 lactations. Cows were in 2 research herds of the University of Minnesota and calved from September 2003 to June 2008. The JE × HO crossbred cows had significantly less body weight during the first (-56 kg), second (-67 kg), and third (-82 kg) lactations than pure HO cows. However, JE × HO cows had significantly greater body condition score during the first (2.94 vs. 2.84), second (2.97 vs. 2.84), and third (2.99 vs. 2.87) lactations than pure HO cows. For fertility, JE × HO cows had fewer days to first breeding during the first (-10.6d), second (-8.4d), and third (-12.3d) lactations than pure HO cows. Crossbred cows were not significantly different from pure HO cows for number of services during first lactation; however, JE × HO cows had significantly fewer services (2.2) than pure HO cows (2.7) during the second lactation. Also, JE × HO cows had significantly fewer days open than pure HO cows in the first (-24 d), second (-42 d), and third (-42 d) lactations. For survival, JE × HO cows were not significantly different from pure HO cows for percentage of cows calving a second time; however, a tendency existed for a higher percentage of JE × HO cows (63.8%) than pure HO cows (49.4%) to calve a third time, and a higher percentage of JE × HO cows calved a third time within 28, 34, and 40 mo of first calving than pure HO cows.

Bedding Options for an Alternative Housing System for Dairy Cows: A Descriptive Study

Availability of bedding material for compost bedded pack barns is a concern for dairy producers who use this type of alternative housing system. The material most commonly used in these barns is dry sawdust. The objective of this descriptive study was to evaluate different types of bedding material that could potentially substitute or partially substitute for sawdust in these housing systems. The study was conducted at the West Central Research & Outreach Center in Morris, Minnesota, from November 2006 to March 2007. Materials included: pine sawdust (control) (SD), corn cobs (CC), pine woodchip fines (WC), and soybean straw (SS). Some of these materials were evaluated as mixtures on a 2:1 volume-to-volume ratio. These mixtures included: woodchips/sawdust (WC/SD), woodchips/soybean straw (WC/SS), and soybean straw/sawdust (SS/SD). Experimental bedded packs were used, each with one of the bedding materials, and 16 cows were placed on each pack. Replicated samples of the bedded pack material were collected twice a month and analyzed for dry matter. C:N ratios and pH were analyzed monthly. Temperatures of each pack were measured weekly at various depths (15.2, 30.5, 45.7, and 61.0 cm). Cows were scored for hygiene (1=clean, 5=dirty) twice a month. Moisture content of SD was 59.7; CC, 44.5; WC/SD, 60.6; SS/SD, 58.2; WC/SS, 60.7; and SS, 60.6. SD pH was 8.7; CC, 7.7; WC/SD, 8.6; SS/SD, 8.6; WC/SS, 8.3; and SS, 8.6. C:N ratio of SD was 37.3; CC, 29.2; WC/SD, 47.5; SS/SD, 25.6; WC/SS, 31.0; and SS, 22.8. Hygiene score of cows on SD was 2.4; CC, 2.7; WC/SD, 2.5; SS/SD, 2.9; WC/SS, 2.6; and SS, 2.8. Based on these results and our observations, it appears that any of the bedding materials evaluated in this study would work in this type of housing system if proper bedding management is applied on a consistent basis. It was concluded that ideal bedding material for compost barns should be dry, processed to less than 2.5 cm long, offer structural integrity, and have good water absorption and holding capacity.

Compost: A Potential Value-Added Product for Dairy Operations?

The objective of this study was to evaluate the composting potential of various bedding materials that were previously used in experimental compost bedded packs for dairy cows. Each material was placed in windrows (1.8 m high, 9.1 m long, and 2.3 m wide) from April 2007 to September 2007 and managed as needed to promote composting. Materials included: sawdust (SD) (control), corn cobs (CC), wood chip fines/sawdust mix (WC/SD), soybean straw (SS), wood chip fines/soybean straw mix (WC/SS), and soybean straw/sawdust mix (SS/SD). Replicated samples were taken weekly and analyzed for dry matter (DM). Carbon:nitrogen ratio (C:N ratio), pH, total C, total N, NH4-N, and NO3-N were measured once monthly. Temperature was measured twice weekly. Total P, total K, and EC were measured at the beginning and end of the composting period. Windrow temperatures exceeded 55°C for 10 to 96 days, and coliform populations were reduced from 106 or 107 to 500 cfu/mL or fewer in all materials. CC, SS/WC, WC/SS, and SS were the only materials that decreased (P < 0.05) in moisture content from day 0 to day 138. Materials were similar when comparing day 0 and day 138 for NH4-N, total N, and inorganic N concentrations. SS, SS/SD, WC/SS, and WC/SD all decreased in total C and C:N ratio(P < 0.05) from day 0 to day 138. C:N ratios were below 20:1 at the end of the composting period, with the exception of SD and WC/SD. Based on these results, all materials composted during the time period and would potentially work as a soil amendment/mulch if proper composting takes place.